This coupler is for a standard shopsmith that has a drive hub with 4 grooves and  the accessory hub has 5 grooves.

New in February of 2024, this item is now injection molded, providing a superior product with better strength characteristics and more consistent fit and finish. Color may vary from photo.

This power coupler set allows a custom coupling length, as short as 2.6 inches to as long as 38 inches, the standard coupler is 5 inches long. These parts are molded, using a glass filled polypropylene material. 3/4 inch PVC pipe may be cut to desired length. 

Bonding of the coupler is best using a high strength epoxy such a JB Weld "steel", prepping the pipe and coupler by scuffing the bond surfaces using 80 to 220 grit sandpaper and applying epoxy to both the pipe and coupler ends before joining will result in the highest strength bond.  A better quality super glue (cyanoacrylic adhesive) could work as well, I tried harbor freight "gel" and it wasn't as strong as epoxy.  PVC will work but the bond strength isn't great.  My strength testing showed the bond joints breaking first, leaving the coupler and pipe undamaged.

I am bringing back a PVC pipe version because some customers liked it over the wood dowel version. I developed a new molded design because some of my customers were able to break the 3D printed coupler during their ordinary use.  The ABS 3D printed design was usually okay but some accessories and uses could cause issues with more hardcore user. 

The belt sander accessory is the hardest on my 3D printed couplers.   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  couplers have good static torque strength, they did 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.  The new molded design should hold up far better to misalignment due to the glass filler in the resin.

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 wasn't, however my new molded coupler might be indestructable. 

The following YouTube video shows the adaptable coupler running over the range of speeds and shows that a shorter wood dowel should be used when running at the high RPM's of a joiner or planer.

https://www.youtube.com/watch?v=hEg36ctsjWc

(if the link doesn't work search for: power couplers in use )

Rather than buying dowel, the user could also rip his own 3/4 inch square wood dowel stock as well. Wood dowel at Lowe's or Home Depot < $4 for a 36 inch long dowel. Use of a soft knot free pine is recommended rather than a higher strength wood like oak or hickory.

I am liable only to the extent of the purchase price of this part. Use at your own risk. There is inherent risk using any Shopsmith equipment, loads, imbalance, speeds, feeds, 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 item for any reason within 30 days of purchasing contact me for details on getting a refund.

This power coupler is not related to the shopsmith company or any authorized retailer of shopsmith equipment in any way and would not be endorsed for use with shopsmith equipment.