Extra Short Power Coupler for Shopsmith New Design!!!

Description

This robust extra short power coupler is being offered for Shopsmith owners that have a need for a very short coupler. The coupler has an overall length of  less than 1.20 inches versus the OEM coupler that is 5 inches long. This coupler will allow the hub of the accessory nearly touch the drive hub. It is a monolithic 3D print using ABS plastic.
Keep in mind the shaft alignments need to be much closer since the length is very short. Misalignment causes asymmetrical loading at best and interference at its worse. Misalignment will likely cause premature failure due to wear.
The belt sander accessory is the hardest on my 3D printed couplers.  I bought a belt sander accessory last year to figure out why.  There are a number of potential issues. First is centering alignment between the headstock and beltsander,  it needs to be very good, preferably less than 1/16 of an inch, also the length of the dowel needs to be on the longer end, probably 1.5X the OEM coupler length. If not aligned there will be plastic debris from internal grinding. Another possible issue is shaft runout (slightly bend of shaft) on the beltsander, as an accessory sometimes things get accidently bent, which would exhibit itself as grinding too. Aligning the shafts isn't difficult but will take several minutes to an hour depending on how rusty things are.  Both vertical and horizontal centering can be adjusted.
Another Belt sander concern is belt tension, especially if the rubber roller has age hardened.  People tend to tension it greater, which dramatically increases the torque load, this might be evident by the headstock struggling on start up.
While my 3D couplers have good static torque strength, they will not hold up with cyclic fatigue stress from mis-alignment, and high drag from excessive belt tension, particularly if one or more of the couplers has snug fit on one of the stub ends and a snug fit at the wood dowel interface. If the coupler gets "wear in" at lighter loads on an accessory like a bandsaw, to loosen up the fits, they can hold up better, but still it is only a matter of time before grinding takes off the nubs inside of the coupler unless shaft centering is adjusted.
If you have doubts about compatibility with your belt sander, the OEM Shopsmith coupler may be a better option.  Shopsmith claims their coupler is indestructable.  My 3D printed one isn't. That being said, if the alignment is good and belt tension isn't excessive, the coupler will last, I haven't broken one yet, however I am not using the belt sander day in/out.
(Updated Youtube video's coming soon) See the following YouTube videos if you are interested in how the extra short coupler is used, what its performance is at highest RPM's and what its strength is in comparison to various Shopsmith power coupler designs:
https://www.youtube.com/watch?v=hEg36ctsjWc
https://www.youtube.com/watch?v=F22xO0QOZbM
https://www.youtube.com/watch?v=UL4M1D6Ie1c
(if the link doesn't work search for: power couplers in use )
Do not use a coupler that shows any signs of delamination, cracks or visible defects. Do not attempt to repair.
I am liable only to the extent of the purchase price of this part. Use at your own risk. There is inherent danger using any Shopsmith equipment, loads, speeds, feeds, unbalance and setups are determined by the user. If you do not agree to the limits of my liability please do not purchase this item.
If you are not happy with this for any reason with 30 days of purchase, please contact me about a refund.
This is not related to the Shopsmith company or any Shopsmith authorized retailer in any way. And probably would not be recommended for use by Shopsmith.