Messages

1041

G-Code, CAD, and CAM discussions / Re: Digitizing wizard results

« on: February 01, 2012, 08:35:46 AM »

Thanks Russ. Just a thought Darryl - "normally" you'd take the wizard output file and use it in a CAD package to create a model of your original object. You'd then use CAD to produce a toolpath. If you want to skip these steps you need to cut with a ballnose that's pretty much the same size as your probe tip. Sorry if I'm stating the bl**ding obvious 

Ian

1042

G-Code, CAD, and CAM discussions / Re: Digitizing wizard results

« on: February 01, 2012, 07:53:09 AM »

Russ - doesn't your option just add in X,Y and Z i.e. it doesn't add in any G commands so in answer to IB's last question - neither?

Ian

1043

General Mach Discussion / Re: How many limit switches

« on: February 01, 2012, 05:31:06 AM »

Many options but minimum, if you want limits AND homing AND gantry aligning is 4 switches and 2 input pins.

Limits and homing: A switch mounted on one end of your gantry (your Y) that hits a wedge at each each end of X travel - that's your X switch. A switch on your Z assembly (not the bit that goes up and down) that hits a wedge on each end of your gantry - that's your Y switch. A switch on the moving part of Z that hits a wedge on each end of the stationary part of the Z assembly - that's your Z switch. Wire all these in series to 1 input pin and set that pin in ports n pins for limits and homing for X,Y and Z.

To add gantry aligning to the above: Several options: 1 option: A switch mounted on the other end of your gantry (your Y) that hits a wedge at one end of X - the end you want to call home. Wire this to a second input pin. Set it as home of your slaved axis in ports n pins.

1044

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: January 31, 2012, 04:51:33 AM »

Took me a while to get my head round your pics at first but then I realized (I think) you've rotated the parts in your pics anti-clockwise by 90 degrees!!! (Your start/end from your code is top-right but in your pics it looks like it's top-left!

The second one I turned the CV distance on and set it to 25 units (whatever a unit is , I dunno).

This is saying it can start rounding when you're within 25 inches (your units) of the corner. Your whole hole is only a couple of inches so your ALLWAYS within 25 inches so this setting is going to have no effect at all. I'd suggest you try a CV distance of 0.25 and work down to 0.125 or so - that sort of range.

The third I slowed it to 238IPM. Still no difference.

Well I wouldn't say NO difference. It's slightly better but I agree still no good. Again your CV distance of 25 inches is going to have no effect. BTW - are your X and Y axis vel and accel the same? The rounding doesn't look symetrical.

The last one I checked off the "stopCV ON >0". The results were way better, and something I could live with. It's only thin material that will be an issue anyways.
The machine didn't seem to run any harder than normal.

Stop CV on > 0 is turning OFF CV - you're effectively cutting Exact Stop. If your happy with this then OK but I'd take this as a clue to trying CV feed starting at say around 50%. Of course if you get down to just a few % your effectively turning OFF CV again.

We must be running different versions(;-) I'll go back to drinking coffe now.

Yeah - but what's in the coffee Tel?  

A vid for our viewing pleasure.
http://www.youtube.com/watch?v=aXEFGmkqvQs&feature=player_embedded

1045

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: January 30, 2012, 05:23:16 PM »

Sorry Tel, it's been a long old day and I'm about to hit the sack but you've lost me there old buddy. He's rightly got kerf to the left so I'm not with you. You want to run that by me again?

Ian

1046

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: January 30, 2012, 01:10:28 PM »

LOL - Thanks John - you've made my day 

1047

VB and the development of wizards / Re: QueryPerformanceCounter in currency type mismatch

« on: January 30, 2012, 01:07:31 PM »

AFAIK the currency type isn't supported by CB. It's listed yes - but supported no. FWIW the currency type as used here is a complete kludge anyway and is only used because VB (and thus CB) doesn't support unsigned types - which as you've found can be a real PITA - Thank Bill G. for that.

1048

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: January 30, 2012, 10:01:12 AM »

rrc1962 - a peace offering  

Before I first bought Mach I contacted Art and asked how good the CV was because at the time I'd struggled to figure out exactly how to tune it which we all know is not hugely well documented. His answer was the defining reason why I bought the licence and then spent a lot of time tweaking and playing to see what it could do. I'm no expert but I do have a pretty good feel for it and have helped Brian in the past to trouble shoot CV faults and suggested corrections to errors in the CV documentation. I see a lot of posts where folks recommend similar settings to those you've suggested and to me, this is a shame. Not only is CV capable of so much more but settings that work for one person can be useless for others. It so much depends on the individual machine's capabilities. I hope I've helped get accross in this thread why IMHO "one size fits all" harsh settings are doing Mach's CV a big disservice.

Anyway I hope you havn't dropped me off your Christmas card list but if so you arn't the first and I doubt you'll be the last  

Cheers

Ian

1049

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: January 30, 2012, 09:40:47 AM »

Yes - most CAMs will "roll" round reflex angles - or at least they should AFAIK. They will not do this for any other angle - they can't because you can't "roll" around those. You will have to create those other arcs yourself in your CAD.

Ian

1050

General Mach Discussion / Re: corners getting radiused at higher speed on plasma table

« on: January 30, 2012, 09:18:43 AM »

Hi Dan - There is actually a clue here for you perhaps which may help you in your tuning. If you're happy with the sharpness of the outside corners, that shows that CV is pretty much holding round those small arcs. You could try putting similar size arcs on the inside path. They won't cut as sharp as the outside of course but they may be better than what you have at the moment. One more thing to try anyway.

Ian