L297-8 drivers

[Bri4n]

I am considering using the L297-8 for my first CNC build and I was wondering how much power supply I would need? The motors I'll be using are 1.8V 4.2A 1.8/Step 0.42OHM.

[jalessi]

Bri4n,

The L297-8 is not a good match for a 4.2 amp stepper motor, it will severely limit the performance of your motor.


Jeff...

[Bri4n]

I have not yet purchased anything, so I can change but I will need to stick with an open source (free) design. What do you recomend? The 2 will work together in a pinch?

[pminmo]

Your going about this backwards. You need to decide the machine mechanicals based on what you intend to cut, then decide on the motors and drivers.

[Bri4n]

I am going to use the JGRO plans and for now going to cut wood. I was looking for your forums last night but couldn't find the link.... BTW you have an excellent wealth of info there. What would you reccomend?

[pminmo]

What screw would you use on your two longer axis?

[Bri4n]

1/2 10 acme rod.

[pminmo]

The problem with 1/2-10 is you not going to be happy with rapids on your long axis. Z and the gantry axis would be ok. The l297-8 would be ok for them with a suitable motor. Kelling inc has about the best value for the motor, allthough for the Z the PK266's at MPJA are a pretty good deal with the exception of it being a single axis motor.

[Bri4n]

Would my combonation be okay just to get started with? I have plans to upgrade in the near future, for now I just want to get up and running.


Edit; Would any of the bipolar boards on your site work better?

[pminmo]

Picstep would be a better choice.

[Bri4n]

Thanks I will look into it when I get home from work in the morning.

[Bri4n]

I looked pic step over what kind of performance would I get? Is this something I could run with for a while and get decent speed? Or should I just wait and buy a kit at Hobbycnc or one of the others?