Reached The End Of My Rope With This

[Uwe]

Hmm, good one. I'd remove the cover on the position sensor next and observe the two spinning disks that block or open the light path for the two optical sensors. The manual says to move the disks by hand to set proper needle down and up positions. Perhaps the disk came loose and only gets dragged along at a certain minimum speed. Make sure the light source LED of the sensor is actually on when the reducer is installed - perhaps it has a flaky electrical connection that fails with just a little more or less pull.

[dikman]

As Uwe suggested, have you disabled the needle positioner to see what happens? It certainly sounds like the needle positioning circuitry is getting itself in a knot, and it's caused by the addition of the speed reducer. If the circuitry gets a signal feed from the motor and the needle positioner then perhaps it can't cope with the additional rotations of the handwheel relative to the motor when the power is cut?

[Hockeymender]

As Uwe suggested, have you disabled the needle positioner to see what happens? It certainly sounds like the needle positioning circuitry is getting itself in a knot, and it's caused by the addition of the speed reducer. If the circuitry gets a signal feed from the motor and the needle positioner then perhaps it can't cope with the additional rotations of the handwheel relative to the motor when the power is cut?

Yes, I have unplugged the synchronizer and when that happens the machine will stop instantly when the pedal is released (howbeit the needle can be anywhere in it's travel).

[Uwe]

So the control box can at least tell if the sensor is plugged in or not, that's a good sign.

With the needle position sensor connected, does the machine keep running past the next needle-down position and make another stitch or two before it gives up, or does it run out of juice before it reaches the next needle-down position?

I'd try these debugging steps:

Does the motor always stop at the same needle position or does it stop at random positions. If it always stops at the same absolute position, the position calibration is off. If it stops at random positions, the position signal is missing and the motor gives up.

While sewing VERY slowly, let go of the pedal shortly before the next needle-down position. Does the machine run past the next needle-down position?

Second try while sewing slowly, let go of the pedal shortly AFTER it reaches needle-down position. If it does not continue until the next needle-down, the control board gives up before the next position signal gets sent due to too many rotations without position signal, likely due to speed reduction gearing. If it still runs past the next needle-down, the sensor signal is definitely not working and the gearing is not at fault for the motor giving up too early.

After the machine stops, heel the pedal. Does the motor advance to the next needle-UP position? If yes, then only the needle-down sensor signal is not working - needle-up sensor and control box work properly. If no, neither position sensor signals work or control board ignores them.

On a side-note: with one of my needle position servo motors, if I had the speed dialed way down, the motor would actually speed up when I let go of the pedal to move to the next needle-down position. That was just too freaky for me to get used to, so I disconnected it. I'm actually not using needle positioning on any of my NPS-enabled motors. Because I sew leather extremely slow at about a stitch per second, my reaction time is plenty fast to stop the needle exactly where I want it and the NPS just seems intrusive to me. But that's just my personal preference. I do have unused position sensors sitting around for testing if need be. My Consew CSM1000 position sensor may be the same design as yours.

[Hockeymender]

Well I am happy to report that I have solved the problem! With the help of a local tech (who is the most knowledgeable sewing machine tech I know) I was able to sort out what was going on. The control box gets it's speed info from the motor and the synchronizer. If the data being sent does not fall within certain parameters, errors result. It would appear the the speed info going to the brain of this setup was being thrown out of the a fore mentioned parameters by using the smallest pulley on the speed reducer. That small pulley caused the reading from the synchronizer to miss the mark so to speak and nothing worked. I changed the pulley in use to the next one up on the reducer and that solved the issue. Seems it got the speed of the hand wheel raised enough that it was back within the computers liking and all is now good.

As a side note, I ended up using a smaller pulley on the motor to compensate for the speed increase that resulted in going up a size on the reducer. The smaller motor pulley brought the overall speed down to an acceptable level.

This has been a long few days, but now it's back to the hockey equipment. Thanks to all for the input and help.

[dikman]

So Uwe was basically right. I would have thought that there would be a parameter within the control box settings that would allow for this situation - somewhere. Still, it's provided valuable info that speed reducers, combined with a servo motor, may create unintended problems.

[Uwe]

I'm glad you were able to figure it out! Clearly the control box knows exactly why it can't provide the needle position function - it just doesn't tell you about it. They must have run out of money programming useful error codes into the control box logic. The only error code the manual mentions is one for power failure - I'm not exactly sure how it will display that particular error code if there's no power.

Edited October 15, 2015 by Uwe

[dikman]

Good point about the error code for power!

I suspect that the reality is the programmers didn't consider that a speed reducer might be used with a servo - after all, a servo should be able to give the control without the need for a reducer.

[dikman]

Further confirmation that needle positioners don't like speed reducers being fitted! I can't fit a larger pulley to replace the handwheel on my Singer 211G166, so although the servo has slowed it right down I figured that fitting a reducer would help with low speed torque. I made a reducer and using what pulleys I had handy gave me a 2.2:1 reduction. I fired it up and the needle moved a couple of times, went clunk and it all stopped. Turned it off, tried again and this time tripped the cct. breaker in the shed plus the bigger one feeding the shed itself!! (That one had me worried). The display showed an E5 error message, which indicated a needle positioner fault. I reset the breakers, disabled the positioner and tried again and this time it worked.

It was about this time that I recalled this posting......

I have a choice - needle positioner and whatever speed setting I can get from the servo or no positioner + speed reducer + whatever setting I can get from the servo. I have another pulley coming that will give me a 2.7:1 reduction, so I'm thinking that I will be better off with the reducer and the reduced low speed and increased torque it will give. (Plus I put too much effort into making the reducer to not use it.....).

[Constabulary]

Yep - had the same problem with my Jack Servo + 3:1 Speed reducer, always E5 Error. So I kicked out the NPS which I do not need at slow speed - its a nice feature but not that much important to me. Sometimes less technology is better.