Messages

6251

Show"N"Tell ( What you have made with your CNC machine.) / Re: Very small parts of another kind

« on: November 15, 2010, 12:06:32 PM »

Thanks for all the information Mike.

I had always thought of DeskCNC as working with it's own  proprietary controller rather than a creation tool for GCode to use with Mach.
I can see the need for an accurate and rigid machine construction for this small stuff. 
Keep up the excellent work and of course keep posting the pictures.

Tweakie.

6252

Show"N"Tell ( What you have made with your CNC machine.) / Re: Very small parts, smallest possible engravings.

« on: November 15, 2010, 11:44:52 AM »

Hi Glad,

I can't engrave brass, to be able to do it would cost mega bucks I am afraid. 
Small CO2 lasers, like mine, see all metals as being reflectors and the only chance you have is to change the appearance of a surface coating. Their saving grace is that they are extremely good with acrylics and can cut up to 10mm thickness.

Tweakie.

6253

General Mach Discussion / Re: HELP! - breakout board diagnosis help needed

« on: November 15, 2010, 08:15:10 AM »

Hi Jen,

Thought you would have tested the wires continuity and connection points but worth a try.

what i would like to know is what the BOB expects in the way of input from the parallel port. is it just a nice square 5v "wave" for "step" and the same to change "dir"?

The direction signal is either high or low and remains in it’s set state until another command tells it to change (axis move in opposite direction). The step signal is a square wave pulse which Mach allows to be altered in terms of width and active high/low.
Most BoB's require a 5 Volt peak to peak signal here and some computers, especially laptops, only output around 3.3Volts and these do cause problems.
Most PC parallel ports are more than capable of sourcing 10 mA per pin so would light your BoB leds but it is risky to over do it and possibly damage the port.

Just a thought here but have you tried Config / Ports and Pins - check the ‘Sherline ½ Pulse Mode’ box ?  this alters the pulse width and may cause different results.

Lets hope it is the BoB and that your new one solves the problem.

Tweakie.

6254

Show"N"Tell ( What you have made with your CNC machine.) / Re: Very small parts, smallest possible engravings.

« on: November 15, 2010, 06:44:19 AM »

Sorry Glad we are hijacking your thread here.

Rich,

There is an interesting abnormally with the 0.5mm x 0.5mm matrix in so far as the dot size is smaller than I can cut a hole in a piece of kapton. It would appear that as the center of the beam contains more energy if you fire it quick enough you can get a smaller dot size. Strange.
The 0.5mm x 0.5mm tests have been done on anodized ally these photos are of traffolite engraving laminate.
Here is a slightly closer shot of the previous pic.

Tweakie.

6255

General Mach Discussion / Re: HELP! - breakout board diagnosis help needed

« on: November 15, 2010, 05:23:14 AM »

Hi Jen,

At the risk of stating the obvious, are you certain that you are making the correct connections between your C35 and your stepper drivers ?.
Have you also checked that the active high / active low signal condition between Mach and your drivers is correct ?.

Tweakie.

nb. Meaning of life and purpose of life are the same thing and can't be discussed here without upsetting the moderators 

6256

Show"N"Tell ( What you have made with your CNC machine.) / Re: Very small parts, smallest possible engravings.

« on: November 15, 2010, 05:10:22 AM »

If any of you had any experience with small scale engraving please respond.

Excellent work Glad. Real neat job.

Although not really relevant to rotary engraving I am trying to produce a small checkers board. I am cheating a bit by using a laser but so far with an 8 x 8 matrix I am down to 0.5mm x 0.5mm. These were the initial tests with a 14 x 14 matrix and the smallest here is 1.25mm x 1.25mm. The problem is photographing the result, looks like I will have to invest in one of those USB microscopes 

Tweakie.

6257

Show"N"Tell ( What you have made with your CNC machine.) / Re: Very small parts of another kind

« on: November 15, 2010, 04:03:53 AM »

More than surprising Mike that is just excellent.

Which software did you use to create the raster toolpath from your image please ?

Tweakie.

6258

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: November 15, 2010, 03:04:38 AM »

Art,

Thank you for the information. I must admit to not fully understanding how the dots are generated but perhaps it will become clearer after more thought. One thing that I had not considered is that the banding is created from the X step info - I had, mistakenly, thought that if it was software related it would have been related to the Y axis stepover.

You have given me an avenue to investigate regarding care in the initial image sizing and pixel count rather than just taking an image and scaling to fit at the last moment.

I will experiment with the grayscale issue a bit more but so far I have only been able to resolve, at any one time, 5 shades out of a possible 8. So I need to discover just why I am getting such a large step size so that I cannot see more than 8 shades. http://www.cooperman.talktalk.net/grayscale1.bmp

There has to be a solution to this "banding" and I just hope that I find it sooner rather than later. 

Tweakie.

6259

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: November 14, 2010, 11:32:17 AM »

Hi Art,

I understand what you say and the effect is demonstrated in the background of this image http://www.machsupport.com/forum/index.php?action=dlattach;topic=12444.0;attach=23043;image . The background gradient contains more shades than the 8 available from the plugin so it is split into the nearest match and thus the bands which only affect the background and not the foreground.

What I am trying to resolve is, I think, different and can best be seen in this image http://www.cooperman.talktalk.net/files/27_files/image762.jpg which is purely monochrome with no shades of gray.
I can produce a number of identical images, one at a time, side by side on the same material and with exactly the same settings yet the banding pattern, across the whole image, is different between each image.

Grateful of any additional thoughts you may have on this one.

Tweakie.

6260

Mach SDK plugin questions and answers. / Re: Impact engraving plugin

« on: November 14, 2010, 03:53:23 AM »

Excellent work Obal.

I am having a problem with "banding" (horizontal bands of differing contrast) please look at this image http://www.cooperman.talktalk.net/files/27_files/image762.jpg

On one of your images it looks like you have the same problem - Is this the case ?

Tweakie.