Tamiya MB-01 Chassis

[berman 5313]

On 8/30/2023 at 4:33 AM, Willy iine said:

So I finished my MB01 chassis and for the most part the car drives very well.  Unfortunately for me, the steering angle is insufficient in stock from so I cut off the steering's full lock stops as I uploaded in my Stories on instagram this morning.  #pretendRCshop 

After the mod the turn radius is a lot smaller, but still on the wide side which is at the very limit of my pretend pylon test course.   It should not be this way as my other m-chassis have turn radius that are MUCH SMALLER to the point I can use dual rate.

I trimmed off an area of the steering linkage to gain a few more degrees (I don't care as this is my test mule) until I found that the lower ball joint (the plastic thing you snap into the upper and lower arms) kept popping off after hard turns.  LOL

I don't know, perhaps with a stiffer diff I can rotate the car better with throttle since it's RWD, but this will be a problem if I turn this thing into a FWD setup.   I can still drive the car in my small space, but again, it shouldn't be this way.

Just to put into perspective, all my 1:10 full size cars (including my F104) can turn fine on my pretend pylon test course.. my buggies, no problem.  I drive my Kyosho Beetles all the time.  TRF420X.. absolutely no problem.  Why a m-chassis has a much larger turn radius than my sedans and even F1 car makes no sense to me.  

So, if one intends to drive this car in small space I would get a different chassis.  I have absolutely no issue with my M06 with the Beetle body on my pretend pylon test course for example..

I don't have an MB01, but I'm going to hazard a guess you are at the limitations of those huge plastic drive cups. The dogbone is fouling on the cup, and your steering servo is asking for more throw, pushing the dogbone on the cup, and pressing the arms off the lower ball joint. Is there any evidence on the dogbones that the cups have been touching the shaft? Just an idea...

No happy the body can't be lowered to a desirable height, but as with other m-chassis cars, I've had to shorten the dampers and ride height of the chassis to get body where I want it to sit.

[Willy iine 17928]

2 hours ago, berman said:

I don't have an MB01, but I'm going to hazard a guess you are at the limitations of those huge plastic drive cups. The dogbone is fouling on the cup, and your steering servo is asking for more throw, pushing the dogbone on the cup, and pressing the arms off the lower ball joint. Is there any evidence on the dogbones that the cups have been touching the shaft? Just an idea...

No happy the body can't be lowered to a desirable height, but as with other m-chassis cars, I've had to shorten the dampers and ride height of the chassis to get body where I want it to sit.

If you have a chance to look at the photos on my instagram page Stories and while it's in Japanese, I show and explain what the problem is.   It's best you see the photos as you will know exactly what I'm trying to explain.   It will only be there for like another 15 hours or so as instagram erases  Stories images in 24 hours.  

 It's not something you can just adjust with dampers;  the body was not designed for the MB01 and will require more camber and or different offset wheels.   I will be able to use the MB01 on other bodies, I believe, with less or no issue...like the Miata body which I am going to investigate in the future... given my interest in the MB01 don't dwindle away.     The car drives well though, I'll give them that.  Not sure how durable at the track though, that ball joint could become an issue.. for concourse driving, probably no issue.  👍

[Busdriver 6088]

1 hour ago, Willy iine said:

If you have a chance to look at the photos on my instagram page Stories and while it's in Japanese, I show and explain what the problem is.   It's best you see the photos as you will know exactly what I'm trying to explain.   It will only be there for like another 15 hours or so as instagram erases  Stories images in 24 hours.  

 It's not something you can just adjust with dampers;  the body was not designed for the MB01 and will require more camber and or different offset wheels.   I will be able to use the MB01 on other bodies, I believe, with less or no issue...like the Miata body which I am going to investigate in the future... given my interest in the MB01 don't dwindle away.     The car drives well though, I'll give them that.  Not sure how durable at the track though, that ball joint could become an issue.. for concourse driving, probably no issue.  👍

Funny I had a feeling there may be an issue. Ever since the sneak preview pictures there’s been something not right about the stance. Also the fact that the wheels are different front to back is strange. I’m jus waiting for a couple of bits and I’m gong to start building mine. Aim to use it for my mk2 Escort and the Fiat 131 body when it’s available. Might try the Abarth on an M06 but I think the motor might get in the way?

[toyolien 4002]

@Willy iine Do you think that you could use 60d tires on the front of the fiat body or do you have to use the 55mm tires that Tamiya spec? Even the body sets alone say to only use 55mm's. Seems a bit odd 

[Willy iine 17928]

41 minutes ago, toyolien said:

@Willy iine Do you think that you could use 60d tires on the front of the fiat body or do you have to use the 55mm tires that Tamiya spec? Even the body sets alone say to only use 55mm's. Seems a bit odd 

I’m using the smaller kit tires on the front and it still rubs the front bumper unless the body is set up like a high lift 4x4.  I think it really depends on the shape of the body and the Abarth is not an ideal fit imho..  it’s okay, I’m going to finish the body and run it on my other m-chassis at the proper lower ride height.  

[Raman36 1521]

17 hours ago, Willy iine said:

I think it is worth mentioning that the Abarth body is a direct drop-in to the Tamiya's Mini Cooper body setup.    

The Abarth body has a horrible time fitting properly on the MB01 unless you have a donkey setup with a raised 4x4 look.   I am going to get another body for the MB01 and run the Abarth on my competition m-chassis (most likely my TOP Racing Sabre or the Xpress XM1 Competition with adjustable camber).

Pictures available in my Stories on instagram for 24hrs if anyone is interested in checking out what I'm talking about.   #pretendRCshop 

Is this the reason why in the pictures the front looks so high up?

I have ran it on the sabre Mini. Figuring body posts is fun.

[Willy iine 17928]

18 minutes ago, Raman36 said:

Is this the reason why in the pictures the front looks so high up?

I have ran it on the sabre Mini. Figuring body posts is fun.

Yes, the body needs to be set up ridiculously high on the MB01. 

I finished masking the body.  Going to give it some paint this pm… wish me hope please.. 

[Raman36 1521]

1 hour ago, Willy iine said:

I’m using the smaller kit tires on the front and it still rubs the front bumper unless the body is set up like a high lift 4x4.  I think it really depends on the shape of the body and the Abarth is not an ideal fit imho..  it’s okay, I’m going to finish the body and run it on my other m-chassis at the proper lower ride height.  

The diff output cups can be changed to the ones from M05/M06 Or TT02S, the ones that have a flat spot. You can also run the diffs from the TT02/XV02.  The CVDs are the same as the M05/06, so in front drive you can use the DCJ that releases with M05 V2. 
 

The plastic cup that transfers power from gear box to motor, I’m sure a hop up will be in the works.

Disappointing that MB01 was released with the Abarth body when it can’t sit low enough. They should have design the body posts on a way to fix that.. it’s like the Renault R5, released with wheels well inside the rear arches. Lazy on Tamiya part

[Willy iine 17928]

27 minutes ago, Raman36 said:

The diff output cups can be changed to the ones from M05/M06 Or TT02S, the ones that have a flat spot. You can also run the diffs from the TT02/XV02.  The CVDs are the same as the M05/06, so in front drive you can use the DCJ that releases with M05 V2. 
 

The plastic cup that transfers power from gear box to motor, I’m sure a hop up will be in the works.

Disappointing that MB01 was released with the Abarth body when it can’t sit low enough. They should have design the body posts on a way to fix that.. it’s like the Renault R5, released with wheels well inside the rear arches. Lazy on Tamiya part

I can't agree more!!   The body is going to look great.. given I don't mess it up... already crushed the engine compartment corners while working on it due to flimsy flim..   (or just me being clumsy and stupid as usual) and you all  know I HATE  working on polycarbonate bodies..    so this is why in retaliation it's going to look great.   

[toyolien 4002]

1 hour ago, Willy iine said:

I’m using the smaller kit tires on the front and it still rubs the front bumper unless the body is set up like a high lift 4x4.  I think it really depends on the shape of the body and the Abarth is not an ideal fit imho..  it’s okay, I’m going to finish the body and run it on my other m-chassis at the proper lower ride height.  

Thanks. Was going to pick a body up for my M08 but definitely want to use 60d tires. Will look at other options 👍

[Rinskie 274]

I wonder how the Fiat body will fit on the M08? I was half tempted to pick up a MB01 just to scarf the wheels/tires and body then sell the kit along. 

[Willy iine 17928]

39 minutes ago, Rinskie said:

I wonder how the Fiat body will fit on the M08? I was half tempted to pick up a MB01 just to scarf the wheels/tires and body then sell the kit along. 

Is the M08's front camber adjustable?  If so, I think you can make it fit pretty well.  Like on my M06, I modified the front end to add camber.. there is no rubbing even at this ride height on my Beetle.   

If the wheelbase and body post locations were the same on the Abarth, I would've test fitted it, but the Abarth is the same as the Mini Cooper at 210mm ( was it?).  It's a drop-in replacement which is very cool for me as my m-chassis are mostly setup for the Mini Cooper body.

[Willy iine 17928]

I decided to run my TA05 M-Four under the Abarth body.  My competition chassis are on the wider side and the M-Four is the narrowest of them all.  I noticed the MiniCooper wheels are like 1mm less aggressive in offset compared to the Abarth wheels.. which did not help.  I still wanted to run the Abarth wheels on the Abarth body so with some adjustments on the chassis I got it to where I'm happy with the wheel gap on the front with zero rubbing.      Photos in my Stories on instagram #pretendRCshop 

The MB01 chassis will be placed in my closet for the time being.. someday soon I shall get a Miata body and wheels and re-try.

[ChrisRx718 4163]

@Willy iine Do you have any pictures of the ride height issue? 

I'm keen to build an MB-01 albeit with a Golf MK2 Rally body (waiting on Tamiya for that) - do you foresee the same issues with that kind of setup? 

Also look forward to seeing some images of your TA05 M-Four 

[Willy iine 17928]

1 hour ago, ChrisRx718 said:

@Willy iine Do you have any pictures of the ride height issue? 

I'm keen to build an MB-01 albeit with a Golf MK2 Rally body (waiting on Tamiya for that) - do you foresee the same issues with that kind of setup? 

Also look forward to seeing some images of your TA05 M-Four 

I will re-upload the photos on my Instagram page later this am as I keep getting -200 errors when I try to post photos here.  

I think it is an issue more specifically with the Abarth body.  I hope to get my hands on a Miata body soon..

Edit;  I reuploaded the photos on my Stories for comparison between MB01 and my MFour setup: .  #pretendRCshop 

Edited September 1 by Willy iine

[ChrisRx718 4163]

Oh wow, that is some serious arch gap at the front. Is that as-per the instruction manual? That's disappointing.

[Kowalski86 2167]

I'm surprised by that gap and the tire rub issues, almost makes me think of when I tried to hodge-podge a TT-02 Brat together. No crude front wheel gap, but it had its share of tire rub.

Funny how none of the youtubers have complained about the MB01s shortcomings.

[Willy iine 17928]

1 hour ago, ChrisRx718 said:

Oh wow, that is some serious arch gap at the front. Is that as-per the instruction manual? That's disappointing.

Yes, as per manual.   It is quite unfortunate.  If you use dual rate or set end point to not rub the inside of the bumper while turning, one will only be able to drive this thing on a 1:10 sedan track or large open space.  To me, m-chassis is supposed to be for tight space so it makes no sense that Tamiya designed the MB01 this way.   It can barely turn on my pretend pylon test course (in stock form) where even my 1:10 sedans and F1 cars can turn no problem.     Their previous m-chassis have much better turn radius.  I modified my MB01 to turn tighter, but even so, it's still not ideal.. plus can't run my Abarth body on it so the MB01 to me is kind of useless/pointless/flop.   But this is good knowledge to have, so was not a waste to try it.  👍

[ChrisRx718 4163]

Is it the chassis that's a problem or just that particular body?

I just realised that I have a kind of spiritual predecessor to this in my possession; a 3Racing TT01-M conversion:

I built this as a pseudo drift car but really struggled with steering lock / angle. This is equipped (at the front) with M-chassis UJs which helped (big plastic drive cups at this scale are really restrictive). 

It's kind of mothballed at the moment, but still very much in working order. It has a Miata shell as it happens!

 

[Willy iine 17928]

@ChrisRx718  It's both.  The MB01 turn radius in stock form is lousy.. I am sure they will run fine at a large track, but it could barely turn on my pretend pylon test course which is where it will be driven most of the time.

I cut off the steering stops and trimmed an area on the steering linkage to provide max steering angle before the front inner sidewall hits the front damper.   At that point the car was like turning 'decently' but the lower ball joint on the suspension arm kept popping out as the steering linkage keep pulling at it at full lock.  I was able to find an end point where the car would turn on my test course and ball joint not pop out... but it's only marginally better as far as turn radius.   

I uploaded all the steps I took on my instagram Stories a few days ago..  I don't make posts until the cars are complete and I guess I move pretty fast on my daily blogs so if you need me to re-upload something, let me know.  Wish TC would give us bigger attachment memory too..  I am always at 99-100% these days.

[Raman36 1521]

I was thinking of picking up and MB01 for my son so he can join me in M chassis club race. He wants to run the Alpine body. Now I’m wondering if it will sit low enough on MB01.

Is it the Abarth that’s the issue or the Chassis body posts? 

[Pylon80 1390]

On 8/31/2023 at 9:44 AM, Raman36 said:

it’s like the Renault R5, released with wheels well inside the rear arches

The same was true for the Golf Mk1, although that is a very easy fix with longer axles and wider hexes. Then again the original pan cars for both the R5 Turbo and the Golf Mk1 didn't fit any better than the M-05 re-releases 

[Raman36 1521]

15 minutes ago, Pylon80 said:

The same was true for the Golf Mk1, although that is a very easy fix with longer axles and wider hexes. Then again the original pan cars for both the R5 Turbo and the Golf Mk1 didn't fit any better than the M-05 re-releases 

I addressed it with wider axles and some + offset wheels. 

[Busdriver 6088]

I’m halfway through building mine. Simple concept typically over engineered. I’m doing long chassis, high motor and will use 60 mm all round. Ready for the 131 bodyshell( pre order in)

[Raman36 1521]

51 minutes ago, Busdriver said:

I’m halfway through building mine. Simple concept typically over engineered. I’m doing long chassis, high motor and will use 60 mm all round. Ready for the 131 bodyshell( pre order in)

Did you order the MF01X kit with the Fiat or the body set? I ask because I haven’t seen a part number for body set yet