Radius grinding machine ideas!

[Gary Huston]

Ok, so I need to pick the collective brains of you guys. I make some machine accessories that need to have a radius ground on them. Currently I use a modified cylinder grinder that has the main motor disabled and used as a centre. The radius is roughly 4 inches long but only a partial radius. The part has a base plate welded to it so the part can’t be totally revolved and prohibits anything revolving completely around. I could carry on using the current machine but it’s a two hour round trip for half an hours work. I really want to try and make something so I can do it all in house, preferably desk top sized. I attach some photos which will hopefully make it more obvious. The yellow line is how far the grind needs to go and the yellow hole is the pivot point. The radius needs to be pretty accurate as another plate runs over it making the slot at the top fluid tight. It’s not watertight but needs to keep liquid plastic at 180 degrees in! If anyone can suggest a machine I can build from readily available parts or a machine I can cannibalise I would be grateful. i would prefer something using a grinding wheel rather than a belt as I think a wheel would be more accurate. I only have a hobby mill and lathe but have access to most machines.

[Carnel]

Often choosing the right sequence in making the parts of a device simplifies such a problem. Is it possible to first make the cilindrical part with the required specs and afterwards join (weld) the flat parts to it?

[Gary Huston]

Often choosing the right sequence in making the parts of a device simplifies such a problem. Is it possible to first make the cilindrical part with the required specs and afterwards join (weld) the flat parts to it?

No because welding on the base plate can cause it to warp. Even if i could do it that way round i'm still stuck with the same problem of how to grind the radius.

[JoeH]

Seems like if you could set up something that uses a small diameter wheel it would be easier to build a fixture to rotate your assembly while also enabling you to slide the part along lengthwise.

[Gary Huston]

Seems like if you could set up something that uses a small diameter wheel it would be easier to build a fixture to rotate your assembly while also enabling you to slide the part along lengthwise.

That’s the sort of thing I’m aiming for although the setup I use at present uses 8” discs and it works better when the discs are new than worn smaller. This is it with the discs almost shot..