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newbie getting started
« on: December 03, 2007, 10:53:48 AM »
Trying to find a good setup to build a 3axis machine.

what is the gecko g100? 

Is there a good cnc all in one package ready for purchase because I don't know much about the controlers and other hardware.  Is there a good basic 3 axis package that works good with mach 3? 

Any help is greatly appreciated! ???
Re: newbie getting started
« Reply #1 on: December 03, 2007, 01:17:20 PM »
I just purchased a control unit from Mike Beck, havent received it yet, but its complete with motors.
 http://mikebeck.org/

Ron
Re: newbie getting started
« Reply #2 on: December 03, 2007, 02:34:35 PM »
are there any drives, controls or servo motors that are not compatable or more compatable with mach 3?  Are gecko drives good? I am looking to hold some accurate profiles (.0002" over 1") for a grinding machine. I can't seem to find good newbie info. ::)
Re: newbie getting started
« Reply #3 on: December 04, 2007, 06:40:06 PM »
well, here is what I ordered:

 
Qty Description Unit Price Amount
1 Mach3 cnc controller   
2 G320 Geckdriver
2 KL34-170-90 DC Servo Motor
2 US Digital: E5S-500-250-EG-PKG2
1 KL-7220, 72V, 20A
1 C11 - Multifunction breakout board

2 questions:

1 the encoders have 500 CPR.  What can I expect for accuracy with a .200" lead ball screw?

2 What should I use for a spindle motor to push a 14" dia grinding wheel?

Any suggestions?

Offline Hood

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Re: newbie getting started
« Reply #4 on: December 04, 2007, 06:55:08 PM »
Cant answer your question about the spindle I am afraid but the resolution one is :-
You have 0.200 lead screw so that is 5 turns to move an inch, your encoder is 500CPR which equates to 500 x 4 =2000 quadrature. So 5 turns x 2000 pulses =10,000 pulses per inch so  1/10,000 gives you a resolution of 0.0001inch.

Hood
Re: newbie getting started
« Reply #5 on: December 04, 2007, 07:24:36 PM »
Ok, so i am a little lost on how you got the 500 x 4 part .  I was thinking .2" devided by 500 CPR (lead dist / CPR )  What I am doing wrong Hood?

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Re: newbie getting started
« Reply #6 on: December 04, 2007, 07:40:53 PM »
The CPR is the line count but Mach uses Quadrature which is 4x the line count. Mach is using the rising and falling of each of the square waves and because you have channel A and B that is 2 rising and 2 falling so a line count of 500 is actually 2000 (500 x 4) as far as Mach is concerned.
Hood
Re: newbie getting started
« Reply #7 on: December 04, 2007, 07:44:47 PM »
Thanks hood!

Not to beat a dead horse but if I have good ball screws and no backlash your saying I can count on accurate positioning within about .0001"?  sounds too good!

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Re: newbie getting started
« Reply #8 on: December 04, 2007, 07:46:33 PM »
if it was an ideal world and everything was backlash and flex free then yes.
Hood