Messages

571

General Mach Discussion / Re: Problems,Problems, Problems, Wiring

« on: May 27, 2008, 11:33:47 AM »

I honestly have no idea - since I didn't do it. If Brian did it, it would probably be alright for you then.

There is no problem with an XML file - all it means is a configuration of Mach 3 that you are using. You will be well capable of doing that by the time we are finished. If you are at the machine now, connect up your BOB (have you got a 5 volt power supply for it ) and we can run through setting up your XML file.

572

General Mach Discussion / Re: Problems,Problems, Problems, Wiring

« on: May 27, 2008, 12:29:22 AM »

You seem to be making heavy weather of this - and looking at it as one big wiring problem.

It is, in fact several little wiring problems, each one fairly simple.

I have re wired my set up to a PC case for more room

I am not sure what this means. With Mach 3 there are three basic ways to connect to your P.C. All work, and it depends on your own needs.
1. I have a lead from the computer LPT1 (printer) port to a dumb (no power unit) Break Out Board in my control box.
2. If there are not enough inputs/outputs from your LPT1 port, you might get a commercial port connected to your computer which gives you additional inputs and outputs. This may or may not come with a break out board.
3. You can invest in one of the new smooth steppers, which connect to the P.C. via a USB port (These are new - so I have no idea what USB connection you are referring to, unless it is part of the C10)

I will assume therefore that you have a computer, and have connected it to your C10 breakout board via the printer port cable.

You require a 5 volt supply to the C10 board, which connects to the board on the top right hand side (assuming the printer port cable at the top)
I do not reccomend that you take the 5 volt from your P.C.

At the same time as connecting the 5 volt supply, connect a 5 volt jumper to the enable pin - next to 5v - or you will not get any output from the board.

The paperwork that comes with the C10 is misleading. You cannot get inputs and outputs from all pins, if you are using the computer LPT1 port. If you are using the LPT1 port you are limited to 3 sets of pins - and they cannot be altered for input or output.
Pins 2-9 are outputs only - normally used for connecting to the axis drives (in your case the Geckos)
Pins 1,14,16 and 17 are also outputs only - I use mine to control Spindle motor M3 M4 and M5, together with coolant
Pins 10,11,12,13 and 15 are Inputs to the system - only these 5.
The rest of the wires - 18 to 25 are signal return wires to the computer.

This completes your C10 board. If you connect this to your computer and power up the 5 volt supply, you can test the various pins. My favourite way to do this is (on Config/Ports and Pins/Outputs) allocate M3 and M4 in turn on each pair on pins. By typing in M3 or M4 on the MD! line of Mach 3 you can see the pins change voltage with a voltmeter.

Your Geckos are completely seperate to the BOB and should be treated as such. They should be wired with your supply voltage for the drives and firmly wired to your motors, as per their own diagram. When you turn on their power supply, I think the red led will go on ( I might be wrong on that)

To connect the BOB to the Geckos requires three wires to each drive. These should be taken from the bottom row of pins - 2,common,3 - 4,common,5 - 6,common,7. the numbered pins go to the step and dir on the Gecko, and the common goes to the Gecko common (which is next to the step and dir pins.) The common should be +5 volts, so ensure that the jumpers for pins 2 - 9 common (above pins 4 and 5) are set for 5 volts. The Geckos have a disable pin - leave this unconnected.

This should get you going. Only do one drive at once, do not try and do all three together.

I assume you can then work through Mach and set up the various configurations - if not, come back and we'll have another go.

573

General Mach Discussion / Re: button to change feed, search variable

« on: May 24, 2008, 01:15:06 PM »

Andy -

What is the feedrate you have set on your motors (Config/Motor tuning)?  This is the maximum speed for the axis. You can only change your feedrate to something under this.

You can write a Visual Basic program to change the feed rate when you push a button, or you can change the Feed Rate DRO by entering new data.

574

General Mach Discussion / Re: 3 dimmensional trim path

« on: May 24, 2008, 04:52:41 AM »

What size are the parts you are looking to trim, what is this trim path on the diagrams you have got. To trim the trimpath, will it require all three axis to move simultaneously, or can you fasten the part down on your table is such a way that only two axis need to move to follow the path (yes - the third will have to come down and up at the end - with the tool - but does not take part in the trimming)

To give you an idea - a CNC machine is programmed on a graph of X and Y with commands which move the cutter from where it is now, to where you want it. e.g. starting at point 0,0 - G0 X1Y0, G0 X1Y1, G0 X0Y1, G0 X0Y0 - will move the cutter in a square of 1 unit dimension. If you then want to add the Z axis up and down, you can add the z position to any line as well (in fact Mach3 will deal with 6 axis). As written, the axis move simultaneously - if you want one to move, it is the command followed by the axis to move.

If your drawings show positional information, then you can write programs from it. BUT to make it worth while, you really need to be repeating it a few more times - repeatability is one of the advantages of CNC - say a minimum of 6 depending on how quickly you can write the program. Also CNC does not do curves (apart from circles) so any curve has to be built up from little straight lines.

If these parts are all different - you may find that some form of probe tool and a mapping program would be an advantage so you could map the trim edge and run a program from that.

You will also have to take into account the diameter of your tooling - so you have plenty to go at.

575

General Mach Discussion / Re: general problems with mach3

« on: May 24, 2008, 03:53:11 AM »

Sid -

No - what I am saying is - it is a bit like shop sales people on an electronic till. If they make a mistake they have no idea and charge you just the same. I always have a rough idea how much the items I have bought are.

By all means use Arts software - but I think you should have an idea of the answer before you start, just to make sure that if you make a mistake inputting the information (say by a factor of 10) or your fingure hits the wrong key and it comes up with a different result to the one you were expecting, you know to have a second look.

I suppose the same can be said of me- I should calculate - then use Arts Software to confirm it - just in case I have made a mistake.

Endgrainguy -

Yes if you are using this for woodwork - and are only looking for a couple of thou in accuracy, then you should be alright once you have got over this hiccup. You must excuse me, I work in steel where 1/2 thou is the difference between fitting and not fitting. Yes - if you understand the point I was making, gearing down the drive between motor and leadscrew will give you that much more accuracy - and your motors should be capable of (to a point) speeding up to compensate. It is a question of compromise for the job in hand.

Jim

576

General Mach Discussion / Re: general problems with mach3

« on: May 23, 2008, 07:48:55 AM »

Once you have found the reason - the rest should be fairly simple.

I have great respect for Art and the Mach software, but I cannot agree with allowing Mach 3 to determine you number of pulses per inch. The only trouble is - if the answer is wrong, how do you know. I appreciate Art was probably trying to simplify things, and he has done in so many other respects.

Steps per inch is not difficult to calculate - so calculate it. The either use Mach 3 system, or a set of digital calipers to confirm what you knew all along.

Endgrainguy - well done - but wait til you get going with backlash, offsets etc etc. It's great fun.

Was my calcu;ation of your steps per inch correct - or am I far too low - your accuracy will suffer if it is too low. There is also the problem, that if you miss any steps - each step is a greater distance, so your error is worse.

577

General Mach Discussion / Re: general problems with mach3

« on: May 22, 2008, 03:27:24 PM »

It seems to me that you are making far too much of this.

1. You started off by saying that you bought your copy of Mach 3 on E Bay.

Start at the beginning.With your P.C. . Format the C Drive and run in your back up copy of Windows. Do not load anything else onto your machine, except your software to connect to the internet. This should get rid of any **** that found it's way onto your machine.

Download onto the machine the latest (Tried and Tested version) of Mach 3. This does everything that a disc version does - but is limited to 500 lines - (but at the moment your are not even managing one.) Do not download any of the developement versions.
I am not sure what speed you are wanting to run at, but the latest version of can be set to several speeds. Try a kernel speed of 45,000. Once you are up and running, you can try your disc version.

I assume you have configured your ports and pins with the pin numbers for fastening up your machine.

The next thing is you motor speeds - Particularly the "number of steps per unit". There is no guess work in this, it cannot be wrong, it doesn't alter from time to time.
The drives you are using will use micro steps - you say you are using 25 microsteps. I have not heard one as high as this and it is probably unnescessary. Microsteps are not used to determine accuracy, because they are inaccurate in themselves.
The motors you use will be 1.8 degree (probably) - that is 200 steps per revolution
If your motors are direct drive to the leadscrew, then this is 1. If there is any gearing down then specify the gearing - mine are 3
You are saying that you have a 20mm leadscrew. I cannot know wether you are working in mm or ins. The factor for this could be - divide by 20 if you are in MM, and then multiply if working in inches.

If you are working in MM then your equation is 25 x 200 x 1 - divide by 20 i.e. = 250  - or for inches - (x25.4) = 6350. Now - either I have missed something - and I am hopelessly low on your steps per unit - or
Your accuracy is **** becasue your steps per unit is too low. Mine for instance is 60,000 per inch - not 6000. The problem appears to be the lead screw whcih you seem to be saying moves the table 20mm per turn. Mine moves the table 1/10th of an inch, about 8 times more slowly.

You can only, by definition get an accuracy  of 1/6th thou, and that is using 25 microsteps. If you look at mine it is 1/60th. Micro steps are not inherently as accurate as full steps. I can get an accuracy of  less than 0.2 thou guaranteed - even ignoring the micro steps (on a Gecko it is 10)

The motors on your machine will turn much more rapidly, so, to offset the high ratio of the leadscrew, you should introduce a gear down facility of about 5 to 10. You motors will then need to make more steps per unit, giving you better accuracy.

I will say again - there is no alteration of your number of steps per unit necessary once you have calculated it.Set it in your configuration - set accleration to 0.5 - i.e. slow so as not to miss steps. Set your speed at say 10 inches - not too fast.

I am afraid my 63 years old pair of eyes have to use glasses and a digital vernier caliper - and I would urge you to buy one. Mine cost £10 - 20$ and is accurate to 1/2 thou.

You should then be able to set up your machine, zero all axis, then check each one by moving one inch with an MDI command and checking with a vernier caliper. You should not be more than a thou out. Make sure you always move the carriage in the same direction, i,e, move right, zero DRO's move right again 1 unit, check with vernier. If you are more than a thou out, something is wrong, but if your maths is right, it should not be the steps per inch.

It could be backlash, missng steps, etc etc - but that is another story.

578

General Mach Discussion / Re: Tool diameter measurement

« on: May 22, 2008, 02:01:18 PM »

My experience with lasers is down to two Maplin lasers shining ot various detectors on my lathe/mill. I am down to less than 1/2 thou accuracy, and with a lens to focus the laser properly, I could get it finer. You could then shine this onto a detector. You could then move the tool in slowly to break the laser beam, but my concerns about the angle of the flutes hold the same argument.

579

General Mach Discussion / Re: Tool diameter measurement

« on: May 22, 2008, 01:56:32 PM »

Yes - you could, I am sure, use a probe to measure the current diameter of a cutting tool, compare that with the current diameter stored, and either change the diameter, or change the wear factor. You could do this quite simply with a vis basic program.

The problem would be, however, where do you measure the tool from.

If it is across the flutes of a slot drill, then you must be sure that your measuring tool is a right angles to the flute, or you will get an incorrect reading. I cannot think of a way to achieve this with any certainty.

Perhaps the only way would be with an electronic type probe, which triggers when the cutter touches it, and you rotate the cutter at a fast speed and move the probe into it on a slow feed.

580

General Mach Discussion / Re: Can I turno On/Off I/O at any time in Mach3?

« on: May 20, 2008, 04:36:09 AM »

There are many ways to do this.

If you control  X and Y and move to the position. Control the cylinder movement with a Z axis to bring down the hydraulic cyclinder. STOP. Manually punch the hole. START. Move the cylinder back up. Move to the next position - the code will look like this -

G0 X10Y10 - move to position 10,10
G0 Z0         - move the hydraulic cylinder down to the punching position.
M1             - wait for the hole to be punched
Z10             - move the cylinder up, out of the way
G0 X35Y35   - move to position 35,35
G0 Z0          - move the hydraulic cylinder down to the punching position
M1              - wait for the hole to be punched.

The computer will not move the table until it has moved the cylinder up out of the way.

If you only do X and Y then you only need
G0 X35Y35   - move to 35,35
M1              - wait for cylinder to be moved down and the hole to be punched.
G0 X47Y53  - move to the next hole
M1              - wait for cylinder to be moved down and the hole to be punched.

Here the "Resume" button can be in series with a switch on your punch, so that you cannot move the table if the cylinder is not fully "up" out of the way.

If you do the whole thing -
G0 X35Y35    - move to the next hole
G0 X0            - bring the cylinder down
M3                - punch the hole
M5                - if needed to retract the punch
G0 X10          - move the cylinder up, out of the way
G0 X25Y50    - move to the next hole
Here M3 operates a relay to start the pumps on the hydraulic cylinder. M5 stops it, or releases a pressure valve retracting the punch.
The table WILL NOT move until each line is completed. You can put a "pause" in to delay, say 10 seconds, to allow the cylinder to fully retract. You could have a safety switch connected, so that the computer would not advance until the cylinder was fully "home"