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2017 POTD Thread Archive
- Thread starter jpfabricator
- Start date
- Joined
- Feb 2, 2017
- Messages
- 1,236
Beautiful work. Nicely done!
- Joined
- Mar 12, 2014
- Messages
- 1,531
I'm working on a project to drive the leadscrew on my G4000 lathe with a stepper motor. For threading I'll still need to use the gears, but for everything else, it will be nice to not have to hear the gears whining and wearing out.
The stepper motor is a 3 N-m Nema 23 and the motor driver is a DM556T. The power supply is 24V at 15A. Preliminary work shows that the motor has plenty of torque, even at about 500 RPM on the leadscrew.
The system will include a tachometer to measure the spindle speed and the controller will track the spindle so I'll have continuously variable control, calibrated in thousandths/turn, from about 0.5 to about 12 with a knob (or maybe UP and DOWN buttons). An electronic stop will be one of the features. An LCD display will show the spindle RPM, the feed rate, the direction, and other things. Right now the controller is an Arduino Mega2560 which has much more capability than needed. When the control software is done, it will be ported to an Arduino Nano (about $2.50; these things are amazingly cheap).
I've done a lot of research into the acceleration profiles and mathematics associated with it and the software is coming along nicely. A gentleman named David Austin did some really good work on this back in 2005. It seems that most stepper motor control algorithms use his work. I'm almost to the phase where I'll take everything out to the shop to experiment with the acceleration parameters.
I'll be happy to share the software if there is interest.
More later...
Glen Zoerner
Spicewood, TX
The stepper motor is a 3 N-m Nema 23 and the motor driver is a DM556T. The power supply is 24V at 15A. Preliminary work shows that the motor has plenty of torque, even at about 500 RPM on the leadscrew.
The system will include a tachometer to measure the spindle speed and the controller will track the spindle so I'll have continuously variable control, calibrated in thousandths/turn, from about 0.5 to about 12 with a knob (or maybe UP and DOWN buttons). An electronic stop will be one of the features. An LCD display will show the spindle RPM, the feed rate, the direction, and other things. Right now the controller is an Arduino Mega2560 which has much more capability than needed. When the control software is done, it will be ported to an Arduino Nano (about $2.50; these things are amazingly cheap).
I've done a lot of research into the acceleration profiles and mathematics associated with it and the software is coming along nicely. A gentleman named David Austin did some really good work on this back in 2005. It seems that most stepper motor control algorithms use his work. I'm almost to the phase where I'll take everything out to the shop to experiment with the acceleration parameters.
I'll be happy to share the software if there is interest.
More later...
Glen Zoerner
Spicewood, TX
- Joined
- Aug 7, 2015
- Messages
- 13
I am interested!
I've thought about doing something similar for my compound slide. (Something more elegant and controllable than a hand drill and T-shaped rod.)
I have most of the parts (stepper motor, driver, power supply, and an Arduino), but haven't made time to try and cobble something together.
Measuring and using spindle speed is a brilliant idea. I did not think of that...
- Joined
- Feb 2, 2017
- Messages
- 1,236
Dumb question--how does it work? Does the saddle hit the micro-stop then slip the clutch?
- Joined
- Jul 2, 2014
- Messages
- 7,594
Carriage stops like that are only used as manual limits. They are not used (on purpose!) for stopping a powered carriage! There are carriage stops that disengage the feed gears and stop the carriage, some factory, some shop built, but that takes the micro stop to a considerably higher level. Nowdays, much of that is done electronically with limit switches and similar.
Installed a new garage door opener in the garage attached to my house. Last summer, I closed it, and the door stopped on a piece of equipment in the doorway, and after that, the opener didn't work anymore. It was maybe 20 years old or so, from before the time they had to come with a sensor that something is in the doorway. I believe it was designed to "notice" when it closes on something, and auto-reverse, but it didn't this time.
Anyway, there was a Chamberlain 1/2hp opener for $150cdn on black friday, so I bought it and installed it today:
Today's lesson:
For attaching the wiring for the two sensors and the control panel, Chamberlain includes maybe 2 dozen or so staples that I suppose you hammer in over the wires to hold them in place. If I used them, there is 100% certainty that one or more fingers would be mashed by the hammer. Instead, I was going to use the stapler I know I have to hold the wires in place, but naturally, I couldn't find it. Went to the store and bought a cheap light duty Bostich manual stapler and short staples. I've used a variety of staplers before, so I get it out of the packaging, pull out the tray, not quite enough space for one row of staples, looks/feels like it can/should come out a bit further...nope...shouldn't have done that...unscrew it, push the tray in a bit, now it goes in all the way again...yay. Pull it out, break off part of the row of staples, put it on the tray, push the tray in...tray stops once the staples get to the body of the stapler. look at it a bit, nothing seems out of place, bit more force, and the tray with staples are in...yay. try it out, get that satisfying snap, but no staple is dispensed. try it a few more times, no staples. look at the side, the little window shows all red, indicating it's empty. try to pull out the tray and see what's up...nope, pulls out a little, but not like before and can't see any staples on the bit that comes out. unscrew the stapler again, take it totally apart, staples are on the tray right where I put them, nothing obvious to push them forwards to the dispenser. examine the tray, which also has the 'empty' indicator in red, notice that the red part is spring-loaded, but there's no obvious way (to me) to insert the staples on the tray, so the red part is behind them to push them towards the dispenser. Finally give up, look at the packaging for instructions on how to insert the staples. doh. you pull out the tray, then turn the stapler upside down and put the staples in the bottom, then push the tray back in.
So, RTFM.
Anyway, there was a Chamberlain 1/2hp opener for $150cdn on black friday, so I bought it and installed it today:
Today's lesson:
For attaching the wiring for the two sensors and the control panel, Chamberlain includes maybe 2 dozen or so staples that I suppose you hammer in over the wires to hold them in place. If I used them, there is 100% certainty that one or more fingers would be mashed by the hammer. Instead, I was going to use the stapler I know I have to hold the wires in place, but naturally, I couldn't find it. Went to the store and bought a cheap light duty Bostich manual stapler and short staples. I've used a variety of staplers before, so I get it out of the packaging, pull out the tray, not quite enough space for one row of staples, looks/feels like it can/should come out a bit further...nope...shouldn't have done that...unscrew it, push the tray in a bit, now it goes in all the way again...yay. Pull it out, break off part of the row of staples, put it on the tray, push the tray in...tray stops once the staples get to the body of the stapler. look at it a bit, nothing seems out of place, bit more force, and the tray with staples are in...yay. try it out, get that satisfying snap, but no staple is dispensed. try it a few more times, no staples. look at the side, the little window shows all red, indicating it's empty. try to pull out the tray and see what's up...nope, pulls out a little, but not like before and can't see any staples on the bit that comes out. unscrew the stapler again, take it totally apart, staples are on the tray right where I put them, nothing obvious to push them forwards to the dispenser. examine the tray, which also has the 'empty' indicator in red, notice that the red part is spring-loaded, but there's no obvious way (to me) to insert the staples on the tray, so the red part is behind them to push them towards the dispenser. Finally give up, look at the packaging for instructions on how to insert the staples. doh. you pull out the tray, then turn the stapler upside down and put the staples in the bottom, then push the tray back in.
So, RTFM.