OK  Looking for input from anyone doing cnc surface grinding. There was a Fellow that contacted me a WHILE back but cleaning out the email I lost his info.

Surface grinding LOOKS simple enough BUT there is a great deal more to it than meets the eye. TO GET IT RIGHT.

I am at the starting point with the screen inputs.

(;-) TP

Have a small manual bench top grinder that is used infrequently and made by Sandford.
Can see accounting for wheel wear as a challenge which relates to bringing something to tolerance.
BTW, anyone can grind a surface parallel and flat,but to a tolerance ...that is a quest.

Seems you'll need some kind of Z DRO reset based on both wheel diameter ( maybe depends on how things are done) and Z height after dressing and also after so manny passes.
May be worthwhile having a work sequence defined before doing the remainder of the screen design.

Rough manual sequence below:
1.Dress wheel
2.Touch off wheel to surface high point
3.Amount of material to be removed is known
4.Do a number of passes
5.Check surface flatness and dimension.
6.Now have new amount of material to be removed (maybe call the above a rough grind)
7.Continue grinding, maybe redress wheel and if so need to touch off again (call this a fine grind)
8. Now go for surface finish and final dimension, so the passes increase and Z feed is less.

Note that in the above the wheel was never measured and is more or less "a go as you know" sequence.
There was only one or two postings on grinding posted in the last few years that I can recall.

FWIW,
RICH



RICH

One of the tricks is to do alternating passes not starting at the same side each time . This helps keep the Wheel Flat as with each pass it uses the opposite leading edge of the Wheel for equal wear.

AND that is a bear to track inside a Gcode file without conditional Gcode(;-).

I now have a working model. The bear was to get it to SEE where it is at and react at the start of each pass as to continue or adjust for the finish pass.

When I get that portion done THEN I will work on Trueing and setting WHeel Diameter(Zcorrection) It is fairly easy IF you test the wheel on the trueing device as when done the Zheight correction IS the truing device Height as it is always a fixed point in Z.

Got it very close BUT more testing needed.
 GEEs My head hurts now, (;-) TP

OK FINALLY got that one squared away. Geting the Cross Over grinding right was tricky. With cross over each loop is offset slightly so the edge of grind line do not match up so they overlap each other. that further helps with uneven wheel wear.

(;-) TP

Looking good and your spot on about the cross over....good work.
Will you be able to set the crossover or will it just be some % of the step over?
I know that my grinder has a lot of backlash in the X and Y  ......thinking that maybe BC  could be used and would
satisfy doing a surface. In general, similar considerations as a mill conversion would apply when  converting a manual surface grinder
to CNC.

RICH

Looking VERY NICE, TERRY!!!

IF, it is available, I want a copy!!! Love the work, simple and to the point.

Scott

Scott I have a touch of clean up to do on a couple of MISS matched buttons then I will send it too you. 

Thanks for all your help in the past, (;-) TP

Nice work, Terry!

By the way, may I ask why CNC? Isn't hydraulic much faster, quieter and simpler?

Dan

BR,

Are you programming for a client or is this your own conversion? If the latter, how are you driving the table? I will be building a surface grinder hopefully sometime later this year and would appreciate any tips and tricks.

It appears you have a feed rate of 10. Just from observation, it seems to me the automatic surface grinders move a lot faster than that. Again IF you did this conversion, what was your max table speed target?

HIYA SImpson , Have not CNCed the grinder yet even thought there is one sitting in the shop(;-).  Just worked on the screenset to make sure I can make Mach3 do what needs to be done program wise to drive it correctly.

Question for you . Where did you get the small flexable dust sheids you used on the switches foryour 4th axis control panel ? They would work well on the new hand pendant for the plasma table. that Micro metalic  plasma dust is a killer for hand pendants(;-)

Bet you didn't think we were keeping tabs on Ya did you ?

(;-) TP