Author Topic: Laping my Granite surface plate.  (Read 463 times)

Offline mattinker

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Laping my Granite surface plate.
« on: February 04, 2018, 08:29:02 PM »
As the title indicates, laping my 3' square Granite Surface plate.

Regards, Matthew


Offline sparky961

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Re: Laping my Granite surface plate.
« Reply #1 on: February 04, 2018, 10:02:09 PM »
Good effort, but the additional audio (radio or TV in the background) made it very hard to pay attention to what you were saying.

Offline mattinker

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Re: Laping my Granite surface plate.
« Reply #2 on: February 05, 2018, 04:29:45 AM »
Good effort, but the additional audio (radio or TV in the background) made it very hard to pay attention to what you were saying.

You are quiet right, I have the habit of having the radio on when in the workshop! I realised this too late to re-record. I've been looking into doing "voice over" but I still haven't got it worked out yet.

Regards, Matthew

Offline PekkaNF

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Re: Laping my Granite surface plate.
« Reply #3 on: February 05, 2018, 09:34:21 AM »
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 wotking on grinder guard to make the parts for repeatometerkind of tool.

You probably said, but how coarse diamond dust did you use?

Thank you,
Pekka

Offline mattinker

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Re: Laping my Granite surface plate.
« Reply #4 on: February 05, 2018, 10:28:37 AM »


You probably said, but how coarse diamond dust did you use?

Thank you,
Pekka

Pekka,

Thank you. I did say it, the diamond flour that I used was 45 to 54. I am waiting for the weather to warm up before the final lap and maybe finish with a finer diamond flour. Rob Renzetie has started on a laping seriesfor his 3' x 4' plate. So far he's built the stand/cabinet.

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

Regards, Matthew

Offline PekkaNF

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Re: Laping my Granite surface plate.
« Reply #5 on: February 06, 2018, 04:07:11 AM »
I got bit work than I can do.

And my repeatometer is waiting surface grinder to finish. I though that I had it almost ready and then bearings started to makse noice. That one is fixed. original guards and dust removal was a bit ligh. I'm building new one. Got 50% of guard parts welded together. Hope it is smooth sailing from there.

RE. The diamond dust...you use normal ebay stuff? I'm going to order some. Do you recommend just that one grade or finer too. I think my granite plate shows same magnitude dips than yours.

The brake rotor was only thing I could think of reasonable size/flat/material/cost that I could come up as a lap.

They are about 20 per piece when sourced from autoshop....I checked few old ones. Old are rusty/wonky/hard and not worth the effort IMHO. Something happens them when used.

Pekka

Offline krv3000

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Re: Laping my Granite surface plate.
« Reply #6 on: February 06, 2018, 04:21:01 PM »
a job well dun  :clap: