BT-01.. ?!

[Re-Bugged 11299]

14 hours ago, Kowalski86 said:

On a side note, It's next to impossible to find Tamiya on-road spring sets here in the US.

Feel your pain, same in Australia too. It would be nice to experiment with a few different springs.

I’d buy a set of shocks from the XV02RS in a heartbeat if they were available separately after building the kit. Looks as though they are in the XM-01 which is nice. 

[Sogogi 3359]

I was able to get few sets from japan but yeah it is pita….

[Alexei 725]

got my BT-01 yesterday. had to get it with the Supra body. i got some ball bearing and oil dampers for it, but will also look into to reduce suspension slop.

[Jason1145 4683]

4 hours ago, Alexei said:

got my BT-01 yesterday. had to get it with the Supra body. i got some ball bearing and oil dampers for it, but will also look into to reduce suspension slop.

You’re so lucky to get a mini me of your 1:1 car, this is a quirk I really like too, I’m just waiting for Tamiya to re-re their Gen7 Celica then I can make a nicer mini me.
Good luck with the BT-01 it’s on my shopping list with that Supra shell too 👍

 

[Alexei 725]

2 hours ago, Jason1145 said:

You’re so lucky to get a mini me of your 1:1 car, this is a quirk I really like too, I’m just waiting for Tamiya to re-re their Gen7 Celica then I can make a nicer mini me.
Good luck with the BT-01 it’s on my shopping list with that Supra shell too 👍

 

when i saw it had a Supra body i had to get one. of course, im curious about what weird design Tamiya has come up with regarding the BT-01.

since the BT-01 can be FWD too, it would be perfect to bring out some FWD bodies, like the Celica.

[Kowalski86 4082]

6 hours ago, Alexei said:

will also look into to reduce suspension slop.

You're going to want a set of low friction pivot balls, the plastic ones wear and get sloppy in like 3 runs. Outside of that a lot of the slop is from the suspension arms.

Take it from my own experiences, don't judge the "slop" just by how it feels in your hand, run it around a bit and start troubleshooting the slop only if you don't like how to drives.

[Alexei 725]

16 hours ago, Kowalski86 said:

You're going to want a set of low friction pivot balls, the plastic ones wear and get sloppy in like 3 runs. Outside of that a lot of the slop is from the suspension arms.

Take it from my own experiences, don't judge the "slop" just by how it feels in your hand, run it around a bit and start troubleshooting the slop only if you don't like how to drives.

the suspension steel ball set is on my list. im also thinking the reinforced adjuster ball links.

i watched a few videos where i saw the rear wheels buckle in and change toe quite a bit, but im not sure if that was because of the increased power, but i wont use a powerful motor anyway (got a torque tuned motor laying around i will use). i will see for myself how it works, and go from there.

[OldSchoolRC1 1074]

I decided to take a chance on the BT01 - it was cheap, and the different chassis configurations intrigued me... 

As ordered, with a few select hop ups. Bearings, CVA's, metal pivot balls and a different set of wheels. 

And it went together pretty quickly. First I built it up MR. Pretty interesting, but not really the way I wanted it. 

So I rebuilt it FR instead. This is one chunky monkey of a chassis! If you like Tamiya ABS, this kit is for you! 

I had a Supra body laying around in decent condition with the holes already drilled, so it got dropped on. 

Didn't install electronics yet, I'd like to do something a little more custom than the stock chassis, just need a free afternoon to get it done. 

I don't know what to make of this chassis TBH. I have no idea how the same company who makes precision TRF kits can put this out. The slop is flat terrible, even by Tamiya standards. The rear wheels, even with the metal pivots can change toe by about 5 degrees. Ouch. 

And please Tamiya, no more chassis specific body mounts! If I trim these down, that's it unless I want to by 2 more complete parts trees. There's got to be a better way. 

It is good looking with the body on, and of course the build goes together perfectly though I found the various chassis configuration addendum a bit confusing. The various setups are interesting though, and I think it's worth a little more work. Have to do something about that slop. It makes the TT02 look like a precision machine in comparison.  I've got some ideas.... but first, I'll track down a servo and get it out for a test run to see how it does. 

[Kowalski86 4082]

43 minutes ago, OldSchoolRC1 said:

And please Tamiya, no more chassis specific body mounts! If I trim these down, that's it unless I want to by 2 more complete parts trees. There's got to be a better way.

You could try these, supposedly they're designed to go right on top of shortened body posts.

https://www.tamiyausa.com/shop/option-parts/rc-body-mount-extension-set

[Jason1145 4683]

@OldSchoolRC1 please report back how it handles its first drive stock with just the metal pivot balls upgraded, this BT01 is on my list but if it drives a lot worse than a stock TT02 I may skip it and just get another of those or a TT01E instead 😂

[Alexei 725]

On 7/10/2024 at 6:29 PM, Jason1145 said:

@OldSchoolRC1 please report back how it handles its first drive stock with just the metal pivot balls upgraded, this BT01 is on my list but if it drives a lot worse than a stock TT02 I may skip it and just get another of those or a TT01E instead 😂

it is gonna be much different to 4WD, that just how it is with a RWD RC car. but i saw this video on youtube and i think it looks pretty good zooming around on the track.

 

[Alexei 725]

On 7/10/2024 at 3:04 PM, OldSchoolRC1 said:

So I rebuilt it FR instead. This is one chunky monkey of a chassis! If you like Tamiya ABS, this kit is for you! 

 

chunky for sure. i just built mine too, and i thought it would be on the heavier side. i weighed it and surprisingly it wasnt even that heavy. i think it was around 820g for chassis with motor, but no wheels, no dampers and no electronics (except motor).

[OldSchoolRC1 1074]

Quick report on the BT. Finally got the electronics in (stock) and took it out for 2 packs. Despite all the slop, it drives well. The silvercan doesn't really overpower the rear and it's pretty surefooted under acceleration. Occasionally needed a quick countersteer coming out of turns to keep it in line, but that's the fun of RWD. Braking is tricky sometimes, sometimes it would be fairly planted, other times it would kick right out. I think that's the slop talking. 

I run smaller 2200mah packs with my Tamiyas usually and made a quick foam block to support the smaller battery. Hopefully can use it in several vehicles.  

A few outdoor shots - forgive the body posts, I haven't quite settled on a body just yet. 

The rear tires move around...a lot. First shot is at rest, about 2d of rear toe in. Under acceleration, it turns into 5 degrees. Hmm... 

There's a good amount on mods here waiting to happen. I'd really like to experiment with that rear suspension. I think I have some options here...
 

[qatmix 822]

I’m currently doing a back to back test of the different layouts. The one thing I will state is whilst it seems a bit sloppy, it actually handles really well. (Torque tuned motor). 

It’s as kit other than bearings and CVA shocks and the metal pivot balls. 

[ABigChungus 70]

I finished building my BT-01 yesterday in the FR layout. I built it with virtually every hop up listed on the BT-01's upgrade sheet. I also followed a Youtuber named Kisakanezawa, who has made a series and a blog about the chasis detailing her racing progress and the tinkering she has carried out. Her information and recommendations were highly useful. 

As everybody already knows or has heard about this kit, there is a tremendous amount of slop in the suspension arms. Quite possibly some of the worst in a Tamiya kit, which is quite alarming for the debut of a brand new chasis. So this means that shimming the suspension arms is ESSENTIAL.

I purchased Tamiya's 5mm shim set to do this.  I needed 0.5mm worth of shims on three of the suspension arms, and 0.4mm on one of then. Doing this eliminated NEARLY all of the slop and wobble in the arms. Note, not ALL, but NEARLY all. The rear in particular does still have a very slight amount of unwanted movement which I cannot fix with shims, as adding more means the arms will not move freely and will bind. I would say this whole shimming process has made the BT-01 more in line as to what you would expect a model from Tamiya to be like straight from the box, and more in line with how Tamiya intended the chasis to perform. I cannkt believe that Tamiya would have intentionally released a model with this much slop. So in conclusion, shimming the suspension arms may well be the single most important upgrade you can do on the car, after the obvious ball bearings of course.

TT02 Super mini CVA oil dampers were added (oil dampers really needed to come with the kit!) as well as the TT02 low friction suspension balls for the suspension arms. I added Low Friction King pins and bearings for the steering arms, and the Hi-Torque Servo Saver with the aluminium servo horn. With all of these in place, I have a nice, fairly strong steering set up which is virtually free of slop, and a nice suspension set up which isn't binding or wobbling.

I also changed my wheels and tyres to a set of Tamiya 24mm ones as I read that grippier tyres, especially in the rear, will work better than the kit supplied tyres. I installed the TT02  universal shafts and metal drive cups in the rear, and lightweight one piece hubs for the front wheels. All of these replace the stock plastic big chunky cups and shafts  which quite possibly also cause slop.

For the motor, I went with the Super Stock RZ. Kisakanezawa mentioned that currently/officially the BT01 can only run a 24 Tooth Pinion Gear, which she felt out of the box was quite slow with a 70 Tooth Spur Gear. She realised that the MB-01 and BT-01 share the same Gearbox, but the MB-01 has a 65T Spur Gear. By fitting the 65T Spur into the BT-01, you can then run a 29T pinion gear for higher speeds. I did install the Yeah Racing fan set after this, as understandably my motor did get quite hot. This also generates a lot more wheelspin and makes the car a lot more back happy when you put the power down when cornering!

Having driven it for most of the day yesterday, it performs a lot better than expected. How much of that is down to purely the shims or various other bits I threw in, I am not sure, but I imagine the shims have made the biggest difference. It definitely did not wander off or meander, it had a nice  pace to it with the MB01's Spur gear, and it steered and controlled well, as long as you are easy into the corners. I think the most important upgrade you can do, if you want to buy this chasis, is to get those suspension arms shimmed first. Once you've done that, the car is in a far better shape than it is out of the box. After that it's down to you what you want to upgrade, but for a chasis that many considered a write off, it has left me pleasantly surprised at how well it came out.

[Kowalski86 4082]

2 hours ago, ABigChungus said:

By fitting the 65T Spur into the BT-01, you can then run a 29T pinion gear for higher speeds.

If you want even more speed, you can run a "high speed" spur gear from a TT01 and a 31t pinion. That probably wouldn't be a bad idea for anyone wanting to build a FWD BT-01.

[YoShImUrA53 37]

On 7/28/2024 at 7:33 AM, ABigChungus said:

I finished building my BT-01 yesterday in the FR layout. I built it with virtually every hop up listed on the BT-01's upgrade sheet. I also followed a Youtuber named Kisakanezawa, who has made a series and a blog about the chasis detailing her racing progress and the tinkering she has carried out. Her information and recommendations were highly useful. 

As everybody already knows or has heard about this kit, there is a tremendous amount of slop in the suspension arms. Quite possibly some of the worst in a Tamiya kit, which is quite alarming for the debut of a brand new chasis. So this means that shimming the suspension arms is ESSENTIAL.

I purchased Tamiya's 5mm shim set to do this.  I needed 0.5mm worth of shims on three of the suspension arms, and 0.4mm on one of then. Doing this eliminated NEARLY all of the slop and wobble in the arms. Note, not ALL, but NEARLY all. The rear in particular does still have a very slight amount of unwanted movement which I cannot fix with shims, as adding more means the arms will not move freely and will bind. I would say this whole shimming process has made the BT-01 more in line as to what you would expect a model from Tamiya to be like straight from the box, and more in line with how Tamiya intended the chasis to perform. I cannkt believe that Tamiya would have intentionally released a model with this much slop. So in conclusion, shimming the suspension arms may well be the single most important upgrade you can do on the car, after the obvious ball bearings of course.

TT02 Super mini CVA oil dampers were added (oil dampers really needed to come with the kit!) as well as the TT02 low friction suspension balls for the suspension arms. I added Low Friction King pins and bearings for the steering arms, and the Hi-Torque Servo Saver with the aluminium servo horn. With all of these in place, I have a nice, fairly strong steering set up which is virtually free of slop, and a nice suspension set up which isn't binding or wobbling.

I also changed my wheels and tyres to a set of Tamiya 24mm ones as I read that grippier tyres, especially in the rear, will work better than the kit supplied tyres. I installed the TT02  universal shafts and metal drive cups in the rear, and lightweight one piece hubs for the front wheels. All of these replace the stock plastic big chunky cups and shafts  which quite possibly also cause slop.

For the motor, I went with the Super Stock RZ. Kisakanezawa mentioned that currently/officially the BT01 can only run a 24 Tooth Pinion Gear, which she felt out of the box was quite slow with a 70 Tooth Spur Gear. She realised that the MB-01 and BT-01 share the same Gearbox, but the MB-01 has a 65T Spur Gear. By fitting the 65T Spur into the BT-01, you can then run a 29T pinion gear for higher speeds. I did install the Yeah Racing fan set after this, as understandably my motor did get quite hot. This also generates a lot more wheelspin and makes the car a lot more back happy when you put the power down when cornering!

Having driven it for most of the day yesterday, it performs a lot better than expected. How much of that is down to purely the shims or various other bits I threw in, I am not sure, but I imagine the shims have made the biggest difference. It definitely did not wander off or meander, it had a nice  pace to it with the MB01's Spur gear, and it steered and controlled well, as long as you are easy into the corners. I think the most important upgrade you can do, if you want to buy this chasis, is to get those suspension arms shimmed first. Once you've done that, the car is in a far better shape than it is out of the box. After that it's down to you what you want to upgrade, but for a chasis that many considered a write off, it has left me pleasantly surprised at how well it came out.

 

Great info! Thanks!

[Alexei 725]

a project idea i got for the rear suspension of the BT-01 is to fit some regular arms from a TT-02. whether it will work or is really needed i dont know, but i want to try.  and i have some idea. i found a part that converts the 5mm plastic arms to use 3mm hinges instead. the conversion part if Wrap-Up Next 0743FD and looks like this:

 

so the idea is to take TT-02 rear arms and cut off the ends, and drill a 3mm hole through to fit the 3mm hinge pin. similar to the TT-01D suspension.