Jump to content
Honza

MF-01X mid motor conversion (WIP) - link in first post

Recommended Posts

EDIT 12.Nov 2022 - files can be downloaded here https://www.printables.com/model/268346-mf-01x-mid-motor

 

 

I think that I got far enough that I can present my next project :)

Since Tamiya released the MF01X, I was thinking that it wasted so much potential by making it rear motor with quite high CoG. I decided I'd make my own TL02 by converting it to mid motor. First idea was mounting motor in the center insert - 257mm wheelbase provided just enough space - but although this solution worked, it had poor maintability and motor cooling was suboptimal. Also, it worked only for standard size, taking away what makes MF-01 so insteresting. That was end of the project for some time..

But recently, I decided to revisit the project. Since I built gearboxes on my rally car around TL01 gears, I have some reference, which makes work a bit easier. To make things more interesting (ie:harder), I made decisions that would shape the design:

- Cover all wheelbase options - from 210mm beyond, so it can function as M-chassis as well as full size "TL02"

- make it look like a production part - That means that it should use as little extra material as possible and shape that could theoretically be made by an injection molding. Of course, design should complement the rest of the chassis

- use as little extra parts as possible, no custom gears - originally, I wanted to use only stock gears, but it wasn't possible, the motor would stick to far out. But M0X gears are quite cheap and allow me to get proper M05 gear ratio. One disadvantage is, that it adds complexity to already complex gearing... Well, hopefully it won't be as bad.

So this is basic layout of gears I'm building around. you can see that motor rotation is reversed due to an extra gear, similarly to M07.

IMG_20220630_094709.jpg.7edc72c8880f927b083bf6c6978a77bb.jpg

And early design of the gearbox - so far without internals:

IMG_20220630_094832.jpg.04d6c0a100faeb57b4d8f4ad81dbe3b3.jpg

 

In the end, whole conversion should require just a few printed parts, M05 gear set and some 5mm shafts. Hopefully I'll be able to finish the design soon 🙂 Reason why I started this topic was to get some feedback earlier in development, so I can fix things I could've overlooked. 

Share this post


Link to post
Share on other sites

Awesome, can't wait to see it made.

I'd also be really interested to see if anyone could lock the front wheels and add rear wheel steering to the MF01x so you can flip the body and make it front engine like the XV01. It's something I've thought about, but I don't have the skills! 

  • Like 1

Share this post


Link to post
Share on other sites
30 minutes ago, Nikko85 said:

I'd also be really interested to see if anyone could lock the front wheels and add rear wheel steering to the MF01x

That would require a complete redesign of the chassis - something I wanted to avoid (for now) in this project.

You could lock the front and flip the car, but there's 1st issue: front axle has a kick-up angle, which wouldn't work well on the rear. And steering of the rear axle would be another issue due to MF01's geometry: dampers are in the way of the steering links. So they'd have to be moved away, but I'm not sure if there's be space behind the motor... Also, the motor would rotate in the opposite direction.

Share this post


Link to post
Share on other sites
2 hours ago, Honza said:

That would require a complete redesign of the chassis - something I wanted to avoid (for now) in this project.

You could lock the front and flip the car, but there's 1st issue: front axle has a kick-up angle, which wouldn't work well on the rear. And steering of the rear axle would be another issue due to MF01's geometry: dampers are in the way of the steering links. So they'd have to be moved away, but I'm not sure if there's be space behind the motor... Also, the motor would rotate in the opposite direction.

Yes, but apart from all that, it should be easy, right?:D

Looking forward to seeing how this one works out, good luck.

  • Haha 1

Share this post


Link to post
Share on other sites

Finally had some time to work on the model. The left half now have atleast some internal structure and a motor mount. The motor mount will be 3D printed, but it's designed with an aluminium variant in mind. There should be enough room for pinion sizes from 14 to 24T, covering gear ratios of TL01 and M07.

gearbox half.png

Share this post


Link to post
Share on other sites

Getting closer to completion 🙂 If everything's going well, I could start printing next week. I guess it's the right time to get the M-chassis gear set 😀

IMG_20220708_194220.jpg

  • Like 2

Share this post


Link to post
Share on other sites

An interesting project there! My first Tamiya was a TL01 so looking forward to seeing this develop.

 

Luke

Share this post


Link to post
Share on other sites
45 minutes ago, lukej said:

My first Tamiya was a TL01

thanks :) My first ever RC was a TL-01, (although a chinese copy), so I have soft spot for it, too. :)

  • Like 1

Share this post


Link to post
Share on other sites

I decided to add a little bumper, which will serve two purposes: to hold the diff case together and to serve as downstop for the 54606 M05 V2. arms. Now I need to figure out damper stays, I want to keep M05 geometry to utilise top links included in the kit. However I forgot to double check position of suspension mounts and found that M05 has shifted rear hubs compared to the TL01 suspension I am using - hopefully I won't need to do any major modifications because of that...

IMG_20220711_092545.jpg

  • Like 1

Share this post


Link to post
Share on other sites
On 7/8/2022 at 7:44 PM, Honza said:

If everything's going well, I could start printing next week.

...it didn't go well. The part that should've been easiest, adding rear damper stay and top link mount, was actually quite hard to figure out - I didn't realize that spur sits higher on MF01X, which also moves it backwards - leaving nearly no space for top link mount. So, after trying to replicate M05 geometry (including modification of right half of the gearbox to reduce size of the casing around the spur) I gave up and used the weird solution from MF01X. It'll look super weird on the mid motor, because damper stay have to be behind the dampers, but it will re-use more kit parts, which goes with the original plan. :) 

mf01x rear.png

Share this post


Link to post
Share on other sites

Finally, I've been able ti start printing. From a quick test, everything seems to fit. The driveshaft length is only about 2mm shorter, so I made a hole in the bevel housing, so original driveshaft can be reused after drilling a hole for the cross pin. In theory, there should be enough space that'd allow one driveshaft for multiple wheelbases (and maybe 6x6 extension 😁)IMG_20220722_075837.thumb.jpg.1c9d4e8685302cfd599ca09e246e867d.jpg

Share this post


Link to post
Share on other sites

Over the weekend, I finally printed the left half. There were some problems, but in the end, everything fit together and gears run fine :) Unfortunately this is the last progress for next few weeks, because I go to vacation with no 3D printer around :)

There are still some issues that need to be changed, but overall, the design should work.

received_3245629562326286.thumb.jpeg.e5514b63399df2a01f3b808b26298d53.jpeg

Here I just wanted to see how it looks with a motor. It seems that even BL motors will fit, even though it wasn't priority during design.

received_387124463535138.thumb.jpeg.feca569d72bff2c5a6d4b96a5cdd8385.jpeg

Now there's a question - If I, amateur with a year experience in F360 could design this, why Tamiya couldn't? 😀

  • Like 2

Share this post


Link to post
Share on other sites

Interesting project.

In near future I planning to buy MF-01X.  Good rally M-chassis. Construction with mid motor change the game in drivers experience. 

Good quality of FDM printing, what printer and settings do you use?

 

Share this post


Link to post
Share on other sites

@SimTechRC thank you :) Yes, MF-01 would be quite capable, if Tamiya did a mid motor variant. I made a variant with motor in the extension section and it worked quite well, but maintenance and cooling was an issue, as well as lining up the driveshaft correctly. Also, it only worked with standard 257mm wheelbase.

I think that print quality looks much better on the photo :) It's printed on Ender 3 with  5010 cooling fan and Capricorn tube (reduced retractions to 3mm). It's Creality's variant of PLA+, printed at 195C, otherwise mostly stock settings in PrusaSlicer, 0.2mm layer height and low speeds

  • Like 1

Share this post


Link to post
Share on other sites

I forgot to upload this here :) Test fit on my Frankenstein chassis

IMG_20220809_203251.jpg

IMG_20220809_203206.jpg

  • Like 5

Share this post


Link to post
Share on other sites

Are you tested your setup?

Interesting, how it feeling in compare with standart mount?

Share this post


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

Are you tested your setup?

Interesting, how it feeling in compare with standart mount?

Not yet, the chassis donated some parts to other project.. and now I'm out of country, so I cannot do any progress. I just found the photos in my phone and decided to upload them here.

 

  • Like 1

Share this post


Link to post
Share on other sites

So, it took a bit longer, but it's already done first few meters on its own :) It's just missing the crosspin in rear bevel gear, I need to drill a new hole to driveshaft

currently it's in 254mm config, I'll do a custom center piece (with cable management space :D) later.

received_474321214383591.jpeg

received_1119603738940837.jpeg

  • Like 5

Share this post


Link to post
Share on other sites

Wow, it's been a while since I posted here. Just few words about progress:

I printed new center piece for proper wheelbase, new ASA motor mount and quickly assembled the car for a race in October.. unfortunately, weather was really bad and moisture got into receiver even before the race started, so my other car had to run the race for two drivers.

I didn't have much time, but I did some progress on the gearbox - I modified the design so it can be printed without additional supports (there are only few included in the model), fixed some mistakes and reprinted it from PETG. Now I just need to find time for a test drive - if it's sicesfull, I might finally release the files.

Unfortunately I didn't make much pictures recently - here is at least one i did during the ASA motor mount instalation. It shows all extra parts needed for the conversion.

 

received_1305720750181879.jpeg

Share this post


Link to post
Share on other sites

So, the project is not quite finished, but development of current model ended. It has some things to iron out, but they will be addressed in new model which will be drawn from scratch. Right now, it's printable and works, so I can finally share it

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

This model includes some modifications from the last model I printed (reinforced motor mount, motor moved 1,5mm to the left, reinforced suspension mounts), but hopefully I didn't make any mistake that would make it unusable.

Let me know how it prints! Any feedback will be appreciated.

Share this post


Link to post
Share on other sites

IMG_20221120_223923.thumb.jpg.b8aca03cfeb30a55283ac4accb1c78a2.jpg

I finally did photo of the car with PETG parts (yes, cable management is still awful :D) Semi-transparent material I used, highlights all errors, but also creates interesting texture, visible here. 

IMG_20221120_223624.thumb.jpg.7f322d4aa012d943385b63407c3624f3.jpg

I also did a crashtest.. I was afraid that part around the hinge pin will be the weakest point, but this is how production part would crack. Of course, material itself is weaker than production part, so I added some material. 

received_1151167402439722.thumb.jpeg.cef6f79739eebe20b783d22938a35be3.jpeg

  • Like 1

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...