Jump to content
Honza

MF-01M - A mid motor 4WD rally M-chassis

Recommended Posts

I spent recent months designing MF-01X conversion to put motor in front of rear axle. And now, I'll finaly use it to build a 4WD rally M-chassis! πŸ˜„

I always liked M-chassis bodies more than the regular ones. Maybe because they are often used for classic cars, maybe because I like small hatchbacks, maybe because Tamiya released more rally themed bodies for M-chassis than for regular chassis - or all above. πŸ˜„

So after building my "TL-02" I decided to get another chassis and build it in the original scale - and find out, what does it take to use it to the full potential. Ofcourse, that'll involve a lot of 3D printing 😁

I used this chassis as an introduction to the hobby for a member of younger generation - so starting point is a completed Rally Beetle chassis. So far with no mods with exception of YR bearing set:

received_723395382600508.thumb.jpeg.57e35134a4afe2eea9f3f1b81e735e18.jpeg

Then I printed some parts, stripped down the rear end and rebuilt it. Unfortunatelly, I didn't make pictures, quality wasn't as good as I expected and i needed to do a lot of post processing, with no time fotntaking photos... Anyway, some photos of previous version are on my model page.

The result looks like this.Β 

received_1271236473748189.thumb.jpeg.05f20b1abd2e7280093e1c5ebc08bff0.jpeg

Next step will be fitting front CVDs. I opted for Square RC parts, which I used on another Rally chassis. Unfortunately they don't have wide angle variant - still, I'll need to cut into C-hubs to use them to the full potential. Why do I need wide angle steering? This chassis is built for Czech Scale Stage rally, which is ran on narrow tracks withΒ  corners so tight, that even M-chassis is hard to navigate with stock steering.

received_1467115310485036.thumb.jpeg.1e795ec7f73ed6478a3ee330eb9fa147.jpeg

The steering mod will also require some cutting into the chassis, so I'll continue later :)

  • Like 13

Share this post


Link to post
Share on other sites

Didn't have much time, but I atleast installed CVDs. Simply cutting off the C-shaped limiter was enough to reach limit of CVDs. That was easy πŸ˜„

Β 

received_760514178838251.jpeg

  • Like 7

Share this post


Link to post
Share on other sites

No ideaΒ :lol:

I like the MF01X so I'm keen to follow this journey. What wheelbase do you achieve with the mid-ship motor case? It looks the same (225mm?)

I'm building a custom-ish MF01X myself albeit from the Tamiya parts bin. Feels like Tamiya have almost given up on the little thing given the shortage of Hop Ups currently available. I hope they don't drop it, it seems to have been popular.

  • Like 3
  • Sad 1

Share this post


Link to post
Share on other sites
56 minutes ago, ChrisRx718 said:

I'm building a custom-ish MF01X myself albeit from the Tamiya parts bin. Feels like Tamiya have almost given up on the little thing given the shortage of Hop Ups currently available. I hope they don't drop it, it seems to have been popular.

Unless if they release a driveshaft hop-up for the MB-01 Im sure that the MF will stick around for some time, they are releasing a Golf with that chassis.

I'm curious to see how this build goes, for rallying I do suggest inspecting the rear dog bones since those can pop out after a long session of drifting.

The M-chassis does have a neat variety of bodys, thats for sure!

  • Like 2

Share this post


Link to post
Share on other sites
1 hour ago, ChrisRx718 said:

I like the MF01X so I'm keen to follow this journey. What wheelbase do you achieve with the mid-ship motor case? It looks the same (225mm?)

I'm building a custom-ish MF01X myself albeit from the Tamiya parts bin. Feels like Tamiya have almost given up on the little thing given the shortage of Hop Ups currently available. I hope they don't drop it, it seems to have been popular.

Β 

It's 239mm, since donor kit and my body of choice is that wheelbase. But it can be configured in 210 and 225 in the same way as the original. Only the unoffficial "super short" variant is not possible.

Agree with @Kowalski86, MF will should stick around atleast until Tamiya releases another "mini XV" type of chassis. I think that hop-ups are less available due to discontinuation of its "cousins"...

23 minutes ago, Kowalski86 said:

I'm curious to see how this build goes, for rallying I do suggest inspecting the rear dog bones since those can pop out after a long session of drifting.

Thanks, I'll keep an eye on that.

  • Like 2

Share this post


Link to post
Share on other sites
10 minutes ago, Honza said:

Agree with @Kowalski86, MF will should stick around atleast until Tamiya releases another "mini XV" type of chassis. I think that hop-ups are less available due to discontinuation of its "cousins"...

Thanks, I'll keep an eye on that.

Anytime, you've already fixed the rear binding issue on the rear passengers side. Its mostly in the raised position when the dog bones can slide out.

The only hop-up that I recall for the MF-01x is an aluminum motor mount. I don't think that it was meant for compeitive racing like the other M-chassis so it didn't get manyΒ hop-ups. But it also has direct steering and not many parts to "hop-up".

Share this post


Link to post
Share on other sites

Progress has been slow, as I was sick with covid past few days. Now I'm feeling better, so I did a few things.

My old savox got new case, I cleaned and greased gears and bearings in the process. I also printed new, longer horn, but it'll be replaced by high-torque servo saver in the future.

received_513341537625339.thumb.jpeg.b2cd248bb155c7e6af78875e69e22d0b.jpeg

I also adjusted design of new parts and printed them. Now the harder part - split the chassis to fit them.

received_1259929328272189.thumb.jpeg.3570475d6f1ed99c8ff0a9c658b27b09.jpeg

  • Like 5

Share this post


Link to post
Share on other sites

Finally got to install the servo. And when I was at it, I also put some AW grease in the front diff.

received_937565717253494.thumb.jpeg.b16d78223a5972cfd3e9a440e1c414b4.jpeg

Then I installed new shorty battery holders. I never liked that the pack is sticking out of the car, so the new holders are protecting the battery from all sides

received_744253170411764.thumb.jpeg.faa5364098f36f6913e2d8e3f75515be.jpegreceived_720665636223244.thumb.jpeg.f9d049c59f175bbe812ef0f0a391bb46.jpegreceived_722310986297244.thumb.jpeg.1e4ee96882da870f5cbf95b852939ce9.jpeg

  • Like 4

Share this post


Link to post
Share on other sites

I'm sure you noticed that I left original pogo stick "shocks" on the car. That's because I wanted to use slightly longer CVA mini shocks from my other car - unfortunately they were a bit too long and collided with the original front mount. There are options that put the dampers more upright, but I wanted to stay close to the original angle. Eventually I found that when I fit the dampers upside down, the spring collar just barely clears the tower. Longer eyelets then provide enough space to add pivot balls above the damper. And original 3mm spacers create some room for additional mount. PerfectΒ πŸ™‚

Now some little CAD work..

IMG_20230304_174804.jpg.cdda25a50be9dbf13f3fc2e631e87d4f.jpg

Printed and mounted on the chassis

received_1518725901947743.thumb.jpeg.ee7d2729c1ceb587bbdedc2cf050b9c3.jpeg

And complete with dampers. The angle is not same as the original, but it's close enough.

received_139413902379951.thumb.jpeg.14707754716408769356498734619ff2.jpeg

Dampers are just long enough to provide full suspension travel and space around is very tight. But it works :)Β It sits a few milimeters higher than original dampers.

received_2815782258554429.thumb.jpeg.160ceaa22ff54e32145f73152836860a.jpeg

Β 

  • Like 6

Share this post


Link to post
Share on other sites

Finally pulled out dremel today to do some "irreversible" mods

My conversion requires 3mm shorter driveshaft. After reading @ChrisRx718Β 's thread, I was affraid it'll take a while. But the drill went through in seconds, maybe the tool I made helped. The excess shaft length is not an issue, as I designed a hole in the gear case - in theory, I could use a single shaft for all wheelbases, too. The gear fits perfectly and the car is finally 4WD πŸ˜„

received_886381022645131.thumb.jpeg.ebb0629279b5dfcd4e45f933055ac1e6.jpegreceived_218628474026387.thumb.jpeg.790df3ead3edb46516c365383e009283.jpeg

Another mod was needed around the steering links - the longer arm caused collision of links with the chassis, so I needed to cut the holes. Before:

received_731137141833445.thumb.jpeg.5a4db78a676a7b7e8ea0f60e69077817.jpeg

After (before cleaning and deburring). I also cut some material on the bottom so I could put the servo a few mm lower.

received_223205973566036.thumb.jpeg.e6321149d754a16eece2c29b2c6835ee.jpeg

Full steering lock. Not great, but better than stock πŸ˜„ Going further would require modification of the entire front suspension.

received_2140868672772379.thumb.jpeg.5f88df3695e5501d35b871b4b06e2b17.jpeg

  • Like 6

Share this post


Link to post
Share on other sites

This looks fantastic. I prefer the red to the green. Should you ever want another Guinea Pig I'd be happy to test out that mid motor mod!

I do feel this is what Tamiya should have done with the MF01x in the first place, just to balance out some of the weight. It would make for a better trail truck for sure keeping the weight off the back.

I really really hope Tamiya release a front motor variant, a la the XV01 in this form.

Β 

  • Like 1

Share this post


Link to post
Share on other sites
10 hours ago, Nikko85 said:

This looks fantastic. I prefer the red to the green. Should you ever want another Guinea Pig I'd be happy to test out that mid motor mod!

Thanks :)Β The mod has been released a few months ago, feel free to download it :)There's also assembly manual I finally finished a few weeks ago πŸ˜„ The more feedback I get the better.

https://www.printables.com/model/268346-mid-motor-conversion-for-tamiya-mf-01x

  • Like 2
  • Thanks 1

Share this post


Link to post
Share on other sites

Some work ahas been done. :)

While changing oil in dampers, i found that I built them with spacers and forgot about that.. πŸ€¦β€β™‚οΈ I dug up CVAs micros and found that they have same travel. Now I could mount them right side up, which allowed me to do another mod - by cutting part of the arm and removing shims, I could move the shocks 3mm backwards.

received_618162973488782.thumb.jpeg.e6c222f12122eb884abad93035ca8bf4.jpeg

received_963212164693094.thumb.jpeg.a56973bfae69cb1ea6aa8e6d16ebc321.jpeg

The rear was much more straightforward - I modified rear arms to increase travel in low position - now I reach same height without dogbines falling out. Then I printed new, 3mm higher danper stay so CVAs fit perfectly.

received_608612374465715.thumb.jpeg.497d652022d20cd5f4ed99f842659c35.jpeg

Last thing, I fitted electronics and made a cover. I need to work on the design, but for now, it works :)Β 

received_1713887599085938.thumb.jpeg.1f74e94022f22dc7ca459f16061cfb28.jpeg

Β 

  • Like 5

Share this post


Link to post
Share on other sites

First race today and although I didn't plan to race the MF today, I took it for a ride with a borrowed body. Unfortunatelly, the servo seized, burned and took ESC's BEC. Today was very "lucky", I didn't finish a single stage...

received_231930499211289.jpeg

received_601778771545783.jpeg

  • Sad 1

Share this post


Link to post
Share on other sites

so, I finally got to order new electronics, to fix the car after complete electronics failure. New ESC, Tamiya/HW 1060, (water resistant, co I can ditch dlthe cover) and a new servo for my second rally car - the old servo now goes to MF, with a new case - what a difference! I totally forgot there was a Futaba logo 😁

received_1363865014156151.thumb.jpeg.0b888946bb5b22037b78e95dbd005064.jpegreceived_160783189960244.thumb.jpeg.4684be73328644142d9614e8c54364b2.jpeg

I also got some MST springs. The rear suspension finally worksΒ :D But front still needs some work...Β 

received_1377190176412661.thumb.jpeg.de647bd61059b7913300f35028a71b6e.jpeg

(sorry for the picture quality - I don't have proper lighting and phone flash does terrible job)

  • Like 4

Share this post


Link to post
Share on other sites

Is this a better solution than a tl01 with m03 arms?

great work on all the fabrication.Β 

Share this post


Link to post
Share on other sites

@bermanΒ Thank you :)

Β 

13 hours ago, Butler said:

Is this a better solution than a tl01 with m03 arms?

I don't have a mini TL-01, so I can't tell performance-wise, but it is more modern design, so there are several advantages compared to TL-01:

- It can be adjusted to all wheelbases

- the motor doesn't stick as far out of the chassis

- it has square hole for lithium batteries.Β 

- its gearing is identical to M-05 (although compared to TL-01, it has one extra gear contact, which might result in lower efficiency)

- it can be equipped with downstops using M-05 V2 arms.

- it supports 1510 bearings in the front, for M-05 ball differential or sealed gear differential

Β 

  • Like 1
  • Thanks 2

Share this post


Link to post
Share on other sites

Finally started with the body. It's been a while since the last time I cut painted a body and it shows πŸ˜ƒ

Also made new damper stays for front dampers - they are way stiffer than rears, so I'll have to experiment a bit to make the front work..

received_749059383433832.jpeg

  • Like 4

Share this post


Link to post
Share on other sites

And the car is finally finished! Unfortunately I couldn't finish it in time for this week's race - so proper test is going to happen in next few weeks.

received_777858953972701.thumb.jpeg.ad9e9ed2645cbea88e69e6cd0846da0e.jpegreceived_954311825813211.thumb.jpeg.6f276735ed56d5730c84e5571b2cdd77.jpeg

received_791337402404129.thumb.jpeg.aa50d63329c46fe61a02b08be4e7f21d.jpeg

There were some changes going on the chassis, too. First, new front damper stay to fit the full length Mini CVAs properly.

received_6487901314582109.thumb.jpeg.c494f4ae1a97bb68429c5baeecb7ce3b.jpeg

You can see new foam bumper on the photo - it's M-05 bumper designed by KmanSweden. It fits MF-01X aswell - I just did some changes to fit thicker, 20mm foam.

received_270304932249937.thumb.jpeg.30f157e452796e3c8170491e49e8b3c3.jpegreceived_675199124330822.thumb.jpeg.34b7a3c6902241aa4c5f4a972c116060.jpeg

The last thing is a receiver box integrated into the rear body post brace - It was an easy way to waterproof the receiver - the ESC should be waterproof, so the large box protecting all electronics is not necessary anymore.

received_963992968368823.thumb.jpeg.3962ec5d7808bf3857f11c4c8709f34a.jpeg

  • Like 3

Share this post


Link to post
Share on other sites

Okay, we're not finished 😁

The car completed its first race without any issues. However, I cannot get the front suspension work even with #100 oil and softest springs I could find - so redesign of the front axle is in the works, using the XV-01 design as a template. Hopefully I can manage to fit working design into the 1.55 wheels. This mod should allow me to fit slightly longer arms - similar in length to the rear axle.

Anyway, here are some photos - in the parc ferme, next to my Lancia and other Minis, and on the track.

received_1330749984536955.thumb.jpeg.cccfb3f87199b76df74f7c26b6508fc0.jpegreceived_823551668672586.thumb.jpeg.ff3afc495cb7e437ac020741c4d8ceef.jpegreceived_173072295735139.thumb.jpeg.137cde31fb7b593da5cdb5eda61d841a.jpeg

Β 

Β 

  • Like 6

Share this post


Link to post
Share on other sites

Early prototype of XV-01 knuckle modified to fit into 1.55 wheel. Looks promising :) The XV-01 arm collides with the rim at 50Β° angle, but it should be possible to design an arm that will work.

received_1734424123667472.jpeg

received_795630365625300.jpeg

  • Like 2

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...