Honza

What's F/R weight distribution? Looks like all the heavy components are in front of the centerline, so it might be usable as a FWD.

The suspension mounts are same, so it shouldn't be an issue. However, there aren't many options of 190mm wide, short-WB bodies. Speaking of suspension mounts, looks like Tamiya is taking notes from the community - I've seen something similar to A6 parts sold by Embie racing as a tuning option for XV-02 😁

What if the fake motor is cut out?

@Pylon80 that's important part I forgot to mention - DCJ became a thing because of combination of high grip carpet and spool, where vibrations can be quite significant issue. Meanwhile I run 54° drift CVDs on my rally car (we have very tight tracks here) and I haven't had any issues.

@Alex97 thanks for the manual. Looks like it uses same TRF417 wheel axles as M-07, so there's still chance that uprights will fit the 2wd Tamiyas to make a rally version but I wonder why Tamiya lists M-03 universals as an option, when they are 1mm longer. I wonder what went wrong with the hardware bags, I've never had an issue, it always has been lego-like experience. The chassis is definitely a step-up from MF-01X and looks great. Still, I'm not fan of XV-02 design due to upright battery, I think there are better designs for a 4wd M-chassis. Unfortunately that's how Tamiya is with prices nowadays. If they added more blue stuff, it would be in R kit range with minimum performance gains... I would like the opposite - a cheaper version similar to M-07/8 - plastic CVA shocks, CVDs only on the front axle, I wouldn't even mind open diff on the rearaxle. Just keep the good plastic. And maybe throw a rally body on. That would be awesome replacement for MF-01. Btw, can you check if large rallyblocks fit? A lot of people run full size tires on minis, if body allows it, since they perform a lot better, but it looks like there isn't a lot of space around the front axle.

The only difference between DT-03 and DT-03T are wheels and body mounts.. you could probably do a similar thing with TD2/4 to get the aqroshot body work. Other than that, there was Asterion XV-01T kit, maybe there are still available somewhere

Huh, I realised I haven't shown my "FF-05" in this thread. Here's the build thread if anyone missed it The chassis is sitting in a box, waiting for electronics, since I completed it. But I'm thinking about digging it up and making a rally conversion, since turnout of 2wds is quite low this season. That will require more of the red parts

That's property of universal joints. They add angle variation throughout rotation, which causes vibration. The variation becomes quite severe above ~30 Deg, which is shown in a graph bellow (from wiki) Another graph, showing angular velocity variations (which result in vibrations) Withou wheels, there's less inertia, so the vibrations don't show up. Some lighter set of wheels can reduce the chatter. In the same way, a looser diff may help to spread variations between the wheels. But that's only dealing with symptoms, not the cause. If you want to get rid of vibrations entirely, you'll need double cardan shafts. Those work by adding a second universal joint shifted by 90deg, which will compensate the angle variations of the first joint nearly perfectly.

@Alex97 wow, that was quick! It's unfortunate that there were such issues. It's weird that reviewers didn't mention this, especially this one: The unboxing video linked earlier has shown traditionally labeled hardware bags. Could yours be some bad batch? Hopefully it won't stop you from finishing the kit Btw, would you check PN of wheel axles in the manual? I'm curious if they are compatible with existing models

I'm curious, has anyone tried to use TT-02S-type or SRX suspension on BT-01? I guess that the main issue would be the lack of rear toe-in, which would require either second front axle on the rear or active rear toe-in upgrade, which would be rather expensive.

Nope, but competitionX did an unboxing video where they list through the Manual. It's good enough quality to see how it's build, but not good enough to see PNs.

That picture reminded me another useful part - #3485068 U-shaped hinge pin. That will reinforce the front so it'll be able to handle some jumps I recommend using foam on the inner diff cup - this suspension geometry may cause a lot of axial movement. In the future, CVDs or DCJs would save a lot of headache One thing I noticed here is that the front driveshaft is angled forward. You can't do anything about it due to arm shape, but be aware that this will cause it to lift the front on throttle and dive on brake.

Interesting project! One more advantage of M-03 is, that it's compatible with some TL-01B parts, that can come handy - apart from suspension it's front bumper and I've also seen rear shock tower extensions, that could come handy. You forgot here the cheaper version of FF-04, which is XV-01 I've always seen it as a FWD chassis with added rear drivetrain (and always wondered, if you could add rear gearbox to FF-04 to create an XV-01 TC Evo) Interesting, I remember this buggy from times when it was based around Durango and had motor in front of the axle. I should check out the development.

Another race This time, the Mazda wasn't the only m-chassis on the start Finally got to finish my own mini rally tires. They are old, slightly worn clones of Tamiya tires made of softer compound - they work much better than Tamiya's own tires. Another, not pictured, modification is installation of stainless steel hinge pins - although it didn't help with front arms breaking, it at least held them together to get over the finish line. I also involuntarily tested water resistance of THW-1060 😁

Exactly what could be expected from a TT-02 successor 😃 Sorry, I couldn't help it.

I noticed that, too, when I've been looking for alloy caster blocks. Maybe it's too complex shape to make a cheap part?

Thanks! Go ahead and share your build here, it's always great to see another build

It's based off XV-01, so it does have buggy diffs I also didn't like the large diffs on XV-02/XM-01. M-08 uses the same diff, so It should be possible to replicate this setup, (photo by @qatmix) with arms quite close to the diff. XV-02 doesn't have downstops either, even thou arms support it and all that'd be needed to make them work would be a slightly different skidplate. Use of XM-01 arms would be shortcut that'd allow me using stock XV-01 gearbox bottoms and simpler chassis plate. But I like M-07/8 arms, so I'll probably do the more complicated route

Yes, they use same suspension mounts as XV-01/2, which gives quite wide variety of suspension mounts. I assume they'll use fibre reinforced plastic as XV-02. The disadvantage is, that the arms have no droop settings and suspension mounts are wider than M-07/8 style, giving slightly shorter arm. For the rear, I intend using Tamiya parts. I can use M3 nuts or metal columns inside 3D printed parts they'll mount to to make them stronger. For the front, I'm not sure yet, but using Tamiya mount could be a viable option. This solution would provide longer arms and downstop setting, as well as easier rear toe-in setup. I intend to use XM-01 uprights, if they are compatible with M-07 arms.

It's been a while, but I did some work on the design. I decided to give a try to belt variant first.. and it looks like it could work. I still want to do shaft driven variant as well, I just need to get some TD4 parts. Back in march, I even tried to print one of early iterations to test how it fits with stock parts. It does quite well Still deciding whether I'm gonna use M-07 or XM-01 arms. I still like the former more, even though it means that I'll need custom gearbox bottoms.

I meant specifically the high/low suspension settings. Overall, the car cannot be worse than MF-01 😃

That's why I thought that it's uprights would be useful for Rally conversion of M07/8, if it fits. Hopefully it'll work better than MF-01X 😃

Interesting, it would mean that its uprights wouldn't be compatible with M-07. No M-07Ra then 😭 Looking in the manual shown in competitionX video, it does seem that it re-uses older type of swing shafts with wrong geometry from M-03 set. But wheel axles are the newer type with retainer springs - have Tamiya ever released an universal set that would use those axles on M-xx, TT-02 or others? It weird that they even show M-03 universals as an option, since it already comes with universals, but it doesn't show M-05 DCJ set.

I found 70mm CVD swing shafts under #19805979 - they are listed as spare to #53791 set @BuggyDad mentions. The same CVD set is meant for DF-03, which uses #19805551 - so if you're looking for dogbones, those should be the length you're looking for.

As a bonus, M-05 V.2 arms add the downstop option, the chassis is prepared for that. Front differential case can also fit M-05/6 ball diff.