Closed Loop steppers

[Gary]

It looks like the motors are 1.2Nm holding torque so with a ratio of 7.2 that would be about 8.6Nm of holding torque, so the actual torque running would be about 4-6Nm depending on the speed /voltage.
You are right, you will need to dump the existing X and Y motors because of the gearbox, not specifically because of the max speed but also because of the 45arc minutes of backlash and that the system uses belt and pulley so that 45 arc minutes would equate to quite a bit of movement.
I would personally use a mid sized 34 frame motor if you are going to continue using the existing belts or going to a 60mm diameter (3Nm) motor if converting to ball screw.
I would also consider reducing the height of the router to make in a bit more ridged.

[funkmonkey]

yeh I was going to chop a little out of the legs to get it closer to the deck to improve the stability, also the head does not move down any where near the base plate so it needs to drop down.

Thanks for the help you guys, so to recap:

Ditch the Vexta motors

Buy two new 34 frame motors

Drop the height of the x, y & z axis closer to the table

But what kit do I need to get this running? drivers, breakout etc?

[Gary]

Motors, Drivers, breakout board, power supply, pc and cnc contol software.

yeh I was going to chop a little out of the legs to get it closer to the deck to improve the stability, also the head does not move down any where near the base plate so it needs to drop down.

Thanks for the help you guys, so to recap:

Ditch the Vexta motors

Buy two new 34 frame motors

Drop the height of the x, y & z axis closer to the table

But what kit do I need to get this running? drivers, breakout etc?

[funkmonkey]

Ok, so is any better than others as there seems to be a lot about?

Also the software side, we use Machine Strat, Delcam & Bobcad here. Do the drivers need specific headers in the G-code text to run?

[funkmonkey]

Just Looking through a box of old motors I have here at work,

There are three with the following detail

1.8 degree step, Holding Torque 550mNm

2 VDC 2.8A

Are these any good? Noticed that you put down a torque of 3Nm so what is mNm?

[Gary]

3nm is 300mnm just like 300mnm is 30 ncm.
5.5Nm is a reasonable amount of holding torque and if you use the existing belt they should give you enough torque to run the machine, but you need to define what you are using it for to determine how much power you need.

Just Looking through a box of old motors I have here at work,

There are three with the following detail

1.8 degree step, Holding Torque 550mNm

2 VDC 2.8A

Are these any good? Noticed that you put down a torque of 3Nm so what is mNm?

[funkmonkey]

I want to build a router out of it, mostly for machining wood, but would like the ability to do the odd ally job too.

[Gary]

Normally stepper drivers are totally dumb and only react to clock and direction.
So as long as you can get your software to generate clock and direction the driver should work fine.

Ok, so is any better than others as there seems to be a lot about?

Also the software side, we use Machine Strat, Delcam & Bobcad here. Do the drivers need specific headers in the G-code text to run?

[funkmonkey]

these drivers sound a little like me!!:dance: