3D Printed Bushing Differential Mount Bushing

[otis147]

The original bushing for my mc2 diff mount failed, so I printed a new one from TPU.
Installed with white lithium grease into the aluminum mount from ~2014.

Printed on a Bambu x1c
Sainsmart 95A TPU
99% infill
CONCENTRIC INFILL
CONCENTRIC TOP AND BOTTOM LAYERS

You will need 2 of them, I was able to press them in by hand with the grease. Makes for a solid mount for sure.



https://www.thingiverse.com/thing:7329707

[my8950]

Count the miles, see how long it stays in one piece.
It may be an alternative if it will hold up.

[otis147]

I've used 3d printed tpu bushings for suspension and handle bar mounts on my 1967 Honda scrambler 305 for about 4 years now and 5k miles, so far no issues. Much like these cars, rubber parts for it are unobtainium

[my8950]

Interesting, I am behind with 3D printing stuff, it's hard for me to grasp in my mind.
But, doing a search for TPU bushings, it seems like there is a lot of positive results out there.
So, yes, seems like you're on to something...

[brokencase]

I've done a few TPU suspension items and have had no problems.

However there is a new flex filament option that you might find interesting - PEBA
https://www.amazon.com/dp/B0FRM6T9M3

This is more resilient than TPU and comes in 85A shure, which is a bit softer the typical 95A TPU.

I bought a roll off of Amazon, but I have not yet printed anything with it.

[my8950]

Does this filament require anything special?
Or does using this need a certain type of printer?
A colleague has a printer from Micro Center, I'm sure it's nothing super special, but maybe it would work?

[otis147]

95 shore is the same as the black powerflex bushings.

Just make sure the filament is dry dry dry, and depending on the setup, you may have to have a special feed setup if you have too much friction on the spool.

[DPDISXR4Ti]

If you're so inclined, please feel free to share the design in this thread....

https://forum.merkurclub.net/forum/view ... hp?t=43153

[andyofcolumbusmerkur]

I have the early style MC2 rear diff mount (oval shape) Does anyone make a replacement bushing for it?

[brokencase]

As far as printing TPU...
You want a 3d printer with a direct drive extruder.
You might need to work up a decent TPU profile, but more often modern slicing software comes with a fairly good TPU profile.
TPU prints much slower that typical FDM filaments. A large SOLID bushing can take 24hrs or more.
As I recall printing the rebound buffers for the rear of Scorpio took about 10 hrs to print and they were only 27% infill.
Printing a solid TPU pad for my harbor freight 1.5 ton aluminum jack took around 24 hours.
https://www.thingiverse.com/thing:2989830
A small upper trunnion bushing for a Sprite (about 1" in diameter 3/4" tall) can print in an an hour or so.
Just trying to give you a rough idea of the time involved.

I bought a cheap (sub $100) Aquila style 3d printer that I converted to a direct drive extruder and that I devote exclusively to TPU.
The reason being is that I often print TPU and when you switch between TPU and other filaments you sometimes can get a clogged nozzle. Its just easier to have a TPU setup available all the time. You do not need an expensive 3d printer to print TPU.

Andy - bushings are fairly easy to 3d model. If you can pick off the critical measurements of your "early style MC2 rear diff mount" I can make you a model of it. By critical dimensions I mean like the measurements I show in my parametric sway bar bushing here:
https://www.thingiverse.com/thing:6027060

Because TPU can take a long while to print it is wise to quickly print a test model at a low infill in PLA to confirm fitment before printing the the final solid TPU version. Also this is why I make the models parametric. If your measurements are off you can easily tweak the model to get a better fit. Sometimes you only need to scale the model in the slicer.

My most recent and interesting TPU project:
https://www.thingiverse.com/thing:7292161
Worked out great. Time will tell how long they will hold up but I think the 3d printed tires will hold up better than the ones that were on the saw previously. It was strange. I went to use the bandsaw and it was a bit cold in the basement (60F or so) The bandsaw tires that I put on the saw about 10 years ago just shattered. I was lucky to shut the saw down in a hurry before damaging the blade and anything else.

[otis147]

As far as printing TPU...
You want a 3d printer with a direct drive extruder.
You might need to work up a decent TPU profile, but more often modern slicing software comes with a fairly good TPU profile.
TPU prints much slower that typical FDM filaments. A large SOLID bushing can take 24hrs or more.
As I recall printing the rebound buffers for the rear of Scorpio took about 10 hrs to print and they were only 27% infill.
Printing a solid TPU pad for my harbor freight 1.5 ton aluminum jack took around 24 hours.
https://www.thingiverse.com/thing:2989830
A small upper trunnion bushing for a Sprite (about 1" in diameter 3/4" tall) can print in an an hour or so.
Just trying to give you a rough idea of the time involved.

I bought a cheap (sub $100) Aquila style 3d printer that I converted to a direct drive extruder and that I devote exclusively to TPU.
The reason being is that I often print TPU and when you switch between TPU and other filaments you sometimes can get a clogged nozzle. Its just easier to have a TPU setup available all the time. You do not need an expensive 3d printer to print TPU.

Andy - bushings are fairly easy to 3d model. If you can pick off the critical measurements of your "early style MC2 rear diff mount" I can make you a model of it. By critical dimensions I mean like the measurements I show in my parametric sway bar bushing here:
https://www.thingiverse.com/thing:6027060

Because TPU can take a long while to print it is wise to quickly print a test model at a low infill in PLA to confirm fitment before printing the the final solid TPU version. Also this is why I make the models parametric. If your measurements are off you can easily tweak the model to get a better fit. Sometimes you only need to scale the model in the slicer.

My most recent and interesting TPU project:
https://www.thingiverse.com/thing:7292161
Worked out great. Time will tell how long they will hold up but I think the 3d printed tires will hold up better than the ones that were on the saw previously. It was strange. I went to use the bandsaw and it was a bit cold in the basement (60F or so) The bandsaw tires that I put on the saw about 10 years ago just shattered. I was lucky to shut the saw down in a hurry before damaging the blade and anything else.

I recently got some of the HF TPU from Bambu labs, and it cuts print time down exponentially for TPU. Highly recommend. Also don't forget if using TPU for bushing, to grease the hell out of them so they don't squeek. I use white lithium grease myself. Your mileage may vary.

[brokencase]

I recently got some of the HF TPU from Bambu labs, and it cuts print time down exponentially for TPU. Highly recommend. Also don't forget if using TPU for bushing, to grease the hell out of them so they don't squeek. I use white lithium grease myself. Your mileage may vary.

Thanks for the heads up. My Artillery x4 pro is a high speed printer and I'll have to try out the HF TPU.

I guess the only issue is getting the profile right. That and the fact that I think I still have two rolls of old style TPU to go through.

[andyofcolumbusmerkur]

Thanks for offer. I haven't drawn up anything in autocad for almost 25 years. Currently the differential mount is back in the car. I used a piece of timing belt wrapped around. Then filled in the voids with urethane. Someday I will get a 3d printer just for printing bushings and RC car tires.

[brokencase]

Thanks for offer. I haven't drawn up anything in autocad for almost 25 years. Currently the differential mount is back in the car. I used a piece of timing belt wrapped around. Then filled in the voids with urethane. Someday I will get a 3d printer just for printing bushings and RC car tires.

You don't always need CAD Andy. In some cases I've created models just from scanned images of traced drawings, or photos.

This model was done in this way. https://www.thingiverse.com/thing:7140073
A image was cleaned up in Paint Shop Pro and then the resulting image was converted to vector format using Inkscape's "trace" function.

The resulting vector file (.svg) was then imported into OpenSCAD and then extruded to create the desired thickness.
The model was then scaled to measured dimensions from the actual part in the X and Y axis.
There was a little CAD work to create the raised internal lip.

All programs mentioned are free.

So if you can trace the outline of your bushing on a sheet of paper then a model can easily be made.

But I understand that even this can be difficult with the bushing mounted on the diff.

[otis147]

Thanks for offer. I haven't drawn up anything in autocad for almost 25 years. Currently the differential mount is back in the car. I used a piece of timing belt wrapped around. Then filled in the voids with urethane. Someday I will get a 3d printer just for printing bushings and RC car tires.

If you take it out again, you can always send it to me and I can make one up and print it for you.