Reached The End Of My Rope With This

[Hockeymender]

I have a Consew 227-R-2 that has for a very long time been on an off the arm table with a speed reducer and a Goldstar GBSM550S servo motor with a needle positioner. I purchased a new table (same type just much nicer) and moved everything to the new table. When I get everything together, the needle positioner refuses to work. The motor stops when the pedal is released, but the machine runs till it has expended all its energy. I have tried different motors (have several of this type), syncronizers and control boxes, all with the same result. The only way the needle positioner will work is if I bypass the reducer and go motor to machine (which is to fast). Cannot figure out what happened between tables to produce this issue. Open to any ideas.

[Northmount]

Is the pedal rod too short now?

Tom

[Hockeymender]

Is the pedal rod too short now?

Tom

No. Everything was sized according to the setup on the new table. Everything lines up correctly.

[BondoBobCustomSaddles]

Joe, you are close to Toledo, give Bob a call at Toledo industrial sewing machines. Number is in the suppliers section. I am sure he can help you.

Go Wings!

Bob

[DrmCa]

The only reason why the machine may keep spinning after you shut off the motor is that the brake clutch in the motor is not engaged.

Is the brake applied if you remove the rod connecting motor lever with the pedal?

[Hockeymender]

The only reason why the machine may keep spinning after you shut off the motor is that the brake clutch in the motor is not engaged.

Is the brake applied if you remove the rod connecting motor lever with the pedal?

The machine doesn't keep spinning after the motor is shut off. When the machine is in use and the pedal is released to its resting position, the machine continues to go till it runs out of its own energy. The lever on the control box is in the up position but there is no braking action. None of this occurs when the reducer is bypassed. Every function works exactly right with no reducer. All worked on the old table, this issue once everything was moved.

Go Wings!

Bob

Go Blackhawks! Played in that organization once upon a time.

Sorry Bob.

Edited October 10, 2015 by Hockeymender

[DrmCa]

Sounds like one of the V belts in the reducer is slipping?

[Hockeymender]

Sounds like one of the V belts in the reducer is slipping?

That's what I thought. Tried several different belts in both positions and like everything else I tried, didn't make a difference.

[dikman]

If it all worked before, i.e. the only difference is the new table, then the logical thing is to put everything back as it was, on the old table, and see what happens. If you still have problems then it's obvious that you've changed something else in the process. If it works fine on the old table then obviously your new table has a curse on it.

I'm also at a loss to understand how it keeps running, if the motor has stopped.

[Constabulary]

I guess you mean when you step off the pedal the motor is still running and that spins the machine right?

Check if the plug of the needle positioner sensor is properly plugged in. I remember when I installed my 1st servo I had a similar problem.

Next thing I´d check it the sensor / magnet lever alignment in the accelerator unit - you probably have to adjust the internal lever a little bit.

[Hockeymender]

If it all worked before, i.e. the only difference is the new table, then the logical thing is to put everything back as it was, on the old table, and see what happens. If you still have problems then it's obvious that you've changed something else in the process. If it works fine on the old table then obviously your new table has a curse on it.

I'm also at a loss to understand how it keeps running, if the motor has stopped.

Unfortunately I can't go back to the old table, as it is no longer around. I have gone over everything multiple times (connections etc.) and all is as it should be. I'm starting to wonder about the possibility of a curse..........

[BondoBobCustomSaddles]

It's probably that Blackhawk Curse!

Bob

[Hockeymender]

It's probably that Blackhawk Curse!

Bob

Nah...it's more likely all that negative red/white energy around these parts

As the title states, I don't know what else to do with this. There are a couple more guys I'm going to consult Monday about it and maybe they can spot whatever it is that I am missing.

[dikman]

Always good to have someone else look at it. I know that sometimes it's possible to miss something because one is trying too hard!!

As for the motor, I thought servo motors stopped as soon as they were switched off (mine does) unlike clutch motors, which will keep spinning a long time due to their flywheel.

[Wizcrafts]

Always good to have someone else look at it. I know that sometimes it's possible to miss something because one is trying too hard!!

As for the motor, I thought servo motors stopped as soon as they were switched off (mine does) unlike clutch motors, which will keep spinning a long time due to their flywheel.

The Family Sew FS-550s servo motor has a brake pad that can be adjusted for free play, or removed entirely. If removed, the motor will run on a bit, depending on how fast it was spinning at the last stitch. I assume other brands of servo may also use an adjustable mechanical brake pad that could allow run on.

[Hockeymender]

As a last ditch effort, I tried a different speed reducer, on the off chance something was not right with the one I was using. Same ol, same ol. The longer this goes, the more determined I am to get to the bottom of the matter.

[Uwe]

I think the needle positioner motors are designed to keep running after you let go of the pedal until it receives a signal from the position sensor that it has reached the desired needle position. The motor control boards probably have some safety feature to give up after some time if it fails to receive that position signal.

Usually the needle position sensor itself has a little LED that lights up in that "correct" signaling position. If the LED lights up and the motor keep spinning then the signal doesn't make it to the motor control board somehow. Or perhaps the sensor itself is slipping on the hand wheel, never signaling the correct position. The motor will eventually give up spinning if it never gets that correct needle position signal, which may look like it's spinning until it runs out of juice somehow.

Trouble shooting steps I would take are:

1. Make sure the sensor is firmly mounted to the handwheel

2. Make sure the position sensor LED lights up in correct position as you turn the handwheel manually

3. Make sure that LED blinks as you sew, every time it reaches the needle down position

If the motor spins past the LED lighting up, then the sensor wire connector may not be seated properly.

There's also a chance that the motor control board simply gives up before it ever receives the next target needle position signal due to a large speed reducing ratio ( i.e. the control board logic may think "I'm gonna make at most ten more turns and then give up unless I get a position signal"). That might explain why it works properly without a speed reducer (e.g. position signal every five motor turns), but fails if a speed reducer is installed (e.g. position signal every 15 motor turns). This may be a safety feature to make sure the motor fails safely if the needle position fails to report, so as not to keep the motor spinning indefinitely with no pedal input.

I'd love to take a look at it in person, but I'm in Texas this week.

Edited October 12, 2015 by Uwe

[Hockeymender]

I wish this had a LED on it, but it does not. I am starting to wonder if there is a difference (however slight) in the positioning of the speed reducer in relation to the motor on this table versus the old one that could be responsible for a tension or torque change that is causing the sensor to send improper signals.

[Uwe]

So how can the motor stop and the machine keeps going as you say, like a bike that keeps rolling once you stop pedaling? That sounds like there's a one-way clutch or a loose set screws in the system somewhere. Is the handwheel/belt not directly/tightly coupled to the machine? Does the machine keep going but the belt does not move? I'm confused!

If the belts are tight and nothing is slipping, the motor will keep driving the machine even after you let go of the pedal, until it receives a sensor signal or gives up.

Unplugging the sensor cable from the back of the control box should make the motor work "normal", stopping everything the instant you let go of the pedal, with or without speed reducer installed.

We're gonna need a couple photos or a video pretty soon . . .

Edited October 12, 2015 by Uwe

[Hockeymender]

Everything is tight, everything is connected correctly, belt tensions are correctly set. When the pedal is depressed, the machine operates. When the pedal is released (and the actuator lever goes back to its resting position) instead of the machine stopping in the needle down position, it just runs until (as it appears to me) all momentum is spent. Proper operation is the needle stopping in the down position instantly when the pedal is released. The needle can be raised via a heel back motion. As stated before, when the speed reducer is removed from the scenario, everything functions perfectly. It's pretty clear the reducer is creating the problem (otherwise I would have the same trouble sans reducer, but I don't). It's a matter of figuring out what the reducer is doing (or not) that causes the needle positioning system not to function. All these components played very nice together on the other table.

[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.