Messages

5411

General Mach Discussion / Re: Running back to limit switches with G28

« on: August 08, 2011, 09:58:51 PM »

First you set up the limited switch to be a Zhome as well as the Zlimit. Set the Zhome in pins and ports to the SAME pins and port as the Z+limit. Don't wory MACH will know the difference.

Now when you want to RefHome Z issue a G28.1 Z0.000.  The Z will Retract back to the switch then back off the switch and reset Zhome to Zero.  Make sure that you set up Zhome to Zero itself it is in the Setup section where you set teh pins and port.

NOW a note. IF you use the Zhome as a refernce you WILL have to Refhome when you first start up the machine. Tht way each time you rereference home it will allow the" WORK "home to be the Same point.

IF you do not refhome on start up AND set up the board to cut and set your Work home 0,0,0 to the part when you do the Zrefhome at midpoint your Work Z0 point may not be the same.

The refhome tells MACH where it is in 3d space in relation to your machine. IF you do not do a physical Refhome at startup then MACH will assume Machine Zero to be at the location where it currently sits.

You do NOT have to refhome MACH for it to work correctly ONLY to insure it knows where it is at a SET relation to the TABLE where your part is attached.  If Mach sets "itself" on startup up then YOU refhome at midpoint then MACH will NOT remember where your part was when you started. It will go to where it thinks it is NOW.

Clear as Mudd ??

IF you list what you have tried to fix the lost steps maybe someone here has the solution to the problem.

Does the value ALWAY stay the same no matter how big the program is?
Does it do it WITH the SPINDLE off and run the program?


 (;-) TP

5412

General Mach Discussion / Re: Running back to limit switches with G28

« on: August 08, 2011, 09:23:33 PM »

G28 only "moves" to the Home position as defined in config. Usually Z0.0000 IF you want to RefHome (send it to the home switch and back off then reset Zhome) the Z then use G28.1.

You need to FIX the lost Z steps problem not try to MASK it . Masking will only work IF you know where the break even point will be in the Gcode before it gets out of hand. That in reality could be ANYWHERE. SO how would you know it is time to refhome again???

Just a thought, (;-)

5413

G-Code, CAD, and CAM discussions / Re: G40, G41 and G42 have no effect.

« on: August 08, 2011, 09:14:39 PM »

As Rich said please post the DXF of the part your need. One of us will figure it out. 

(;-) TP

5414

General Mach Discussion / Re: Most Recommended USB Controller

« on: August 07, 2011, 06:47:46 PM »

Ray everyone I talked to said it was great.

BUT I would suggest suggest you call TOM at Kflop and discuss with him your needs. He is a very knowledgeable STRAIGHT shooter. I hear they have rigid tapping running with it as well .

BUT I am not sure whether that is with servo mode OR encoder VFD mode.  It does support a spindle encoder. But it would have to support electronic gearing to do it encoder/VFD mode.



(;-) TP

5415

General Mach Discussion / Re: Most Recommended USB Controller

« on: August 07, 2011, 12:31:59 PM »

Ray you would really like the Kflop you can run it either way. Gcode, C, VB ,etc A programmers pair of dice (;-)

(;-0 TP

5416

General Mach Discussion / Re: Wireless Xbox controller cautionary tale

« on: August 07, 2011, 12:42:33 AM »

Out of curiousity have any of yous guys tried the Keyboard adapter for the Xbox controller??

(;-) TP

5417

General Mach Discussion / Re: Axis stay short of where they should go

« on: August 06, 2011, 10:42:01 PM »

OK do you have any info on the Axis drives such as steppers?, micro stepping drives? , gear reduction?, turns per inch on the screws, is it rack and pinion?

 What are the  settings you are using  now?

The Calibration routine will work but you have to keep refining the settings until it is perfect.Most times it is NOT always a one shot deal.

Run the routine let it setup the settings then measure the error and adjust the settings by the % of error. Then measure it again repeat if needed.

ALWAYS move in the same direction to measure AFTER you take up any slack(backlash in the axis) That will eliminate backlash in your measurement.

  Calipers will work just fine. Just be consistant on how you measure it. NOTE: some low end digital  calipers are only accurate to +/- .005.

(;-) TP

5418

General Mach Discussion / Re: Axis stay short of where they should go

« on: August 06, 2011, 09:06:51 PM »

First you need to recalculate the steps per unit to get that part correct so it moves the correct distance per command.

(;-) TP

5419

General Mach Discussion / Re: Axis stay short of where they should go

« on: August 06, 2011, 07:22:26 PM »

The  way To calculate back lash is to set up a dial indicator against the Spindle or tool in the spindle  using step jog set for.001 steps back the axis up until you see the dial indicator move a full .001"( Take the slack out of the movement). Then single step it in the opposite direction dirction unitl you see it move .001" again in the opposite direction. the amount of .001" steps is your backlash.

There are also some settings for backlash you may want to read up on such as Shuttlespeed tha can effect your backlash corrections.

(;-) TP

5420

General Mach Discussion / Re: Axis stay short of where they should go

« on: August 06, 2011, 06:05:18 PM »

Like I said your steps per unit where not perfect to begin with(;-) DID you fix that problem?

How did you measure the backlash?

(;-) TP