Author Topic: Another granite surface plate lapping attempt  (Read 785 times)

Offline PekkaNF

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Another granite surface plate lapping attempt
« on: February 08, 2018, 01:56:53 PM »
This might be a long haul and I was not going to "publish" this project, because it will have many little tasks and not all of them will be very innovative or unique.

This is greatly inspired on Mathews thread:,12450.0.html

I find your videos very informative. I have same thing on my plan for the next summer.

I have worn Mahr 800*600 mm granite plate. Thinking of using that one to scrape disc brake rotor relatively flat, then sprincle that with diamond flour and lap the offending granite plate bit more flat.

Yesterday I was working on grinder guard to make the parts for repeatometerkind of tool.

Thank you,

I'm looking forward to seeing your brake disc lap!
Regards, Matthew

Last summer I almost made a try, got some diamond dust and started finding a appropriate lapping plate for granite lapping. I would not bother if I only had to lap one surface plate, but my long time intention is to make some measurement jigs and tools from granite.

I thought that cheapest semi ready lapping plate might be a car disc brake rotor. Bought one last summer and it got put away.

So I digged it out od storage yesterday and took it inside to warm up (it is unseasonaly warm here, -12C).

Blued and lapped 10 minutes today. Looks like a little more lapping and then it might be a starting point.

Offline mattinker

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Re: Another granite surface plate lapping attempt
« Reply #1 on: February 08, 2018, 03:57:07 PM »

regards, Matthew.