- Joined
- Dec 30, 2018
- Messages
- 73
A week ago I decided I needed something to get a flat uniform finish on some steel parts. Something like a surface grinder. Everything is closed during the lockdown so I was stuck with what I had on hand.
After three revisions this is what I ended up with:
I think the design is pretty self explanatory:
The grinder sits on a thick piece of pvc which hinges on another piece of PVC which is epoxied to the marble block. The marble block has felt feet.
Height adjustment is done using the large allen key. The small bolt locks the larger one in place. If I need more clearance, I place blocks under the large bolt.
Grinding procedure: I spray the slab with some Q20 and then clamp the part in my Grinding Vise. Then manually slide the part underneath the wheel.
Evaluation:
It works better than I expected. I get a perfectly flat (for my purposes) finish with ease. I can lower the wheel in incredibly small increments.
As a test I put a .04 mm (0.0015 inch) feeler gauge between a piece of steel I was grinding and the wheel, with the wheel just touching the feeler gauge.
Removed the gauge - after three small adjustments on the large allen key the wheel touched the steel.
Vibrations are quite manageable. I removed the crumbly crap from the center of the grinding wheel and filled the hole with pratley putty. Then drilled the hole in the CENTER of the disk and finished it with a boring bar.
For the sides, two acetal discs were used to get the wheel perpendicular to the axis.
Still to do:
After three revisions this is what I ended up with:
I think the design is pretty self explanatory:
The grinder sits on a thick piece of pvc which hinges on another piece of PVC which is epoxied to the marble block. The marble block has felt feet.
Height adjustment is done using the large allen key. The small bolt locks the larger one in place. If I need more clearance, I place blocks under the large bolt.
Grinding procedure: I spray the slab with some Q20 and then clamp the part in my Grinding Vise. Then manually slide the part underneath the wheel.
Evaluation:
It works better than I expected. I get a perfectly flat (for my purposes) finish with ease. I can lower the wheel in incredibly small increments.
As a test I put a .04 mm (0.0015 inch) feeler gauge between a piece of steel I was grinding and the wheel, with the wheel just touching the feeler gauge.
Removed the gauge - after three small adjustments on the large allen key the wheel touched the steel.
Vibrations are quite manageable. I removed the crumbly crap from the center of the grinding wheel and filled the hole with pratley putty. Then drilled the hole in the CENTER of the disk and finished it with a boring bar.
For the sides, two acetal discs were used to get the wheel perpendicular to the axis.
Still to do:
- Create a parallellogram structure to ensure grind lines are parallel. Difficult to do freehand.
- Get a better way of dressing the wheel - my homemade tool : a set of washers on a steel rod works, but it's difficult to get the thing as level as I want.
- Learn to keep knuckles away from wheel.
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