Messages

231

General Mach Discussion / Re: Probe plug in what is "maximum z height for stuck probe" option do?

« on: January 23, 2009, 06:08:45 AM »

You could use a bit of aluminium TIG rod or piano wire , insulate it with a bit of biro ink-tube, pop it in a regular drill chuck and then link the piano wire through your probe to your Mach system.

instant disposable probe for testing

232

General Mach Discussion / Re: Introduction

« on: January 22, 2009, 04:08:04 PM »

Hello and welcome it's a very useful site. Possibly the best product support I've ever seen. Pop up some pictures of your machines, it's nice to see what everyone's using.

233

General Mach Discussion / Re: Offsets for spherical tools

« on: January 22, 2009, 03:47:28 PM »

well, that wasn't too hard. Reading the manual, I came up with this.

It's only a demo file to check toolpaths on my laptop, so no units, spindle or anything fancy like that.

(vague parabola generator)

(SET THE VERTEX POINT OF THE PARABOLA AS 0,0,0)
G0 Y0
G0 Z0
G0 X-30
G0 Y100
#1=-30
M98 P33 L300
M30

O33
G0 Z[0.002*#1*#1]
g2 y-100 i0 j0
G0 Z180
G0 Y100
G0 X#1
#1 = [#1+1]
M99

So it should be a relatively simple matter to integrate some small X and Z offsets by calculating the tangential angle of a line against the profile of the parabola and altering the position of the tool before it does its G2 scan. I think

What strikes me about this is the incredible economy and flexibility of handwritten G-code. The things I've seen spewed out by CAM programs is nobody's business, great reams of g01 here and g01 there, it's a nonsense.

Of course my code above might, in proper CNC terms, be a murderous bag of hacks, do say if so. I can learn.

234

General Mach Discussion / Re: Offsets for spherical tools

« on: January 22, 2009, 12:16:34 PM »

 

Just read up on parametric programming. I can see that what I want to do is possible but it's going to need a lot of that very special coffee and a good lie-down afterwards. I will lock the children in the cupboard, unplug the dog and prepare for some very in-depth algebra.

235

General Mach Discussion / Re: Mach Turn used for metal spinning?

« on: January 22, 2009, 05:11:53 AM »

excellent, thanks. I should be able to do something with this

236

General Mach Discussion / Re: My machines shakes really bad when cutting a circle

« on: January 21, 2009, 04:05:44 AM »

Odd, mine's ok, cuts nice small circles. What comands are you using for the circle? If as hood says it's a string of G01s then it would rattle between them with G61 on. G64 is the right medicine for curves.

237

General Mach Discussion / Re: Mach Turn used for metal spinning?

« on: January 21, 2009, 04:01:03 AM »

great. Could you point me at the video? Much appreciated

238

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.

239

General Mach Discussion / Re: Offsets for spherical tools

« on: January 20, 2009, 08:53:30 PM »

Brilliant, thanks - I'm making microwave reflectors for milimeter wave systems (potentially - it's an ongoing thing). I'll have another go at the manual, i looked ages ago but it was a bit opaque. Perhaps it will be clearer after more coffee. If there's a special coffee I must drink, do let me know

240

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