Messages

1001

General Mach Discussion / Help needed to get web camera going.

« on: December 15, 2007, 03:29:54 PM »

I've just got a web camera - an Advent ADE-A1 - and I,ve got it working on the computer - click MyComputer/Scanners and Cameras/USB Video Device - and up comes the picture.

I've got the plug-in installed on Mach3 Mill and Turn - but all I'm getting in "Unable to turn on camera" when I fire it up.
It doesn't, to me, seem to be pointing at the right driver, but I can't figure out how to change it.

Can anybody help???

1002

General Mach Discussion / Re: spindle speed encoder conection

« on: December 15, 2007, 02:41:14 PM »

You can do it even more simply.  If you scan the posts it came up a short while ago. I bought an optical transmitter and receiver all in one - they are set at a V angle. You shine it on the spindle (mine is on the chuck). As a reflector I "borrowed" a small shiny stick on from my grand-daughter. I painted the rest of the track matt black.

This is wired directly to the +5v and 0v for power - and one wire into the "index" input on the computer - no need even for the slotted disc.

1003

General Mach Discussion / Re: Help about "24VDC/5.0A "

« on: December 15, 2007, 02:26:52 PM »

If three motors turn on simultaneously they could sink 7.5 amps - way beyond the capabilities of your power supply. If you have four motors - 10 amps.

You could be clever and only run programs that do not move more than 2 motors at once - but ?

A simple way I have my power supply is from two 12 volt leisure batteries which I charge up now and then. The advantage with batteries is that the overall voltage is steady at 24 v (in series) , no matter what the current drawn way beyond the 10 amp mark. It is a bit expensive - about £80 (UK) but, I find, very simple.

I have the input protected by a diode bridge in case I connect them the wrong way round inadvertantly.

1004

General Mach Discussion / Re: Trouble cutting accurate parts

« on: December 15, 2007, 12:31:03 PM »

Walt - Mach3 cannot do this. If you reverse direction, then Mach3 reverses direction immediately.  What sort of motors are on the mill, are they servos with some sort of reaout to locate them. They certainly can't be steppers doing such an odd move. If they were steppers, they might not reverse straight away, but your DRO's have no feedback from steppers and would count down straight away.

If this is the case then Mach 3 is putting out the pulses, and the reverse sugnal, but your machine is not immediately picking up the reverse pulse - there is some delay in interprting it - as you see about 5 thous worth. I cannot think what to do. Have you a breakout board that is delaying these pulses (although if it delayed one, it sould delay them all). I don't see how you can measure the timing of the pulses without some sophisticated measurement devices.

The only thing I can suggest is slow down your traverse speeds and see if this is reflected in a lower than 5 thou readout when you change direction. It is certainly odd - anybody else have a thought.

Jim.

1005

General Mach Discussion / Re: TECHNO ISEL

« on: December 14, 2007, 07:54:20 AM »

I am not familiar with the  particular machine you are talking about, but the mastercam software should be OK. It will convert the file into G code which is what a machine runs on, and, as far as I know, is common to most machines.

Unfortunately, however, I do not think Mach3 will run on Windows 98, so you will have to update your computer to Windows XP or Vista. The problem with that is, if you buy a new computer, it may not have the correct ports for connecting to your miller. Is there some interface card between the Compaq and the milling machine How does the Compaq communicate with it ??

1006

General Mach Discussion / Re: Do I need to do REF HOME every time I turn on the machine? :)

« on: December 14, 2007, 07:46:11 AM »

Sentinel - it is a big learning curve.

As Chaoticone says - home the machine - however my machine is a lathe, with a milling head attached. The home switches are with the table ( which on the lathe carries the cutting tool, but on a mill it carries the work piece ) to the left just under the chuck, and as far towards me as it will come (without disengaging the lead screw).

Neither of the home positions is ideal for the starting position for either the lathe or the mill. This is where the offsets come in.
The HOME homes the machine co-ordinates to 0,0. The offsets then move the machine to the starting point for working (on mine there are at least two different ones) and then zero's again. This, as Chaoticone says, is the work co-ordinate - the point that your program calls 0,0. It can be a different position for each type of job.

The next thing is the tool offsets !!!

1007

General Mach Discussion / Re: Trouble cutting accurate parts

« on: December 14, 2007, 05:38:58 AM »

Walt - I have read all these suggestions and whilst I am not confused and they are all good suggestions, lets get down to the nitty gritty.

You have the machine in front of you - what is it doing wrong. Is it cutting too small or too large - and from that, does your axis appear to miss or gains steps. That is the first step.

Having said that, and I missed it first time round, plastic is very difficult to cut. As daft as it seems, the cutters must be very sharp, and the speeds must be properly controlled. (I only say this because my local plastic supplier who uses CNC said so).

I think I would try the cut manually first, say setting the cutter at exactly the right position with the spindle running, and then jogging the cutter up the cut, using a low percentage of the jog speed to do it with. Then measure the result and see if it is accurate.

If you CAN cut it accurately, then you can progress and see why the program won't do it.

JIm

1008

General Mach Discussion / Re: Micro-stepping Question

« on: December 14, 2007, 05:18:32 AM »

Hello Bill - seeing you are watching the topic.
The drivers cards for the motors control how many pulses they put out to the motors, to move one step of the rotation. On my cards you can switch between 1,2,4 and 8. That moves your motor 1 step. If you have 1.8 degree motors, then you need 200 of these to turn the spindle 1 revolution.

Mach3 then needs to know how many pulses you need to move 1 inch (or 1mm). So you start at your step rate multiplied by your motor angle multiplied by any gearing multiplied by your leadscrew.  e.g. mine is 1/8 step, 1.8 degree motors, 3 to 1 gearing and a  1/10inch leadscrew, so Mach3 needs to put out 8 x 200 x 3 x 10 i.e. 48,000 pulses per inch.

If I have to put out 4.8 pulses per 1/1000th of an inch it is certainly accurate.

Jim Pinder

1009

General Mach Discussion / Re: Odd Startup Behavior

« on: December 12, 2007, 03:57:07 AM »

It is unlikely you would get the same problem on two different cards.

I assume you are using pins 2 - 9 for activating the motors, leaving 1,14,16 and 17 as additional outputs.
It would appear that the fault does not lie with pin 16 - which, I assume, switched the spindle on and off correctly, but lies with the "dir" pin for the axis in question.

You say that you press F5 - so I assume this must be set up on your system hotkeys. Check on your system hotkeys set-up and make sure Pin ?? is not inadvertantly set up to also react to F5. (Or indeed on someother program that may be running in the background - although to be fair pins 2 - 9 were only data pins if used with a printer)

Does the fault occur if you use the mouse on the screen

If you feel you are running out of pins, and are only using three axis, you can use pins8,9 as general output pins as well.

1010

General Mach Discussion / Re: Input Pins Are allways high (+5 volts) can not toogle on/off Limit Switch

« on: December 12, 2007, 03:39:25 AM »

Thie diagram above is totally misleading.

You do NOT need a seperate supply to your switches. As I said in my first post - if you are using the LPT1 printer port, then this already has internal resistors in the computer to pull up the pin to +5v. All you need is a switch to 0v. The diagram shows this.

The only reason I can see that they have put in a seperate power supply is for those machines that use a secondary port that may not already have the pull up resistors.

Wire it as shown, but scrap all the **** about a seperate power supply.

NO - you are getting confused about Mach 3.  0v is always LOW, +5v is always HIGH.  All you are telling Mach 3 is when the switch is ACTIVE.  In other words if you leave it normally open, and switch it to low when hit - then it is ACTIVE LOW, if you normally have it conected to 0v and the switch opens when hit - then it is ACTIVE HIGH