Topics

1

General Mach Discussion / Clicking RESET on screen turns DROs to zero

« on: June 07, 2023, 12:52:56 PM »

I´ve just installed MACH3 on my third home-built CNC machine, 3 axis for the moment, A axis pending mechanics, harmonic drive etc.
My knowledge of the program is admittedly scratchy, but after nearly 8 years of using the 25? functions that everyone needs, and many hours of milling, I can´t find out why this is happening...
So here´s the thing; if I need to press RESET on the MACH screen, after say an MDI g-code entry, the machine stops...ok up to here. But when I press Reset again to unlock MACH, the DRO´s mysteriously all go to zero, hence I lose my position.
This didnt happen on my other two machines, so any help offered I will be very grateful.

Thanks,

Frank

2

General Mach Discussion / 3D tool-path software for milling with discs instead of cylindrical tools?

« on: July 10, 2019, 03:26:23 AM »

I mill polystyrene to make the occasional theatre or museum prop, and sometimes even dinosaurs and the like, on a home built 4 axis machine, using MACH3,   and DESKPROTO to create  tool paths. Check out http://www.formato3d.com/ One big step to achieve faster finishing came with the addition of a hot wire roughing sequence, made possible using a work around within DESKPROTO  that BR549 very kindly suggested.

I´m a sculptor, (www.franknorton.com) and my current project is  to build a machine capable of milling stone, obviously super-rigid and a much more powerful spindle. Initially it will be 3 axis plus rotary, but with a view to 5 axis. I want to do bas-reliefs in marble and sandstone.
Industrial software packages like ALPHACAM STONE   for tool-path generation in the stone and granite  sector have a function where they use diamond coated discs, the smaller ones in the region of 12”/300mm in diameter,  to rough “mill” the block of stone, the surplus material  is then removed manually by hammer and chisel!...before true milling with diamond and tungsten carbide tools. This greatly reduces working time.
But I know of no software...DESKPROTO definetely cant...that allows you to configure a disc as a tool for roughing out in this way.
Failing the use of a specific program which includes discs in the tool library, any tool-path 3D software where all the tool geometry parameters are configurable....diameter in both planes for example, or diameter in one plane and thickness in the other......would do.
Any ideas?
Many thanks in advance,

Frank Norton.

3

General Mach Discussion / Real 4th axis software for tilting spindle? Not trunnion table way...

« on: November 28, 2017, 12:41:57 PM »

Hi,
I built a 3 axis milling machine 2 years ago with also has a rotary (A) axis, for milling polystyrene and polyurethane foam, it works fine. I use DESKPROTO to generate the g-codes, and of course Mach (3) to control my machine. Some of my work at www.franknorton.com.
Now I want to build a milling machine for marble and other stones. I´d like it to have a real fourth axis; that is, I´d like the spindle to actually tilt, and so get to under cuts on the material I´m milling.
A full 5 axis machine seems to be too complex mechanically....eventually I´d like to, but I want to be more realistic with my next build.
The spindle could tilt either parallel to the X or the Y axis, it doesn’t concern me at this stage.
DESKPROTO can´t generate g-codes for this kind of machine; it can for 5 axis index machine, where you tilt your work piece on a rotary trunnion table.
This is complicated while milling big pieces, a more straightforward approach seems to me to be for the spindle to do the tilting, so as to get to those hidden undercuts.
But I need a software package to generate my g-codes.
Any ideas? I don’t mind paying a reasonable amount of money.
Thanks!
Frank Norton.

4

General Mach Discussion / When I Hold Feed then Start Cycle, A axis abruptly turns;-(

« on: February 16, 2016, 08:25:25 AM »

Hi all!
I´m at present doing 4 axis machining of polystyrene foam, using DESKPROTO  to generate g-codes, and an A axis to spin the part.
I´ve just noticed something strange and problematic in MACH3 when I need to pause in the middle of a routine.

I touch the FEED HOLD button  on the MACH screen, and within a few seconds (probably MACH needs time to reference where it is to ready itself for starting again)…MACH  pauses, as if on Hold. Fine up to here.

But when I wish to re-commence, and I click on the Cycle Start button on the MACH screen, the A axis mysteriously and abruptly spins to Machine Zero, no matter what angle the routine has been working at, and milling commences.

Attached a Screen Shot: you can see the a axis is now at 1.9125º, bt it should be at 0º. (which it this case is actually 0º at Machine Coordinates)
And if it had been working at say 270º, as happened some days ago, it still spins abruptly to Machine Zero for that (A) axis.

Am I doing something wrong here??

Thanks!!

If its not obvious, I´m pretty much of a new-comer

5

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

6

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
 

7

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

8

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

9

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

« on: November 22, 2014, 06:03:26 AM »

Hi!
I´ve come onto a problem that  as a relative beginner has me baffled ; (.
I´m milling polistrirene foam, quite quickly, on a home built machine thats X axis is 13 feet long,  Y axis 2 feet 4 inches and  Z 35 inches. (4000mm x 2000mm x 900mm aprox).
I´m using Easy Steppers, by Leadshine, NEMA 34, ES_MH33480, which give 8Nm,with encoders,  driven by ES DH 2306 Hybrid Servo Drivers.An economical alternative to servos.
I tend to give feed rates of 12000mm per minute in DESKPROTO, the software that generates the g codes. I then vary the feed rate in the MACH3 screen, depending on the area being milled, often way above 100%.
I´ve discovered that if  I speed up above a certain rate, much lower than the machine is capable of delivering, the distance travelled in both X and Y axis is not accurate ; (. But the machine does not loose steps nor position (due to the encoders) as I can G0 X0 Y0 Z0 and it goes back perfectly to the work piece zero point.
If I then decrease % speed, again on the MACH screen, it reverts to correct travel, and milles the piece with the desired form.
 I´ve yet to try changing to another computer, it has XP installed.
If I manually instruct for example, G0 x 2000mm, it goes perfectly there, even though the speed percentage is quite high. G 0 X 0 and it come back perfectly.
Anyone any ideas?
I made a short video, I´ll try and post it.
Thanks in advance,
Frank.
www.franknorton.com
PS This is a second attenpt to upload this Post, hope I´m not repeating it; )

10

General Mach Discussion / Position and direction problems on all axis only with Slow Jog Percentage

« on: January 05, 2014, 07:36:34 AM »

Hi all! This is my first time on the Forum, hope to be able to concisely explain my problem and not waste people´s time. I´ve checked the Forum for similar problems but cant find anything.
I´ve been 3D milling polistirene for 2 months at “normal” feed-rate perfectly, (“normal” for my home-built cnc machine being 1875mm/minute) using g-codes from MESHCAM and recently DESKPROTO, and want now to use CAMBAM to mill aluminium NEMA plates  for a bigger, stronger router, and as my home built router is not very strong, So I´ll need to use quite slow feed rates, which is fine by me.
So, to the point:
If I set the Slow Jog Percentage DRO to 3% or lower, and manually jog  in a +X direction, all works well…the tool moves  at the same rate/distance as the DRO.
However, if I jog in a –X direction, the tool does not keep up with the DRO…if the DRO says 20mm of movement, the tool has only moved about a third of that.
In the Y axis, again at 3% or lower in Slow Jog Percentage, whatever direction I jog, the tool moves the in same direction, always – .
 If I jog in a –Y direction, the tool and DRO are equal. If I jog in a +Y direction, the tool as well as going in the wrong direction, only goes about half the distance the DRO reads.
In Z, similar to X…..in  – direction (down) the DRO and actual distance travelled is the same…in + direction (upward) it loses position.
Its as if the motors at these low speeds don’t have the torque necessary, to do the job, as well as having direction problems.
Attached is xml file.
I´ve tried changing kernel speed , and also step and direction pulse width in the motor setting, all to no avail.
My PC has XP sp3, 1.67Ghz and 2.25GB Ram., and a www.cnc-robotica.com USB interface.
My MACH is licensed,  and is Version R3.043.022.
Many thanks in advance,
Frank