Hello Guest it is May 28, 2024, 03:25:05 PM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Topics - JohnHaine

Pages: « 1 2 3 4 5 »
21
General Mach Discussion / Simple Threading - lathe heads for the hills...
« on: December 18, 2015, 05:10:42 PM »
I have Mach 3 V3.043.062 installed on my lathe and need to cut athread.  I input the thread parameters into the DROs and post the code.  The lathe is set up with the tool set to the stock diameter for X and Z=+3mm but tool well to the right of the chuck so it's cutting air for safety.  When I cllick Cycle Start the carriage heads at full chuff toward the chuck, to some very negative Z value that isn't in any of the code that I can see.  I E-stop the system quickly!  I don't think this should be happening, and it didn't happen when I tried threading a year or two back.  Can anyone advise please?

Also, on the "settings" page for the Wizard it asks for the "Splindle Direction" and the default is set to CW.  My lathe is a converted Myford so the usual spindle direction is CCW, just to verify that I should select "CCW", is that correct?  (For a right-hand thread of course.)

Thanks, John.

 

22
General Mach Discussion / Where do button scripts live please?
« on: August 23, 2015, 01:05:40 PM »
I've upgraded to '062 to solve a turn issue but my previous version in "MILL" mode had custom button scripts on the offset screen to drive a touch probe, and also for tool height setting.  I'd like to find these and transfer them to the new version but I can't find them!  Presumably not in the .xml file?

Where are they please?

John.

23
General Mach Discussion / Mach 3 Turn OD sphere wizard
« on: July 12, 2015, 07:55:32 AM »
I'm trying to turn a hemisphere on the end of a bar, the same diameter as the bar.  When I try to use the wizard, when I click the post code button Mach 3 crashes and can't be re-launched without re-starting the PC.  Is this a known bug please?  I would say which version I'm using but to do that I'd need to restart the PC!

Is there another sphere wizard anyone can recommend?

24
General Mach Discussion / G code to generate a mathematical profile
« on: August 12, 2014, 10:56:55 AM »
Hi all, I have a question about the best way to accurately mill a defined profile on the edge of a plate.  The plate will be mounted flat on the mill table on a sacrificial spacer, and the edge milled using just X and Y moves.  The curve I want to generate will be generated by a simple mathematical formula, and with care I can avoid the necessity of cutter radius compensation.

Ideally I would like a G code instruction of the form "Gxy X1 Y1 X2 Z2...Xn Yn" where the Xs and Ys are a series of coordinates of points along the desired profile; and the controller would use a suitable interpolator to smooth between the points.  However, as far as I can see there is no such Gxy instruction in Mach 3!

The obvious alternative is to use a (long) series of small line increments and a G01 move:
G01 X1 Y1
G01 X2 Y2
....
G01 Xn Yn

but this could be a large program (but no matter, I can generate it from a simple Excel spreadsheet). 

My question is, am I missing something?  Is there a better / well known way to do this please?

25
General Mach Discussion / CNC turning of gear cutters
« on: February 01, 2014, 01:49:12 PM »
Hi all, I've decided it's time I cut some gears and want to make some cutters.  There's a standard method of making cutters where you profile turn arcs of a circle on the edge of a bit of gauge plate, using a form tool which has two hardened circular buttons fixed to a plate with the right spacing and diameter.  Now it seems to me that with a CNC lathe it ought to be possible to form the arcs directly with the right G Code.

So I have found the formulas for the cutter dimensions, but I just thought that I'd ask here if anyone else has done this and has any tips (or even some G code they can share)?

Thanks,  John.

27
I have been successful at loading Tweakie's script for auto tool height setting; and also turned it into a macro so it can be called from within a program.  Turning it into a macro was easy, I just copied the button script and saved it as "M900.m1s" in the macro folder.  

However, I have now hit a strange problem which I wonder if anyone can help with?

I have added a feature to the macro that inserts an extra probing pass.  So, first it lowers the tool at a reasonably high speed (100mm/min for example) until the probe triggers; then raises the tool by .25mm; then lowers it at a slow speed (20mm/min) until it again triggers.  This I did because I found, as have others, that the accuracy of setting seems to depend on speed, presumably because of delays between the probe signal being asserted and the software actually seeing it.  This works very well as a macro, being quicker to reach a more accurate setting from a higher starting position which is desirable if you are changing a tool.

However, copying the modified macro back into the button script doesn't work!  When I press the button, the tool lowers to the probe as before, but when it reaches it it stops, then after a few seconds starts to randomly and very slightly "jiggle" up and down, whilst the following message appears in the status window:

"Probe Ignore, activated at call for probe"

I'm baffled, can anyone help please?

A subsidiary question: having written a macro, is it not possible to just call it from within the button script?  It isn't obvious why not, since for example the original script contained various calls to built-in macros (for spindle stop for example).

TIA,

John.

28
General Mach Discussion / Expected backlash
« on: January 21, 2013, 09:08:25 AM »
Hi folks, as a result of a slightly unexpected error in the dimensions of a piece I profiled I realised that I could not ignore the backlash on the slides of my little Novamill.  Measurement showed it to be 0.03 mm on X and Y, 0.02 mm on Z.  I have turned on compensation and set these parameters and it seems to work fine, but I was wondering what level of backlash was to be expected?  I have posted this question on the Denford forum and Angeltech has suggested I adjust the thrust bearings, which is good advice that I'll follow, as well as looking at the gibs, but would be nice to know what I could expect?  The machine though oldish has spent most of its life gathering dust in a school, having clearly not had anyone who had a clue in charge judging by the cutter jammed in a collet when I bought it off ebay!  So I don't think there will be significant wear.

John.

29
General Mach Discussion / Exporting tool offset tables?
« on: November 13, 2012, 06:19:48 AM »
Slowly getting to grips with more advanced Mach 3 features and setting up tool offset tables.  Now I also need tool tables for my CAM program, for which I use G Simple (though I'm sure most CAM programs need tool tables.  Is there any easy way to export or copy the tool tables from Mach 3 to avoid having to re-type all the data, does anyone know please?

John.

30
General Mach Discussion / Mouse interfacing
« on: September 16, 2012, 08:09:23 AM »
It seems to me that an optical mouse would make a good basis for an "MPG".  One could mount the mouse electronics in a little housing, looking at the surface of a disc rotated by the jog wheel.  The easiest approach would be to cannibalise an off the shelf mouse rather than try to use the bare sensing chip.  However most of the mice you get these days have a USB input and this is handled on the chip itself so you would have to interface using USB.  Has anyone interfaced a mouse to Mach, does anyone know please?

John.

Pages: « 1 2 3 4 5 »