Reached The End Of My Rope With This

[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.