Mirror polishing machine

[Ajohn]

Some people use a piece of hardwood with a slot in it plus bolt, penny washer and wing nut for the removable location. I've also seen 3 long ones being used for small mirrors on larger tables.

I've not done any very thin blanks but one idea of getting rid of any uneven surface on the table is to cover it with several layers of wet news paper. This wont help with astig due to table wobble.

I've used the same sort of idea to make it a bit easier to clean up when changing grits during ginding, dry though as the blanks have been fairly thick. Polythene may be way way better for that.

John

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[Astrobits]

Personally I don't like the slotted wood and bolt approach as there are holes and grooves in that setup that can trap abrasive particles while the simple wedge is much easier to clean.

Nigel

[JRM]

Hi guys,

I will use the block and a small wedge for now on the 20, but do intend to use the slotted setup in future for smaller glass.

Rick M

[JRM]

Just an update for those following this thread,

The machine works great, I have used it for an hour and a half so far with no issues, nice and smooth rotations well using the 10"

pitch lap.

The only issue I guess you could say is when the session is done and the turntable is stopped it looks like it is still turning, vertigo

they call it but it's a weird feeling.

thanks for following along, hope you enjoyed, any questions feel free to ask.

Rick M

[JRM]

Hi All,

 After a couple hours work I had noticed the turntable was getting rough in its cycles so to speak and realized the wheels under it

were creating a groove in the plywood and where they run over the grain was causing the issues.

The remedy was to get a disk cut out of sheet metal and i attached it under the turntable for the wheels to run on, problem

solved, cycles smooth as butter now, so for future references if you plan a wooden turntable don't forget a metal track for the wheels

to run on.

Rick M

 

[Astrobits]

I had about a dozen wheels under my mirror table and had no problems over several years of use. Perhaps it was just too much load on your three wheels that did the damage.

Nigel

[JRM]

Hi Nigel,

 Not enough wheels for the weight appears to have been the problem, also my wheels are not flat, they curve up towards the center.

I will get 5 or 6 flat surface wheels and place them under the turntable in the near future because I doubt the three wills will handle the

weight for long. lesson learned.

Thanks

Rick M