design idea.

[massajamesb]

Not a crappy machine at all. I love Hypertherm

It is a bit small to expect clean and accurate bolt holes out of 1/4 plate. The resulting beveled edge that is inherant to the plasma process will surprise and frustrate you when you go to insert a bolt in your 1/2" hole, and find it fits in the top of the hole, but the bottom of the hole is .45" instead of .5

That plasma will also have a very light duty cycle when asked to cut 1/4 plate, and it will not cut it in a hurry. Expect your cut speed on 1/4 plate to be in the 20-25 inch/min range.

You will find a higher amperage plasma will aid you in cleaner bolt holes, and faster cut speeds.
What you are trying to do will work, and is more than possible, but will have its' limitations. I am guessing if you do much chassis fab, you will be wanting to upgrade within a couple of weeks, but that is just my guess.

Hope that makes it a bit clearer...

[oneturboneeded]

that helps thanks. now how would i go about using 2 drive steppers? just wire them togather?

[massajamesb]

Well, if you had two smaller steppers, they could theoretically be wired to the same driver, if you had a big enough driver. I do not recommend this. Use one driver per motor, and either connect them both to the same output from the breakout board, or slave them inside Mach, if you are using Mach.

[oneturboneeded]

wow that was almost like Chinese to me. guess i have to learn more. so i would put it to another out on the controller and just have the software control the 2 motors togather

[Robin Hewitt]

Originally Posted by oneturboneeded wow that was almost like Chinese to me. guess i have to learn more. so i would put it to another out on the controller and just have the software control the 2 motors togather

It is much easier to put a rack down either side and drive the two pinions on either end of the same shaft with one motor.

This two motor idea seems needlessly complicated.

It really is very simple, perhaps we are not explaining it very well

[oneturboneeded]

yea i feel retarded cause i dont get it or it might be it just does not fit in my design idea?

[massajamesb]

You should not feel retarded, just uninformed.
I have not been able to get to my shop to take a decent picture of how it all goes together, but will try to tomorrow, if I feel better.

Two motors are generally not neccesary, but will work.
To save money and time, you just use one motor on one side , with a shaft that goes across the table that has your driven gears, one on each side. When the motor rotates, it rotates that shaft, spinning gears on both sides of the table, acting like two motors.

[oneturboneeded]

o ok that makes sence to me.

[Perp]

look at posting # 21 (link below) for pictures of the shaft system described above (it is of another members machine) you may want to read the whole thread, its got some great info and pictures

http://www.cnczone.com/forums/showth...t=32058&page=2

[Torchhead]

Dual drive systems (motor on each side), often called "slaving" are not overly complicated and offer certain advantages (double the drive torque, auto squaring) and don't have long drive shafts across the gantry. I have a two motor dual drive gantry that I have been using for almost 5 years in production cutting and the servos are tiny compared to today's standards. Both systems work and both are used with success but choose the one that is easier for you to build. If you have a way to turn a precision shaft with bearings than that might be the best. If you don't mind buying an extra motor and motor drive card then the dual drive system will serve you well.

You cannot and should not hook two motors to one driver card. In servos it would be a nightmare. With steppers it would cause resonance problems and negate the smoothness from microstepping.

tomCAUDLE
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