LOC Precision “LOC-IV” high-power model rocket assembly (part 1 of 3)

[Music] hey everybody dave thomas here again and in this video i am building the lock precision lock 4 high power model rocket now i'm not quite sure why they call this the lock 4 because it has 3 inch fins it might be the fourth one they came up with or it could be because it uses a 4 inch body tube i don't know but it's a pretty cool looking rocket and in my opinion this is a great rocket for doing your level 1 certification with it's big enough that you'll be able to see it fly relatively slowly it's not going to go way up high although it can but it's going to give you a flight that you'll be able to watch instead of just have the rocket disappear on a high power motor and it shouldn't fly so high that you have a hard time recovering it and so what they show here is with an h123 motor that has an expected altitude of about 2 000 feet and this is still low enough that if you wanted to fly this without any type of dual recovery system it's not going to go floating off into the next county and i am of the opinion that your certification flight should be as simple as possible and this is a good one for it now if you are looking for something a bit more advanced this rocket can also be set up for dual deployment either with a shoot release or with true dual deployment with two different parachutes and we'll go over the options for that as we get into the kit build the instructions that come with this kit are pretty basic and assume that you've had experience building other model rockets before now that being said there really isn't too much more beyond your fairly advanced say mid power rocket that you won't see in here it's just that everything is bigger now let's check our parts this kit comes in what's basically just a big plastic bag and everything is pretty much packed into this the body tubes so we have the the main booster body tube here that's slotted for fins and inside of it is a coupler all right there's also an upper body tube and this is what will become the payload bay and that payload bay can either be used strictly as a payload bay so if you want to fly you know an egg or half a dozen eggs or something else up there you can this can also be modified to house an actual dual deployment parachute system in which case this would hold one of your two parachutes all right we have a large plastic nose cone okay this is the motor mount and you can see here um the pack stuff in here as well so shake this out and this is the parachute it is 36 inches in diameter i'm just going to leave it packed for now all right uses 38 millimeter motors and we've got a couple of sub packages here this is the bulk plate for the payload section and these are the centering rings for the motor mount this also includes a screw eye here that will attach to the shock cord and this is really kind of neat this little hook like thing here this is the engine retainer and though it looks relatively simple it's pretty effective and does not cost a lot and so that's one of the things that we often see with high power kits is the kit does not come with a motor retainer you have to buy that separately and high power motor retainers can easily run 30 or more and so i really like seeing this in this kit then we have a shock cord and rail buttons and so the kit here says as a launch lug it looks like lock has replaced those with rail buttons all right we have the fin set there's a total of three eighth inch plywood fins there then we have the main decal and then a smaller kind of generic lock precision decal okay and that looks like everything that is supposed to be here is here so i'm going to clear this away and we will get to work now before i start in on the engine mount assembly which is the first step in the instructions i'm going to treat my fins with some diluted wood filler here to help fill in the grain now you don't have to do this you could just sand the fins and then when the rocket's assembled put primer on it and it may require a couple of coats to get a nice smooth finish by doing this i'll get a nicer smooth finish before i do any sanding or primer on that and this will just help fill in some of the deeper grain here so what i'm going to do is take a blob of this it doesn't matter whether you use an english blob or a metric blob either one will work and now i'm just going to add about an equal amount of water i'm going to start with about 50 percent and then work my way up if it needs to be a little more liquidy okay and i'm just going to mix this around [Music] a little bit more in and there are several brands of this they all they're all pretty much the same they're they're water-based they're non-toxic and you can find them in most home and hardware stores [Music] now since these fins are plywood i'm not too worried about them warping when you do this with balsa fins it can cause some warping if you don't do it evenly okay here i'm just going to take a paintbrush and just put this in you can go ahead and just keep crossing directions we're not trying to make a smooth finish yet we're trying to fill in the wood grain i am going to avoid getting down in here below where the surface would be so this would be the the fin tab here that goes down into the body tube i don't need it to be smooth in fact i'd like i'd rather have it a bit rough so that the adhesives work better when we go to put the glue the fins in okay we'll also be rounding off the edges of the fins so i don't need to worry about putting this on the thin edges and here i'm going to go ahead just so i don't make myself mess up here i'm just going to draw a line here where the fin tab goes in and stay above that in fact i'm not going to go to the line and stay a little bit above it because we're going to have fin fillets that will go right above that as well and i want those to adhere better [Music] [Music] okay so that's pretty good again i'm not worried about the edges because we're gonna round those off anyway okay so i'm gonna stand this up and let it dry and when i come back i'll have the other two fins done as well i've let the filler dry overnight it doesn't necessarily take that long and so this is what it looks like when we get it out it's very bumpy and such but it's very easy to sand down so i'm just going to use some 120 grit sandpaper here okay and that's already got most of it down basically i'm going to send back down to the wood grain and what's going to be left behind should be filling in most of the little pores and valleys within the grain [Music] all right so that's about all there is to it and then if you want to do it at this point we can also round off the edges here for the leading edge and for the trailing edge as is recommended in the instructions i'm going to go ahead and finish the rest of these off camera so filling the fins was a step that we could do ahead of time and then the fins could be drying while we did some of the next steps in my case i let them dry overnight but if you're in more of a hurry you could have done the fins put the filler on those and then do this next step which is actually this first step in the instructions so we need one of the centering rings here with a hole in it there are two of them we'll use the other one later and within the package of small parts that goes along with the centering rings are these three pieces so we've got this t-nut with teeth on it here and then this is the actual z motor retainer and then we just got a little phillips head screw here so this is going to go into the hole and you can either take a hammer or a strong pair of pliers or if you have really strong thumbs and we're gonna push that all the way in so the teeth are fully engaged in the wood now i'm gonna have to do this off camera because i don't have a good surface here to hammer this in so i will come back with this placed inside where it belong so i just used a hammer and with a couple of taps was able to drive this in and so now this is the aft end so the t-nut will face inside the rocket and then this works by simply putting the z bracket on there and then putting in the screw okay and then the z bracket here holds the motor in by overlapping the edge of the motor itself actually quite an ingenious little uh and yet simple device okay now the instructions say to put epoxy on this make sure it doesn't come off which i will do but i'm going to wait on doing that until i assemble the motor mount that's what way i have to make one less batch of epoxy and for the moment i'm going to go ahead and take that off now at this point i want to dry fit everything together so this is the middle centering ring i'm going to put it on first and this is why i wanted to do this okay that's really tight that is as well yep okay so all these are going to require a little bit of sanding i'm also going to lightly sand pretty much the entire tube um the through the wall fins here will actually attach to the motor mount tube and so we want to have this roughed up so that the epoxy has a better surface to grip to but since we won't be able to see exactly where these are going to come down it's just best to to lightly sand the entire tube to glue get that glossy surface off there [Music] [Music] i sanded out the insides of my centering rings here and basically i just had to remove the layer of partially carbonized wood there from the laser cutter and i ended up using a sanding drum on a rotary tool to do this just do it on low speed so you don't take off too much at once if you need to do it by hand just some coarse sandpaper run it around the inside a little bit but now all of these fit onto my tube here okay and so the next thing i'm going to do is add the hardware to this ring and this simply consists of the eye bolt here two nuts and two washers and we're just going to sandwich the ring here between the two of them so i'll put on a nut and put that on pretty close to the end of the threads i'm going to leave just a little bit of thread there and then a washer and that's going to pass through the hole here and then my other nut goes like that okay this is so i'm gonna go ahead and extend this net up as far as it'll go okay and then tighten it down there so that's just putting it in place making sure everything fits now i'm going to epoxy this and i'm going to epoxy it while it's loose so that way i can put some epoxy on the the bolt itself um pass it through have some epoxy in the hole here basically epoxy the whole assembly so nothing comes loose and then while i've got epoxy made up for that i will also do the epoxy on my other ring for the engine retainer there all right so i've got a little bit of five minute epoxy here and just need to mix it up i'm using jb weld brand there are lots of brands out there any of them are fine if you don't have five minute epoxy 15 minutes fine too 30 minute will work as well but it may tend to run a lot more i'm using five minutes so i can have this handleable fairly quickly and it doesn't really matter if you have the clear epoxy or the black kind of the brown kind as long as it's a good epoxy that's fine all right so i'm going to go ahead and very quickly do my t-nut here i'm just going to work in a little bit of epoxy all around the edges all right but i don't want any oops almost got there i don't want any on the threads okay and i can just let that harden okay so for this part i want to epoxy anything that can potentially move so i'll put a little bit here on the threads at the top of the eye bolt and then move [Music] my nut all the way up and i'll put a little bit more on here where the nut and the washer will come together okay and then put some here around the hole and in the hole and then around on this side as well okay and that's poked through there so now i'm just going to put my washer on top of that okay and i crank that down i really should be wearing gloves here i'm being a little bit sloppy but epoxy can cause allergic reactions in some people all right if you do get it on yourself use a little rubbing alcohol and it will wipe right off as long as it hasn't hardened yet all right and now i'm just going to take a wrench here and tighten this nut and i want to keep the eye bolt here parallel with the edge okay that's good there so now i'm going to let that harden as well now at this point i have dry fitted all of the centering rings onto the motor mount tube no glue yet and so the forward one should be right here almost to the edge of the motor mount tube that gives us just enough room there to put in a fill it and then initially the instructions say to put the middle ring at about five and a half inches from the aft end and then to put the aft ring here at about an eighth of an inch from that end so about like that and then we need to see how the fins are going to fit here all right so when the fins go through the wall they're going to come in like this and we want to have them in contact with the centering rings so i'm moving my middle ring there okay i'm going to go ahead and mark that right here so i know where that ring has to go okay i'm going to check this again okay so once more that way and then i can move these a little bit one way or another okay now i'm going to go ahead and dry fit this into the tube because we also may find that we need some sanding here yep we're going to need a little bit of sanding so i'm going to go ahead and let my epoxy finish curing on the hardware here so i don't run into a problem with that and then i'm going to go back with my dremel my rotary tool and just sand lightly around these rings until everything fits inside but what i'm going for here is we need to have the space so that this space here corresponds with the slots for the fins so that the fins will go in through here all right and so they stick out and then the motor mount is going to be inside about like that now one other thing you might want to do if you have a motor casing available when we're doing these fits go ahead and stick your motor casing in and put on the z clip that's going to hold it there so that we make sure that wherever this aft ring gets placed that we have enough clearance for the motor mount retainer to work correctly so to illustrate this i've got a 38 millimeter three grain cesarone case here now in the cesarone motors they're millimeter cases do not come with an aft closure it's actually built in to the nozzle assembly that comes with the reload and so i over the past several launches i've just retained a couple of these used ones for the purpose of spacing here so i'll just put that on so that's what it would look like loaded and right now i've got this set at the eighth of an inch it's recommended so that would go in there the clip would simply go into place this way and just screw that down okay and so it's a little bit thick but it should work just fine i don't want to go up too much see if i go and get it just completely almost completely flush there and i screw that down that will just do it there okay so if you don't have a motor with which to check your spacing go with the measurements in the instructions they'll work fine i've sanded the outer parts of my rings now and before i test fit them again one thing that can happen is the you get a little bit of a lip that forms here on the inside of the tube where the the cardboard gets squished in a little bit and so if you chamfer that outward either with a thumbnail like that where you can use a metal handle like this okay you just angle that outward instead of inward okay and so now we can put this in check for fit and it won't get hung up there so that one goes in nicely and i've lost my place on that that's okay so right now i'm just checking so that one goes in and that's trying to move on me as well that's okay so make sure all of the rings go in so we wanted to go in snugly and not dangle around in there and something else you can do in here in the instructions it has this is one of the finishing steps but you can just put in a little bit of thin cyanoacrylate glue or super glue around the edge here let it soak in and then wipe it off and after it dries if you need to you can sand it a little bit but it helps prevent this um lip formation by the cardboard here so you don't get that garbage in there okay that's up to you but especially if you got if you have a tube that keeps trying to fold in like that that's one way to get rid of the problem i'm ready to put on the forward centering ring now and for this i'm going to use a 15 minute epoxy just to give me a little bit longer working time in general as you go up in in setting times you also go up in strength and so i want a stronger bond here but to be honest if all you have is five minute epoxy just put on a good heavy layer and it's gonna be fine i've built complete models using only five minute epoxy i've built complete models using only 30 minute epoxy just be aware that if if you need some extra strength put a little extra on there and actually the i'm gonna as we go through here i'm gonna show some ways that i tend to over build anyway uh beyond that which is in the instructions so this i tend to get the the motor mounts especially very strong okay so here i'm just going to take this and again i want to get my eighth of an inch or so here um and if you want to give a little bit more so that's getting almost to a quarter inch there that's fine um you know you could stick this down an inch and it really wouldn't hurt anything might get a little bit more charring of your shock cord all right so i'm just going to lay this down all the way around here [Music] [Music] okay and now i'm going to move it forward and just push that epoxy up ahead and give it just a little bit of a twist as i go and this just helps get the epoxy into everywhere and that now has formed a really nice it without me having to do anything else and here i just need to make sure i get this even all the way around if you got a little bit of an angle on that it'll still fit don't worry about it okay and now once that's there i'm just going to fill in the back side here [Music] [Music] [Music] okay and this doesn't have to look pretty so if you want to leave it just as it is right now that's fine what i'm going to do here is actually form a fillet in it if for nothing else it's good practice for when we do the fins and this is a little trick i picked up from another online video and here i'm just going to take a little bit of rubbing alcohol on my glove and i'll pull my glove tight so my fingers relatively smooth and then using the alcohol it keeps the epoxy from sticking to my glove and so this allows me to make a really nice smooth fillet here now i had to bump up there and where i had the nut but we'll use the same technique when we do the fins and so a little bit of practice here where you can't see anything is a good idea and then a little bit of excess here i'm just going to stick over my eye bolt assembly okay and now i'm just going to let this harden for a while before we go on to the next ring while i'm waiting for the centering rings to finish curing we can look ahead here to the payload bay and how we want to set this up and this is something i mentioned earlier in the video so that depending on how you want to build this rocket you can do this in one of three ways so you could eliminate the payload bay completely and just glue the coupler in halfway up and then glue this to the main body tube and then everything would hook in to the nose cone much like it would be on a smaller model rocket the way the instructions are written this bulk plate goes into one end of the coupler and this is going to require a little bit of sanding but basically this goes until it's just right inside there like that and then we'd have an eye bolt here and then the coupler gets glued into the tube on this end and so with the bulk plate in there you have quite a bit of room inside the third option is to either build or buy a uh avionics bay kit and that would fit inside this coupler and it would come with its own bulkheads and everything so you wouldn't need this and so you'd have this in here you would not have as much space anymore because there would be a bolt plate here right which fills up a goodly portion of the payload bay and then you'd also have the nose count all right if we put the nose cone alongside this okay so if we had the nose cone there and the payload bay there basically there is only let's see when you get it okay so if we've got the nose cone in place and its shoulder comes down to that far and the coupler is in place there's not a whole lot of room there there's just enough room for a parachute which would be what you'd be using it for if you set this up for dual deployment so i want to give myself the maximum versatility here so i'm going to go ahead for now and i will install the bulkhead plate here but instead of gluing this in i'm going to use some reusable plastic rivets and so those will go in at four equidistant points around here and will hold this in but give me the option of removing them again in case i want to put an avionics bay in here the two avionics bays i'm familiar with one's made by lock the ones made by apogee they come with their own coupler and so if i decide that it's time for the avionics bay i can just remove those rivets pull this out with its hardware attached set it aside install the avionics bay into here and then set this up for dual deployment okay so the first thing i'm gonna have to do before we do anything else here is i need to sand off the edge here so that it will fit inside here properly so i used my rotary tool and sanded the circumference here i also put a slight bevel on the edge just to make it go in easier so now if we test fit this it goes in very nicely all right and when we glue this it'll go on with just a little bit of an indentation all the way around and that'll give us room for a nice fill it in there but before that we need to install our hardware and this is going to get go together a lot like what we saw with the eye bolts going on the centering rings and so once again we're simply going to put this together i'm just going to dry fit this quickly okay one difference is it's got bigger fender washers here than the one on the centering ring it's a little bit longer here we go okay so that'll all go together like that and then this will fit in here like this and i want to put this all together at the same time so i'm going to get enough epoxy ready to do both the eye bolt and then the inside here this time i've made up a batch of 15 minute epoxy mainly here to give me some extra working time since i'm doing two pieces with this and just like we did before i'm going to start by just putting a little bit of epoxy on the threads here and then moving that nut up that'll give us a good lock there okay i'm gonna put a little bit more here on the underside of the nut okay and then my fender washer and then some more put this on the underside of the fender washer it's going to come into contact with the bulkhead and that'll go in here okay and then we're gonna put on some more it's actually more than i need right there okay another fender washer and i'll move that around so it gets all gluey and then finally we'll put on the nut like that and here it doesn't matter what position the eye bolt itself is in now i'm going to take a wrench here and just tighten that down there's a blob here right on the end of the bolt i'm just going to spread it around onto the nut itself all right and this little drip that got out here is nothing to worry about i'm just going to wipe it off so i don't get epoxy on somewhere that i don't want it okay now i'm going to do this in two spots here so i'm going to put a bead of epoxy first right around here with the understanding that it's going to get pushed forward so i'm doing this just inside the edge it doesn't need to be very thick if you wanted you could actually even use wood glue i wouldn't use white glue for this but wood carpenters would glue [Music] since this is between cardboard and plywood and it's not going to get particularly hot and it's not going to have a lot of force on it if you wanted to use wood glue here that worked just fine all right so now i'm going to put this in and push downward here until i get just that lip on the inside okay so i've got just it's inset within the coupler a little bit we look inside there see we get a light in okay that has pushed up the epoxy ahead of it forming a little fillet there and now what i'm going to do is using my remaining epoxy i will fill in this and try and keep it down off that edge we want it just inside so i'm just running out of epoxy here i'm going to go ahead and make up some more and what i'll do is make up enough to completely cover the wood here and that's just to give it a little bit more resilience since this will be taking the brunt of the ejection charge when it goes off so here i've added some 30 minute epoxy across the surface and then move that into the the joints around the edge as well and the main reason for the the 30 minute epoxy is that it will remain fluid enough to give a uniform surface here so it will flow outward fill in the low spots and things like that that the the shorter epoxies just won't do so once again we can hurry up and wait some more i'll put this aside and we'll move on to the next step another step we can do while we're waiting for epoxy to cure is to mark the body tube for where the rail buttons are going to go now in the instructions it still shows this being for a launch lug and it won't be it'll be for a rail button okay so i'm just going to take a tape measure here and the idea is just to find a midpoint so this is right about 10 centimeters between fin slots here so i'm just going to make a mark there and then you can put this on a door frame now door frames aren't very portable and this is a fairly wide body tube and so door frames often aren't deep enough anyway so the other thing you can do is get yourself a piece of angle aluminum like this and that will just sit against the body tube here and you can check and make sure your straightness by looking at the fin slots now i can just hold this against the body tube and draw a line all the way down like that now since this kit uses rail buttons we won't be able to place those exactly until we get the motor mount in most likely one is going to go right here at the base of the rocket and then the other one will go about halfway between where the motor mount ends and where the coupler comes in which should be somewhere in here ideally you want this to be right around the center of gravity [Music] [Music] [Music] you

Channel: Rocketry Education and Research (R.E.A.R.)

Views: 9,332

Keywords: LOC Precision Rocketry, LOC-IV, high-power rocketry, model rocketry

Id: CcEg-Gu76_g

Length: 47min 5sec (2825 seconds)

Published: Sat Oct 02 2021