Foam cutter with 4 independent of each other?

[LesFoster]

Hello, I am in the process of assembling a hotwire machine, and would like advise on controlling 4 independent of each other, I have download one screenset but I am unable to get it to function. I have imported a DXF file into Mach3 and then stripped the TAP file in Word and then analyze it in EXECL. Found a lot of miss direction in directional control. Any help would appreciated.
Thanks Les

[Hood]

Afraid I dont have a clue what you are meaning
What does 

4 Independent of each other

mean? Are you talking of axis? If yes then what are you actually expecting, if it is that you want one axis to move at one feedrate while another is moving at another and the others are also moving at different feedrates then that is not possible. If that is not what you are meaning then please try and explain more.

Hood

[LesFoster]

Thanks Hood -your input puts me that much closer- I will crack this nut

I missed the AXIS in my title. The answer is yes to independent travel, one solution is to run two complete units and play with steps per inch or insert G4 (Dwell) in the G-code script. But other than that you are saying, the feedrate stays consistant between the towers? Is it possible to play with the G-code lines to slow one tower?
Thanks Again
Les

[Hood]

I think trying to run two computers to control one machine may cause all sorts of problems. Examples may be how to synchronise moves so they start at the same time, one will finish before the other, do you need to wait until both have stopped before you move them again etc etc.
If you could explain what you are trying to do it may hep.
Hood

[LesFoster]

Ok ... For example, I want to cut a tapered column or a column with one end being square. I want the flexibility to duplicate anything.
Les

[BR549]

OK you do have 6 axis to play with AND I can see a way to do MOST of what you want BUT it would take some work to verify it to be true in real time

Each side of the Primary axis CAN be an independant axis Such as X= XB  Y=YC  and then A as a rotary?? and a spare Z

BUT I don't think MACH can  control them in multiple planes at the same time. You would have to work one plane at a time.

Take a cone one end would have to be at the focal point of the cone while the other axis moved in a circle. You could NOT cut both circles of a trunicated cone at the same time(2 planes).

Interesting project, (;-) TP

[Hood]

Do you have a pic of this foam cutter that you could post?
Hood

[BR549]

oK I played around with the concept a little and think this one is a no go.  While you can do independant axis in linear mode if you can do the Gcoding. But you don't end up with anything that you can't do normally. AND you cannot do independant arc or circle moves that I can figure out.

BUT that is just my opinion , You mileage may vary(;-) TP

[kf2qd]

Here's what I hear you descibing - you wnat to build a foam cutter with vertically mounted parallel X-Y stages at each end, and a hot foam cutting wire streched between them. A typical use is for cutting foam cores for model airplane wings.

Here's how I would set it up - One X-Y stage would be called X & Y in  Mach and the other would be A & B. A is parallel to X and B is parallel to Y.  A & B are both configured as LINEAR. And I am assuming the steps per inch are the same for all axis.

There are 2 ways of controlling the motion - if your parts have no tapers you could pprogram everything as X & Y moves and all motion is available, go to the Functin Cfg menu and select formulas and in the A line put X and in the B line put Y. The AB stage will copy the motion of the XY stage. If you want some other ratio (AB end 3/4 of the XY end  then you would put x*.75 in the A line and y*.75 for B)

The other method has more flexibility - but is restricted to G0 and G1 - No changes in formulas, A =A, B=B, but you would have to program only in line segments. each line would  look like this - G1 X___ Y___ A___ B___ F___ and would start and finish at the same time. As long as you used short line segments you would hardly notice them, and a quick touch with sandpaper would take care of that, BUT both ends of the motion could have completely different motin profiles. Airfoil 1 and the XY end, and Airfoil B on the AB end. You could even program a twist intothe profile, End XY is parallel to the X axis and AB is rotated 3 degress to the A axis.

Does this sound like what you are trying to do?

[kf2qd]

Here's an idea of what a foam cutter might look like. ( sorry about how it looks , it was a quickie...)