3-Axis Stepper Controller

GreekPIC · Oct 15, 2004

I think the quill is not rigid enough. When it is all the way down it has a play of 2-3mm!! (at least the small ones like this). Where I work we have bigger (and more expensive) drills which I guess could manage the side forces).

You could replace the bearings (and add some more) to make the quill more rigid.

MP1 · Oct 16, 2004

Alberto, this would make a cnc if you already have these parts and choose to add the steppers and controller. But if you do not already have these parts, I think you would spend more money for these than just building a unit from the ground up. As greekpic has stated, side play is a very important concern if you intend to make precise duplicates.
Have you decided upon a software package to run this? I am just curious.

MP

Nilo · Oct 16, 2004

Any detailed picture of xyz board? I mean, complete with terminal blocks and limiting switch, etc ... I know everything is in the schematics, but I think it would be good to see the "as-built".

GreekPIC · Oct 16, 2004

I'll post one as soon as I fix my camera

alberto2 · Oct 19, 2004

Dear Mp i like turboCNC but also i like delcam PowerMill

alberto2 · Oct 22, 2004

Here you are some pictures of my electronics box with 3-Axis Stepper Controller and relay board! ;D

View attachment 36106

MP1 · Oct 23, 2004

Nice clean looking work, Alberto.
I have never used a toroid with my CNC. How is it?

MP

alberto2 · Oct 23, 2004

Mp i think that it's the best choice, because with less dimensions it offers greater power as regards a traditional one.
I found that toroidal in a old power supply bought in a surplus shop.
it has a diameter of 100 mm and develops about 22Amp without any buzzing or overheating.
The best thing is that I have paid for it only 12 euro!!! ;D

alberto2 · Oct 26, 2004

MP i have a question for you:
If you measure with a digital volmeter pin 11 and 14 of ucn5804B which value do you have (before and after a motor startup)?
I think that my ttl computer parallel port voltage il too low! Before the motor startup pin 11 is 0.23V and after 0.53 V but anything moves it can be the resistor network?
(On pin 14 i have a value of 6.7V and my software is turbocnc)

View attachment 36132

MP1 · Oct 26, 2004

Alberto, you should have 5 volts coming from the parallel port. Perhaps you could check these pins with the UCN5804 disconnected. It is also necessary to add a large delay to the program or you will not get a good voltage reading. This is a fast pulse of 5 volts, so it will be hard to measure unless you slow it down. You might get better result with a logic probe. Some parallel ports only give about 3 volts, but I have only seen this on some (very few) laptops.
I made a small board with LEDs on the control pins tied low with a resistor of 470 ohm. When my program would light the LEDs, I knew it would pulse the motors.

MP

alberto2 · Oct 28, 2004

MP i have tested my parallel port without ucn 5804B.
first with leds an after with a digital volmeter and when pin 2-3-4 are hight (stepper pulse) and pins 5-6-7 (stepper dir) there are only 2.6volt!!!
How can i do?
Is a problem of turbocnc? (there are a lots of parameters to specific! as frequenze.... )
My cnc computer is an IBM aptiva pentium1 133Mhz
You think that an Opto-Isolated version is the solution?

GreekPIC · Oct 28, 2004

You can use pull up resistors. MP can help with the values, but tying a resistor between each pin and +5V will make shure it's +5V when high. When its low it's grounded so it's 0V regardless of the resistor.

Hope that helps.

Nikolas

Nilo · Oct 29, 2004

Here you are some pictures of my electronics box with 3-Axis Stepper Controller and relay board! ;D

Beautifull work!

Can you send a zoomed in picture only for the XYZ board with components and connections?

MP1 · Oct 30, 2004

Alberto, assuming you have used the slowest delay possible so that your pulse is not faster than the device you used to test it, then I would believe you might have a problem with your parallel card. I cannot see how the program could cause this problem since the program only tells the processor to send pulses. It does not tell the computer what level to send.
You can use opto isolators and pull up resistors, but be sure this output voltage is not due to something going out on your parallel card or you will have other problems later. If you need to use pull-up resistors, the voltage should be +5 and the resistor should limit the current to the spec of the opto isolator you use. For example, if it you want 10 ma of current, 5V/470 ohm = .0106 amps. Close enough. This is a pretty standard value for these devices.

MP

MP

alberto2 · Nov 1, 2004

In the schematic i have seen two resistors RM1 and RM2. Where can i find values?

MP1 · Nov 2, 2004

These two power resistors are used to limit the current to your steppers if this is needed. Figure out how much current your stepper can take and use this resistance to keep the controller below this amount. It is not published because you will have to calculate it from your stepper specs. If you do not need it, it is best to leave it out.

MP

alberto2 · Nov 2, 2004

how can i calculate them? wich is the general formula?

MP1 · Nov 3, 2004

V/R = A

MP

GreekPIC · Nov 5, 2004

Here you go, Nilo. Sorry about the quality, it's not my camera but I think you can tell where everything goes...

Nikolas

View attachment 36172

GreekPIC · Nov 5, 2004

...

View attachment 36173

3-Axis Stepper Controller

3-Axis Stepper Controller

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