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Would you pay $760 for a new lapping plate?

Mechanola

Stainless
Joined
Mar 21, 2011
Location
Äsch
Friends, I have more and more onesies to do with critical parts of movie cameras. Aperture plates, the part of the film gate behind which the film gets exposed, intermediate parts, lens mounts, ground glasses, ground focusing prisms. Be it that a prism surface become finer or the contrary, be it that a lens turret should be made flat on the back side.

For that I need a lapping plate or disc. Looking out I am finding a few dealers, even OEM, that ask prices such as CHF 760, about even with the US Dollar. 150 mm diameter, 15 mm thick, cast iron, grooves grid. I mean, what? A piece of iron, grooves milled, lapped flat on a machine in a quarter hour? Can anybody help me understand what is going on? I can’t afford such madness.
 
They don't sell many and they need to make a living and stay in business. Also, large businesses often buy from trusted suppliers without bothering to actually check the price - it's irrelevant in the big picture. I make my own lapping plates from Durabar. They cost me basically the price of the cast iron.
 
I wouldn't here in the USA...however you all voted in $25 dollar minimumm wage.....

So you need to pay the piper.
 
The price is not irrelevant to me. What big picture? Am I Picasso?

Not all cantons have introduced minimum wages. If I reckon with the suggested $25, about 28 hours of paid labour would be contained. Come on!
 
Mechanola,
Tom Lipton, who has written several popular books on machining has a YouTube channel called "Oxtoolco". He has done a 4 part series on making lapping plates from scratch. I think that you might find these videos very helpful. Here is the link to the first one in the series:
Making flat lapping plates 1 - YouTube

This is a real professional doing professional quality work, not a home experimenter.

Hope it helps!
Cheers,
Michael
 
I don't know the OP's needs, but those stones won't be flat to any super tolerance, which is what you're paying with a proper lapping plate......that and its made in Switzerland :)

No not as flat as a true lapping plate but that said I have been able to get things flatter than I can machine flat with them.
 
150 mm diameter, 15 mm thick, cast iron, grooves grid. I mean, what? A piece of iron, grooves milled, lapped flat on a machine in a quarter hour? Can anybody help me understand what is going on? I can’t afford such madness.

Surely you can. There are no problems, only opportunities.

Make the one you need and three more. Keep a spare. Sell the other two at a price that undercuts their price. Make it cheap ENOUGH, I'd buy one from you meself.

I'm too damned lazy to make one AND too "cheap" to pay good coin for something I have the right sort of scrap to JF make. If I weren't lazy, of course.

"Catch 22", that last part can be...

:)
 
Mechanola,
Tom Lipton, who has written several popular books on machining has a YouTube channel called "Oxtoolco". He has done a 4 part series on making lapping plates from scratch. I think that you might find these videos very helpful. Here is the link to the first one in the series:
Making flat lapping plates 1 - YouTube

This is a real professional doing professional quality work, not a home experimenter.

Hope it helps!
Cheers,
Michael

Excellent craftsmanship but generating flats of that size can be done in minutes through a different method and completely automatic. I'd have to live in a cardboard box otherwise.
 
Thanks to all of you. After some thinking I have come to the conclusion that I should buy a lapping machine and make my plates on that. I could then proceed to sell plates at low prices in order to destroy the competitors. Then I would be the king of lapping plates and after some time I would have to ask about the same prices as they’re now because as the king I want to live in luxury.

I shall find something that fits my purse. Again, thank you all
Although our information is false, we do not guaranteey
 
Then I would be the king of lapping plates and after some time I would have to ask about the same prices as they’re now because as the king I want to live in luxury.

Just remember that "Uneasy lies the head that wears a cast iron crown". Your court jester will plot against you, the Queen will be seeing a bauxite mine owner on the side, and the Crown Prince just got in an order of mercury and lead. Beware!
 
Last edited:
Thanks to all of you. After some thinking I have come to the conclusion that I should buy a lapping machine and make my plates on that. I could then proceed to sell plates at low prices in order to destroy the competitors. Then I would be the king of lapping plates and after some time I would have to ask about the same prices as they’re now because as the king I want to live in luxury.

I shall find something that fits my purse. Again, thank you all
Although our information is false, we do not guaranteey

There isn't a big demand for lapping plates. Them who use 'em often know how to make 'em. And you'll also need a decent saw, a sturdy lathe and depending on the grooving, a shaper comes in handy.
 
I understand the OP.
But
1. is smooth,
2. is flat locally,
3. is flat overall.
4. is inspected, realistically, with a guarantee and test certs from the maker.
 
How flat do you have to be? A granite plate and some fine grit sandpaper works for me in a pinch

Umm.. he dasn't need a very large one, so ...hand-selecting stone door or window sills by comparing the light reflections used to serve me rather well, too.

Cheap as mass-market granite/gabro surface plates can be, brand-new, let alone how many old ones have salvageable zones?

Or unfinished CI chuck backplates at only around $60 each, or CI angle plates at even less?

Can't see building much of a "kingdom" off the back of from-scratch Cast Iron ones..
 
Excellent craftsmanship but generating flats of that size can be done in minutes through a different method and completely automatic. I'd have to live in a cardboard box otherwise.

Do you be so kind to share your much faster method. Thinking of making a few myself.

Thanks
 








 
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