Topics

11

General Mach Discussion / limited lines query

« on: September 07, 2009, 06:29:07 PM »

Hi. Probably a short answer to this one. If a licensed copy of mach is limited to 10,000,000 lines, does this mean ten million lines of code as written or ten million lines of code as executed? If I set a subroutine of 10 lines to execute 1,000,000 times, would this crash it, or would it just see ten lines over and over again?

not that this is ever likely to bother me as I haven't written anything bigger than a Kilobyte

12

Share Your GCode / 10-blade pump impeller- G68 demonstration

« on: August 28, 2009, 09:16:13 PM »

Here's a little one I've been trying to get right for a while. It's a ten-bladed impeller, made using G68 angular offsets, nested subroutines and primitive parametrics. As an actual pump impeller it's probably pretty crappy, but it shows the principle well and you could easily get the feel of this code and apply it to any sort of rotational shape.

One thing that hexed me throughout was trying to apply a tool diameter offset to the program ... try it and see what happens, it's extremely wierd. Is there a way round this, or can tool offsets not be used in G68? Let me know, I'm intrigued as to what it is.

(CENTRIFUGAL IMPELLER)
(TEN BLADES)
(NOT DESIGNED AS SUCH)
(THIS IS JUST A DEMO :p )

G40
G64
G21
G0 X0 Y0


#1=0
#2=4.5

M3 M8

G00 Z1.00
M98 P777 L5
G00 Z10
M5 M9
G00 X0 Y0
M30

O777
#2=[#2-4.0]
M98 P333 L10
G00 Z1.0
M99


O333
G68 A0 B0 R#1
G00 Z1.0
G00 X100 Y-60 F700
G00 Z[#2+1]
G01 Z#2 F150
G02 X45  Y0 R50
G03 X100 Y-60 R80
#1 = [#1+36]
G40
G69
M99
%

13

Show"N"Tell ( What you have made with your CNC machine.) / Ku band power divider (~10 GHz)

« on: August 26, 2009, 09:15:57 PM »

My usual machining supplier let me down badly last week, letting me know on Friday afternoon that the parts I'd ordered two weeks ago had been junked in making them by a combination of last-minute rushing and crappy programming. So i had to program the Y-shaped waveguide section in, run the electrical tests on it as  a bare block with a cavity, program the back side, foam-run it, cut the whole thing in metal, paint, pack and ship across country by Monday lunchtime.

This is the inside of the thing, it's a y-shaped waveguide designed to split power evenly between two outputs for a hot-standby satellite reciever. Tolerances are low in here.



This is the outside of it, trimmed and assembled. Those are M4 screws. The whole thing is about 75mm long, maybe 85mm wide, and very light. (long being along the waveguide port axes)



I did the drilling and edge trimming on the Bridgeport as this was needed quickly but production ones will have a jig set and it'll be full CNC all the way apart from the tapping. The bad news is that I spent the entire weekend going at it like a madman, and spent Monday in bed. The good news is that it went out on time even if it was hung up in the cab of a van so that the paint could dry en route.

Mach performed amazingly well throughout, and being able to run a copy on my laptop as well as the machine allows me to take work home and code off-site. just as importantly the big Excel worked well, although I could do with a new cutter soon, this one's been through a lot, so to speak

Best of all I have the capacity to make my own now ... no more pigs' ears and a better bottom line for me. Nice!

14

General Mach Discussion / Mach Turn used for metal spinning?

« on: January 20, 2009, 08:56:28 PM »

Anyone here used Mach3 Turn for spinning or shear forming?

I'll be getting hold of some hand spinning equipment soon and I'm thinking of CNC/PNC upgrades in the future.

15

General Mach Discussion / Offsets for spherical tools

« on: January 20, 2009, 11:36:14 AM »

Hi. Simple question, difficult machining. Can mach3 be set up to allow for a spherical offset system? I need to machine a compound curve - a reflector parabola, in fact - and a spherical or ball-nosed cutter would be the thing to do it. Can a simple offset be used to do this or will I have to wear out  a calculator translating 3D values into real controlled point movements?

Also, pointing me to a section herein on building formulae into G-code would be extremely useful.

Thanks in advance

16

General Mach Discussion / toolpath display: odd problem

« on: January 19, 2009, 09:09:46 AM »

Hi. Strange one, this. My toolpath display 3D model looks fine, the line-by-line simulation goes nicely from one fixture to the other and the program works perfectly. On the other hand , when I actually run it, the green "done" line appears only over the first fixture (on the left). Pics of the fixtures are here: http://www.machsupport.com/forum/index.php/topic,9956.0.html - the left hand fixture is G56, and the right hand is G55. It starts on the left, chops out a hole, then goes right and does the bolt holes, face relief and edge trim, then returns to the start position on G56 and rewinds. Any ideas? it's not stopping me working but I'd like it to display properly. Ta

17

Show"N"Tell ( Your Machines) / Excel Pinnacle vertical mill

« on: December 26, 2008, 08:03:44 PM »

Height - 7 feet, spindle - 4hp, 415v 3ph, 4200 RPM max expanding sheave drive and automatic airbrake, 3x 10 amp stepper drives, routout stepper driver, microstepping to 32,000 steps per inch. Maximum X,Y speed - 1200 mm/minute and of course Mach3 running on an old 950MHz PC with two parallel cards.

Note to self - more pictures required! it's quite a big beast. The first two pictures are of the twin-jet travelling coolant system I made up. I'm cutting large parts on two fixtures with a significant variation in Z offsets, and the static feed was either missing the tool or getting spun off the chuck and vapourising all over the floor.





It works a treat, I'd like a lot more pressure but that'll mean making a new coolant pump as the old one gets tired, bless it. 10-15PSI at the nozzle would be good! The clamp is a giant 85mm hose clamp, and the jets are now angled at 45 and 225 degrees to X so that on normal X or Y oriented cuts the coolant flow is approximately the same.

More photos when I remember!

18

General Mach Discussion / Mach3 skips to subroutine, crashes Z, ruins part :(

« on: December 03, 2008, 11:37:44 AM »

I've got a program spread across two fixtures for making a large waveguide flange. The start point is at G54 X100 Y130 (left hand fixture), and the whole cycle finishes there, returning from a similar position on the right hand (G55) fixture. This normally executes well, using a 3-axis movement to clear the fixtures and a fast return to the start point. I've done about 40 flanges so far, and they're all good, but today Mach3 has run away twice. The first time it drove the cutter up (Y+) without any provocation, shredding the jig and snapping the cutter. Secondly, without any warning, it was returning to the start point when it seemed to hop to a subroutine I'd written for boring a 10mm clearance hole. Again, the cutter broke as Z fed down and stubbed it into the part.

This isn't funny, I've trashed over £60 of carbide cutters and aluminium blanks today and we're going to be in trouble if I can't sort this out. Any clues?

19

General Mach Discussion / Hall effect home switches - Nonsense and bother

« on: February 25, 2008, 05:33:39 PM »

Well, I'm annoyed again.

My machine has three hall-effect proximity switches for homing. These have inbuilt magnets and react to plain steel vanes on the slides, or the leadscrew nut in the case of Z. They trigger a logic  pin on my second port with an arrangement that uses a 2k2 resistor in series with the sensor, and the whole lot across a 9V supply (these sensors originally had a 9v line). Across the resistor is the input side of a darlington-output optoisolator in series with a common LED to give a combined junction voltage of around 2.2 volts (plus a current limiting resistor). Effectively when the sensor is triggered its resistance rises from around 300 ohms to 13K; the voltage across the 2k2 resistor drops sharply to below 2.2 volts and the opto shuts off, allowing the logic pin on its output side to float high.

All this is very fine and well, but when I reference the axes, zero all, turn off the automatic zeroing and move all the axes -10mm, then re-home them all, they end up in slightly different places to where they started.. not usually much, 1-2 microns usually, with the exception of Y which can be much further out.

A few questions:

 - Do hall proximity sensors work best if the vane passes very close by it, or does a bit of separation help?
 - Can i expect day-to-day drift due to temperature and age affecting the interface circuit?
 - Is it really reasonable to expect a machine to home accurately to EXACTLY the same position 24 hours after it last did it?
 - if so, how?

I can find precision switches giving 1 micron repeatability on RS, but if I'm to have three of them they'll be around £500, and I won't be popular with the bean-countress.

Suggestions? I did consider that of "buy a new one from Haas" as very favourable, but... see above  Thanks in advance.

20

General Mach Discussion / Writing macros, OEM inputs and outputs

« on: February 11, 2008, 10:07:32 AM »

Hello all

Is there a good tutorial or other thread on here which can give me a good overview of writing macros?

Also, how can I configure the OEM inputs and outputs (including renaming them if possible). I've looked though the manual but can't find either ... might just have missed it, do refer me back to the right page if that is the case.

Thanks