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View Full Version : looking for scraping guidance. Repost (Pinging Forest Addy)



AlexK
04-29-2010, 06:33 PM
I have new Chinese 12x36 lathe. The cross slide binds at a certain position.
I took the crossslide apart.
The tapered gib was roughly machined and not flat. I have lapped it and it is perfectly flat now but dovetail recess where taper gib goes is not flat ether. You can feel gib rocking.

Looks like I need to learn scraping.
I have ordered Connelly's "Machine Tool Reconditioning" book and Michael Morgan "Basic Hand Scraping" DVD.

What tools do you recommend for hand scraping?

Any advise is appreciated,
Alex

AlexK
04-29-2010, 06:35 PM
Almost forgot.. I have a surface grinder. Is there any way I can use it in the process of "truing" the cross slide?

NzOldun
04-29-2010, 09:18 PM
I have new Chinese 12x36 lathe. The cross slide binds at a certain position.
I took the crossslide apart.
The tapered gib was roughly machined and not flat. I have lapped it and it is perfectly flat now but dovetail recess where taper gib goes is not flat ether. You can feel gib rocking.

Looks like I need to learn scraping.
I have ordered Connelly's "Machine Tool Reconditioning" book and Michael Morgan "Basic Hand Scraping" DVD.

What tools do you recommend for hand scraping?

Any advise is appreciated,
Alex

Get an old (Scrap) parallel faced, parallel side file. Grind off the remaining teeth towards the bottom end, sides and edges. Grind across the end to a slight curvature and also so that the two edges on the end of the faces are at about 100-105 degrees to the faces, producing a slight 'V' ridge in the middle of the end, right across the end. Harden the end to white hard! Hone the faces and ends so that you have a razor sharp edge on the two bottom edges of the file. Happy scraping!

You will need to periodically re-hone the edges, as they become dull. If you can see light reflected off the two cutting edges - they're dull!

Cheap and easy start point. Better than carbide because you can get a razor edge.