Messages

181

General Mach Discussion / Re: Accuracy and adjustment

« on: April 07, 2014, 10:03:43 AM »

I'd cut a 50mm square, then a 100mm square, then a 200mm square with the part zero at the bottom left corner of the parts and the same starting point on the machine.
The results should point to the error source,

 - Nick

182

General Mach Discussion / Re: Help sort- going in circles - need a compass

« on: April 07, 2014, 09:48:32 AM »

Set your machine zero (check in Offsets Tab) at full positive travel of all axes using the Right Hand Rule, bear in mind that this references Tool Travel -

http://www.tadesite.com/article_pic/cnc-Dia.jpg

You can then set Tool Offsets that deal with the length of tooling from a fixed datum point such as your quill face, set your edge/surface finder first and use your edge/surface finder to get values with which to Set Home Offsets where you want your general working zero offset to, I'm currently using table surface centre of travel. Then use your finder to define Work Offsets that account for the height and position of your vice or fixture.

Home swithches are absolutely brilliant, with Home Offsets set all you then need is a Ref All Home and you're ready to select tool and work offsets and pick up where you left off before powering everything down the day before,

Regards,
Nick

183

General Mach Discussion / Re: 3D printing with Mach 3

« on: April 07, 2014, 09:19:23 AM »

Not a direct answer to any of your questions but I know you could use a PIC chip and suspect you could use an Arduino or Stamp PC to take the Mach spindle speed output and run a stepper driver with it.
Regards,
Nick

184

Show"N"Tell ( Your Machines) / Small Tools, Tool Offsets & Toolholders

« on: April 07, 2014, 06:02:14 AM »

My CNC Mill came with a Coventry Quick Change Holder installed plus 1 x 6mm endmill holder and 1 x 10mm endmill holder to fit it.
Once I'd implemented Tool Offsets I had visions of a rack of tool holders with permanently fitted tools, on investigated pricing for additional holders, at £65 and upwards each that will have to wait a while, in the mean time I came up with a viable alternative for tooling up to 7mm -



The ER11 collet chuck shafts were cut down and flats cut, the 10mm shafts allow a tool to be perfectly repeatably installed in the 10mm holder with just a grubscrew, they're far more affordable at £15 or so each.

The funny looking holder with a big thread is a JT6 holder I picked up at a local tool shop, I fitted it with a Myford spindle nose, that lets me use my Myford ER25, ER32 and ER40 collet chucks  

 - Nick

185

Show"N"Tell ( What you have made with your CNC machine.) / Milling something I'd normally turn

« on: April 06, 2014, 05:47:30 AM »

I prototyped this manually on the lathe, (I don't have a CNC lathe yet) and found the 5 different internal diameters and depths plus threading the second (18.6 ID 8mm deep) section entirely do-able but didn't really fancy doing a batch of 10 or more that way.
I'd modelled the job in CAD as the back face has geometry which can't be turned - a closely spaced combination of straight and circular features.
Only after I'd CNCd the rear face did it occurr to me to flip the part and CNC profile the IDs, then thread milling crept into my mind and while I had the fixture set up picked up a 14tpi threadmill and cut the full thread in one pass.
Here's the first one off the mill -



There was no reason not to bung it on the mill, it just seems I'm still dragging around my Manual Machinist's Mindset which has me thinking round parts should only be in a lathe - I'm now working on that

 - Nick

186

*****VIDEOS***** / ECC 4th Axis Test

« on: April 01, 2014, 05:19:01 AM »

I've finally got the Ebay Cheap Chinese 4th up and running with the help of a compatible driver board from Routout CNC, this video shows some testing for a part I'm currently manually machining, two sides have been faced, the compound curved section has been roughed out with a 6mm 2 flute endmill and part of the first pass with a 6mm 2 flute ball end mill is shown.



I now have to machine a permanent plate for the 4th axis & it's tailstock with eccentric buttons underneath to fit the table slots for axis alignment and Y position plus one for X position. 
Apologies for the ropey camera work, also the video quality was far better before uploading to Photobucket

 - Nick

187

General Mach Discussion / Re: Need help with spindle relay

« on: April 01, 2014, 03:37:25 AM »

One of the least complex ways to go would be to use a micro-relay driven by the board & use that to switch 5v to power your spindle relay.

 - Nick

188

General Mach Discussion / Re: G28 G91 Z0.

« on: March 27, 2014, 12:19:18 PM »

I've just tried it on my laptop (no driver loaded) and it works as you expect with Z going to zero and stopping.

189

General Mach Discussion / Re: G28 G91 Z0.

« on: March 27, 2014, 11:53:23 AM »

Would any of this this -

(BORE 0.050 HOLE 0.076 DP)
(T2  D=0.0394 CR=0. - ZMIN=-0.076 - FLAT END MILL)
G90 ( G90:Absolute prog )
G94 ( G94:Inch per minute )
G40 ( G40:Tool radius comp off )
G49 ( G49:Tool offset comp cancel )
G17 ( G17:X-Y plane selection )
G20 ( G20:Inch system selection )
G28 G91 Z0. ( G28:Return to home G91:Incremental programming )
G90 ( G90:Absolute prog )

(BORE1)
M5 ( M05:Spindle Stop )

Throw any light on your issues?
If you're setting a tool length your code is turning that off and may be trying to drive the reference level from which you measure your tool to the desired location rather than the tool tip.
..
 - Nick

190

General Mach Discussion / Re: Work & Tool Offset Backup Location?

« on: March 26, 2014, 09:48:10 AM »

Brilliant! Thanks Russ,
I had the .xml stuff but hadn't transferred the .dat stuff from the macros folder,
Many Thanks,
Nick