Reached The End Of My Rope With This

[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.

[gottaknow]

It's a shame that aftermarket control boxes don't have more parameters that can be customized. I guess I'm pretty spoiled with my production machines. The new Juki 9010-SH needle feed lockstitch features a direct drive motor on the top shaft, controlled by a SC-920 control box. The box has 124 programmable parameters to cover every single condition that you can think of, and some I'd never heard of. The cost does however reflect the additional features.

Regards, Eric

[saints1589]

Not to highjack this thread, but are you an Esposito as in Phil and Tony?

[dikman]

That Juki sounds nice, no belts to worry about. My little servos have a few parameters in the "manual" that look interesting, but there doesn't seem to be any way to access them (which makes me wonder why they put them in!!).