Proth surface grinder- Coolant Unit fan function?

I have brought a 1983 model Proth (Taiwanese, similar to Chevalier) surface grinder back into operation after a break of 24 years.

I'm unsure of the purpose of the 2hp fan unit atop the left end of the coolant tank unit. There is a mesh basket (inside the side door) directly below the black return pipe from the grinder. A mesh screen, not in the path of coolant, is fitted between basket area and fan. Is the fan merely for cooling the coolant? I set it up so that it exhausts through the wall to avoid air blowing grit around the room.

I was going to fit a rubber seal in the gap where the fan outlet meets the PVC pipe, but in its current open state, it works like a venturi, drawing air in and expelling it outside. This might be helpful when grinding cast iron dry - to reduce iron dust floating in the air?

-Brian McKenzie

" I'm unsure of the purpose of the 2hp fan unit atop the left end of the coolant tank unit. "

That is the mist collection fan. There should be a 2 to 3 inch diameter vacuum hose connecting the fan inlet to the grinding wheel housing outlet fitting. The fitting is a short length of vertical pipe at the top of the wheel housing. There may be a adjustable plate inside the wheel housing that directs the wheel spray to the outlet pipe. The mist is a mix of dust and coolant. The coolant condenses in the fan housing and drips down into the sump. There is a second hose that connects the table drain to the sump. It looks like you have the table drain hose sitting inside the fan inlet port. The fan outlet should have a leak free connection to the pvc outside vent pipe. You do not want to breath the mist or have it settle on the other machines in the area.

Robert

Back then coolants were oil based and stunk. Maybe it was a vent fan like you have in the bathroom if you need it?

Thanks Robert,

It's all making perfect sense - now that I have further compared your description with what I have here. No scoop, nor vacuum hose came with the machine so I'll cobble something up. The machine has a cast lug on the left side of the wheel housing for mounting same.

I looked online for images showing something similar: http://i.ebayimg.com/images/i/331757621875-0-1/s-l1000.jpg is a close approximation to the Proth grinder. Some smaller parts look identical.

The original weak mag chuck was choked up internally and discarded. There was also corrosion between it and the cast table top. I struggled initially to finish grind the iron table flat before any slight temperature change got in the way. Resorted to grinding wet finally.

Instructions with the new chuck said to grind its underside first - with it not clamped to machine table. I can see why now, as there was minor uneveness, with hollows around screw locations etc. presumably as the steel had relaxed from time of the manufacturers original finish grind.

Thanks for responding.
Brian McKenzie