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

[Gebbly]

10 minutes ago, Honza said:

Thanks @Gebbly for reminding me this thread

No worries. I'm very interested in your design as I occasionally toy with the idea of a Wild Willy MF-01X inspired by @JennyMo

https://www.tamiyaclub.com/forum/index.php?/topic/81529-who-has-a-short-willy-mf-01x-wild-willy-2/

and a mid-engine would be a cool addition to the idea

[Honza]

6 hours ago, Gebbly said:

and a mid-engine would be a cool addition to the idea

Unfortunately mid motor wouldn't work with that - the motor sits in the space of the extension that gets removed for the WW's super short wheelbase. The shortest you can go is standart S wheelbase of 210mm. 

[Gebbly]

Oh thats a shame. Still an interesting project though

[wtcc5]

@Honza: Great design and documentation! Deserves definitely more likes!

[Honza]

@wtcc5 Thank you, comment from a great designer means a lot 🙂

[Honza]

I did a little test today - a separated suspension arm mount that I plan to use on next version

I tried to break it using TL-01B arms (I'd like to make a buggy version, too). Unfortunately it didn't break as cleanly as I'd like and damaged chassis mockup as well. I have to add some reinforcements and weak spots for more controlled damage.

[CRC505]

Amazing works!

[Honza]

A little redesign helped - the hinge pin hole cleanly broke from the rest of the mount, without damage of the mounting to the chassis. 

So I tried to level up and printed the mount again out of ASA. I tried PETG suspension arm, which shateret withou damage to the mount - so I tried a 3mm nail bent to L-shape - the nail bent further, the mount cracked at layers, but still held together and didn't damage the PLA "chassis". So I guess it works and I can move forward with the design

[Honza]

Finally had some time to work on the project. It's finally starting to look like the final part

[Honza]

A little update - I added "hump" for a fan. Overheating was quite an issue on the previous model.

Fan can be replaced with a small grill for cooler motors - even that may help with cooling.

[Honza]

Getting closer to finishing the model. The new design of damper stay is much more flexible than the previous version. In the basic form, it's similar to the previous version.

 

But, as an option, there's second version that can hold ball joints for adjustable top links. That means, that It'll be fully compatible with various Tamiya suspension variants, including TL-01LA.

 

[Honza]

https://www.printables.com/model/712311-v2-mid-motor-conversion-for-tamiya-mf-01x

I forgot to update the topic, I released the files for the V2 conversion Check out builds forum for photos of the real thing

[Honza]

I printed parts for someone for their Brat conversion. They are happy with it, but asked if it's possible to get slower gearing. So I gave it a try - looks like it might work with no need to modify design of the chassis. The ratio is close to 20:1

 

[Gebbly]

Fascinating watching as this develops. I would never have thought of things like building into the design controlled break points so as not to damage other parts in an impact.

[Honza]

@Gebbly thank you 😃 About designed breaking points - having to reprint a part that takes 6h is something that inspires you 😁 

There's speedrun challenge going on, so I thought it would be fun to make a quick modification - using smaller spur gear with slightly altered position, I made a "high speed" modification, with FDR ranging from 4,66 to 2,8. Not sure if it has any real use, but it helped me to move forward with the low range gearing.

 

[Redgrinde]

Looks good, thanks for posting those files.  I just finished building the V2.1 it took forever to get the gears, everything is selling out because of that Speed Challenge.  I'm printing your speed version now to see how it does compared to the original.  I'm only planning on running silver cans for testing, maybe torque tuned after that so not to much speed.

Have you seen Jack-O-Trades unlimited MF-01X, his solution to a mid mount is interesting.

Thanks again for your comments over on Printables I ended up printing in PETG, ASA, and PC Blend.  The PC Blend with HIPS as support turned out the cleanest (and is the first one I'm building), the HIPS just pulls right off of it nice and clean.  I look forward to seeing what else you come up with.  

 

[Honza]

1 hour ago, Redgrinde said:

Looks good, thanks for posting those files.  I just finished building the V2.1

Thank you! If you shared some photos, I'd be happy, It's nice to see different versions of my creation

1 hour ago, Redgrinde said:

it took forever to get the gears, everything is selling out because of that Speed ChallengeI. 'm printing your speed version now to see how it does compared to the original. I'm only planning on running silver cans for testing, maybe torque tuned after that so not to much speed.

Have you seen Jack-O-Trades unlimited MF-01X, his solution to a mid mount is interesting.

That's weird, because my conversion uses M-05 gears, not TL-01 speed tuned set that is widely used in the challenge... I doubt there's many people running my conversion, since it automatically means falling to unlimited class 😃

The speed version was just a crazy idea to widen the gear range, as opposed to low range presented earlier. I'm not sure whether it has any real use that won't burn motors at large, as MF-01X's gearing is far from efficient 🙂 

I did see Jack-O-trade's conversion and it reminded me how I started with this chassis:

My variant had motor hidden inside the extension. It was a maintenance nightmare 😃 It also required floating motor mount, because I couldn't line up bearings properly. But main reason, why I moved forward to current version is, that I wanted to make a proper M-chassis. This solution could barely fit into standard wheelbase.

1 hour ago, Redgrinde said:

Thanks again for your comments over on Printables I ended up printing in PETG, ASA, and PC Blend.  The PC Blend with HIPS as support turned out the cleanest (and is the first one I'm building), the HIPS just pulls right off of it nice and clean. 

You're welcome, your comments made me aware of another use case that I didn't anticipate 🙂 Now I will think about multi material printing in the future designs.

What printer do you have that allows for material combination? I'd like to try something similar in the future, but single head printer might be quite challenging with different materials... Do you have any pics how the finished part looks?

1 hour ago, Redgrinde said:

I look forward to seeing what else you come up with.  

Thank you I'm looking forward for feedback.

One sneak peak of another development of MF-01X - I never liked the short front arms and since Tamiya released XM-01 with similar front hub geometry, I wanted to try it. This is the result. I still need proper hardware to put it together, but it looks promising

I'm also looking into improvements in the mid motor conversion. Right now I realized that I put rear suspension mount screws to close to the arm hinge pin, with results in some issue. Unfortunately it cannot be properly solved without full redesign... Hotfix moves hingepins 1mm further apart, I'll upload this variant.

[Redgrinde]

Here are some pics. The Blue is PETG, Red is ASA, and Black is PC Blend.

Most of these were printed on a dual head Prusa XL, PC Blend and HIPS worked very well and just pulled apart.  I'll get another set printed at some point and get some in process pictures.  

I haven't run it much yet, hoping to get out today and see how it does.  I am looking forward to seeing what you cook up next.  

 

[Honza]

@RedgrindeLooks great! Tha is for feedback. Did you have any issues with PC blend shrinking? I noticed that the motor mount isn't fully seated on one pic

It should sit on tabs around the circular hole.

The red ASA damper mount might crack. I recommend printing the flat variant, which also eliminates the rear upright extension:

https://www.printables.com/model/713517-short-top-link-damper-stay

 

[Honza]

Finally some progress with low range gearing, first prototype is getting ready to be tested:

[Redgrinde]

The white piece is Nylon and it decided it would not sit flush no matter how much I wanted it to.  I printed another one but haven't rebuilt it yet.  

Low range gearing looks interesting, do you have a specific scenario/challenge you are building it for?

[Honza]

1 hour ago, Redgrinde said:

The white piece is Nylon and it decided it would not sit flush no matter how much I wanted it to.  I printed another one but haven't rebuilt it yet.  

Is it possible that it shrunk and wouldn't fit around the ring on the transmission? It's quite tight fit, materials with more shrinkage may need additional adjustments.

1 hour ago, Redgrinde said:

Low range gearing looks interesting, do you have a specific scenario/challenge you are building it for?

I send my conversion to someone who build Subaru Brat on it, they wished for slower gearing so it could drive off road. It could be also used on the original Mercedes and Jimmy kits.