Messages

81

General Mach Discussion / Re: Stepper rregular or stalling in MDI or program run

« on: December 21, 2006, 10:59:17 PM »

Is the machine put together? Until you home the axis you jogging will not be at full speed. I believe there is a setting someplace to set a homed condition.

When you are going into MDI or running a program you are using a different feedrate than the default jog speed. Doing a g0 move will move at the max speed you have set in tuning. try using a g1 move and slowly increase the feedrate untill it stalls out on you, then back off your max velicity in the motor tuning dialog.

You also may need to modify your acceleration times. You may be accelerating too fast.

82

General Mach Discussion / Re: Bridgeport extrak retrofit

« on: December 21, 2006, 05:40:52 PM »

Servo. Big Servo! 12:40 ratio. 1/4" pitch ballscrew. 2500lpr encoder. Glentek Analog Servo Drive interfaced with a Skyko Pixie.

Ive got to do something about that ratio. It comes out to 133333 1/3 steps per inch. I wanted a 10 tooth but they dont make a 10 tooth L size timing belt pulley in anything wider than 1/2". I may jump to 16 or 20 tooth.

Heres my little project log with pics on cnczone:

http://www.cnczone.com/forums/showthread.php?t=28668

83

General Mach Discussion / Re: Bridgeport extrak retrofit

« on: December 21, 2006, 05:30:15 PM »

I have scales on X, Y and Z (Knee) on my supermax. My knee has an airassisted ballscrew to take some of the load off it. I can rapid the knee at 120ipm!

The only problem is that with the scales I have (Heidenhain 20um with 5x interpolator for a ultimate quad res of 1um) is I can easily go faster then the parallel port can read the scales in rapid. There are 25400 lines per inch with quadrature and that figures out to 10.5khz at 100ipm.

Dosent really matter to me though. I am just keeping the scales for when I use the machine manually.

84

General Mach Discussion / Re: max feed rate?

« on: December 21, 2006, 05:20:57 PM »

Yep. Get a faster computer.

Heck, I have seen P4s at goodwill!

Or Frys has some pretty good deals on no frills computers.

85

General Mach Discussion / Re: max feed rate?

« on: December 20, 2006, 02:47:24 PM »

How fast is your machine. My mill did the exact thing. Jogged just fine, but when I stuck in code it went all wonky at 45khz. I turned down to 35khz and ran perfect. I then changed the PC to a 2.4ghz p4 with 512m ram with a Lava dual PCI port card and it runs perfect at 45khz. My mill (Full size knee mill bit bigger than a Bridgeport) Now does full rapids at 180ipm X and 150 Y and runs the roadrunner file pretty darned fast. Before the new computer/card the fastest rapids I could get were 120 ipm each axis.

My feeling is it is a computer problem, not interference.

86

General Mach Discussion / Re: I'am new on your site......and a total beginner...

« on: December 18, 2006, 11:42:20 AM »

http://www.pmdx.com makes a pretty cool breakout board that snaps on top of up to 4 geckos. I think stepper only though. I used their pmdx-121 in the past and they have some nice stuff.

When it comes to building a router ebay can be your best friend.

87

General Mach Discussion / Re: Spindle timing/index

« on: December 15, 2006, 12:57:38 PM »

Thats not really going to work for me. I dont want to do any modifications to the head if I can get away with it. Plus I cant see anywhere to install something like that.

I went back to find where I saw something about using multiple marks in index mode and cant find it. Argh!

I guess I can give it a try and see what happens.

88

General Mach Discussion / Spindle timing/index

« on: December 14, 2006, 10:49:43 PM »

OK, I want to enable Mach3 to control my spindle on my mill using the feedback features. Right now I have speed control using one of cnc4pc's step/dir to 10v control boards. I also want to be able to stop the spindle at a certain spot so I can take advantage of the back face cycle. I plan on using two Keyence retrorefective fiberoptic sensors. The question is do I use both the index and timing inputs, or just index? I saw something in the manual about you can use multiple marks with index but one needs to be 50% bigger than the others. So that means the spindle will top at the large spot?

89

Mach3 and G-Rex / Re: To Grex or not to Grex?

« on: April 18, 2006, 12:32:48 PM »

In all reality I will not be ready to start wiring for more than a month. Hopefully this weekend I will pick up the base that I am using and then figure things out from there. Sounds like I will probably go with the GRex Figure two months to figure out exactly how I want.

Do you guys think it would be better to tie the encoders to the motors screws directly or hook to the axis? I would like to use the closed loop system in the GRex to eliminate as much backlash as possible.

-Jerry

90

Mach3 and G-Rex / Re: To Grex or not to Grex?

« on: April 17, 2006, 07:24:47 PM »

Guess that pretty much tels me whereI want to go, though I am using steppers so I doubt I wil get that fast...

Whats the difference between the g101 and g100.  case/terminals/psu + the rabbit board? Is the g101 as simple as slapping the rabbit board on it and loading the firmware or do need to flash the rabbit board too?

Sorry id this is repeated elsewhere, but I searched in vain on the gecko site for a detailed description of the units and their differences and was only able to garner a morsel of informtion on the web.

-Jerry