Window Transmission Gears 3D Printing

Markos

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The metal/bronze stuff is like pot metal so I wouldn't keep your hopes up. I think the nylon will do fine. One question though, would it be stronger if the ridges for the metal cog were in the valleys of the plastic gear? You would maintain an overall thickness around the plastic ring. I'm not sure, but curious.

I've been thinking about using ULTEM for the relay bases. It is propane torch resilient!

http://www.stratasys.com/materials/fdm/ultem-9085

 

TravL350

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Can't you machine a 1-piece out of delrin? I know a forum member has made a part using that material w/success.....unsure about th price or if it is correct material to make a gear from?

-Mo
Hi Mo - I got a quote for machining a delrin gear, as well as a PTFE (Teflon) and it was going to be about $150 do CNC any plastic, so probably cost prohibitive considering you can occasionally find the whole gearbox for less than $50. Also, like Steve said, I am not sure a plastic cored gear would hold on to the spindle for very long before stripping.
 
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TravL350

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The metal/bronze stuff is like pot metal so I wouldn't keep your hopes up. I think the nylon will do fine. One question though, would it be stronger if the ridges for the metal cog were in the valleys of the plastic gear? You would maintain an overall thickness around the plastic ring.

Yes I think that would make it a bit stronger! I'm less worried about failure in that area though, because I think either one of the sets of teeth will give out first
 

Stevehose

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Looks like you could just make an open sided gear with the inner teeth to match the metal teeth and slip it onto the metal gear then bond it with some nasty adhesive?
 

TravL350

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Looks like you could just make an open sided gear with the inner teeth to match the metal teeth and slip it onto the metal gear then bond it with some nasty adhesive?

Yes, I think so Steve - hopefully with this design we won't even need an adhesive. The Nylon will expand a bit as it soaks in grease which should make the press fit even tighter
 

m73

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Hi Mo - I got a quote for machining a delrin gear, as well as a PTFE (Teflon) and it was going to be about $150 do CNC any plastic, so probably cost prohibitive considering you can occasionally find the whole gearbox for less than $50. Also, like Steve said, I am not sure a plastic cored gear would hold on to the spindle for very long before stripping.

That's a lot of $$ for such a part! How about re-sleeving the striped outer edge only?

I would round the perimeter, then re-make the gear portion + a center portion w/recess to fit on-top on the metal area. That way you have max adhesion surface area. Maybe even make the center recess on both sides if space willing.

Of course you are much closer to a solution than this....just thinking outside the box.

Best of luck,

-M
 

TravL350

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I just received a NOS transmission I bought from eBay and discovered it's gearing is 38:1 instead of 48:1 like my car has.

BMW part no. on the box is 51371801878 - same as the 48:1 as far as I can tell.

Bosch P/N is:
0 142 800 004 for the 48:1
3 136 201 001 for the 38:1

Anyone know the history on this?

Travis
 

TravL350

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Got parts today!
Here is the nylon 12 gear:
08c6a238b3929030dee22089ff464468.jpg
b9d2b3132622a3d5e501011eee710ecd.jpg


With the existing metal core pressed in:
a94acc933decd1e4ad408db7e4c26058.jpg
ef3e90d521aa8c9744b110d5aed48cec.jpg


And here is the SS/Bronze part:
97735454bbcd0198561ed93542a761bd.jpg

0ca991cd7b5fe4e6a1c0e62eb2c4b852.jpg


The metal one came out far better than I expected! It seems very strong and dense. Not sure how noisy it will be though.
I'll put these both in my car this weekend and compare functionality / noise between the two new parts
 

rsporsche

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looking forward to hearing how the 2 different products work. i'm not in need right now ... but sooner or later a bunch of us will.
 

TravL350

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Thanks Markos! I didn't include splines in the metal part because I had to "under-size" the hole to allow for shrinkage. I'm planning to drill out the hole a bit, then press it on to the splined shaft. However, the material is very hard. I was expecting it to be softer & more workable because of the bronze infiltration, but it seems much more like steel. So, I'm not sure if I'll be able to successfully press it on to the splined shaft.
 

TravL350

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I managed to drive the splined shaft into the gear (took some serious pounding) to "cut" the splines into the hole. Next time I'll make the hole in the 3D part 0.5mm larger diameter so I won't have to drill it out

6afa8e2fb21cc838081929141d29558d.jpg
 

Markos

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Hmm this stuff seems stronger than what I have been told. I wanted to print CSI airbox brackets but I figured it wasn't strong enough.
 

TravL350

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Hmm this stuff seems stronger than what I have been told. I wanted to print CSI airbox brackets but I figured it wasn't strong enough.

Yeah, I am pretty impressed by the material. The finish is rough but it's way stronger than any plastic 3D print I've ever seen.
 

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The weekend got away from me (as often happens) so no update on this yet. But I did manage to waste an hour this morning reading more about 3D printing in metal materials. Interesting point of view from Jay Leno:

"Recently, we had the chance to visit Jay Leno’s Garage and talk with him about making vintage auto parts with additive metals and Direct Metal Laser Sintering (DMLS). As Jay said, “Remember the early days of 3D printing where you had to make it in plastic? You know, remember those days like four years ago? Well forget that! We’ve moved on!”

Jay was interested in the implications of DMLS for his favorite hobby, collecting and restoring old automobiles. Holding up a vintage piece, Jay said, “When you have old parts like this for a White steam car – there are barely any cars left, let alone parts – this is a revelation. You can actually have parts made in metal of a better quality than it even was originally.”

We worked with Jay and his shop foreman, Bernard Juchli, on a burner, a piece that functions “like a pilot light on your water heater,” for one of his White steam cars. Previously, Jay’s shop has used plastic 3D printers to build patterns for metal casting. This time, Juchli used Stratasys Direct Manufacturing’s additive metals expertise to build the production part in Inconel 718, a nickel-based super alloy that is extremely heat and corrosive resistant – perfect for the under hood environment of an antique car.

“The neat part is,” Bernard said, “we drew this in GibbsCAM because I was thinking of machining it. It would have involved quite a lot of machining to get all these cross-drillings. By printing it, we already had that done.” DMLS’ ability to handle complex geometries and internal features makes it an ideal process for reverse-engineering rare parts.

Additive metals have opened up new markets to high-quality parts, fast, and there’s very little limitations. Serious car restorers no longer have to struggle with parts that are impossible to find. “There’s no part of a motorcycle, automobile, steam engine, that can’t be reproduced,” said Jay. Stratasys Direct Manufacturing can take any part or 3D model and make functional, accurate parts.

“Think about it. There’s nothing you can’t reproduce… we’re making things that no longer exist and now, they exist again.”
 
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