How to Build a Roll Cage| Step by Step

[Music] [Applause] [Music] [Applause] [Music] [Applause] [Music] hey guys welcome to our next video and this is how you build a roll cage over the course of this video we're going to show you how to start from scratch with prepping the chassis getting the base plates ready to weld in welding in the base plates how we go about measuring and bending the tubes and how we go to fit the tubes to the chassis as tightly as possible we're going to go over racing regulations in terms of champ car fia drift and all different kinds of specifications and what you need to know on how to build a cage that's going to fit your requirement we're going to cover extras where we can tie in tubes to strut towers and make the chassis more rigid while keeping the center of gravity low and all the other benefits that comes to having a roll cage in your race car in this video we will cover roll cage base plate material thickness and square inch requirements for your chassis where and how to mount the base plates to the chassis tubing diameter thickness and material bending rolling and notching what tools you will need welding procedures to make sure that you can weld all the way around every joint and more what most people don't know about fdf rate shop is that i actually started the company as an automotive fabrication business where i would improve people's chassis by installing roll cages and doing fabrication work to them making them more rigid by stitch welding and just general fabrication maybe installing spoilers diffusers and stuff like that for time attack i then jumped into a lot of rally racing and building rally cars where the roll cages had to be alloy steels and up to the highest standard they were constantly being scrutinized at every event and inspected so the level that we had to build the roll cages at was extremely high and at that point that's kind of when i got out of building roll cages this might have been two or three years ago since then i've been building roll cages not nearly as frequently but still a few a year overall i've probably done a couple hundred roll cages by myself with the help of an employee or whoever was working with me at the time i was known for making high quality roll cages that i prominently tig welded just for the the aesthetics and also when you're using alloy steels for them for the most part it did have to be tig welded anyways and that really instills the tight fitment policy that i run by and that everything needs to fit perfectly you can't have any gaps anywhere or else you're going to have a bad well that's especially with materials like chromoly are going to be susceptible to cracking and breaking so everything needs to fit perfectly the bevels have to be perfect and not just have to be perfect and that has given me the ability to make these cages at a very high standard so with that i'm able to take on these projects and share my knowledge with people as i don't do these projects too often anymore but i still have a lot of knowledge in the area that i can share with everybody else before i completely get out of it and focus on suspension engineering and design um so this is how to build a roll cage by josiah feliz myself at my shop fdf race shop i'm going to be working with donnie and my other employee cam for the most part on building this who are also skilled welders skilled fabricators and they learned everything from me of course [Music] so when you're building a roll cage you're going to need just a couple small tools on hand pretty much at all times when you're in the car outside of the car you need some bigger tools like a two bender tube notcher a bandsaw or chop saw or cold cut saw however you want to cut the material but inside the car you're going to want a digital angle finder this is my tool of choice this one can just be easily bought at any hardware store in the uh in canada it's canadian tire in the us it's probably a number of places a marker tape measure pen and the pen is just for writing on paper which is attached to my clipboard this is just for taking notes writing down measurements whenever i measure to bend the tubes inside the car i take xyz measurements of the chassis so that i can then put those points into my software and determine where i want to put the bends in my tubes so other than that you may want the snowboard just to take notes on two blanks and positions and whatnot you just need to have it on hand other people use straight edges and you can also get like uh notching assistant tools where you can like slide it up and it'll tell you where to notch the tube especially if there's multiple copes going into one point i have used them before i did not like using them i found that they weren't accurate enough for me they were kind of difficult and i could do it faster just by myself but i think they're called pipe notchers or something like that anyways you can find them on google if you want to use those there's also other tools that help you align two tubes when you're making an x again i've never been one to use that tool i did make one just over from my experience i'm able to build them the cage fast enough and line things up perfectly just from my experience if you need straight edges and you want to add a couple clamps to this this little concoction here and i also missed one very important thing a ratchet strap ratchet strap a ratchet strap may be one of the most used tools when i build roll cages and it doesn't need to be anything special this is like a typical thousand pound ratchet strap that people use to fasten down their four-wheeler or something they're not expensive but what do we use it for well when you're fitting a tight fitting roll cage and especially when you're about to drop the cage to weld the tops or however some people may do it you're going to need a ratchet strap to pull and manipulate the tubes in a way that allows you to move the cage around in order to weld certain areas so for example if the main hoop fits tightly against both b-pillars we can put the ratchet strap around the tubes bring the tubes together so that we can drop it off of the rocker and then lower the cage and weld the tops once we're done we can lift the cage back up let the ratchet strap go and the tubes go back into place it's it's pretty difficult for you to ratchet something beyond the point of deformation so that it won't come back very slim chance that you'll be able to do that especially with one of these because you probably will run out of leverage or the strap will break so no worries there any time we pull tubes in they will always go back to where they were that's what you want on hand then we'll go over a couple of the tools that i have that you can easily buy online or at a store or build yourself like i did okay so one of the most important tools you're going to need is a tube notcher over here at our workhorse lathe that we use every day i converted or i made an adapter on the cross slide saddle where we can fasten a tube into this clamp and put it at any angle that i want this lathe will actually go from zero to 60 to i've even had it up to like 65 70 degrees it gets a bit spooky at that angle but it is doable and you simply lock it in put the tube in i can back the tube out track it in and then go through to the cut because the hole saw is actually installed into the chuck so for you guys that don't have anything like this or if you do old ladies are awesome for absolutely everything if you wanted to get yourself a reasonably priced unreal tube notcher i would suggest getting yourself a lathe and then doing what i did with this because they're similar products that go for three four five thousand dollars they use an end mill in the chuck and then they have a basically a cross slide just like a lathe but all they can do is notch tubes where i can do way more than notch tubes with this i can do so many other things with it the lathe is quite possibly our mvp machine of the shots used for absolutely everything if you need to face something shorter if you need to cut something square even if it's not around you can put square objects in here make them square like it's just the mvp of the shop so get yourself a lathe or if you don't you can get standard tube notchers for two three four hundred dollars they've got like a v block and then a hole saw arbor that you can just notch anything up to like 50 or 60 degrees i wouldn't suggest trying to do a cage with a zip cut or any other way where you got to like trace the notch and then cut it yourself it's going to take you a really long time it can be done i did it when i was a kid building a go-kart but that's how you learn the hard way and then you really appreciate stuff like this so tube notcher is the first main tool that you need oh he's getting grippy uh the second tool that you're gonna need this is our two bender i actually built this myself like seven years ago and i built it vertically rather than horizontal like all the other ones because you can easily use a digital angle finder that you can put on the tube and you can easily measure the angle that you're bending it at as well as you can put the tube in and you can put a clamp on it stick this on the clamp and you can also measure the degree of rotation that you need all done with this and all on a vertical bender it also is good for space i know a main hoop in a shop takes up a lot of floor space to do so when you go up towards the roof you just need a straight line this two bender uses a pneumatic hydraulic cylinder it can do 55 degrees per pin position so to do a full 180 degree bend it actually doesn't take that long to do with this i would recommend getting something hydraulic because doing it manually can take a long time and for the third tool of choice this is our bandsaw 7x12 meaning it'll cut anything 7 inches tall by 12 inches wide this is about the biggest size that i think you would ever need and it's also the most common size that you can buy i've been known to get a little carried away on the bandsaw because you can do just about anything with it you can um clamp tubes in different ways i have a couple drilled holes here with a half inch threads in them so that i can clamp odd shaped objects you can stand it up and cut stuff like this with it if you do have a large cope that you need to do like 60 70 degrees you can pre-cut it with the bandsaw to make it a lot easier on your tube notcher you can do anything with these a lot more than just with the chop saw like most people might have but if your budget's only 100 to 200 for a cutting piece of equipment a chop saw is best if you can go up to like 700 bucks or like a thousand bucks then you can easily get yourself a bandsaw and this particular one is like six years old they've warranted the ram everything still works so i would say invest in one of these because it works really well tool number four this is our very versatile miller 211 welder you can put a 120 volt or 220 volt plug on it and this is primarily what we use for sheet metal and thin panel welding and even for the base plates because you're welding to the sheet metal of the unibody this welder has really good heat control it doesn't destroy the material like our production welders do this is one of our five welders that we have here so yeah this is my go-to for doing roll cage base plates for the tubes itself i will tend to favor my lincoln 255 power mig which i'll show you in a second but uh if if if i didn't have the link in this this would do just fine you put the 220 outlet in crank the heat up a little bit and you can do any tubing size that you're going to be using for a roll cage unless you're using alloy steels if you're using chromoly then i would you're going to have to use a tig welder which is this cannot do this is a mig welder okay tools number five and six this is our production welder it's a powermig-255 puts out a lot of heat it's very consistent you can weld anything with it and it's going to give you a really good weld every time it's got it's just a newer machine a lot more robust it's duty cycle is like 90 so that means that you can run at full capacity that this machine can handle for 9 out of 10 minutes of running this is our tig welder it's got a liquid cooler it goes up to 350 amps and this is what you'd be using if you're doing alloy steels on a roll cage this welder can also do aluminum and stainless and a bunch of different other stuff but yeah this is what you'd use if you're doing a chromoly cage or a dockle cage or anything that t45 anything that requires tig welding with a special filler wire this is our industrial belt sander designed specifically for doing metal it has a rubber back on the wheel so that you can really dig into the steel and remove a lot of material this would be in replacement of like your pedestal grinder or just a handheld grinder we can remove a lot of material and bevel tubes really quickly with this whereas a grinder might take you a little bit longer but they do the same thing so another tool that you're going to need for doing a roll cage is a grinder or a belt sander or a pedal steel grinder they're all going to do the same thing but you're going to need one of [Music] those [Music] [Applause] [Music] so [Music] so this is the rear base plate design on the 350z we've decided to box in the rear strut towers so that we can add a strut bar the back stay and join into the main hoop all with a nice flat contact spot for an easy weld and easy fabrication and plus it cleans it up strengthens everything it's easy to weld with good prep this is a good example of what to do on good roll cage base plate and also how to strengthen the chassis and brace the rear suspension points of the car okay now that we've got these rear boxes tacked in place we could actually go ahead and weld these up because these boxes do not need to be removed in any way after this point once we weld it completely the tubes can just be tacked in place when we build the roll cage the tacks can easily be cut so that we can manipulate the tubes in order to weld everything and put back in place because we've put this flat locator on each side of the tower making it easy to drop we've also got a great landing spot for a nice beefy strut bar to go in here we're going to use inch and three quarter 095 wall dom material donnie is currently cleaning up the base plates for the main hoop and the half laterals or a-pillar tubes once we get those we'll show you attacking those in place [Music] okay so donnie's got this base plate tacked in place we put a couple of bends in it to get us around the to the approximate shape of the chassis and then we did a method called tack and whack basically the plate fits almost perfect you apply a couple tacks around the border and then you tack it and then you whack it with the hammer to get it to fit to the body line now you need to be careful with doing this because it's only doable within reason to the point where you're not going to mess up the actual chassis itself because this plate is significantly thicker than the base material that we're welding to so if you need to hit it and bend it a lot you're going to end up deforming the chassis and affecting the integrity of the plate so we make sure that we don't need to modify it that much to the point where it's actually going to start bending the car just to get the plate to fit so we got the plate to fit pretty well before we put it in place you can also notice that we are actually able to weld this plate in completely because our main hoop is going to sit roughly in this area and we're actually going to be able to drop it off this shelf and weld the tops of the cage also notice the location is close to the side of the car it's attached to this center cross section which is another brace for the chassis and there's a lot of integrity here the car's pinch weld is directly below this this has a lot of structural integrity in this area so that in a rollover you're not going to push the tube through this section of the car whereas in other cases if you went directly to the floor just behind the driver's seat you may find that in a rollover if all you did was put a plate on the floor you could actually blow that plate right through the floor so you have zero chance of that happening in this area specifically for a 350z look at the chassis that you're doing a roll cage in and analyze the area that you're choosing because whenever you do roll over all that load has to be able to be distributed throughout the car in an area that isn't going to tear which in the 350 this is the perfect spot [Music] donnie and i have completed the front boxes um if you take a look in here we've got our platform for our tube landing and then all of our structural bracing all in one plate uh we beef up the rocker of this car we give it a good foundation to land to with enough space to weld all the way around the tube and yeah this the way we've designed these as well we don't need to actually remove these either because they're narrow enough that we can ratchet strap the tubes over which will allow us to drop the cage to the floor about nine inches down from here to the floor giving us a ton of room to weld at the top and then putting it back up in place where then we can finally tack it in in place and continue on with the rest of the cage which is like your door bars your intrusion bars your harness bar your half your your diagonal brace and whatever other tubes you want to add we're almost done with our base plates we just need to do one more plate on the strut tower because with this cage we're actually going through the firewall to the tower as per the champ car rules this is going to allow us to make this chassis as rigid as possible without adding any points against this car specifically uh they allow for eight an eight-point roll cage and tying in both strut towers with drifting you actually can't go to the strut towers because they want us to maintain that crumple zone we can only go to the firewall where we put tubes to protect our feet these are called intrusion bars what we're doing is intrusion bars but also front strut tower braces as well tying it all together okay so to finish off the base plates we're going to be showing you what we're going to be doing here for our seventh and eighth point of this roll cage it's an eight-point roll cage so we're actually going to be having intrusion tubes going through the firewall here where we're going to bore a hole and then the tube is the final landing spot it's going to be right here on the strut tower we're leaving this for now because locating this tube is is pretty tricky to do before any other tubes are in place and as you can see this would be a really difficult area to get a welder inside and around there's no way to be to manipulate this tube because it's going through a hole so we're going to leave it for now the plan is what i've done on some fia cages on a couple subaru sti's and some uh mitsubishi evos as we actually drill a hole here in the strut tower we run the tube through the hole we cut it flush with the chassis and then we actually weld it from the inside of the strut tower this is gives us a we can we can also put a weld as far as we can get to around on this side but what we want to make sure is that we have a full weld around the entire circumference of the tube and the only way to do that in this area is to actually bring the tube through a hole cut it flush weld around and then weld wherever else possible and seal up the rest now we're getting into some of the exciting stuff running and making the tubes for the roll cage the first thing that we do is the main hoop now this car is running in the champ car series so that means we have to build this cage to the champ car rules the champ car rules say that we for a car weighing over 2500 pounds we can use either inch and a half by 120 wall dom or we can use inch and three quarter by 095 wall dlm based on my experience in just looking up the data on these two materials you have a lighter weight tube per foot if you go with inch and three quarter and you have about 15 percent more stiffness with an inch and three quarter tube i actually just checked this on my software the tube at a foot long inch and three quarter actually weighs one pound and eight ounces and inch and a half tube with 120 wall weighs one pound and at 12 ounces so you're getting a lighter weight tube that's actually more rigid so that's the obvious choice the only thing with inch and three quarter is it's a little more difficult to run because the centerline bend radius is larger making it harder to fit in newer chassis that have a lot of curves and tight corners either way we're gonna go with inch and three quarter because it's the better option structurally even though it requires a little more effort on our end for the design i also have the 350z fully designed with inch and a half and i don't for inch and three quarters so it's going to be a lot more work for me so this is how we're going to do the main hoop design first we're going to be measuring the width of the main hoop overall for this chassis i'm getting an exact reading of 56 and 3 8 now i don't want to run exactly 56 and 3 8 because that's going to leave me a very tight fitting main hoop with almost zero room for error so i'm going to write down the actual amount and then when i go over to the design i figure out what my spring radius is and a couple of the things that i account for and i'm going to make an adjustment to this number the next measurement we need is when are we going to make our first bend what we do is we measure when the chassis natural body lines start to bend and we actually want to go slightly after that point um the reason is mostly based on my experience but it gives the tube a better angle to meet the roof than if you started the bend lower and it's also going to leave a large gap in this area if you start the bend lower so the higher the bend the tighter the cage is going to fit to the body and the better angle you're going to get when you come up to the roof because if you're coming up to the roof like this you're going to have a very large band at a very large radius that isn't going to form well with the unibody structure here you want to come out with a little more aggressive an angle that means that this bend needs to be slightly higher without interfering with the body of course so here i have a measurement of when the chassis starts to move in it's around 23 inches i think it's safe to say that we start our bend around 24 inches because the tube has a large radius it's not actually 24 inches and then over it's going to be pretty gradual that's where i want the center of my bend to be on this particular main hoop your next point is going to be the distance between the two bends on the top this car is very oddly shaped so i have to do some double checking with a couple of pre-bent tubes to make sure that it's gonna fit but i basically am seeing that i'm gonna start with a 38 inch between the centers of each bend at the top and then i'm going to confirm that with a couple pre-bent pieces that i have and make sure that between the two centers i'm able to fit that inside of the car the last measurement i need is the base plate to the roof this car specifically is the only one that i've ever had to do differently because it is so super hard to get the main hoop to touch the roof and have the back stays have enough room to get to the plate here because there's a bulkhead here that interferes with that tube completely so the main hoop actually has to be slightly lower than the roof and then positioned underneath this bulkhead here this is a 350z specific problem a couple people that i've seen or a couple cages that i've seen actually they do not do a good job on these cars these cars are pretty tricky because the main hoops actually quite a bit lower than the front of the car so the tubes need to go up a lot down make a couple weird um corrections and bends and then finally land at the base so there's a couple things different with this that don't necessarily apply to the regular chassis like like a 240 for example super easy bmws are pretty easy and so on so the distance from the plate to where i want the top of my main hoop to be is approximately 34. this number doesn't need to be exact because one thing that you do is position the main hoop in without having the bottoms exactly where they're gonna be and even if it's too long too long is better than too short you can put it in place where you want it you can easily scribe and then you can cut the bottoms off to fit perfectly if you're new with doing cages i would recommend doing it too long because the main hoop takes up 100 to 120 inches with on your average car that's a lot of wasted material if if you make it too short and nobody likes too short of a main hoop especially inspectors if you don't if you have too much of a gap between the main hoop and the roof you will fail i think drifting is pretty lenient but other series like the champ car or like rally and fia they're not lenient at all so cut it too long if you're going to cut it anyway and that does it for the dimensions that we need we're going to take these numbers over to bentek plug them in and see what it spits out okay so here's where we start the main hoop design as you can see i'm using the bentek software and this is going to give us what we need to do on our main hoop starting with the lower dimensions here you want to measure between the two b-pillars of your chassis and put your figure that you get here for this car we got a figure of 58 inches wide the height is from your base plate to the roof on this number we got 37 inches and where i want to begin my bend i measured to be 21 inches this measurement here when you're measuring it on the chassis the bend needs to start slightly after the body starts to bend so if my body window sill starts to taper in towards the roof at around 19 inches i may want to start my bend around 21 inches it varies between chassis but that is typically what i found when designing the main hoop in between the center of the two top vents i got a number of 41 and then i want my two my two b pillars are going to be square on their way up to the first bend so here i am also going to put 58 degrees and then this is going to give you the basic design of your main hoop as you can see i have the dimensions on the outside of the tube that's because i measured to the inside of the chassis outside of the tube meets the inside of the chassis you can also do center line or you can do inside dimensions depending on what you're using this layout for but for this we're using the outside dimensions from here we are then given bend instructions which are easily laid out in a bend instructions form from here it's going to give me my bend location and the degree with the spring angle and the clr which is the estimated actual centerline radius that we are given after we bend a tube we have a 4.5 inch centerline radius die but we're actually bending it to 4.68 this accounts for the spring so you can see the first bend is 22 the two top ends are 68 the next bend is 22 giving us a full 180 degrees with the distances to each bend and then the overall cut length [Music] oh [Music] so here we are guys at the two bender about to form up our main hoop when i did the main hoop i input it into bentek and what bentek gives me is a a couple distances that i need to mark on my tube so that i know where to put the tube and do my bend and move on to the next point do the second bend third bend and fourth bend to form the full main hoop so here you can see i've got a little hatch mark this is where the first bend's going to start um i have a second mark just after that third mark and then a fourth mark when you come down to this end this is all you need to do to ensure that you have a perfectly true main hoop you need a flat edge i'm just using a piece of scrap metal i clamp it to the end just with a pair of vice grips this is as basic as it gets and what you do is put your level on this you make sure that your first bend is at zero degrees and then you make sure every bend after that is also at zero degrees and every time i go to the next hatch mark and then re-tighten the clamp i check that this is zero then i do my second bend slide it through check that this is zero slide through and so on so that you make sure that your main hoop is as straight as an arrow so we're gonna do our first bend first bend is at 32 degrees with a spring back angle of one degree what that means is once i hit 32 degrees i need to go one degree past because when i release the pressure on the cylinder it's going to spring back to the 32 that we want to [Music] achieve [Music] okay so we've reached our angle of 32 degrees on this end i'm gonna stop there because our tube on the back side is actually at one degree already giving us the 33 total with the one degree of spring back [Music] okay so we're on our second bend we've lined up the die with the second hatch this bend needs to go to 57 degrees so we're probably gonna have to go to around 35 40. pull this pin move it to the next spot and then finish off [Music] [Music] [Music] we're on to our third bend so we've done the first two here first one was at 32 second was that 57 our third line here is going to be at 57 and then one more at 32 and that's going to complete the hoop here we go and now we're on to our last band of 32 degrees as you can see we're about 32 degrees away from doing a full 180 degree main hoop [Music] [Music] and there you have it our 180 degree 350z main hoop let's go see how it fits okay so our first initial fit up of the main hoop everything's a bit tight this is pretty normal we designed it to fit tight and in order to get it in the car you may need to leverage one of these but for the first install we're going to point out a couple things the main hoop i just wanted it underneath this bulkhead of the of the roof so that i have enough clearance for the backstay to go from this point and cleanly meet up with the two we need to remove about a quarter inch off each end this is not a big deal you'd be totally fine if you left a full inch on either end so you can put it in scribe your line cut it and then fit it in so it's perfect if you make it too short then then you're screwed so this is a really good start especially since we haven't done an inch and three quarter cage in a 350 before this is a excellent fitting main hoop for a first attempt and then from here i'm going to save the file or the dimensions and i'm not going to make any tweaks because it fits well but sometimes you would say oh for the next time i'm doing this cage i could put this band half a d half inch higher or lower or make these half an inch wider or narrower and so on but we're really happy with the way that this one turned out so we're just going to remove a quarter inch off the bottom put it back in and tack it in place all right take a look here we're going to cut the main hoop bottoms at a 10 degree angle because the main hoop is going to be leaning on a 10 degree angle you can see i've got a stand here that's at the same height as the band side here i'm going to put this at a 10 degree angle right now it's at five we're gonna go six seven eight nine ten and then we're gonna slide it through so we're just taking off that much material when we flip it this actually has to go down instead of up [Music] set this to 10 and cut away okay we've got our main hoop in place where we want it we're going to start with the back stays and i'm going to cut a tube to 29 inches long this is longer than what it needs because i need to compensate for the material that i removed for the notch and then the material that i'm going to cut off to scribe it to this box now this box is just straight edges that's why i did it this way it makes it a lot easier to line the tube up beside the box you can scribe with the marker take over the bandsaw cut on your line and it'll with a bit of experience i can get it every time but you'll get it super close where you just need a little grind and you'd get it perfect let's get some backstage in [Music] so you guys are about to see our first notch general rule of thumb when you're doing tube notches is you don't actually need to go the full radius of the tube or like half the diameter with the hole saw because when you cut through the tube if you're doing the full radius of the tube you're going to be left with two sharp points here and here and you actually want those to be flat and it gives you a nice weld prep so for us this is inch and three quarter tube what i'm gonna do is go in just over half an inch so i touch off on the hole saw i come over i go two turns in one two and then i'm gonna add a hundred thou and that is my half inch that i wanna go on my machine for you it might be different you can use a tape measure you can use a number of different ways a lathe gives you that ability to do it this way so it's it's fast it's easy but you could just put a half inch mark on it with a tape measure and it would be just as good [Music] and then put a line right on the top of the tube so it marks the center of the rotation so the reason we want to put you can see the scribe lines here and then i have a center line here the center line is to tell me at what rotation does this notch fit the tube you can see the center line here fits the tube when the notch is angled like this center lines and scribes you kind of go hand in hand whenever you scratch something you need to know where the middle of the tube is and that's what we just did [Applause] so we've scribed our tube at the one and cut and we've already notched the tube on this end so we can do one of two things since the tube is just a little bit too long we can either re-cut the angle at that end or we can just increase the size of this notch by moving in a little bit which will shorten the tube both ways in this case you just do whichever way is easier which for us is going to be just to re-cut this straight edge on the bandsaw just cut the same angle again remove it going in about a quarter of an inch and yeah [Music] so we're on to the more difficult part of the roll cage which is doing measuring and bending the half laterals the half laterals are the tubes that go from here follow the contours of the chassis down the a-pillar and then to our front box the reason these are difficult is because you need to do for me it's at least three bends to get the shape of the car and you're gonna have to do some rotational angles that means you're gonna have to do a bend then you're gonna have to slide the tube through and rotate it and then do another bend and then you'll have to do probably one more rotation for your third van in order to get the contour of the chassis the car is narrower on the roof than it is at the base quite a bit up to like it's probably 10 inches narrower here than it is down here and that requires a lot of change and direction so to do that i'm using bentek software so the way that the software works is with xyz coordinates that means that the software is going to pick up points that i put in the computer based on the xyz position so inside the car i'm going to pick points where i feel that the tube needs to change direction and i'm going to mark that as my point number one so i will put on my sheet l1 w1 and h1 that's length width and height that's gonna be all my first points my second one will be two two two and then my third one will be three three three so i'll have my first second and third points as my x y and z coordinates which are length with height whichever makes more sense to you is what you can use and yeah it's it sounds simple but to get it right and to get it right the first time is complicated this is where experience helps but if if you don't have experience doing this i would suggest using a non-dlm tube or a non-rated tube like just get an electric welded tube in the same size it's cheap it's like a couple bucks a foot at most you can use that to do like a dummy bend and make sure that you've got it and if you want to make any changes you can easily just throw that tube away or cut it up and use it for something else and it's not a big deal when you mess up this stuff it's just a little more expensive and you don't want to be wasting your dla material so yeah let's uh let's get started [Music] okay so here we are at the bentek software where we input the data that we just measured from the chassis and we can plug it into the computer i've already went ahead and done that as it's kind of a lengthy process that can easily be done through you can just go to tech support or watch videos on how to do it step by step in the software but this is what you should get once you're done you can see along this plane my points are in line and then you can see how they taper off to the left because this is the driver's side half lateral and from this side you can see how the tube needs to go up down down some more and finishing off there so since i want my tube to have three bends i'm just simply going to click on the bend command i'm going to input three bends i'm going to start from the center of my bend on the main hoop and literally just connect the dots and you get your your part and when i double click on the part i can transfer it to where i then get my instructions and this is what that tube looks like and here are my instructions on how to make it it's that easy we're about to bend up our first half lateral we've already squared up the back of the tube this is where squaring up the back is even more critical because we need to change the rotation of the tube after each bend to follow the contours of the chassis [Music] so our first rotational degree is eight and we need to bend it at an angle of 22 degrees so bend at 22 rotate clockwise to eight degrees [Music] okay run our last bend third bend for this tube we have a rotation angle of 11 degrees from zero now if we're talking about absolute angles we're gonna go from zero every time so we went eight degrees clockwise now we're going 11 degrees counterclockwise some people if you have bentek it defaults to incremental now incremental is going from your last point so if we went from eight degrees you would be rotating 19 degrees it's kind of a useless point to make but you can make that mistake pretty easily if you don't notice it so 11 degrees from zero counterclockwise is our next rotation [Music] i'm just in the middle of bending the passenger side half lateral the only difference between the passenger side and the driver's side is when we do our rotational angles the driver side we started going clockwise first the passenger side we're going to go counter-clockwise first because it's a mirror image of each side other than that it's the exact same degrees and rotation and mass [Music] okay so we're here fitting up our second half lateral on the passenger side as you can see the fitment is really good we're pretty much contacting the chassis everywhere right here we will start to contact after i notch this we're coming down here and landing pretty much at the front of our box after i notch that it's gonna slide it back a little bit i'm just gonna make one adjustment and that is to add about two degrees to this bend and that should center the tube on our front box it's pretty common to have to make slight adjustments like that um just in terms of the the amount of the bend or if something didn't spring if it sprung back more than what you thought it would then you would need to add a little bit on each bend but yeah the fitment's really good this is uh first attempt so yeah you can see where we measured all of our points on the chassis and that we put the bends in the tube right where we wanted to and this is what the result is the 350z is a bit odd but we have to give a lot of head clearance here because the chassis actually goes up and then down at the front where most cars the main hoop can be the highest point not the case in the 350 but just one thing to note when we're putting these in we want to align all the forces in in the same direction and in line with all of the tubes so you can see our rear back stays perfectly in line with our half lateral and when we do our other tubes we're going to make sure that they all join into a single junction giving you the most strength and rigidity that the cage is able to offer [Music] our next tube to do is the forehead bar it goes across between the two half laterals doing this tube is probably the only one that i don't actually plug into my computer measure and pick up points and do it i do it really simply i cut a tube straight i notch both ends on the angle that i want but i make the tube just a little about an inch longer than what i actually want it to be and wanted to finish out at once i've cut the tube and notched it i then add a bend on either end usually around 15 degrees of a bend on each side and as you bend it the tube gets shorter and you can slide the tube up higher until it reaches the point where i want it to go which is touching the roof and connecting to the two a-pillars or half-bladders [Music] [Music] so we've notched the two ends of our forehead bar and we slide in as you can see it's too low and it's nowhere near the roof this is where we then add our bends on either end to get it to fit nice and tight to the roof of the car [Music] bending the forehead bar we're just gonna put a bend on either end with the end of the tube right at the front of our die and that's gonna make sure both sides are the exact same [Music] [Applause] [Music] okay so we've completed our forehead bar as you can see i have two ratchet straps to aid me in pulling the forehead bar backwards as the half laterals go back they taper so as you pull the forehead bar back it actually gets tighter and tighter and tighter i'm using these ratchet straps so i can perfectly align them and it holds it in place for when i want to attack it so i'm ready to tack it in place and then we're on to the fun part which is welding everything up top here dropping the cage and welding all of the tops [Music] [Music] [Music] so [Music] [Music] okay so now you just saw us cut all the tacks for the cage and slide it forward drop it down off of its boxes this is what you're left with a cage that's four to five inches away from the roof with nice exposed areas of the tube where you need to finish welding what we did was weld as much as we could with the whole cage up with all the tacks and now that we have this up like this it's an easy process to just finish off the tops of the welds here and then on top of the main hoop at the back [Music] so the next step after welding all of the tops and putting the cage back up in place is to do the door bars the reason i'm doing the door bars next is because some people might go ahead and start doing their harness bar and the diagonal brace but the reason i don't because if you have a harness bar and diagonal brace installed that means the the main hoop and its shape is going to be set in stone like you're not going to be able to move it when we do our door bars everything's so tight to the chassis that when i want to weld the outsides of these door bars i'm going to want to pull the tubes in so that i can get a good weld on that and then let them spring back then i will add the bracing between the main hoop so right now i'm measuring for a nascar style door bar so we are using a ratchet strap here as our straight edge so see it's pretty tight you can use masking tape for this you can use a number of different things string whatever it's just a reference for the outside of my tube so i'm going to measure to the door skin to the outside of my tube getting approximately seven and a half inches outside to outside so that means outside the outside when i move that in my center to center distance is also going to be seven and a half so when i go to my bentek software i'm going to plug that in as my measurement [Music] [Music] [Music] [Music] [Music] [Music] so okay so we've done the curved portions of the nascar door bars where we sneak out to the door skin and then come back in i cut these two lower tubes to the exact same length on both sides this is to make sure that everything is symmetrical so when i put this side in it fit nice and snug when i put this side in it was about i'd say just a bit under a quarter inch of too far of an opening which is no problem at all that just means the spring was just slightly off on one of these bends not a problem at all we take the ratchet strap we pull the tubes together until the both ends touch give it a couple tacks and now i know that my left and my right side are identical so i can go ahead and make two identical pieces here and they fit right in and land on my marks um exactly the same on both sides so our next step is to join the upper and lower tubes with a couple of joiners we're gonna put three in between two is what's required by the rulebook we're gonna do three because it looks better it's a little bit extra integrity and yeah that will sum up us doing the door bars on this [Music] car [Music] so [Music] okay so we've finished up the door bar design we've half welded in all these tubes everything's welded just on the outside typically i weld things on the outside and then i come inside and do all the welds on the inside i knew that i had to pull this over with this strap so that i could fit my intrusion bar up in through these two holes that we've board so i didn't want to fully weld everything it would make it just that much more rigid and harder to do this has already got a ton of tension on it as it is and this tube is barely gonna fit up in there but this is what we're gonna try and attempt here i've already drilled the holes and we've got to just line them up and get them through with some fish waiting [Music] so i can't emphasize this enough the steps that you plan out and take to build a roll cage and be able to weld everything is really really important so as you can see here we've got a spreader bar in place because we had to pull the tubes in in order to slide our intrusion bars through the firewall and into the strut tower we put a hole in the firewall and in the strut tower because we can slide the tube all the way through let our two back bring it back and then we're gonna put a plate on the inside of this tower and weld the tube to the plate and to the tower so now we needed to push the tubes back out to the body of the car and we had to spread it just a little bit wider to make sure that this notch lines up nice and we put a nice strong tack on everything remove the bar and then the cage is pretty much ready to weld up [Music] we're at the final stages of building the roll cage we're about to put in the diagonal brace and the harness bar all of that goes right within the main hoop um the reason i'm doing this almost last is because i had to pull in these tubes in order to weld the outside of the doors and stuff so that's why i do it last plus it's a bit easier to come in and out of this area to wild spots that are already welded now that i can do it i'm going to start by i already made my cut for this tube because the driver is relatively tall i'm going to put this tube on the main hoop almost six inches away from the bend that's the maximum limit the further i have it over the more the seat will be able to sit within the main hoop so if i have it right here the top of your seat's gonna hit this and the driver won't be able to go back very far so the further in i put it the more seat clearance he'll have i just have to be within six inches of this bend normally i tie everything into one junction here but sometimes the size of the driver and where they want to sit we'll change that so once i do this i can then measure and cut my two pieces for the harness bars to get my notch angles i'm just going to use my digital angle finder and simply going to subtract the angle that it's at minus this because this is zero and minus that because that's 90 degrees so i can find out what my difference in angle is and notch them sometimes you can use like a digital protractor or just a normal protractor and you could just put it in this corner and find your angle i just have this handy all the time so that's why i use this there's a number of different ways that you can measure the angle that you need to cut that's how i do it just to give an example of what angle i should put these notches at i have 36 degrees on my level that means i have to subtract 36 from 90 that's 54. this notch is going to be 54 degrees that notch is going to be 36 degrees and it's as simple as that [Music] now that we have the diagonal brace going from the passenger side to the driver's side the top of your diagonal brace needs to be above the driver's head so if you have a right-hand drive car this would need to be going the other way so now that we have that done the harness bar needs to be installed doing the harness bars is tricky just because it's like any x in a roll cage you have to have both tubes at a very specific length in order to be perfectly in line with each other so i start by putting a strip of masking tape across this is going to tell me basically where the intersection point is going to be and then i can measure from here to this line and give me a really good idea of how long this piece needs to be and how long that piece needs to be and the first thing i'm gonna do is the um long notches these notches are 54 degrees each and the reason i'm doing those first is because if i do those two angles first bevel and get them ready i can cut the straight notch one two three times as i'm fitting this piece to get it just perfect it's easier to to remove material off of this notch than it would be this one this one's gonna wreck your whole saw or your whatever you're using to notch your tubes heavy angles will do a lot of damage but you can easily cut this notch a couple times and it's just a lot easier to shorten the tube from this end in so i'm going to take my two measurements from here to here from here to there make my raw material cuts put these notches in it and then we'll we'll pick up from there on how to get them to fit perfectly [Music] so [Music] [Music] [Applause] [Music] okay so we're at the point where we're putting in the last piece and as you can see i've cut it i notched these larger cups first and after notching this side it turns out it's a bit too long which is perfectly fine i can easily cut this notch again and i can match up where it should be cut approximately just by scribing beside the tube here but you just really need to be careful when you do this because you can take as many cuts as you want to get down to that length but if you take too much you'll you're screwed because once it's too short there's no way that you'll be able to make up that difference also something important about doing your harness bar make sure that you look at the regulations of the series that you're trying to build this cage to for the champ car we are only allowed the harness bar to be level or up to two inches lower than the height of the driver's shoulders that's with their seat in position that is to do with the harness bar angle they do not want the harness bar mounted higher than the driver's shoulders and they don't want it mounted too low so there's a small window that this bar can actually go in so when you're building your cage make sure that you've done your seating position that you know where your shoulder height is going to be so that your shoulder strap angle isn't too severe [Music] and there you have it guys perfectly level and inline harness bars um it just takes a little bit of patience on this last piece to cut it down to fit and be perfect these are pretty large angles but time is what you need to build a good roll cage [Music] so [Music] [Music] [Music] well that does it guys we're finished the roll cage um i hope you guys enjoyed the video we spent quite a bit of time on this one uh let us know in the comments if you what you think of it and if you learn something or if you have any questions about anything specifically feel free to ask we'll be happy to share with you how we did something that you may not know make sure you like follow subscribe we're going to keep doing this more and more as we go on installs and how to's with all kinds of stuff because we got a lot of knowledge to share with uh with everybody else so stay tuned for the next video

Channel: FDF Race Shop

Views: 309,331

Keywords: roll cage, building, fabricating, designing, welding, racecar, driftcar, time attack, driving, driver, tutorial, step by step

Id: L5-uc4ZdUWA

Length: 72min 37sec (4357 seconds)

Published: Fri Jan 08 2021