Messages

7421

General Mach Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: August 21, 2010, 05:13:09 AM »

Hi Larry,

Welcome to the forum.
Lots of Guys here only too pleased to help you with any Mach related (or other) problems you may encounter. Post any questions you may have under the 'General Mach Discussion' section. Good fortune with your new machine. 

Tweakie.

7422

Show"N"Tell ( Your Machines) / Re: Our 2440 x 1220mm CnC Router Builds

« on: August 21, 2010, 04:58:19 AM »

Thanks for the pictures Tony. If this works as good as it looks (and I am certain it will) you are going to have a machine to be really proud of. It looks so professional 

Tweakie.

7423

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

« on: August 20, 2010, 12:21:46 PM »

Brilliant work Arbo,

You have just got to get that machine fixed I want to see some more. 

Tweakie.

7424

General Mach Discussion / Re: Strange doubling issue cutting lithophanes...

« on: August 20, 2010, 11:30:38 AM »

I will keep my fingers crossed 

You must post some pictures of your lithophanes perhaps under the 'What you have made with your machines' section we all love pictures.

Tweakie.

7425

General Mach Discussion / Re: Strange doubling issue cutting lithophanes...

« on: August 20, 2010, 10:53:42 AM »

Very nice litho.
I cut a lot of lithos and have never had this problem.

I would be inclined to look for a machanical issue in the Z axis (also the X axis and spindle motor while you are doing it) like backlash, slack in the motor coupling, slack in the thrust bearing, loose parts etc. etc.

Hope this helps.

Tweakie.

7426

General Mach Discussion / Re: PWM and routers?

« on: August 20, 2010, 10:46:13 AM »

If you toggle the IJ mode setting to Inc (config / general config) that should do it.

Tweakie.

7427

Show"N"Tell ( Your Machines) / Re: The Laser Project.

« on: August 19, 2010, 12:27:30 PM »

Hi Sam,

I don't know just how long it took because I was busy doing something else and when I returned it had finished. Probably 1 to 1.5 hours.
Incidentally I made a mistake in the previous posting the vertical increment was 0.15 mm (if it was 0.015 it would still be running  ).

I can't try any lighting effects with this one as it has now been fitted as a replacement for a cat flap. 
I will make another similar and try different lighting effects and post the results.

Tweakie.

7428

Show"N"Tell ( Your Machines) / Re: The Laser Project.

« on: August 19, 2010, 08:53:44 AM »

Hi Dan,

When I re-read my previous posting I had missed out something which may be of interest.

Not all materials will change from a solid to a gas without going through the liquid state it is called 'sublimation' some things do it at room temperature (dry-ice and mothballs both miss out the liquid state) but acrylic needs a laser  .

Tweakie.

7429

Show"N"Tell ( Your Machines) / Re: The Laser Project.

« on: August 19, 2010, 08:13:18 AM »

Hi Dan,

How does this etching work? How does it produce the required shade? Doesn't it just melt the acrylic?

The laser doesn't actually melt the acrylic, the focal point is far too hot for that, it vaporizes it. There is no residue or melted stuff, and the vapor just gets sucked out by my extraction system.
The image itself is generated from a raster scan with the laser being switched on and off as necessary (bit like an inkjet printer I suppose but just one line at a time). This is bit of a painstaking process for my machine because the mass of the combined X and Z axis is such that my maximum, reliable G1 feedrate is only 4000 mm / min. and with a line increment of 0.015 mm it took some time to complete.

Think you can do 3D shapes in a glass cube like those sold in souvenir shops? That would be lovely. But then you need to focus the laser at different heights -  can you do this?

No can't do this. The wavelength of my laser is 10.6 microns and that treats almost all stuff that we see as being transparent as opaque and dumps its energy on the surface. (Different wavelength lasers each see materials differently).

Hope this answers your questions,

Tweakie.

7430

FAQs / Re: newbei: what to buy for my 1st CNC ?

« on: August 19, 2010, 07:25:14 AM »

Sure is Rich.

When you do these things and it is all fresh in your head you don't need a schematic but a few years down the line .......
I got the idea from some other machine photos I saw here somewhere.

Tweakie.