CHAINSAW GO KART! - Part 1

so the chainsaw power go-cart comment in the last video I mean it was a bit of a joke but you know it put some gears in motion I started thinking about all the old hardware I had laying around just collecting dust and all of a sudden the idea began crystallizing in my mind I might actually have enough stuff to pull this off this is my old chainsaw and it looks like my wife put it away dirty I'm so embarrassed this saw hasn't seen a hard day's use in five or six years easy ever since I got the bigger steel saw last time it was even started was probably two if not three years ago this is now my loaner saw this is this all I'd lend my neighborhood yeah I guess now I know why he hasn't come asking for it in a while [Music] for as much flak as these halls get I have to be honest it's never giving me lip in the ten years I've had it my steals are more temperamental than this thing is I think this thing has a Quarren engine in it I just thought I'd light that fire anyway I only really replaced it because it's started to wear out not the engine but like the entire saw shake it by the handle and it moves like a belly dancer this is if I'm not mistaken a 46 CC saw maybe 42 something in there I have no idea how much horsepower this little engine can put out one horsepower maybe though it is a bit old half a horse whatever it is it isn't a lot now I do have a couple of electric motors but unfortunately my longest extension cords are only about 25 foot nonetheless I'd like to try to make it work it's really only gonna be pushing around a couple of scrawny kids anyway and on top of that I'm not trying to build a formula 1 Kart max speed I'd like to shoot for is maybe 2025 miles per hour and even that might be fast but it'll make a lot of noise and I'm pretty sure that's the point using a small power plant means I'm going to have to try to make the cart as light as possible not a deathtrap but light as possible okay well it needs a little more cleaning but that looks to be about it so four wheels I had to go and buy these I didn't just have them lying around now if you do what I did and go look for go-kart wheels in eBay you'll find one of two types very expensive Racing wheels with like Dunlop tires and then you'll find these these are about $15 import and seeing them in person well it'd be a stretch to even call them hand truck wheels the hubs and rims are thin pressed sheet metal now although they might work okay in a cart situation like a hand truck I don't know how much side loading they'd reliably take or for how long for that matter I trust these wheels about as far as I could throw them actually scratch that I could probably throw these pretty far I plan to reinforce these hubs particularly for the drive wheels but we'll cross that bridge when we get to it so big picture I want this engine to turn these wheels of course and the first step will be to figure out how to connect the dots now I'm not a hundred percent sure but this engine at top speed with no load probably does in excess of ten to twelve thousand rpm and although that's great for cutting wood we're giving mom a heart attack it's way too fast for what I needed to do I've got to gear it down and gearing it down also serves get back some of the torque and hopefully turn this into the little engine that could my first inclination was to add a chain like a low gear on a bicycle and I'd imagine that's how most of these things are done but if we do some quick math largest gear I could get on the tire is say 10 inches which would actually mean the gear is actually touching the ground because the wheel is 10 inches too but we'll use 10 to make the math easy the largest gear I could get on the saw and still clear the chain I guess I'd be a sprocket largest sprocket I could get on the saw and still clear the chain is maybe three inches so 10 divided by 3 is 3 and a third that would drop the axle rpm from ten thousand to three thousand which is still too fast I think and really only next me about three times the torque on the ground so in this case I think I need a bigger gear reduction which leads me to the other worm drive that you may remember from the rotary weld table build video I'll put a card up here in the corner for that this gearbox does a ten to one reduction that's three times more than the simple cane drive it has the added benefit of being completely enclosed so I don't have to worry about small fingers getting into a chain drive whatever this particular basically means all right so what you just didn't hear was essentially a long-winded brain fart let's just put it behind us and make pretend it didn't happen shall we a worm Drive isn't going to work here as it can't be back driven meaning if the input doesn't move the output doesn't move if the saw isn't running we're like the kids are stepping on the brake the gearbox rear axle and wheels would be locked up so let's take a 15 minute break I'll get my acts together and we'll regroup I recently got a new toy tool a cordless angle grinder I got what I think was a good price on it from Amazon I bought the tool only no batteries so far it's been a lot of fun I can't tell you how long I've wanted one these it does run slower though than its corded counterpart but seems to do the trick consequently it's also a little quieter I mean sort of what it's really good at though is stealing bison so can anyone give me one legitimate reason why every part of a bicycle requires four specialized tools to remove I wanted the sprockets out of this and I just couldn't break this thing down and I have a machine shop so I threw in the towel and I walked into my local bike shop they pulled all of this stuff out of their trash and just dumped it in my lap so now I feel like a sucker having risked life imprisonment when all I need to do is ask these parts do have some wear and tear but I think I've got enough of them to take a few good ones so it's still the same plan just the execution is going to be a little bit different well to get one of these on the saw and the large one probably on the driveshaft and there'll be an intermediate gear that hopefully gets me to the speed reduction that I need the saw already has a sprocket behind this clutch I'm going to have to remove this clutch so I can install the right sprocket to take the bike chain now I don't know if this is the smartest way to do this but I'm going to stuff the engine with as much rope as I can so it doesn't the piston doesn't move and I can unscrew that clutch there are special tools for this that I don't have or the inclination to make really so there's this bracket I have to change so here's a better look at the backside that's the sprocket to drive the chainsaw chain of course there was a small needle bearing in here I just kind of pressed it out to keep from doing damage while I make the modification I also separated one of the smaller sprockets now I was hoping I would have found somewhat of a larger sprocket on the chainsaw side or a smaller hole in the bike sprocket just so I could make a real nice fit up but to make that modification it's kind of a pain in the butt it sort of fits enough I think to get it centered just doesn't give me a lot of places to attach to I did make a bit of a spacer ring just sort of set the gap between the bike sprocket and the bell of the clutch here that just sets the clearance on the bottom to make sure the chain doesn't really rub anywhere I plan to take weld this in place as solid of a weld as I can get given that I have six attachment points now these sprockets are not hardened I mean their hardest but they're not hardened the thing I don't know is just how high of a carbon content they have and when I go to weld them if I caused more harm than good but if the welds do fail it's not catastrophic I mean the cart won't run but these will be protected inside sort of the chain cover of the saw I would just have to break it down and do it right the second time all right despite that wagon-wheel look I think I feel pretty alright about that like in the puddle I know I got 100% fusion on the bike sprocket and it looks like it took pretty well to whatever this sprocket is made out of given that there's a centrifugal clutch in the back and the amount of weight that will effectively be going through this chain I don't think this thing is going to see any really sudden starts no real shock loading to those welds the chain fits nice with plenty of clearance in the back I'm just going to clean up this top face that sits up against the body the saw put the bearing back in and reinstall the clutch I'm going to finish that out nice and slow on the press it's probably what I should have done in the first place while I'm here I think I'm going to take off some of these Mad Max features for now at least until they start to get into some competitive racing maybe [Music] [Applause] [Music] [Applause] [Music] long time no talk we should catch up sometime you should have just seen me build the wheel hubs and install them the lug nuts are a little long I know but I needed them to pull the tires closed on the split rims that and it turns out I don't have shorter ones I'm building this around a three-quarter inch or nineteen millimeter cold-rolled drive shaft doing this by eye and it looks about right I also built hubs for the large sprocket and a disc brake I pull the front brake system out of a local junkyard came off an old scooter dirtbike it's a little bigger than I was hoping for you can see it doesn't leave a ton of ground clearance but neither does the sprocket you may notice none of the hubs are keyed to the shaft as is this cart won't go very fast now in the interest of an expedient build I'm going to go with my patented 100% guaranteed maintenance proof assembly methods I'm going to weld all the hubs in place but I'm going to make the entire rear axle removable from the frame I don't expect problems but if something does go wrong I've left myself enough space on the hub's to be able to cut them behind the welds that way I really only lose about two and a half or three feet of the 3/4 inch cold rolled just to be clear this is not the correct way to do things so next comes the tricky bit I have to decide how big I want to make this thing I'd like to keep it light so preferably it'd be small that'd make it easier to move around and fit in my car but I don't want it to be tippy fast plate turns are probably inevitable and I prefer not to have this thing roll over alright I'm back in order to get these sizes figured out I had to take a little break to find a seat it seemed some hard times but I think it's got a little bit of life still in it so I think it's the right size for my kids but a little bit bigger than I was expecting be honest the thing that's bumming me out the most is it doesn't really have a lot of style anyway beggars can't be choosers I think I'm going to go for about 28 inches that's something over 70 centimeters I'll see maybe I can play with how it sort of sits in the frame to make it kind of like less prominent but to be fair it's probably a good safe like bucket style seat for the kids this all may end up kind of outboard of the rear bumper not really what I was going for but I think I should be able to make it work anyway with this stuff I think it could take a shot now it's starting to bend up the start of the frame as far as tubing goes on hand I've got a fair amount of these sizes this is about 5/8 60,000 then I've got in might be inch and 1/8 I've got it in heavy wall and thinner wall the problem is I have a lot more of this bigger stuff but it's in shorter pieces I have enough of the small stuff in longer sections that I think it might be easier to use this and bend it instead of weld up a lot of you know shorter pieces I think like a 3/4 maybe a 19 or 20 millimeter light section square tube would have probably been the best but I'm trying to work with what I got here anyway using the smaller stuff means I'm going to have to go with more of like a space frame kind of 3d trusses and a little more complicated but again it's easier to bend and I've got it in some long ish pieces what I don't have though is a die for the bender to bend this size tubing and with one of those up do a quick test bender too and just see how it goes you all right well all told it didn't come out too bad it did turn out an inch wider than I intended it to I think I failed to take into account to tube widths it's the dimension that I want on the inside I wanted it on the outside the other one that got me is that Bend there this wraps over the axle will be a bearing plate like a support plate and the bearing will go on here I want that Bend to be closer to this bearing I had to flip this over in the bender and into two and a half inches that get taken up by the bend I put the mark on the wrong side it just means I'm gonna have to make the bearing plate a little bit longer when you do that next but first let's go back to the bender so on the bender I've got the die that I'm bending around of course set up in the center on the trailing side there's a fixed block square block and on the leading side there's a like a round die a wheel I guess I'm going to make a mark on the tubing right at the back edge of this square block just as a point of reference try to pull a 90 degree Bend and you watch that mark with respect to all of the bending heck I'll put a mark over here too on the roller now with the set up like this what you want to happen is have the roll or roll the stock that you're bending around the die we don't want this to move in the back and in practice it'll probably pull it a bit so I'm really complicated or something with a lot of bends or you get some kind of like a big tolerance stack up at the end you may want to clamp these so it really doesn't move let me pull this Bend around so you can see that mark didn't move so this dimension on the left-hand side would be reliable so there's the bend the die is doing pretty good but maybe you can see where this mark used to be this mark used to be right there so now this is just a sample Bend but if you don't take into account where this extra material is going to wrap like if it's going to wrap inside or outside your dimension this part will either be 2 inches long or 2 inches short and that's what happened here I meant to pull this curve on this side of the mark so it end up here but instead I got the dimension I marked off plus the bend and just made it longer than I wanted I think that's what happened anyway all right the bearing plates gonna chop up a couple of pieces of cold-rolled steel put some holes in it and weld it into the frame I've got both bearing plates welded in and hopefully you can see once the bolts come out of the bearings the axle can drop right out of the bottom now I want to make a second piece that sort of adds structure to the frame and gives me some attachment points for the saw and brake caliper that kind of stuff flush the frame out a little bit basically so this turned out to be about 19 and a quarter inches that's almost 49 centimeters and a project like this the first bends are tend to be the easiest because well there's nothing else they need to match up to the second and subsequent bends are going to have to match this first Bend I've already got one of the corners bent on this piece and I'm about to put in the second Bend which sets the width now instead of doing the math I think I'm just going to show you the mat I want this to be 19 and a quarter when it's finished and I'm going to use the test Bend we did earlier to set that up so if I set this at 19 and a quarter mark on the outside that I see on the table there's the mark the reference mark we took before up against the fixed block of the bender I'm just going to transfer that to the tubing I want to bend and that hopefully gets us the right size okay that fits surprisingly well that will float I don't know about two inches above I'm going to try to guess it a good dimension and sort of fill this thing out weld it up [Music] okay I think that Saul is in there pretty good I may add a gusset or two but it'll have to wait until I know where the sprocket and chain goes that said I'm very tempted to use just one chain I mean it would be so easy but that is only net me maybe a three or four to one reduction I'd hoped to finish the whole back end but I think I'm going to stop part one right about here there's really not that much left to it I still have to route the chain for the chains I'm still undecided what to do there if anyone has any experience with this or a really strong gut feel I'd love to hear your take on it but basically it's the chain and a similar bracket to mount a brake caliper on the right hand side you may have noticed that there's only half a frame just the back end that's because I planned to add a bit of suspension to this I think I'm going to put a hinge in right behind the seat and add one or two big springs again still not 100% sure just playing this by ear that might be overkill I thought it'd be a nice touch anyway next time we'll finish this back end where I'll catch you up with where I am by then and we'll start some work on the front side front half the frame controls steering column linkages that kind of stuff anyway hope you like that thanks for watching

Channel: This Old Tony

Views: 2,460,729

Rating: 4.8899746 out of 5

Keywords: diy, go kart, gokart, go-kart, chainsaw, tig welded frame, bending square tubing, tube bender, hossfeld clone, go kart for kids

Id: v_1UO1GTsg0

Length: 24min 7sec (1447 seconds)

Published: Tue Jun 06 2017

Reddit Comments

[u/gatekeepr]

Can't wait for part 2!

[u/IasoWoW]

At one point he took the grinder out and my first thought was "oh shit he's gonna cannibalize that grinder for the gearing...."

Much relief was had.

[u/andpassword]

I love how he's just decided to, you know, build a go kart. No plans, just ...well, here's how this fits, I guess I'll TIG weld it.

Tony is either the angel or devil on my shoulder while working in the shop...the thing that keeps me coming back is that I can't figure out which one.

[u/[deleted]]

I love that he left in the idea about using the worm drive. It'd be easy to edit out and we'd never know.

[u/[deleted]]

I see builds like this and always question "why dont they use gears from a mountain bike?". The rear gears usually have the tensioner and a selector on it, should be easy enough. With such a weak motor, bicycle gears should hold up to the torque.

[u/likeBruceSpringsteen]

So awesome.