Messages

5421

General Mach Discussion / Re: Axis stay short of where they should go

« on: August 06, 2011, 05:26:08 PM »

Mach will ALWAYS go the closest position it can go to the commanded point based on step size AND it does NOT accumilate error.  IF it did then you would NOT have gone back to zero(;-) IF MACH has to hold short based on step size THEN at the next point it CAN it will add the hold short value back in.

I would guess that your steps per unit are not exactly perfect. When that is so then when you make a LONG move you see the error and when you move BACK to the start it will always be exactly where you started.

Just a thought, (;-)TP

5422

G-Code, CAD, and CAM discussions / Re: G40, G41 and G42 have no effect.

« on: August 06, 2011, 11:26:28 AM »

I have done many gear type parts (belt drive pulleys) in LC using tool comp. IF you do it correctly it works ok. It does cycle the tool comp for every pass which is anoying but the basic process  works fine.

You do have to make sure that the tool table in mach is set correctly with a proper offset value for the application. You have to have a smaller diam tool than the smallest radius your profile requires.

When testing it was min part radius X .625 to make SURE mach would not error on a gouge situation. That may have changed in mach and you can run same min radius. Check the Mach updates list.

Hope that helps. (;-) TP

5423

General Mach Discussion / Re: Type of Construction for Aluminum Milling

« on: August 06, 2011, 11:18:07 AM »

Hood has you on track.  To do metal parts a Mill is best overall.  A router can do simple metal parts BUT its limitations are normally the spindle is way too fast and the machine is NOT near rigid enough to maintain accuracy in metal work.

(;-) TP

5424

General Mach Discussion / Re: How can I continue g-code tomorrow ?

« on: August 06, 2011, 11:11:04 AM »

Yep when you use RFH mach preruns ALL the code at hyperspeed reading (does not move the machine) That way it KNOWS everything it needs to know to restat your program. ALL the modal values are allready set for you.

Just remember it will restart at the END of the previous line to the one you select. IF than line ends in the bottom of a pocket you need to make sure the machine is lined up to MOVE to that spot so it does not crash into the part to get there.

Sling some chips for me , (;-)TP

5425

General Mach Discussion / Re: How can I continue g-code tomorrow ?

« on: August 06, 2011, 01:08:35 AM »

COme on guys just try it in the air with no part or tools loaded. It is not rocket science.

Load a program  move to line inside the program and press run from here and then start and SEE what happens. Follow the prompt from the Message box that will appear. It tells you where you are at position wise and where it will go to get to the part position and gives you some restart options like start spindle.

It will not blow a fuse or cause warts to appear on your finger, just try it  (;-) TP

5426

General Mach Discussion / Re: Type of Construction for Aluminum Milling

« on: August 05, 2011, 03:45:45 PM »

Well that is a pretty open question(;-) What type of parts what type of alum is this production or just hobby. Now HOW big are your parts(;-) and what shape considerations are you talking. SImple 2.5d parts 3d parts 4th/5th axis machining?

It all depends, (;-) TP

5427

General Mach Discussion / Re: How can I continue g-code tomorrow ?

« on: August 05, 2011, 03:06:24 PM »

Easy Just restart at a point that is a line not an arc "previous" to the arc where you stopped. All modal values have to be set. G1/G0? Feedrate, SpindleSpeed,G20/21, G90/91.etc,etc.

Run from here works well and does all that for you based on the Gcode and gives you the option to restart the spindle.

NOW note: None of these options will work well with SUBs or macros or parametric Gcode as in most cases there are no Know values until the function actually runs and Variables are calculated.

Also with tool comp you MUST allow room on your restart for the machine to cycle the comp before it can restart or else you may crash the tool into the part or machine table.

(;-) TP

5428

General Mach Discussion / Re: How can I continue g-code tomorrow ?

« on: August 05, 2011, 02:14:05 PM »

The first problem is that the machine will loose its exact position when you shut it down. You will need to Rereference the machine to home on startup. That will place you back to a known position +/- the accuracy of your referencing switches.

The second option is to reference the machine to a KNOWN point on the material or table and then set the dros to those values. That will reference you BACK to the part. A edge reference in X and Y or a simple center of a hole will do.


THen the easy way toRESTART is to use RUN FROM HERE. There are some quirks to this as well but for the most part it works fine on simple Gcode. Just follow the prompts to restart. NOTE it will take you BACK to the line BEFORE the one you select. So check your tool/fixture clearances to allow a safe move to the start point.

The Run Next Line can work BUT you cannot restart in an arc or you will get that message(;-) at that point mach does NOT know where the last move was from so it cannot determine where the arc should end.

If you want to use Run next line you HAVE to make sure your MODES are set correct for where you are at in the Gcode. Then start from the beginning of a line not an arc.

Just some thoughts, (;-)TP

5429

General Mach Discussion / Re: G31 Probe problem

« on: August 05, 2011, 12:17:24 PM »

HIYA Ian, I had thought about that OR more likely "slaved axis" especialy with a plasma table(;-) they use Slaved axis for the gantry.

(;-) TP

5430

General Mach Discussion / Re: mach3 modbus or serial communication limitations

« on: August 05, 2011, 12:13:39 PM »

Why not simply use a standard or MINI  key board and setup hotkeys for your functions. I use an industrial keyboard that has 24 Fkeys and CAN do more with alternate hotkeys.

Or use the Pokeys usb I/O unit and add the keypad matrix switches (May require programming the I/o functions)

Why reinvent the wheel the old one rolls very smooth(;-) TP