Hi Ian,
First thanks for the favorable comment.
I am in the process of designing a truly Multi-Tool Rotary Platen. I have seen designs with a flat platen that tilts a certain amount. I have seen designs that have say a 2" and a 4 inch wheel that can be flipped. Some of these are just locked down with a nut or handle and could??? possibly rotate during operation which could???? be BAD NEWS. My design incorporates multiple tools on one tool bar with easy selection of available tools via an indexing plate and spring loaded tool locating and locking pin.
My design has a fixed plate that attaches to the 1 1/2" square solid aluminum bar and has holes drilled a different positions around a 360 degree arc. My design of the rotary platen tool plate will have a 4" wheel, 2" wheel, with a flat platen backing plate. It also has a small wheel attachment incorporated into the design that can accept various diameters of small contact rollers that are easily replaceable. The rotary platen can also be rotated to different positions for free belt operations and has position stops to accommodate many grinding needs. The platen also has a spring loaded locking pin to make sure that the rotary platen can't rotate once the appropriate roller or rollers are positioned to the front of the grinder. To change to a different position on the 360 degree arc you just loosen the center bolt tension, pull out the spring loaded pin and rotate and lock it to the next desired position on the 360 degree arc, retighten the center bolt nut/handle. I have been working on this idea for a month or so and I hope to cut the parts on my CNC machine by next week. To my knowledge this is the first such Multi-Tool Rotary Platen of this design. I believe it could be easily adaptable to most any DIY 2 X 72 Grinder. Just a matter of having the correct spacing to position the contact wheels so that they line up with the grinder drive wheel and idler pulley.
I have several items ordered for completion of this item and hope to have them all by next week. I will post some pictures as I progress through the machining, assembly and installation on my 2" X 72" grinder.
John