Projects 4

Surface Grinder

I came up with this idea so I could sharpen my planer knives but it will come in handy for lots
more. I can resurface 123 blocks, parallels, angle plates, V-blocks, etc. I used an angle grinder
that I had laying around and made a mounting bracket that mates to the engraver attachment
bracket I made before. I couldn't find any 4in. diameter 1/2 in. thick grinding wheels anywhere,
so I made it accept 6 x 1/2 standard wheels. The max RPM for these is around 4400. I needed
to check the RPM of the grinder so I used a Digital Laser Photo Tachometer I found at a store
on Ebay. It checked out at 10,600 RPM. This required a modification to slow it down. I pirated
a speed control from an old router and it took it down to 3600 RPM. Later I came across a
variable router speed control at Harbor Freight that would have been easier. I've seen it on sale
for as little as $9.99. Using an old angle grinder came back to bite me, the bearings in it were in
bad shape. The original was metric, so I made a new drive shaft to accept a larger heavier duty
'English' bearing, and it was cheaper too. I changed the threads on the shaft to 1/2-13 too so
it will fit a bigger range of wheels. I hold the work with a 6x12 magnetic chuck from Harbor
Freight. They have a cheaper 8x4 mag chuck that would be a better fit on the X2. The perfect
size I think would be this 5x10 chuck from Wholesale tool.