He did use a servo motor, almost full torque at zero
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electronic lead screw
- Thread starter greenail
- Start date
- Joined
- Feb 1, 2015
- Messages
- 10,091
The stepper has full torque at zero as well. Where steppers fall down is at high RPM. Servos have a much flatter torque vs. RPM curve which is why he was able to use a 3:1 pulley to his advantage. My mistake was thinking that the hybrid stepper that I bought would have a similar curve. I bought the motor/driver kit before I found the torque curve.
Oh. Whats the power rating, in watts of the stepper.. stated, (not graph calculated)?
Really appreciate the graph tho.
I intend to use a 200 watt 24v skew wound brushed DC motor and tack an AMT102 capacitive encoder on its bum, thus a servo, to drive the leadscrew, thru the lathe gearbox, for more torque, as Briney eye indicates. My lathe is bigger than cloughs, so I reckon I need all the torque I can get, for larger dia coarse threading jobs. Direct to LS mounting of a stepper is ONLY recommended by Rocketronics with their ELS 4, cos - I thinks, they r trying to minimize resonances.
- Joined
- Jun 16, 2016
- Messages
- 221
I see my name being taken in vain, so here's an update.
I've changed my setup to an 8:1 ratio between my stepper and leadscrew, and have my drive module set to 400 microsteps per rev. Speed is not an issue since I'm actually generating 20% fewer steps now than I was with a 4:1 drive and 1000 microsteps. I've been sorting the code out before I swap my 2Nm Nema 23 motor for a 3.5Nm Nema 24 motor.
Changing the ratios and microsteps gave me the incentive to finally become conversant with function-like macros, so I'm a big step closer to calling myself a C programmer. No more hand-calculating steps when I build the lookup tables. I'm still avoiding the step to C++ because I really don't see an advantage to all the "syntactical sugar" at this point.
Once I have things sorted out I intend to use my "new" dial force gage to measure just how much mechanical advantage I have. I hope to post some results in the next few days. I'm mildly concerned that I have less wrap on the stepper drive pulley with the greater differential in pulley size, but we'll see what happens. If it's necessary I can make a new motor bracket and incorporate an idler to get more wrap.
I've changed my setup to an 8:1 ratio between my stepper and leadscrew, and have my drive module set to 400 microsteps per rev. Speed is not an issue since I'm actually generating 20% fewer steps now than I was with a 4:1 drive and 1000 microsteps. I've been sorting the code out before I swap my 2Nm Nema 23 motor for a 3.5Nm Nema 24 motor.
Changing the ratios and microsteps gave me the incentive to finally become conversant with function-like macros, so I'm a big step closer to calling myself a C programmer. No more hand-calculating steps when I build the lookup tables. I'm still avoiding the step to C++ because I really don't see an advantage to all the "syntactical sugar" at this point.
Once I have things sorted out I intend to use my "new" dial force gage to measure just how much mechanical advantage I have. I hope to post some results in the next few days. I'm mildly concerned that I have less wrap on the stepper drive pulley with the greater differential in pulley size, but we'll see what happens. If it's necessary I can make a new motor bracket and incorporate an idler to get more wrap.
Wrap???
Yep, lighter cuts suggested twice previously, but my post on that didnt draw any fire..
Ah, got what u mean,, tooth belt traction around the now smaller stepper pulley
Does anyone have info on the Clough42 setup, does he have enuf torque for deep cuts?
Maybe better just to use the lathe as intended? Change gears on mine not too hard to set up, I just have to put up w back gear noise/clatter.
Besides, how many of us are cutting threads all day?
