Machsupport Forum
Mach Discussion => VB and the development of wizards => Topic started by: BR549 on June 26, 2012, 01:08:29 AM
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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
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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
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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
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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
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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
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Looking VERY NICE, TERRY!!!
IF, it is available, I want a copy!!! Love the work, simple and to the point.
Scott
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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
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Nice work, Terry!
By the way, may I ask why CNC? Isn't hydraulic much faster, quieter and simpler?
Dan
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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?
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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
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I call those my 'Jetson' switches . . LOL!!
Radio Shack. . . . .
They are rated for some stupidly high current like 50 amps or some such nonsense. Being 'Shack items, you would likely never get anywhere near that without fireworks, but I'm switching a few ma at 5V, so I figure they might last a while.
Objective was to get the physically biggest switches that I could find so they would be easy to see and operate with gloves on. Placement on the panel was also driven by that requisite. If you need to shut it off in a hurry, any wild swat at the box will most likely get it done.
No, I did not know I was being watched . . . creepy . . . LOL! Have you seen the latest . . . first narrated video. Second 'by request' tutorial style. A bit on the basic side your your level , but you might still drool over the hard tapping . . .
http://www.youtube.com/watch?v=Cu61oBY5-rw&list=UU_rIw6ghqt7MQc6v0jGpf-g&index=1&feature=plcp (http://www.youtube.com/watch?v=Cu61oBY5-rw&list=UU_rIw6ghqt7MQc6v0jGpf-g&index=1&feature=plcp)
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Yes I saw that VIDEO Nice.
NOPE no drooling here Rigid tapped with Mach3 and servo drive Spindle Many YEARS ago in early testing of mach3 (;-). Where do you think Swapaxis / Unswapaxis came from (;-)
So the little switch BOOTY came with the switch? Or was that seperate
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Yes I saw that VIDEO Nice.
NOPE no drooling here Rigid tapped with Mach3 and servo drive Spindle Many YEARS ago in early testing of mach3 (;-). Where do you think Swapaxis / Unswapaxis came from (;-)
Not a problem . . I am drooling enough for both of us. I despise tapping. I have Tapmatic heads and I have built custom floating tap holders. Result; I despise tapping.
Hard tapping is the tip of the iceburg. But it will pay big cash dividends in my case, and that feature alone would make the effort worth while so for the moment, I am enjoying being impaled upon that feature . . . . . however, there are bigger plans afoot.
Swapaxis was a Godsend (a Hoodsend, actually) to my initial work on he 'mini machining center'. I no longer use it for that, but it is useful for quickly placing arcs in planes other than XY.
If is was developed specifically for servo driven spindles, I would have to wonder if it would not have been simpler to just make code to run a rotary axis continuously. Swapping only the step/dir signals and not the rest of the params is problematic.
That said . . I was most happy to have it at the time.
So the little switch BOOTY came with the switch? Or was that seperate
Comes with
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Y0ur Project is LOOKIN GOOD (;-)
(;-) TP
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can you send me a copy to: jerryscncmachining@gmail.com
thankyou it will be greatly appricated. Jerry Carmack
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BR; check out the new 4th axis spindle. It is tagged onto the end of the 'mini machining center thread . . . I think it is in a 'projects' category or something like that
jerry57; I do not know if you are talking to me or someone else. If to me, then what is it you want? If not to me then . . . never mind . . .
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So, how far did this project get? I have a Jet 6x18 surface grinder I'd like to at least automate the xy motions on, can't see why z couldn't be automated as well. Just searching for ideas at this point.
Marty
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did this ever get completed? I am interested
Thanks
David M.
San jose, CA
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did this ever get completed?
Not that I recall,
RICH
The wizard was completed and is used by an OEM for their grinders.
Thus you will not find anything on it nor is it available for public use.
MODIFIED 11/20/16 by RICH