Introduction: Shopsmith Mark V Bandsaw Coupler Replacement
I came across a Shopsmith Mark V for cheap while on a service call a while back. There was significant rusting and several pieces were missing. Among the missing pieces was the coupler that drove the bandsaw via the headstock motor. So what's a maker to do? I could spend $35+ on an OEM from Shopsmith, but what's the fun in that? Much better to make do with the materials at hand than spend hard earned cash unnecessarily.
Please Note: For this work, you must still have either the original metal couplers or metal couplers that fit the shafts of the bandsaw and the headstock motor.
- 1" to 3/4" PVC adapter x2
- 3/4" PVC pipe, 3"long
- 2-part epoxy
- wheel bearing grease (vasoline, etc.)
- copier paper, 1 sheet
- PVC cleaner and cement
- 3d printer
- STL file
Step 1: The Old Way
OK... as you can see, the old way does not look pretty. Me personally, I don't care what something looks like just so long as it works. And this has held up for over two years, so....
Start with two 1" to 3/4" PVC adapters. Using a dremel (or other tool of your choice) cut four slots down the inside sides on the 1" end. These slots give the epoxy something to grab. Cut a 1" diameter circle out of a piece of copier paper and place it in the bottom of the adapter with the adapter standing upright on it's end. Grease one of the metal couplers with vasoline or wheel bearing grease and place in the exact center of the adapter on top of the paper circle, making sure that the slots in the coupler do not line up with the slots you cut in the adapter. Mix up 2-part epoxy and carefully pour the epoxy in the gap between the metal coupler and the walls of the PVC adapter. Do this for both of the adapters/couplers. Once the epoxy has dried, you can push the couplers out from the opposite end, breaking through the paper of need be. Using PVC cleaner and cement, press one of the adapters half way on to the PVC pipe, then press the other adapter on the other end of the pipe. If you can, butt both adapters up against each other, but if the pipe is a bit too long, press the adapters as far on as they will go.
When everything is cured/dried, your adapter is ready to use.
Step 2: The New Way
Now, the new way, on the other hand, looks MUCH better! Wouldn't you say? Plus, it's MUCH easier to do... if you happen to have a 3D printer :)
I have uploaded the STLs needed here, or you can also download them from the Thingiverse page here - http://www.thingiverse.com/thing:2206530
I would advise that you print the SMcoupler_test-fit.stl file first to verify that the coupler will fit your metal coupler. You may need to scale the coupler up a tad if the fit is too tight. Once that is straightened out, print the full coupler with the proper scaling (if need be) and sit back and wait... this is going to take a while!
To print this, you will need to enable supports everywhere (as opposed to just touching the build place). I would also recommend a layer height of 0.3mm (anything lower may look better, but it will take MUCH longer to print unnecessarily) and an infill of at least 60% for strength.
Once the print is finished, remove the support material and clean up the print as you see fit. Enjoy your new, 3D printed bandsaw coupler and congratulate yourself on having saved a few bucks in the process.