Messages

21

General Mach Discussion / Re: MACH3 for combined hot-wire foam cutting and A axis milling?

« on: April 27, 2015, 01:39:50 PM »

Maybe I explained myself badly..I dont want MACH to do that, I have it installed and working fine as a controller.

Heres an .stl file as requested...curious about your idea ; )

22

General Mach Discussion / Re: MACH3 for combined hot-wire foam cutting and A axis milling?

« on: April 27, 2015, 11:12:09 AM »

Hi again!

The problem is, no Hot Wire cutting software I have checked is capable of working from .stl or .obj or other 3D files;-(. Do you know of one that can? Dxf is fine for "simple" shapes, lettering, profiles etc, but not for a human head, for example;-(.

 In my other post of yesterday (http://www.machsupport.com/forum/index.php/topic,29935.0.html)  I suggest what might be a workaround solution; use existing .stl-to-g-code software and "extract" the necessary X and Z coordinates, at say 0, 45, 90, 135 degrees, etc. Then combine hot wire and mill at those angles, using rotary A axis.

There is a video here of the way I need the software to rough out the foam.....

see http://www.hotwiredirect.com/

Thanks again for all your input.

Frank.

23

General Mach Discussion / G code editing to use in Hot Wire cutter/Miller

« on: April 26, 2015, 05:36:56 AM »

Hi guys,
I want to be able to combine hot-wire cutting of polistirene foam with 4 axis milling. For time saving reasons basically.
I do big sculpture in polistyrene, working from 3D  stl files, which I process in DESKPROTO,  and then I mill them  in my home built 4 axis miller . For big pieces, even with a 160mm long carbide tool and fast feeds, it’s a verrrry slow process. There are commercial machines, ALARSIS.com  have one, and HOTWIRE DIRECT another, (see http://www.hotwiredirect.com/ for a video of what I need)  that come with fabulous software that allows you to rough with hotwire, and on the same machine, mill for the finish pass. Result is speed gained in machining process. Unfortunetly, they don’t seem to sell the software they use separately ; -(.
So I´m looking for a program that would help me edit the g-codes DESKPROTO  generates, and find only the ones a hot wire cutter needs to work on the silhouette. What I need to do is identify, then select, then group aside, 1)  all the X axis g-codes, and 2) only the highest (Z axis codes) on each Y axis position.
Typically, the g codes from DESKPROTO or any similar program (for the purpose of this query I have greatly simplified things)   for an stl file are:
One X value, e.g
G1 X1.000 F6000
 Followed by many hundreds of Y and Z values.
G1 Y1.100 Z10.000
G1 Y1.300 Z14.000
G1 Y1.500 Z9.500
Followed by another X axis instruction
G1 X2.000 F6000
Followed again by many hundreds of Y and Z values.
G1 Y2.700 Z2.000
G1 Y4.500 Z3.000
G1 Y6.300 Z4.500.
What I need to “extract” (then save) would be:  1) every X instruction, and 2) only the highest Z axis instruction for all those Y axis instructions,  and 3) no Y instruction, which would look  something like this:
G1 X1.000 Z14.000 F6000
G1 X2.000 Z4.500 F6000
Can anyone suggest some G Code  edit software or some fairly quick & easy edition process that I could use to sift thru and organize these specific g-codes?

Thanks!!     Frank Norton

24

General Mach Discussion / Re: MACH3 for combined hot-wire foam cutting and A axis milling?

« on: April 26, 2015, 05:31:18 AM »

Thanks (at last!) BR for your suggestions, but the problem with that approach I think  is that depending on the shape of the figure you´re doing i.e if it has a hollow area between two high areas,  you run the risk of cutting material from these high areas because the formal milling aproach only "sees" the height of the material at Y=0, whereas the hotwire cuts everything left and right of this point...difficult to explain I fear....Im about to post a fairly detailed explanation from another approach: edit the g codes so as to only go on the highest Z value at any given X axis point.
Frank.

25

General Mach Discussion / Re: Run From Here: strange Z axis plunge to zero ruining jobs!

« on: January 24, 2015, 03:25:25 AM »

Thanks Ozymax, TP, and Hood, as Ozymax said " The screen capture shows '0' in the rapid height box and that is the centre of the job, thus plunging into the job and then running from there." So I changed this to a safe height, and it works perfect!!

I´m away from the machine now, but will check to see if the Safe Z setting is enabled, and to what. Is this the same as the setting that should appear in the Rapid Height box?

Regards to you all and happy milling; )

Frank.

www.franknorton.com

26

General Mach Discussion / Run From Here: strange Z axis plunge to zero ruining jobs!

« on: January 22, 2015, 06:44:14 AM »

I do big rotary A axis milling jobs in polystyrene, and sometimes want to / have to stop halfway into a job and resume the next day.
I´m trying to use the Run From Here function, to save time, some jobs can take hours… but with disastrous results.
What I do is this (obviously I´m doing something very wrong):
I open the Gcodes for the job that’s half done, I manually advance to the Line number I stopped at, (I have tried to key in the line number, instead of manually scrolling down…but to no effect) , and when I get to the line, in this case 36297, manually, I click on the Run From Here button.
After a brief pause, I get a prompt to Press Cycle Start, I do this, and a “Preparational Move To” window emerges, so far so good.
The data shown in this window is (see pdf):
X 1314.004 (I presume this is because the last X instruction was at line 36203 “G1 X 1314.004”)
Y 3.4879121; (this I don’t understand, as I´m doing rotary milling an Y is stationary at Y=0)
Z 153.83 (this Z height would clear all the geometry without crashing into material)
A -109440. This divided by 360 degrees is 304, the number of revolutions I suppose the A axis has made, so in effect it’s the same as A axis going to Home/0 degrees.
BUT…AND HERES THE PROBLEM…the Z axis, on clicking on OK,  dives and crashes into the material, far below the 153.83 value given in the “Preparational Move To” window.  Job ruined. I then E Stop, but when I haven’t had time to EStop, once the Z axis  gets to (probably) Z = 0 level, it starts to move (probably) to the X axis position indicated…job ruined totally.
This has always happened, in my year or so use of  MACH3,  to the extent that I´ve avoided using the Run From Here function, but now I´ve some big jobs to do and using it will be inevitable.
What am I doing wrong? By the way, I use DESKPROTO for g-codes, which I´m very happy with.
All help greatly appreciated!
Frank.
The pdf is a screen shot of those  Prep Moves over the MACH screen
 

27

General Mach Discussion / MACH3 for combined hot-wire foam cutting and A axis milling?

« on: January 18, 2015, 02:03:23 PM »

I mill big sculptural pieces of polystyrene foam on a home-built machine that  is 4000mm long, by 2000mm wide, with a Z movement of 900mm, sometimes flat and sometimes using an A axis. An example of one of these  A-axis pieces could be a human head. I fix the block for the  head to the A-axis chuck using a flat cut at the neck, and if the piece is long, I give it some support at the top of the head, in a tail stock. I use DESKPROTO for G codes, wonderful for the job,  working from .stl files from a DAVID SCANNER. 
Doing things this way generates an AWFUL  lot of waste, polystyrene dust that’s very bulky and difficult to dispose of ;-(.
There are companies that offer polystyrene milling machines combined with hot-wire cutters. They economize on both waste matter generated and on milling time by first roughing out the form (human head for example) using hotwire cutting, before milling, then classical A-axis milling to produce the finished article. A wonderful idea…..
I´m trying to figure out how MACH Lathe could be used to control a hotwire function, to cut  profiles along the X axis with the A axis stationary,  and once done, continue in the normal rotary milling way, to achieve basically the same.
How I see it is this: Somehow I generate  let´s say 4 sets of G-codes for the four outlines of a human head: one for the (front)  neck- chin-lips-nose-eyes-forehead-top of head,  one for  (side) neck-jaw-right ear-side of head-top of head , another for back of neck-back of head-top of head, and lastly one for (other side)  neck-jaw-left ear-side of head-top of head: in a word, four silhouettes or profiles.
My question is,  Could I then program MACH Lathe to “cut” each of these profiles, travelling along the X axis,  having set up a hot wire cutter,  but with the A axis stationary, not rotating, just to get a profile? I would leave maybe a 10mm skin in this roughing stage.
I would then do this another 3 (or even 7 more times to get a roughed-out octagon )  times, spinning my A axis 90 degrees each time (or even 45º) and thus removing almost all surplus material before milling to finish. Hope I´ve explained myself ; )
Anyone got any ideas? I´m getting fairly familiar to MACH Mill, but Mach Lathe is unknown territory for me so far.
Any input grateful, many thanks as ever,

Frank Norton.

www.franknorton.com

28

General Mach Discussion / Re: slow Ref All Axis speed for Homing?

« on: January 18, 2015, 06:15:04 AM »

Many thanks to both Hood and his frozen fingers  and Overloaded for being there too.

Did that, works great !!!

Regards,

Frank.

www.franknorton.com

29

General Mach Discussion / slow Ref All Axis speed for Homing?

« on: January 16, 2015, 05:46:20 AM »

Hia all,
When I Reference my A or X  axis, either in Diagnostics or using Ref All Axis, both my X axis and my A axis usually  overrun the Home switch, because both axis move/spin  quite quickly, causing the Limit switch (on the X axis) to trip.
 On the A axis, the result is that sometimes it homes on one side of the steel slug bolted to the chuck, that passes in front of the proximity switch, but if it overruns, it homes on the other side, giving about a 30 degree difference in the chuck position.
I´ve just read on page 4-10 of the MACH Manual Rev 1.84-A2, that the axis will travel “at a selectable low speed”.
Can anyone tell me where that parameter is selected?
Regards and thanks,
Frank

30

General Mach Discussion / Re: Strange X axis distance travel at higher Feedrate % ; (

« on: December 16, 2014, 08:03:25 AM »

Sorrrrryy, can seem to be able to post that shot. Clicking on Insert Image but doesnt let me select a photo from my pc..strange...