independently controling steppers

[turmite]

I need help with a stepper problem. I have built a 4 axis hybrid machine that uses a pattern under the z head to trace but it is also cnc controled too. It is a 3d wood carving lathe. I need the ability to rotate the pattern and work axis which we will call b and c independently of the cnc controled y axis. I can do it with two computers but tht sure would be a lot of hardware to have sitting in the way. I need to control two axis with speed and direction. What would I look for or how can I do it, or is the two pc's the easiest way out?

turmite

[balsaman]

Why do you need two pc's? Turbocnc can control up to 8 axis'

Eric

[HuFlungDung]

If its any help, Turmite, you can add more serial ports to your computer than just the one that came with it. I'm just guessing that you are wondering where to get enough terminals to make all the connections?

[turmite]

First of all I want to apologize for my spelling. I had some sort of virus yesterday and maybe my mind wasn't too clear when I was typing the above post. Fever does funny things!!

Now lets see if I can explain this so maybe even I can understand it. I am using LPT indexer from Ability Systems on a Digital Tool 902 router. It has very limited g-code ability no m-code at all and as far as I can tell no way to independently control one axis outside of a interpolated move, i.e. all axis arriving at that same point at the same time. This software runs 6 axis but everything is seemingly interpolated. Support is ......... well, I think you get my drift. The software came with the machine and they are no longer in business.

I have 4 parallel ports in the current computer, an old 486, but it is all I really need for this new machine. I am in the process of upgrading the router to mach2 and servos but I am gonna need some major help before I dissamble my machine and lose the ability to make money for a while.

So here is what I need: the ability to turn two rotational axis' with step, direction and speed. While those two axis are rotating the machine will move from home to the starting position the z head will lower and the y axis will move to cut the part using two 4", three insert cutter wheels, while a aluminum tracing wheel follows the pattern that is being rotated by one of the axis.

I was hoping to make the machine with the ability to speed or slow the axis to maniuplate the smoothness of the cut.

Would I be better off just trashing the system I have and get something else?

turmite

[balsaman]

Mach 1 should be able to do this with just one computer. You may want to email Art of Mach 1 and explain what you need and see what he says.

Eric

[anoel]

Sounds like an automated Dupli-Carver instead of a CNC machine.

I "think" that I get where you are going with this...

When the machine is in "Dupli-Carver" mode the Z-Axis is free to move up and down without power. there are two rotary tables under each Z- head wich will rotate as the machine makes incremental moves in Y and then steps over in X then makes another pass in Y. And repeats this until the part is cut.

is this correct.

[turmite]

Balsaman I kinda suspected that would be the option unless I go with two computers and just use one to drive the rotational axis.

anoel you are close. The z axis actually has a floating axis mounted on it with a bottom stop to keep it from going to low. The motor driven z axis will be used to make rapid roughing passes and finally set completely on the pattern for the final pass which is where I need to be able to change speeds on the rotation to make for a very fine finish. I of course will slow the feed speed on the y axis at the same time but I need the ability to change them independently. Another reason is one of the rotational axis is not driven with the same belt system so I can reverse the rotation and cut a left and right hand part at the same time.

turmite