The demo version of Mach3 allows 500 lines (give or take a couple) of code plus there are a few other limitations but nothing serious (not sure about 4th axis here). As long as a GCode program is written carefully 500 lines can be a lot of program.

You really need the full cable but step and direction for 3 axis plus limit switches and PU/PD (with common ground) could amount to only 11 wires so it may be possible, but hey, second user old printer extension cables cost peanuts.

Tweakie.

4 axis actually. and im probably not going to use limit or home switches. unless i get a full DB25 pin cable instead of this stupid 11 wire one.... the reason being is the only axis on my machine i can really have a limit on is the x axis. as its the only axis with linear motion. IE it goes left to right on the machine and has to stop at the ends. all the other axes are rotational with infinity being their theoretical stop point. although the a axis... for the tangential following for the knife is a 1 rotation + 1 rotation configuration meaning 1 step = 1.8 degrees rotation. and the tool axis Z for tool up and down is only a few mm travel but its also a 1 =1 ratio as well. so 180 degrees 1 way = tool down and vice versa. but how would i code tangential knife in EMC2 which is what i will use.

but how would i code tangential knife in EMC2 which is what i will use.

I think this may be the wrong forum to ask that question   

Tweakie.

well where is the right one...

EDIT correct me if im wrong but this is the third party software and hardware support forum right....

Sorry, You are or course quite right, but it is a bit like logging onto the Harbor Freight site and asking questions about Grizzly machines. 

Try this; http://www.linuxcnc.org/component/option,com_kunena/Itemid,20/lang,english/

Tweakie.

well ill look into it Thanks for your help so far Tweakie. When i get the parts later today ill start posting pics of the build. although i am using a base machine that is prefabbed from gerber scientific products. Ill still post pics of it and the integration of the new electronics. one more question all 4 of my steppers are 5 volt 1 amp or slight variations of 5 volt. could i get away with using a 5 volt rail of a pc power supply?

Yes please David. We all like pictures here and I think it goes without saying that we are only too pleased to help you if we can.

A PC power supply would be fine. Steppers are usually driven at up to 5 times or more of their rated voltage (the limiting factor would probably be the insulation breakdown voltage) what must NOT be exceeded, however, is their rated current. (The voltage is generally increased to provide more torque).

Tweakie.

OK the reason i ask about the pc power supply is i  have about 10 of the things im not using. Would running the steppers at 5 volts be fine or shold i run them off like ... 12 volts

I would try 5 Volts and see how you go. Only increase the voltage if you really need more torque.
(the 12 Volt output from the psu is quite low current compared with the 5 Volt).

Tweakie.

yeah the 5 volt rail is 28 amps and the 12 is 18 amps