Tarmo4 Review! – Should you build a 3d printed 4wd rc performance racer?
com youtube channel and another episode of. Should i build it. I’M. Your host jordan visco today we’re going to take a look at this guy right here, which is the tarmo 4, our 3d printable rc vehicle and we’re, going to take a look at what some of the positives and some of the negatives of the design are. So we can help you make the decision for yourself if this is something you want to build and remember, as always, if you’re looking for fun ideas of rc projects to build kits parts or guides check us out at rcprinter.com, okay, so first a quick intro to The project uh – this was actually designed by a guy named chris hellman and he’s known online by his username engineering. Nonsense and you can find chris online on reddit on the subreddit engineering ns, and that forum is monitored by some of the friendliest most helpful people on the internet. So if you have any troubles with building your own tarmal4 they’d be more than happy to help point. You in the right direction. You can also find chris on instagram again with the username engineering ns, so you can check that out as well. So this right here is the tarmo 4, which is a little hint that there are actually three predecessors to this model. The tarmo original tarmal 2 and tarmo 3., this one, the tarma 4 came out in april 2020 so about a year ago, and it currently has about 2 900 downloads on thingiverse the previous version.
The tarmo 3 came out a year before that in april 2019, and it has about 35 000 downloads on thingiverse. The tarma 3 is actually the first uh downloadable version of the tar mode that i was able to find online. But if you check youtube, you can find videos of the earlier versions, the original terminal and the target 2, and the original tarmo dates back to 2018.. So this one right here, the tarmo 4 – is a completely redesigned vehicle from the previous version, the tarmo 3. it’s about 20 percent larger and heavier than the previous version, and it is a complete redesign, meaning that it uses none of the same parts as the previous Project did now. Chris is also working on the next version of the project. The tarmo 5. he’s already got prototypes and he’s posting pictures of those on reddit and instagram. So you can see those based on a post. He uh did on reddit not too long ago. He’S expecting to be able to release the final version of the terminal 5 sometime this summer, so i didn’t hear chris say this anywhere, but my impression of the project just based on how fast it is and how sturdy and thick the different parts are. It makes me think that chris is really trying to go for a serious rc racer here, not just your normal 3d printed rc vehicle, which is basically a toy that moves. This thing is seriously fast and can actually rival some of the brand name cars on my shelves.
So, in my opinion, chris is trying to push the limits of what’s actually possible, with rc 3d printed vehicle here he’s trying to make something that is seriously fun to drive, try and make the fastest possible rc vehicle, but still something that’s going to hold together and Not something you’re going to have to break every single session, so we took a few videos of the tarmo 4 out this morning. Just so you get an idea of what it’s capable of so. As you can see, the tarmo 4 can be a serious bashing machine. If i were to give one tip to people who are looking at building this project, it would be follow the instructions. This thing does take a beating and it does take a lot of stress but it’s not going to do that if you don’t do it right. So follow the directions, use the right battery, use the right, wheels print things properly, follow the guide and you’re going to have a lot more fun. All right. So let’s talk first about printing. This guy, pretty much everything you see here is printed in pla, with the exception of these drive shafts and this bottom bracket here, which are printed in tpu when you’re printing these parts do pay close attention to the online google doc that chris released, where he tells You what percentage infill, to use what a number of walls to use, what line thickness to use when you’re printing these things it’s all very important when you’re printing them that you do follow those instructions or you will be breaking things quite regularly.
When chris says to you know print this part with a .25 line height with 10 in fill and eight walls, he means it. You know when he says this bracket here needs to be in tpu. It does need to be in tpu if you don’t, follow those directions closely: you’re not going to have a reliable vehicle, so, printing, all the parts, was actually quite easy. I didn’t have any problems printing pretty much anything. One thing i did find about printing was that some of the screw holes ended up being a little bit bigger than i wanted in order to get a nice tight fit with the screws, and i ended up having to reprint some of the pieces with just a Little bit over extrusion in order to get the screws to fit in there really nicely so that’s something to watch when you’re printing. If your printer is under extruding a little bit or you know, you’re finding your screws aren’t fitting in there super tight. That might be something that you need to do is just you know, crank up that over extrusion setting a couple of percent, so in general, the design uh is pretty sturdy. The main chassis itself is actually three separate pieces and it’s screwed together down here with. Actually some m4 rod, and that provides something that’s super sturdy and i haven’t been able to break it yet kudos to him on that this machine when compared to all the other rc vehicles that i’ve 3d printed before this is definitely the beefiest one.
The build itself uses a mixture of m3 and m4 screws and a lot of times, you’ll see 3d printed rc vehicles using m2 and m3 screws and so it’s just nice. To know that you know the parts in this are so big and thick that they can take like a bigger thicker beefier screw. You know that’s another indication of what this thing is meant to be able to do so. The only drawback to that, though, is that it’s kind of heavy um. This is definitely the heaviest rc car that i’ve built by far so the print itself doesn’t actually come with a cover, but there’s a few different covers you can find on thingiverse most popular. Is this one right here which is the skull cover, and then you can print little brackets and they can go on top as well, so that it can, you know, look like a regular rc car and also commonly you’ll. See people put this on it, which is the the big rear wing. It goes up top here. I find that they’re all just like a little bit of a pain to take on and off. So usually i have mine open like this and that big wing breaks a lot so that’s something to watch out for as well. So it also comes with this battery box here, which goes right on top of the battery. Again i don’t use it. I find that i’m switching out batteries a lot and to have a screwed down battery box with four different screws in it.
It just takes a bunch of time, so i end up using like little strappies like this guy here little velcro straps or if i find that those aren’t holding good enough i’ll, even throw down a little zip tie there. Okay, so let’s talk about the suspension for a minute uh. The suspension actually uses these 80 millimeter shocks. Here i did initially use uh some junkier shocks that i had lying around. I found that because the build is so heavy, you know you can’t use just terrible quality shocks so do use the ones he recommends in the build guide. So one thing i did notice about the shocks is that i don’t think they’re oriented perfectly in the original design. You can see here that they allow the suspension to come down in an angle about like this, and what i’ve done is i’ve actually printed a higher shock tower here, and the original ones were about a centimeter lower and that allowed the suspension to actually droop down. Even lower increasing that angle – and i found it put too much stress on these bell housings here and i was ending up breaking a bunch of them, so i increased the height of this shock tower and that seems to have helped a little bit and i did The same thing on the back here as well printed with a larger shock tower, and i think that helps, unfortunately, that does decrease the ride height a bit, and you can see here that it doesn’t touch the ground when, when i push it all the way down With these increased shock towers, but it does go pretty close i’d say i’m about three or four millimeters above the ground at the lowest point.
So another issue that i had with the original shock towers before i reprinted these higher ones was because the wheels would drop. So low they’d actually move in more towards the vehicle, whereas these ones move fairly up and down. Originally, they were swinging inwards quite a bit, and when you would press down the wheels themselves would splay out quite a bit and so printing, these higher shock towers, has helped that both front and rear. So let’s talk a bit about the drivetrain chris uses. This d3542 outrunner motor here, which gives this thing a ton of power and lots of torque from the motor. We go into this gear case here and then this gear case transfers all the power onto both a front and rear drive, shaft so rear. One there front one here: these are actually printed out of tpu, which is a pretty cool design. He calls these as torque dampers and when you hit the gas they actually bend and twist, so it reduces some of the stress on the 3d printed plastic helps a lot with the longevity of your terrain. Now this thing is four wheel, drive the front differential is open and the rear differential is locked. When i spin the wheel, all four wheels will spin at the same time, but the front wheels here they can spin separately because of that front, open differential and he uses not a 3d printed front differential it’s, actually an off the shelf traxxas diff.
So this diff seems to work great. I haven’t had any issues with it at all. I would say the back one. The locked one does cause a lot more damage on the rear, drivetrain parts than having an open diff like i have up front. So you might want to think about getting two of those traxxas diffs and putting one in the rear as well. One thing to note about when you’re building this front differential is that chris calls for some wire to actually lock the metal traxxas diff gears into the plastic parts. But most people have found that just some m2 screws in there work the best they don’t fall out. Like the the wire does sometimes and there’s actually on thingiverse there’s, a mod for this, which will accept the head of a m2 screw as well so that’s, something to look into when you’re building you’re going to want some m2 screws to lock this together. So the rear, drive train components are actually what i break most on this vehicle. I i bust off the little input. Diff input gear. Quite a bit. I bust off these bell housings at the back quite a bit. I bust off these axles pretty regularly and that’s. Just because of the amount of power i put through this thing, this right here is a little 2s battery, but that’s not what i normally run normally i’m running this much bigger battery, which is a 3s 50c lipo battery.
Honestly, this is a bit more than this model can handle. Chris recommends a 3s lipo battery, but the one that he recommends is only 15c, which is going to provide a lot less discharge power than something like a 50c battery. So again, if you want to have a model, that’s reliable i’ll, listen to the instructions and buy the right battery now another thing that’s going to cause me to you know: break parts a bit more than i should. Is these wheels right here, so these are actually wheels off of an old traxxas slash and they are 107 millimeters in outside diameter, and chris has designed this thing for a maximum wheel size of a hundred. So definitely when you’re getting wheels for your tarmo 4 buy ones that are the right size now. The good thing about the wheel design is chris, does use a 12 millimeter hex, so that’ll allow you to use a really wide range of tires that you can find at your local hobby store or online okay. So let’s talk about the steering for a bit. The steering itself is pretty beefy and i actually haven’t broken it. Yet we use a metal gear servo here pretty decent servo. We have this little rod that you can build yourself. Chris actually has come out with a 3d printable rod, so you can use that as well, but it’s pretty simple to make these little connecting rods. So you can kind of see under the battery here.
His steering actually has two different connectors there and they both go back and forth. When i move the steering – and that provides just – you know – a little extra stability to the steering there as well, and then he uses these steering link arms that actually have 3d printed ball joints in them and they work really well. I haven’t had any issues with the 3d printed ball joints, so great work there too. One thing about the steering, though, that i do have to say is that the turning radius isn’t great i’m, not sure if that’s, maybe somewhat due to this just being a four wheel, drive vehicle as well. But that is one thing i do wish about. The vehicle is that it would turn a little sharper, but it does have a ton of power. So if i do want to turn sharply, all i do is just split the throttle and i’m facing the other direction. Just like that. So one of the optional things on the bill of materials for the tomo4 is a gyro. I don’t have a gyro installed here. If you do get one, it should help a bit with the stability as it counteracts the bumping forces that jostling around as you’re driving at high speeds. So, as i kind of mentioned earlier, one of the best things about the tarmo 4 is the awesome community. That is going to help you out and that is creating mods for this thing and continuing to develop it and one really nice, reddit user, actually compiled a github list of all the different cool, mods and upgrades that you can do for the tarmo 4.
So i’ll post the link to that in the description below as well. So if you’re looking for any mods for your terminal for you can find them there, so let’s get down to brass tacks here. Should you build a term of four well, i guess it depends. What you’re, looking for, if you’re, looking for a car that can bash with the best of them and push the boundaries of what’s possible with a 3d printed rc vehicle, then yeah this guy’s for you, especially if you know you’re, looking for a vehicle that you can Mod and a community that you can join and contribute to, however, if this is your first foray into rc vehicles or you know the thought of breaking parts and reprinting them all the time is a bit scary to you. In that case, you might want to start with something a little less performance, oriented or even print this one and then stick to a smaller 2s lipo battery and you’re going to have a lot less reprints. And then, when you’re ready, you can step up to a 3s battery all right thanks for your time. We hope you found this review of the tarmo 4 helpful.