3D Printing Obsolete Automotive Replacement Parts


Staff member
Mar 2, 2004
Reaction score
Chicago, IL

I recently bought a 97 Lincoln Mark VIII to fix up, and shortly after discovered that while the AC blows cold, there was no heat on any setting. As someone who often buys, fixes and sells cars, this is nothing I wasn’t prepared to deal with, or so I thought…

So I did some basic research, it turns out this is a pretty common problem with these cars, as the motor that actuates the hot/cold blend door under the dash is known to fail with age. The plastic gets brittle over the years, and eventually cracks. The part itself was really inexpensive, had I been able to buy one. The picture below show the original part, and the broken pieces above it.

This picture shows what the original, broken part looked like.

After doing some searching, I got a call with some bad news. That little plastic lever was no longer available anywhere. Nothing in any dealer stock, nothing in any salvage yard, nothing on the internet. I started thinking there is no way this silly little part is going to stop my completion of this project.

So I gathered up the broken pieces, and scotch-taped them back together. I measured the old part with calipers and modeled it back up in Inventor. I even made some minor improvements to add strength and prevent the same fate. Then I sent the model to our 3d Printer and printed 2 copies right away. When the dashboard was reassembled, the printed part worked perfectly.

I believe the future of 3d printing is going to be huge. Every day people are coming up with more new ways to leverage this technology. After my experience above, I started thinking about all the past hours I have spent scouring swap meets and searching online for some little bracket or piece of trim that was holding up a build. Now I realize that if I can just get it modeled or scanned into 3d data, I can print just about anything.

Here is the Inventor Model

Here is the final part, assembled onto the blend door motor.

Jim Ritter
Application Engineer
Manufacturing CAD and Data Management Specialist
MasterGraphics Inc.



I recently acquired a 3D printer at work and have been dreaming of such tasks.

PLA and ABS plastic are common 3D printer extrusions but have limited structural properties. Higher end printers can do nylon and other more structurally sound materials.
After a member asked me about it, I contacted the author of the article... He sent this email in return

From: Jim Ritter [mailto:Jim.Ritter@mastergraphics.com]
Sent: Tuesday, November 18, 2014 8:09 AM
To: admin@lincolnvscadillac.com
Subject: 3d printed Lincoln parts

You commented on a blog post I made some time back about 3d printing obsolete car parts. If you need a copy of the blend door actuator arm I created, I could have another one printed for about $75. If you are interested, let me know.

Jim Ritter
Application Engineer
MasterGraphics Inc.
N19 W23993 Ridgeview Parkway West
Waukesha WI 53188

(800) 873-7238 Toll-Free
(800) 377-6364 Support
(800) 717-2111 Fax
Very nice work, and very cool tech for sure. That there is one way I can see a person not being slowed down by FMC. The possibilites have my mind reeling now!
That would be perfect for the center console cupholder issue l, been thinking about that ever since this 3d print tech came out. :)
Joey, if you could get him to send you the .stl file for it, it wouldn't cost very much to have printed. I have a friend with 3 3Dprinters, and he'll let me print pretty much anything I want.

I don't see that part costing much more than $15-$20.
As I recall, the OEM part is acetal resin with impregnated metal fibers, so I doubt if it would last long. Also, it is indeed still available, you just have to buy the motor with it.

Not trying to downplay it, it's really cool. There are a ton of other parts that this would be ideal for.

EDIT: Just looked it up, it's Delrin.

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