Messages

771

General Mach Discussion / Re: I want to be clever !

« on: March 26, 2008, 04:58:05 PM »

Thanks for the help - I was doing the right thing - it was the picture size and type that it was baulking at

772

General Mach Discussion / Re: I want to be clever !

« on: March 26, 2008, 04:43:48 PM »

Thanks guys -

I think it is Clinton and Obama before election day !!!

773

General Mach Discussion / Re: How to: Modify z origin when work in progress.

« on: March 26, 2008, 04:38:59 PM »

I found something in Configuration when I was looking at it yesterday - is this what you are looking for

Config/Ports and Pins/Mill Options   -  Allow THC UP/DOWN control even if not in THC mode.

I have no idea how it works though.

774

General Mach Discussion / I want to be clever !

« on: March 26, 2008, 02:12:32 PM »

I want to change my details on the forum and include one of these clever little pictures - I keep doing what I think is right - clicking profile on the options and changing things - but it doesn't change.

What am I doing wrong

775

General Mach Discussion / Re: Home switches

« on: March 26, 2008, 02:08:35 PM »

I am not being critical - but - since you have wired the switches "active high" they will trigger if anything is loose, poorly connected etc.etc.
Are you sure that your installation is well soldered and robust before we start trying to find the problem

The motor moving the carriage can loosen something, or disturb it enough to give a signal. With modern electronics the signal need be only micro seconds long to activate.

Yes - it may be some cross signalling, the way you have run your wires, but before we get into that, test the obvious.
I have just spent all afternoon improving my installation - the system works fine, but funnily enough it is the limit switches and bits that cause the bother. There is a temptation to do without them, because my system runs well enough, but there is something in me that says - no, get it going properly, and life will be simpler.

I don't know !!!

776

General Mach Discussion / Re: Set up Mach3 software for my CNC machine

« on: March 26, 2008, 08:17:34 AM »

I, personally, think that "steps" per unit is misleading. I think it should be pulses.

Your stepper driver boards can run your motors in several different ways, either 1, 1/2, 1/4. or 1/8 step per pulse and some even go further. For best performance you need to run about 1/8 step.

This also has to "multipled in".  When you think about it, for accuracy, you really need as many pulses per inch as you can get. Mine at 4,800 means  that I get 4.8 pulses per thousanth of an inch.

You want to check your drivers, set them for 1/8 step and then multiply by 8 - 28,800 I think.

777

General Mach Discussion / Re: Servo axis switchable between spindle and angular position modes?

« on: March 26, 2008, 06:04:41 AM »

I wasn't thinking of changing the drive wires to the motor - I was thinking of changing the control wires to the driver - as you are saying, principally the "step" wire.

This, in essence, is what you will do anyway - switch from spindle control to axis control - I was just thinking of a way I know Mach 3 could handle as I understand it.

I don't even know if something as simple as configuring Mach so that the step output on both the spindle and the drive appeared on the same pin all the time, and you just used the one you wanted, would work - would one interfere with the other

I think the first question is - have you tried driving your spindle from an axis output - we can work out how to change the configuration after that.

778

General Mach Discussion / Re: Home switches

« on: March 26, 2008, 05:51:33 AM »

Are you saying it trips a limit switch when the carriage is no where near the switch

Now you have the system up and running - have a look at the videos to show you how they are controlled.

779

General Mach Discussion / Re: Online forum has exceded Yahoo membership as of today.

« on: March 26, 2008, 05:37:41 AM »

Benny - I'm not suprised. This is one of the best forums I've been on. Good questions, good answers and a lot of interest. There always seems to be about 500 people on it at any time of day.

780

General Mach Discussion / Re: Set up Mach3 software for my CNC machine

« on: March 26, 2008, 05:27:24 AM »

I take it you have downloaded Mach3. If not, do so. I assume all your cards are connected and wiring completed.
If not, don't worry, becasue you can learn a lot on the workbench, before bothering with the machine. The advice to look through the videos is good, I found them very informative, and if you download them, you can refer to them whilst working on the mill.

If you want to know where to start, then getting the axis moving would be the first thing. I might bore you ( and I have a feeling the Probo boards might already have a lot of this pre organised - however -
Mach 3 needs configuring to run your set up. This is where you need to start thinking. The first thing to do is configure the axis drive motors. These (as far as you are concerned) run on two wires, a "step" wire and a "direction" wire. These two wires go from your breakout board to a driver board (if you have a one piece board they might be already connected internally). There are two wires for each axis. There are normally (but not necessarily) from pins 2,3 - 4,5 - 6,7 and 8,9 on your breakout board to axis x,y,z and a.

To configure these you must start on Config/Motor tuning. Each axis has a page and what you must do is work out how many "steps" (or better word is pulses) the computer has to put out to move your axis one unit (decide NOW if your are working in inches or millimeters). It doesn't stop you running GCode in either measurement, but you have to set your machine up in all the same units.

Example - my motors are 200 steps per rev, and running at 1/8 step - i.e. 1600 per rev. The are geared down 3 to 1 to the leadscrew - 4,800 per turn and the leadscrew needs 10 turns per inch - 48,000 per inch. Enter this in the configuration . Calculate the other axis and enter them. Do not bother with velocity yet - enter perhaps 5 (easy to increase) and acceleration as 1.

In Port and Pins first page make sure port 1 is enabled - ignore the rest. In Ports and Pins/Motor Outputs fill in the information for each axis - as you have wired it - and then enable the axis - make sure ALL the information is in the line. If you are only trying say, one axis, then only fill in that line and enable it. Try jogging the axis - be patient - the jog control takes a bit of getting used to

That is enough diatribe from me - it should at least give you a start - and make a bit of sense of the videos and other information that is available.If you get the axis moving you can increase the speed until the motors start stalling and loosing steps - but bear in mind you have no safeties fitted yet and you do not want expensive collisions at the end of a run. You can jog the axis up and down, or better still start in the middle of the table (set all the DRO's to 0) and try a few GCode commands each way to move the axis  -  you can enter these manually - e.g. G0 X1 will move the table 1 inch G0 X0 will move it back G0 X1 Y1 with move it diagonally.

Try with callipers or whatever to see if your axis does move 1 inch as you have told it to. Bear in mind backlash - but that is another story.

Any more problems come back