Messages

4431

Show"N"Tell ( What you have made with your CNC machine.) / Tangential Knife blade holder.

« on: July 13, 2012, 02:10:16 AM »

I needed a new blade holder for a tangential knife which would enable relatively quick and easy blade change and positional setups.

With just a couple of hours to spare, whilst another CNC job was running, this was the result (the only CNC operation was milling the flat).

Tweakie.

4432

Show"N"Tell ( Your Machines) / Re: My first attempt at a CNC build.

« on: July 12, 2012, 11:36:03 AM »

Brilliant ! 

Tweakie.

4433

Show"N"Tell ( What you have made with your CNC machine.) / Re: Constructing a Low Profile Tool Height Setter.

« on: July 09, 2012, 11:11:20 AM »

Hi Terry,

The physical over travel clearance is 0.5mm before the top of a limit switch is contacted, there is then a little more as a switch is activated.

Tweakie.

4434

General Mach Discussion / Re: Max upload file size?

« on: July 08, 2012, 03:14:53 AM »

Hi Tapio,

I am quoting the obvious but as it says below 'choose file'...

"Allowed file types: brn, doc, dwg, dxf, exe, fla, gif, grab, igs, jpg, Lcam, lset, M1s, m3p, mcc, mpg, msi, nc, ods, pcm, pdf, PNG, png, pst, rar, set, shp, swf, tap, tif, txt, vbs, xls, xml, zip
Maximum attachment size allowed: 6000 KB, per post: 4"

Tweakie.

4435

General Mach Discussion / Re: TB6560

« on: July 05, 2012, 12:00:20 PM »

From memory, the TB6560 chip has a peak output current availability of 3.5 Amps.

The imported controller board (sold as TB6560) recommends stepper motors drawing 3 Amps max.

It may be that connecting stepper motors rated at 4.5 Amps might just be asking for trouble.

Tweakie.

4436

General Mach Discussion / Re: Laser Focal lens selection method

« on: July 05, 2012, 06:58:53 AM »

Hi Andre,

The lens focal length is measured from the centre of the lens to the work.

Line up you machine with your Perspex gauge then measure from the work surface to the position that the old lens was fitted and then, if possible, obtain a new lens with a similar focal length to the distance that you just measured.

There are two common types of lens material used with CO2 lasers. The yellow colour lenses (seen on ebay) are made from Zinc Selenide (ZnSe) and are the cheapest – the grey colour lenses are made from Galium Arsenide (GaAs), are usually quite expensive but are considered to be more hard wearing.

I have lenses of both types but the ZnSe is the one I use all the time.

Remember to fit your new lens with the convex side towards the laser tube and the flat side towards the work.

Tweakie.

4437

Show"N"Tell ( What you have made with your CNC machine.) / Re: Constructing a Low Profile Tool Height Setter.

« on: July 05, 2012, 05:54:52 AM »

The tool path for the re-designed case has now been verified, new case made and anodized.

Tweakie.

4438

Show"N"Tell ( What you have made with your CNC machine.) / Re: Constructing a Low Profile Tool Height Setter.

« on: July 05, 2012, 02:53:35 AM »

Hi Terry,

With my Acceleration of 100 & Feed 200 for the Z axis our good friend Ian has calculated the over travel distance from the activation point to be 0.0555mm 


Tweakie.

4439

General Mach Discussion / Re: Cut parts are wonrg size

« on: July 04, 2012, 02:40:31 AM »

Hi Dave,

Use your existing system to create the GCode for a square part.
When you load it into Mach check the Program Limits DRO's in the tool path window - do they indicate the correct size of the part ??
When you make the part does it come out to the correct dimensions ??

This will tell you if your problem is with your software or your Mach configuration (steps per unit).

Tweakie.

4440

Show"N"Tell ( What you have made with your CNC machine.) / Re: Constructing a Low Profile Tool Height Setter.

« on: July 04, 2012, 01:20:57 AM »

Hi Astroguy,

Sorry for the delay.

By including the over-travel switch, the wiring between this and the main panel makes it difficult to dis-assemble / re-assemble so the case has been re-designed to include a pocket to accommodate a wiring loop and I have just not been able to get the time to test the tool path for the new case yet.
The control board PCB has yet to be laid out and I am still awaiting delivery of some low current opto isolators from China - it is all work in progress. 

Tweakie.