Messages

241

General Mach Discussion / Re: Controller doesn't recognize Mach3 at all.

« on: January 10, 2007, 10:54:39 PM »

Do you have an E-stop installed on your computer?

If you do, try pressing it and then clicking on the flashing reset button. If this works then you have the active low setting on your e-stop configuration the other way around.
hope that helps
anyone else? any suggestions?

Regards
Fernando

242

Tangent Corner / Re: Servo inertia calculations

« on: January 10, 2007, 02:12:06 AM »

I found this document from oriental motor, it states some guidelines of the inertia ratio, but i think it doesnt say why it is needed

243

Tangent Corner / Servo inertia calculations

« on: January 09, 2007, 11:38:29 PM »

Hello guys,
I was looking over at the sureservo manual (automation direct servos) and on a sample calculation it states that the ratio between the load inertia, and the motor's inertia should be kept less than 10.

Does anyone know why is this? and does it apply to steppers too?

Regards
Fernando

244

General Mach Discussion / Re: New CV features

« on: January 09, 2007, 02:52:37 PM »

First off... I think the feed rate overide only affects the FEED rate not the rapid in the later versions of mach.

second, rounding is present in all machines, as Art stated, fanuc, mach and other machines capable of constant velocity. the thing is, most machines that do not have this problem use big enough servos to handle scary accelerations which make rounding a lot less. If you do not use constant velocity you SHOULD NOT see rounding.but maybe your machine is too flimsy that when it stops it wiggles a bit and and bad cuts are seen. if you set your acceleration way down, I mean WAY down, and use exact stop, im sure you wont see this, but then again, cutting times will go way up. so it is basically a trade off situation if your machine cant handle this shaking.

As for light at the end of the tunnel, well there´s QUANTUM, which is a whole new approach to things, which in my opinion is the way of the future, and I am sure there are not many controllers taking that approach.

Regards
Fernando

245

Show"N"Tell ( Your Machines) / Re: Robotic Loader/Unloader

« on: January 08, 2007, 02:31:22 PM »

thats another way Graham,

But how do you tell the mill (and code) to stop until the robot gets the part out and in.
Im not familiar with that code, but im guessing you can tell the robot to send the optional stop while it is doing its thing.

As for triggering the cycle start with an input, im not familiar with that either, im sure someone will pop up and tell us how, but if you have a keyboard emulator (i-pac) you could do it by asigning a buton to the ALT-R combination to make a cycle start
Regards
Fernando
PS. lot sof info on the customization wiki about that

246

Show"N"Tell ( Your Machines) / Re: Robotic Loader/Unloader

« on: January 08, 2007, 01:28:27 PM »

What I would do, and thats just me....
Put an M30 at the end of the gcode, this will shut off (in my case all inputs, you cand put that in the config somewhere) all inputs, and rewind the gcode to the begining.
Just before the M30 i would put an M code to trigger the output signal to de robot.
Then on the code for the robot i would put a dwell at the begining to let all inputs turn off (spindle spindown time for example), then have the robot do its thing, and at the end of the robots code, put an Mcode for an output trigger that would make a cycle start on the mill.

But youd better not run out of stock parts for the robot to put into de mill!

Regards
Fernando

247

Feature Requests / Re: Variable soft limits ???

« on: January 08, 2007, 11:09:44 AM »

You could try doing this by the MDI line,

Just type G01 z-.006, do your cut, then type G01 z-.016, do your second cut, and so on and so forth.

Or you can set a custom step increment in the jog window, the increment would be the total depth divided by the number of cuts, in your example it would be 0.0085", the put mach in jog step mode instead of continuous, and just click the -z jog button once before each cut, the z axis should move just that amount.

Regards
Fernando

248

General Mach Discussion / Re: Changing init line

« on: January 07, 2007, 04:33:44 PM »

Thats right hood.

Either upgrade your mach version (BACKUP YOUR XML!!!) or downgrade to the screen designer that came with mach 3 a while ago, you can find that in the downloads section of this support page.

Regards
Fernando

249

General Mach Discussion / Re: hexapod

« on: January 06, 2007, 01:40:31 PM »

not a chance until Art and Brian get to implementing inverse kinematics. 
Regards
Fernando

250

General Mach Discussion / Moving table VS moving gantry

« on: January 05, 2007, 05:38:41 PM »

Hey Guys,
Ima firm beleiver of definite purpose designing when it comes to building CNC machines. What I mean is, the last machine we built is a big router, suitable for well... routing we have done some 3d releif work and v carving, but the size and weight of the machine make it a little unsuitable for that aplication, mainly because of vibrations, nothing that cant be  fixed by adding supports to reduce the shaking, or using quantum in the near future. The machine is big at 12' by 12'.

Lately we were approached to make a thermoforming tooling out of aluminum. Although we were able to do it, i didnt like the machines performance that much, I know I could have taken deeper depths of cut (cutting at 0.010") and at faster feeds (30 ipm right now). but the machine wouldnt allow it. The mold was about 20" by 26".

Now I was thinking, if I were to build a machine just for that kind of jobs, small print (maybe 48" by 48" or something) designed specifically for milling aluminum at decent rates. What would the best aproach be?
I was thinking in using AC Servos at about .85kW 2000rpm, max rapid rates at about 200ipm, with ballscrews al around, 0.2" lead, with a 2:1 reduction, that turns out at rated force of almost 2000lbs, and a max force of 6400lbs. Using HiWin rails maybe 25mm.

And on top of all this, stiffen the hell out of the frame and all components. That is why i was thinking of going with a fixed gantry and moving bed. that way I can stiffen the gantry a lot without concerns for weight.

So basically I am looking for opinions on that aproach, components and the using of a fixed gantry vs going with the moving gantry.

Thanks in advance
Fernando