Messages

911

Show"N"Tell ( Your Machines) / A Jet knee mill conversion

« on: January 10, 2007, 03:59:53 PM »

I have been working on a Jet knee mill for the last couple months. Its now running, and I finally had time to post a few photos on my web page- see plsntcov.8m.com

The mill is an older one, about 1987 I think. It is in excellent shape, still shows lots of scraping marks on the ways, no detectable wear anywhere. It has a table of 30"x8". Thats not suite a Bridgeport, but my shop is on the second floor, and the mill is almost exactly above my bed. I just wasnt sure I wanted a 2000 pound Bridgeport up there.

I started this conversion with servos and G320s. These were some surplus servos I had, and they have an integral brake. I had it runing for a while, but then one of the brakes locked up and the motor overheated. After some thought- detailed on my web page- I switched to steppers.

For the Z axis I am driving the knee- I like that a lot.

I will be describing this machine as part of my seminar at the Cabin Fever Expo, Jan 20.

Here is a linked photo of the completed machine

 

912

General Mach Discussion / Re: Set Z to zero automatically?Auto tool zero questions

« on: January 10, 2007, 01:55:24 PM »

Does the plate need to have any give to it? It somehow bothers me to have the system feed down and hit a plate with a sharp tool- doesn't the tool dig into the plate a bit?

I considered gluing a sheet of rubber under the plate to add just a bit of give- is that necessary?

913

VB and the development of wizards / Re: External LED's

« on: January 05, 2007, 10:06:26 PM »

You are right, I was looking at the IF...THEN.... END IF problem, I didnt look at the GetLED

914

General Mach Discussion / Re: Cirlce Problem

« on: January 05, 2007, 08:48:54 PM »

In addition to backlash and gibs, you must also be sure your motors are tuned so that you are not loosing steps.

I had one system that used a slow processor- 600mhz I think- and it would jog any axis just fine, but it would not make circles- the extra computing to figure the path swamped the computer and the outputs got ragged and lost steps.

915

General Mach Discussion / Re: Cabin Fever

« on: January 05, 2007, 08:41:41 PM »

Hey, according to my map Huntsville to York is about 770 miles. For us its almost 670  miles from Maine to York. Sometimes you gotta drive a few miles for good stuff. :-)

916

VB and the development of wizards / Re: External LED's

« on: January 05, 2007, 08:27:30 PM »

I think you may need some End IF statements. Try

If GetLED (4) Then     'Cycle Start
   ActivateSignal (OUTPUT10)
Else
   DeActivateSignal (OUTPUT10)
End If

If GetLED (5) Then     'Feed Hold
   ActivateSignal (OUTPUT11)
Else
   DeActivateSignal (OUTPUT11)
End If

As you have it your second line only gets executed if the first ELSE is true.

917

General Mach Discussion / Re: Losing zero ref - related to feed rate changes?

« on: September 24, 2006, 09:00:20 PM »

If you are changing the feed rate while its running you may be exceeding the acceleration limits of your motors and loosing steps. It has been documented here that feed rate over ride also overrides acceleration and will cause this problem. It is advised to write the program for a high feed rate and override it down when you start up, only taking it to 100% when you are sure its running OK.

918

General Mach Discussion / Re: L commands

« on: September 20, 2006, 05:34:33 PM »

The Cr is also know as a line terminator. Without it the program does not know you have reached the end of your line, so it is waiting for more input. Every line must end in a line terminator.

919

General Mach Discussion / Re: How do I activate "allow block delete"

« on: May 06, 2006, 08:22:40 PM »

Ok, so what do you do with Block Delete?