Need Help!- new Machine...question about acme lead screw

[Ncflatlander]

Hey started making parts and now im stuck on if these screws will work they are 5/8 .2 in per rev...is this ok to direct drive this screw? with a stepper motor or does it need to be geared...any help would be great...thanks

[vlmarshall]

Those aren't Acme, they're ballscrews. Nice!

I wish I could offer advice on stepper selection... but I'm really just replying to track this thread's replies, sorry.

[johnmac]

It will depend on the motors. Direct drive them if possible. Stepper motors produce best power when running slow. A direct drive setup will give you better power at higher feed speeds.

Good find!

John

[Ncflatlander]

hey my bad...anyway they where free...i even have extras...so direct drive is the way to go....? if so was looking to use something like the probotix setup...400oz steppers....does anyone think this is ok...my build will be similar to the lionclaw model...any help is great....thanks

[johnmac]

If you direct drive them and use half stepping, it will take 2 step signals from the computer to move the machine .001". That's 2000 pulses to move 1 inch. There comes a point where increasing the pulses per second results in the torque decreasing.

I built my table with ball screws and 425 oz. in. motors, geared down 2:1, for 5 turns of the motor per inch of travel. As soon as I could drive the motors, I changed the gearing to speed it up.

I am running 3 1/2 turns per inch, and at slow and medium speeds I am not strong enough to stop the gantry from moving. At faster speeds, I can.

John

[Ncflatlander]

ok ....so direct drive is under drive...? im new to the steps and everything else...so i should over drive the ball screw...? is this correct...? like a 30 tooth on the motor and a 10 tooth on the ball screw....? and thanks again for all the answers

[CJL5585]

[QUOTE=Ncflatlander;549530]ok ....so direct drive is under drive...? im new to the steps and everything else...so i should over drive the ball screw...? is this correct...? like a 30 tooth on the motor and a 10 tooth on the ball screw....? and thanks again for all the answers[/QUOTE

The ballscrews are great. Will work with almost any size steppers from 180 in/oz up to 1000+ in/oz.

Call me. I live in Morganton, but have a phone number in your city.

Number is 221-2075.

I can answer most of your questions.

Jerry