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Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Sun Jan 09, 2022 2:46 pm
by suntravel
cncsnw wrote: Sun Jan 09, 2022 1:57 pm On the other hand, a person who know what the cam profile is supposed to be, and is moderately proficient with a spreadsheet, ought to be able to cook up their own CNC codes without requiring any CAD software at all.

Isn't it is just a long list of points, with X coordinates varying through a succession of C angles?
Yes it is

Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Mon Jan 10, 2022 10:04 am
by vw_chuck
I see like everything it is never easy. Yes I may be easier to just code this by hand.

Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Thu Jan 13, 2022 12:03 pm
by firebrick43
suntravel wrote: Sun Jan 09, 2022 1:09 am Setting up the spindle as C-axis with the grinder on X should work. If the center of the grinding spindle is on the same height with the C-axis change in diameter of the grinding wheel will not change the cam profiles, only the size which could be easy dialed in after dressing the wheel.


Uwe
A cam can not be on the center of the wheel during the lift portion/closing portion, its geometrically impossible.

Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Thu Jan 13, 2022 5:52 pm
by suntravel
firebrick43 wrote: Thu Jan 13, 2022 12:03 pm
suntravel wrote: Sun Jan 09, 2022 1:09 am Setting up the spindle as C-axis with the grinder on X should work. If the center of the grinding spindle is on the same height with the C-axis change in diameter of the grinding wheel will not change the cam profiles, only the size which could be easy dialed in after dressing the wheel.


Uwe
A cam can not be on the center of the wheel during the lift portion/closing portion, its geometrically impossible.
Have a look at the drawings here:

http://www.metallmodellbau.de/Nockenwel ... schine.php

Uwe

Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Fri Jan 14, 2022 2:30 pm
by vw_chuck
Uwe that is a crazy machine. Serious amount of time went into it. I was also thinking just making a replicator machine like yours but with another wheel the same size as the grinding wheel that follows the original camshaft lobe. No idea if it would work or not. Thanks for the link.

Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Fri Jan 14, 2022 4:50 pm
by suntravel
Here one of the best old engine engeneering books, but sorry also only in German:

http://www.eurospares.com/graphics/engine/Apfelbeck.pdf

Alone the drawings could be helpful to build your own camgrinder, ore something to scan the coordinates for CNC.

Uwe

Re: Acorn for DIY CNC cam grinder on CNC lathe

Posted: Wed Jan 19, 2022 11:06 am
by firebrick43
Found my WOPS manual. Here is a few good pictures showing how the lift portion of the cam is above/below the center line of the wheel and the second shows how wheel diameter changes as dressed changes the geometry of the cam unless there is a program (such as WOPS) that makes compensations for it.

https://photos.app.goo.gl/KdTxcThQQiTyLf1f9
https://photos.app.goo.gl/9H87bJDzxF6A6s3P7