Messages

81

General Mach Discussion / Re: Major/ minor arcs in turn

« on: May 30, 2009, 07:22:06 PM »

Sorry, I should have been more descriptive. If you fit an arc between two points without a signed centre, it can go two different paths and still be a G2 clockwise or G3 counterclockwise. One path is a minor arc, the shorter of the two, and the other is the major, the longer path of the two. One will blend in smoothly with the rest of the geometry, and the other will be abrupt, but the control will still agree with it. An Accurite CNC mill I use has a soft key to let you choose between the two. Mach turn seems to always go for the major, the longer arc if you use an R value instead of a signed centre point.

82

General Mach Discussion / Re: Major/ minor arcs in turn

« on: May 30, 2009, 03:20:02 PM »

Anyone? Surely this is a problem that someone else has had to deal with.

83

General Mach Discussion / Major/ minor arcs in turn

« on: May 29, 2009, 12:11:09 AM »

It was suggested to override a feed speed problem in Turn that you use the R value instead of using I and K arc centers. I like the R value because it is faster to hand code, as I do that a lot. However, with the R value I don't seem to be able to control the arc Major or minor and seem to always end up with the major arcs. I looked through it all and I bet I'm missing something simple, but how do you force Mach Turn to differentiate between major and minor arcs? Thanks.
             DaveA.

84

General Mach Discussion / Re: can mach be set to remember which tool is loaded on shut down?

« on: May 26, 2009, 01:08:39 AM »

There is a "Use persistant tool offsets" box somewhere in Turn, mine boots up with the same tool I shut it down with every time.

85

General Mach Discussion / Re: Turn G3 feedrate problem

« on: May 10, 2009, 01:43:46 PM »

I didn't know that R worked in turn, will try it. It certainly would save me a lot of time when handwriting code that's for sure.

86

General Mach Discussion / Re: Turn G3 feedrate problem

« on: May 10, 2009, 11:22:27 AM »

Yes, I'm betting that this has something to do with the actual circumference of the arc being calculated in. Mach calculates at a greater distance because of a circumference error used in the feedrate calc.

87

General Mach Discussion / Re: Turn G3 feedrate problem

« on: May 09, 2009, 01:40:00 PM »

Yes, you never really can tell this is happening if you think that the sounds are just the two steppers making noise at the same time, and you only take small cuts in aluminium or soft materials. BUT, try it with a larger cut in stainless and you know pretty quick there is something not right, and you can watch the RPM drop significantly as proof. A recent part I did, in stainless, I had some large amounts of material to remove so I was taking decent cuts, but when it got to the G3 it almost caused the toolpost to move and I had to check tool settings afterwards just to make sure it was ok.
   DaveA.

Oh, I always use G95, feed per rev.

88

General Mach Discussion / Re: Turn G3 feedrate problem

« on: May 08, 2009, 12:48:36 AM »

That sucks Hood, hope nothing expensive got wet. Until Hood gets his stuff back running, anyone else ever program a G3 on turn and notice this?

89

General Mach Discussion / Turn G3 feedrate problem

« on: May 04, 2009, 12:52:25 AM »

Melee and myself have been noticing a problem with turn in that the feedrate doubles when in G3. I thought it might just be that I'm too chicken to upgrade my old reliable version 1.84, but he is running version 3.4xx and the problem is identical. Even stranger is that when you use a G0 after the G3 the feedrate in the G3 goes to about 6 times the displayed amount! If there is a G1 after the G3 then it only goes to about double the displayed rate. We thought it might be something to do with Melee's new M71 roughing macro but it does the same thing with a simple G code run. Kind of interesting to watch if you're only taking light cuts in aluminium, but heavy cuts in stainless can be cause for concern!
   DaveA.

90

General Mach Discussion / Re: I'm just a tease

« on: March 18, 2009, 05:59:33 PM »

Will the threading problems be addressed in this release in turn? Or is this release only for mill as is often the case?