BT-01 - What other parts are useful to improve this chassis?

[Jason1145]

Anyone done a build thread on a BT01 yet, or is it too ‘basic’ to justify one? ( I think it’s  been out a while yet I can’t see one in The Builds section)

I am seriously weighing up getting this BT01 as I really like that Supra body, like RWD, and I also fancy a change from the TT01/TT02 chassis design.

I’d like to get everything needed to build it from the start so that’s would be set of bearings for sure, but  which oil shocks would be recommend?

Are there any other parts worth getting at the same time to help improve it etc, not for club racing or anything, just basic car park use and maybe the TC racing by post.

A YouTube videos I saw ( but can’t find again) mentioned there is a lot of slop in the hubs and steering etc, so I was wondering which sized shims do you guys use for these purposes please?

He also suggested replacing some plastic balls with metal ones but I can’t remember the size he said, would those be “pillow balls” and if so does anyone know which ones are correct please?

(I’d go for front motor and RWD fwiw)

Thanks in advance.

[DaveBuildsRC]

I am curious too but like you have not seen any or many builds. Guessing there is stuff at rcmart from yeah racing but I wouldn’t know what to get. best I have seen is this option sheet from Tamiya. 

 

https://tamiyablog.com/2024/02/tamiya-bt-01-chassis-option-parts-list/

[Kowalski86]

I'd just buy standard CVAs, a sturdier no-name pinion (no official brand makes a 29t 0,6 pinion gear), and a set of metal low friction balls. Keep it simple and spend some time driving it.

With on-road cars, I like to buy a budget metal geared servo and run a plastic horn, the wheels on in board and usually they don't break servos. Plus, I'd rather spend an extra $10 on a better servo, vs a cheapo and an expensive servo horn.

The slop is partly due to the linkage cups and partly because the BT uses TT02 front arms all around. You can shim it or buy a bunch of aluminum bits, but it won't ever go away. It's just not a great design imo.

[JimBear]

I think it could have been the @Poor Boys RC video you saw or the "Sloppy Joe" video from RC Kicks. I was a bit hopeful that it might be somewhat better than the MB-01, but it seems Tamiya made two road toads.

[Re-Bugged]

I haven’t got a BT-01, but from what I’ve seen of it, it looked to just be a bigger MB-01 that I don’t think has been very popular?

[Re-Bugged]

 

[skom25]

I do not have BT-01, but I saw many videos ( that above too) and have some experience in that topic.

You can use shims to reduce some play, but you will not remove play which is caused by parts tolerances. BT-01 looks totally awful in that topic. In my opinion, this is main issue.

I think many people expected successor of TT-02 but we got totally wobbly chassis with strange design. I do not like it at all.

[Jason1145]

TT02 steel suspension balls!! That was it, thanks guys that was the video I’d seen.

So seems the BT01 is similar quality to the TT02 , which is fine for me as the price isn’t that much more and it is different, variety, life and all that.

The Poor Boy RC stock running video wasn’t too awful either, yes it’s sloppy but I’m no precision driver and it looks to handle the same all my previous TT01/TT02’s have driven around a car park, so I might even try it bone stock with just bearings.

Thanks all for the input, I’m off now to research how bad the MB01 is, I’ve already got a bad impression of it from what this guy said on this video ( atleast RWD sounds useless on that)

 

 

[Jason1145]

[Juls1]

I’ve got a mb-01 rwd, the car is by no means great. But tamiya nobbled the rwd setup out of the box so it doesn’t work and its an annoying oversight although there is a few possible explanations. 

with the m06 tamiya supplies soft sticky rear tires and slippery hard tires for the front. This works pretty well on the m06.

On the mb01 they supply slippery hard tires for front and rear. This doesn’t work in RWD because the supplied tires are useless, particularly with the short wheelbase and tiny footprint. In FWD setup this works ok, but it does not in rwd. 

so far none of the reviewers have figured this out.

There is 2 reasons they might have done this,

1. So the chassis will work properly in fwd with these tires.

2. To keep the price of front or rwd body kits equal

i think the bt-01 with its longer wheelbase and wider stance may well fair better as a rwd vehicle, but i think with either, tire choice will be everything and whats supplied isn’t necessarily the best starting point. Reducing the slop is a bit of a job, you can’t get much steering angle, but there is a fraction more if you don’t mind cutting plastic. The steering setup is quite light and you don’t need a fancy servo for it to feel like it has fast steering. 

 

[Kowalski86]

5 hours ago, JimBear said:

I was a bit hopeful that it might be somewhat better than the MB-01, but it seems Tamiya made two road toads.

If anything it's likely worse than the MB01, as the BTs arms have to stick out further which makes it more wobbly.

 

[Honza]

4 hours ago, skom25 said:

I think many people expected successor of TT-02 but we got totally wobbly chassis with strange design...

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

[Jason1145]

Well the MB01 I want is the Citroen DS being released shortly so FWD will be fine for that.

Are there p/n or names for those sticky and slippery tyres to keep an eye out for them?

[skom25]

1 hour ago, Honza said:

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

Design of TT-02 is really simple. Everything is easily accessible and slope is not so huge as I expected.

[Aerobert]

4 hours ago, Jason1145 said:

Well the MB01 I want is the Citroen DS being released shortly so FWD will be fine for that.

Are there p/n or names for those sticky and slippery tyres to keep an eye out for them?

Here you can find a list with Tamiya m-chassis tires with a description of their characteristics. 

https://www.m-chassis.com/tamiya-reifen-für-m-chassis

It's a German page but you can translate it with with the Chrome browser, for example. 

[Jason1145]

18 minutes ago, Aerobert said:

Here you can find a list with Tamiya m-chassis tires with a description of their characteristics. 

https://www.m-chassis.com/tamiya-reifen-für-m-chassis

It's a German page but you can translate it with with the Chrome browser, for example. 

Very helpful thank you bud!

[Juls1]

On the mb01 rwd they supply 4 pcs 50683

on the m06 you get 50683 front and 53254 on the rear with 53255.

i noticed on fwd mb01 you get 50683 and 50684

[Jason1145]

On 5/18/2024 at 12:56 AM, Juls1 said:

On the mb01 rwd they supply 4 pcs 50683

on the m06 you get 50683 front and 53254 on the rear with 53255.

i noticed on fwd mb01 you get 50683 and 50688.

Hi Juls1 - 50688 is an Alpine A110 body set?

 

 

[Re-Bugged]

Glad you’re getting it sorted @Jason1145. 
I believe the main issue people have had with the MB-01 is the front suspension (similar design to TT02’s) popping apart while driving, some which have fixed with a washer I believe under the head of the suspension ball screw?

I was thinking about the route Tamiya have taken with the BT-01 and thought maybe an upscaled M07/8 to suit the appropriate body of FWD & RWD 1/10 touring cars would have been better rather than a jack of all Trades master of none BT-01 instead and leave 4WD’s on the TT’s?

[Juls1]

On 5/20/2024 at 2:00 AM, Jason1145 said:

Hi Juls1 - 50688 is an Alpine A110 body set?

 

 

Sorry ment to be 50684

[Honza]

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.

[ThunderDragonCy]

1 hour ago, Honza said:

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.

It wouldn't be difficult for me to knock up a 2 or 3 deg rear toe in upright in cad if anyone wanted to give it a go.

[CT Vernzy]

My wife and kids purchased a BT-01 for me for Father’s Day, and I built it with some modifications.  I have attached some photos.  I used the following parts for my build:

 

-Yeah Racing Aluminum Motor Mount for Tamiya MB-01 BT-01 (TAMB-005BU)

-Yeah Racing Aluminum Bearing Spur Shaft Mount for Tamiya MB-01 BT-01 (TAMB-004BU)

-Oil Gear Differential Unit for XV-02 TT-02 (TAM22049)

-Yeah Racing Steel Bearing Set (18 pcs) For Tamiya MB-01 BT-01 (YBS-0043).

-Assembly Universal Shaft (TT01/TA04) (TAM53792)

-Aluminum Spur Gear Adaptor Set for Tamiya TT02 Blue

-Tamiya TT02 Suspension Arm Balls Low Friction (TAM54559)

-Tamiya Spring Loaded Servo Saver (TAM51000)

-Yeah Racing 55mm Damper Set Blue

-Hobbywing -Xerun XR10 Justock G3S, JS7 25.5T G2.1 Motor Combo

-Ball Cups from 3x23 mm Aluminum Turnbuckle Shafts (TAM49324)

 

The parts that I added were to try to make it perform better.  The aluminum motor mount and bearing spur shaft were mainly for heat dissipation from the motor, and the universal shafts are always more reliable than dog bones.  The oil filled shocks have Tamiya springs on them.  The ball cups really reduced the amount of play in the suspension.  Two sets of suspension balls were added front and rear.  The gear diff unit has the standard 3K fluid that came with the diff.  Since it had been reported that many TT02 parts could be used, I purchased the spur gear adapter set. Shims were added in front of the spur gear adapter to where they meet the bearing on the motor mount housing, with a total shim thickness of 0.2mm.   In the manual, they said that 20, 22 and 24T pinion gears could be used with the 70T spur gear.  With my TT02, I learned that I could change gears other than what was “allowed” by looking at total tooth count.  So, the 70/24 combination for the BT-01 had a total tooth count of 94.  I used a 64T spur from my TT02R and I had a 30T metric pinion.  This gave an FDR of (64/30) x 2.6 = 5.55 when installed in the 24 tooth position on the motor mount.  I then tried this with standard 48p gears, and found that in the middle motor mount position I could use a 66T spur with a 39T pinion, for a total count of 105 teeth.  This gave a final drive ratio of 4.40.  I did not have any larger 48p pinions beyond 41t, so I converted the total tooth count to 64 pitch, which gave a value of 140.  In 64 pitch gears, I had a 78t spur and a 62t pinion, which gave a FDR of 3.27.  I tried it quickly with a NiMH pack, and it ran at 27 mph with the Hobbywing Justock 25.5 combo.  I will eventually convert the esc power connectors to 4 or 5mm bullets for my other batteries.  I used some items that I had in my parts bin, such as a TTX300 3-Channel SLT Transmitter with TR325 Micro Receiver.  I also added a Futaba SU400 servo in place of the Hobby King Trackstar low profile servo that I was originally using.  I also moved the front body mounts to the bumper so that it would accommodate some of my other RC bodies from my TB05/TA07/TA08 cars.

  

This has been a very cool build and is a lot of fun to drive!  It is currently set up as a VTA car, but is not legal because I have the Hobbywing motor in it instead of the Gravity RC motor.  I would love to see a rear wheel drive class using the 25.5 Hobbywing ESC/motor combo, with some sort of spec tire.  This speed motor would allow one really focus on car setup and driving ability, as it is very different from my 4WD USVTA TA-08 car.

 

[CMshooter]

I had to preorder the Porshe bodied BT01, bad reviews or not.   Have a couple test runs on the chassis now and I think I like it.  I built it with bearings and metal balls.  Shimmed everything that moves as best I could during the initial build.  The center links for the steering and not steering at the back had a ton of flex.  I found the aluminum ones from Yeah available separately and ordered them.  It seems if you want any other aluminum parts, you have to order the whole kit.  I did one run with the 540 just to check, and installed a spare torque tuned with a 24 tooth pinion.  I think it will pull more gear, will look into a smaller spur.

I didn't even try the kit tires, just put some VTA wheels on it, if I was doing it again I would order rears for both ends of the chassis.  As it is I will just get some wider hexes for the front to get them out further in the wheelwells.  Cheap blue oil shocks fit well, came with too tall and stiff of springs.  I just used zip ties to bind one coil on each until I can order a spring tuning kit. 

I see the flex in the rear that reviewers complain about changing direction when accelerating.  I chose to set toe in while pushing the wheels forward to take up slop, that way it goes straightest while on throttle.  I addded a couple oz of wheel weights at the rear of chassis to try to get the weight closer to the 40/60 f/r that 2wd Drifters and F1 class drivers seem to prefer.  The car was initially way mor stabil with a 6 cell nimh pack that the lighter 2s lipo.  I figure the lighter lipo will give me the flexibilty to put the weight where I want it.  

I am looking forward to finishing the body.  Got some color on it and test fit.  I hope to get stickers, mirrors, and lights on it next week.

[CMshooter]

He said "Let there be light", and there was.  I have stickered the body, just need to tidy up the wires after the test run tonight.  It drives much easier when I can identify which end is which.  What are everyone's thoughts on the rocker panel Cayenne sticker? I don't care for the font of the lettering or the red, but seems like the car needs something there.