Messages

1

General Mach Discussion / Re: Why is it running off at random?

« on: June 07, 2010, 04:24:06 PM »

Ok I redid the job. The first time I had a glitch. During a straight X cut, the Y had a little freak out. The funny thing is it went back to the correct position on its' own. I didn't even notice it until I was removing the work. The second time it ran fine.

It is the cut between the circles. The code calls for it to cut out the panels last so it is going around the rectangular perimeter.

2

General Mach Discussion / Re: Why is it running off at random?

« on: June 03, 2010, 08:09:27 PM »

I am considering replacing the X axis leadscrew. I have seen 1/2 - 10 2 start and 5 start. These would'nt require any sort of bearing or coupler change.

I have also considered going up to a 5/8 - 8 2 start. This would help with the whipping problem.

What are the pros and cons of these options?

As I understand it, multi-start will reduce the precision but this is a wood router so 1/32" is more than enough.

Neil

3

General Mach Discussion / Are these motor numbers right?

« on: June 03, 2010, 01:48:55 PM »

I used the measured travel method of tuning my motors. I am using the Xylotex 269s with a 25k kernal speed.

The program came up with the following:

X = 15984.63836
Y = 15924.7109
Z = 15948.06245

They are the same motors on all three axis and the same thread screws. I am thinking the difference is due to measuremant error on my part.

Should these all be 16000?
Should I make them 16000?

How does the kernal speed affect these motor's performance? On the driver test I am clean through 75 khz. Would upping the kernal speed from 25k do anything helpful?


Thanks

Neil

4

General Mach Discussion / Re: Why is it running off at random?

« on: June 03, 2010, 01:21:07 PM »

I cleaned and lubricated the lead screw with Boeshield t-9 this morning. I cleaned the screw by spraying Blade & Bit cleaner while traversing the X axis. At full speed I could stall the motor with the rag with only moderate pressure. After lubrication the screw wouldn't stall unless I applied a fair bit of pressure so that helped some.

Last night I made one of the captive slug type dampers. It is crude because I cut it out on the router and the holes aren't perfectly round. My Harbor Freight 7x10 mini lathe is horribly sloppy but I did eventually get a flange that is round.

Installing the damper on the Y axis did little or nothing. The Y runs quiet and smooth all the time. Putting it on the X axis however reduced the noise by at least 50%. It will now rapid at upwards of 90 IPM without stalling. That isn't cutting anything though. It only stalled right in the middle of the travel. The rod is 1/2" x 10 and is nearly 5 ft long. I fear that the high speed whipping may have bent it slightly.

I am going to try running it at 50 IPM for a while and see if there is any problems.

I have a question about the numbers on my motor tuning but I will post that separately.


Neil

5

General Mach Discussion / Re: Why is it running off at random?

« on: June 01, 2010, 11:00:13 PM »

I have 1/2-10 Acme screws and Xylotex 269 motors. (I made a mistake on the 425's)
I am not sure how fast I was going but the max speed is set to 60 ipm

Neil

6

General Mach Discussion / Re: Why is it running off at random?

« on: June 01, 2010, 10:24:27 PM »

The max speed is set to 60 ipm on Xylotex 425 motors. The spindle doesn't appear to be moving all that fast when it goes nuts.

I don't have any dampers on my motors but have been planning on building some. I cut back the speed when I was having resonance issues before. I have also added an optp-isolater board to cut out noise.

Every time I fix one issue, another pops up and I am beginning to hate this machine.

Neil

7

General Mach Discussion / Re: Why is it running off at random?

« on: June 01, 2010, 07:30:58 PM »

So do you think the line goes off directly at the apex, from your pic it looks to me that it is before. Also looks to me like the line going up seems to be at the max height that the circle would be, so that does suggest lost steps to me.
Hood

It does appear that it starts to go wrong just before the apex. The Y axis seems to be functioning but the X axis is falling behind.

I just did the driver test and it is flat line up through 75mHz. At 100 it gets some minor noise. Is there any advantage to upping the Kernal speed?

Neil

8

General Mach Discussion / Re: Why is it running off at random?

« on: June 01, 2010, 06:26:19 PM »

How does that help me with my problem?

Is it some sort of computer setting?

The computer is a dedicated machine with no internet or network connections. I stripped out all the extra windows crap. There is no anti-virus software running.

Neil

9

General Mach Discussion / Re: Why is it running off at random?

« on: June 01, 2010, 06:12:57 PM »

IF you will notice there was a total SHIFT in the offset as when it shifted it shifted on the Center point of an arc/circle. AND stayed on the exact center of that arc/circle.  AND still cut a good arc/circle I have seen it shift IN and I have seen it shift OUT.

 THAT is not lost steps or NOISE as if it was the arc would have been offset by the amount of the missing steps AND it would have still cut the same radius as the code here it did none of the above.

I realize the WORDS are English but this make no sense at all to me. Could I get a "G-Code for Dummies" explanation of this.

10

General Mach Discussion / Re: Why is it running off at random?

« on: June 01, 2010, 05:53:18 PM »

I just realized it has occured when doing a circular cut out or pocket.

The circles are never perfectly round.

Neil