Has anyone installed Clough42's electronic leadscrew on a PM machine?



This is just proof of concept I will have 2 indicating LED's Red and green for run and stop it will be operated off a relay rather than have the switch disconnect power from the motor . this is just another thing you can do with the electric lead screw never crash your lathe again when tapping..
 
For others who may be trying to source timing pulleys for their ELS project I need to share my “boy do I feel dumb” moment. Finding HTD 3m or whatever flavor belt/pulley combo you need in the correct bore/tooth count was quite challenging. Finally dawned on me I have a lathe! I bored out some pulleys I had on hand to 16mm for my drive shafts. Then had a pulley that I trashed by making the bore a hair oversize. Needed a 6mm bore for an encoder so grabbed some rod and turned a bushing with 6mm bore to press fit into the 16+mm pulley. Carefully drilled out the bushing and ran a tap through the set screw holes to clean them up. They work great with less runout and wobble than the original parts.
 
Can anyone help me troubleshoot my ELS? I thought it would be best to post here instead of starting a new thread. I have a PM1030, I used the integrated servo that james used. My encoder is a Omron E6B2-CWZ6C with 1024-pules (4096 count). I coupled it to the spindle with a 1:1 ratio. my servo is connected to the lead screw 1:3 (20t on the servo and 60t on the lead-screw ). I just got it all connected finaly and its not running at the correct rate. pitches are wrong and when I measure the ipr it is also wrong. I have tried all 3 selections on the gear box and I still have no luck. I will post a piece of my configuration.h below. Any help would be greatly appreciated, thank you.

//================================================================================
// LEADSCREW
//
// Define the type and pitch of leadscrew you have in your lathe. If you have an
// imperial leadscrew, define LEADSCREW_TPI. If you have a metric leadscrew,
// define LEADSCREW_HMM (pitch in hundredths of a millimeter). Do not define
// both.
//================================================================================

// For Imperial leadscrews: pitch in Threads Per Inch (TPI)
#define LEADSCREW_TPI 10

// For metric leadscrews: pitch in hundredths of a millimeter (HMM)
// Example: 200hmm = 2mm
//#define LEADSCREW_HMM 200




//================================================================================
// STEPPER/SERVO
//
// Define the number of steps and microsteps for your stepper motor, the pin
// polarity of the driver, and whether to use additional features, like servo
// alarm feedback.
//
// NOTE: If you are using a servo drive with something other than a 1:1 drive
// ratio, you can use the STEPPER_MICROSTEPS to compensate. For example, if you
// have a servo configured for 1000 steps/revolution and it drives the leadscrew
// through a 3:1 reduction, you can set STEPPER_RESOLUTION to 1000 and
// STEPPER_MICROSTEPS to 3.
//================================================================================

// Steps and microsteps
#define STEPPER_MICROSTEPS 6
#define STEPPER_RESOLUTION 500

// Separate step and microstep settings for feed rates. Redefine these if your
// lathe has a separate feed drive train with a different ratio.
#define STEPPER_MICROSTEPS_FEED 10
#define STEPPER_RESOLUTION_FEED STEPPER_RESOLUTION

// Step, direction and enable pins are normally active-high
// #define INVERT_STEP_PIN true
// #define INVERT_DIRECTION_PIN true
#define INVERT_ENABLE_PIN true
#define INVERT_ALARM_PIN true

// Enable servo alarm feedback
#define USE_ALARM_PIN




//================================================================================
// ENCODER
//
// Define the type of encoder you are using on the spindle. The firmware assumes
// the encoder is turning at a 1:1 ratio with the spindle.
//
// NOTE: the firmware is concerned with the quadrature edge count, which is
// four times the number of pulses. For example, if you have a 1024 P/R
// encoder, you need to enter 4096 here.
//================================================================================

// Encoder resolution (counts per revolution)
#define ENCODER_RESOLUTION 4096

// Which encoder input to use
#define ENCODER_USE_EQEP1
//#define ENCODER_USE_EQEP2
Click to expand...
 
Is the servo programmed for the correct micro stepping?

I would calculate the actual pitch that you are seeing and then compare that with the desired pitch that you programmed. The ratio for actual/desired should provide a clue as to how far off you are, in what direction, etc.

It looks like you should be able to adjust the configuration to compensate for the ratio.
 
I did find the problem, I was messing with it all night. Went to bed, made this post then went out this morning. The problem was I had the TPI on the lead screw set wrong. My lathes leadscrew is 8 not 10. It was driving me nuts because it wasnt making any sense. After getting the firmware flashed it all seems to be working now. The biggest problem I had was fitting everything togther. Getting the servo under the bed like pete and tammy did was not easy. It just barely fits, I had to put the servo in then connect the wires from above.
 
I'm planning to cut 1" to 2"of the sheet metal cover above where the servo slides into area beside the spindle motor. So I can wire and then slide in into place. But I guess I should proceed to order the servo first to make sure that will help.

I finished installing my DRO over the last 8 days....might as well take another big bite of the project apple.
 
Just finished up my Clough42 ELS on my PM1130V. What a treat to use now. No constant change gear noise is reason enough to do this!
I did deviate from what others have done by using a worm gearbox to connect the servo motor. I knew the gearbox already has backlash and figured that a slight amount more shouldn't matter. Am trying a 5:1 box and 1:1 on the gearbox. It seems to work ok with one exception, at 75 RPM spindle speed and .001 feed the feed and leadscrew do not turn steadily. With the worm box the servo fits under the cover with the wiring pointing down. I only needed to enlarge the cutout directly under the servo where the wires are. Also removed the lower stud for the cover and used a piece of channel to drop down below the servo and back up to the correct height for a short stud.
KIMG0563[1052].JPG
 
tweinke said:
It seems to work ok with one exception, at 75 RPM spindle speed and .001 feed the feed and leadscrew do not turn steadily.
Click to expand...

What does that mean? Does the leadscrew slow down and speed up or catch or something? I guess it doesn't make sense that at low RPMs you're having an issues. Is it possible it's following the chuck and the chuck is spinning erratically at low speeds?


That looks great. Do you have a link for the gearbox - i couldn't come up with a clever way to fit things under the cover so i ended up cutting a hole in the cover. No regrets even though it would have been cleaner to go the route you did.
 
tweinke said:
Just finished up my Clough42 ELS on my PM1130V. What a treat to use now. No constant change gear noise is reason enough to do this!
I did deviate from what others have done by using a worm gearbox to connect the servo motor. I knew the gearbox already has backlash and figured that a slight amount more shouldn't matter. Am trying a 5:1 box and 1:1 on the gearbox. It seems to work ok with one exception, at 75 RPM spindle speed and .001 feed the feed and leadscrew do not turn steadily. With the worm box the servo fits under the cover with the wiring pointing down. I only needed to enlarge the cutout directly under the servo where the wires are. Also removed the lower stud for the cover and used a piece of channel to drop down below the servo and back up to the correct height for a short stud. View attachment 469431
Click to expand...
That is a timing belt and cogged sheaves driving the encoder, right?
 
You must log in or register to reply here.
Back
Top