Messages

7981

General Mach Discussion / Re: Auto detecting and zeroing of z axis

« on: December 14, 2009, 03:02:34 PM »

After reading other threads here, on this forum, I started using a touch plate for tool height setting and will never look back. A search for 'touch plate' will provide all the info you require but you can, if you wish see how I did it here:- http://www.cooperman.talktalk.net/files/17.htm

Tweakie.

7982

Video P*r*o*b*i*n*g / Re: g code from touch probe?

« on: December 14, 2009, 11:48:55 AM »

Al Lenz has written a brilliant little VB program to do just this. It is called XYZ Converter.exe and can be downloaded from this page.

http://www.machsupport.com/forum/index.php/topic,13301.msg87229.html#msg87229

Tweakie.

7983

General Mach Discussion / Re: Auto detecting and zeroing of z axis

« on: December 14, 2009, 06:09:37 AM »

First reply deleted as I misunderstood the question.

After a lot more thought – If  your workpieces are electrically conductive and the cutter is electrically isolated from the workpiece the auto tool zero button could possibly be redefined as an OEM button and your GCode would then call a macro to touch off the surface of the work automatically for the start of each part.
On the other hand if the workpiece and cutter are electrically connected (both ground) then the alternative would be to use a touch plate (as I and many others have done) but due the proximity of fingers I do not think it would be wise to perform this operation within a running program so placing the macro within the auto tool zero button and manually clicking on it would be preferable.

Tweakie.

7984

Show"N"Tell ( What you have made with your CNC machine.) / Re: Christmas present

« on: December 14, 2009, 04:29:30 AM »

Really nice work Vince.

Tweakie.

7985

Show"N"Tell ( What you have made with your CNC machine.) / Re: An unusual application for Mach ?.

« on: December 13, 2009, 03:42:54 AM »

Thanks Guys.   

Tweakie.

7986

Show"N"Tell ( What you have made with your CNC machine.) / An unusual application for Mach ?.

« on: December 12, 2009, 08:17:07 AM »

Do you remember these (legacy) magnetic access cards ?.

Well I needed to program one – they have a composite core of  flexible magnetic material (very similar to a fridge adornment) and are programmed with a number of magnetic domains, some north up and some north down. Knowing the positions and polarities of the required domains do I make a ‘programmer’ or use Mach ?.  You guessed it Mach wins.

I used a 110Volt coil, half wave rectified, together with a couple of bits of iron and with the spindle relay (and the use of M3 / M4 commands) was able the change the magnetic polarity of the coil to program the domains.

It worked perfectly and serves to indicate the versatility of Mach for what is perhaps an unusual application.

Tweakie.

7987

General Mach Discussion / Re: motor tuning menu wierd in machmill need a good XML file

« on: December 10, 2009, 08:01:31 AM »

Have you tried setting Sherline 1/2 pulse mode in Ports and Pins ?.

Tweakie.

7988

General Mach Discussion / Re: Z axis problems

« on: December 10, 2009, 07:57:14 AM »

Hi BarryM,

You touch the cutter on the surface of the work then zero the Z axis DRO. Then raise the z axis (cutter) clear of the work before clicking on Start.

Tweakie.

7989

General Mach Discussion / Re: router tips burning

« on: December 08, 2009, 03:12:30 AM »

The problem here is heat which is generated by friction.
The low cost bits are made from tool steel (if you are lucky) and will not stand overheating whereas the more expensive carbide bits stand a much better chance of survival.
Cutting bits have side and face clearance which reduces the area in contact with the work and thus quite low friction (heat) is generated but if the cutter flutes become choked with the cuttings then the friction increases at an alarming rate and will ultimately lead to tool failure for all but perhaps the extremely expensive cobalt alloy tools (stellite) which will carry on and just burn their way through.
Using an air jet, aimed at the tip of the tool, will clear these cuttings from the cutter and kerf as well as providing a measure of tool cooling. Shop air, run through a pressure regulator, is just fine for this task.
I have found the single flute carbide cutters to be best for both for wood and plastics as the face and side clearance is much greater than with multi fluted tools. Cuttings don’t get trapped in these tools and so little frictional heating occurs but the low pressure air jet is still desirable. The cutter on the right of this picture is a single flute type and shows the exaggerated side and face clearance quite well.

Tweakie.

7990

General Mach Discussion / Re: ground wiring question

« on: December 07, 2009, 01:58:41 AM »

Barry,

In an ideal situation you would have all your ground wires, screens etc running to a single point ground (to avoid ground loops and possible noise pickup). In reality it is not quite as simple as that but it is what you should aim for.

Tweakie.