Question About Servo Motors

[DDahl]

I've had similar issues with my cobra 4 and the servo for my Seiko flat bed. If you are brave and persistent you can significantly improve your low speed control. First, those servos generally make use of an optical sensor that is virtually an on and off device. This is because the light block and unblock acts SO suddenly (really bad engineering!). The trick is to force the light intensity (pass through to the detector) to change far more gradually. As you improve (slow down) this transition your servo control will dramatically improve. In my case, I found that adding a piece of paper (taped to the moving light blocker) could help do the trick. Just take a pencil and shade a gradient on the piece of paper so that it is the darkest where the light would first shine through the slot and then gradually lightens to no shading as the assembly is rotated. It may take several attempts on your part (paper, tape, and curses) but if you persist and learn from the effects you observe, you can desensitize the servo pretty much to your liking!

Have Fun!

Dave

[Dallas Cowboy]

What is cobra steve saying about this particle?

[particle]

That's interesting Dave - I might give that a try. Thought about a gradient filter as well for photography.

Steve is on the road driving back from Sheridan. I'm not sure he was aware of the problem. I'll practice some more and maybe try the modification but want to make sure I don't void any motor warranties.

[Dallas Cowboy]

Have that sucker master by friday. LOL

[Big G]

Have that sucker master by friday. LOL

when i received my cobra it was way out of time ,, steve walked me through timing it. took a little trial and error to get it right . mine doesnt have much variation in speed with the pedal , but i dont sew fast either. like you i was sewing on a tippmann. i was comfortable with a little more speed. hope you find a answer . i sew at around 600 rpm on holsters. little higher on belts i am sure steve will help you

[mwebert]

Is the light sensitive control how all these servo motors control the speed via the foot peddle? Specifically is this what i would get if purchasing a CB227R or Techsew 2700....or is this a issue only with the motors Cobra use?

[steelhawk]

when i received my cobra it was way out of time ,, steve walked me through timing it. took a little trial and error to get it right . mine doesnt have much variation in speed with the pedal , but i dont sew fast either. like you i was sewing on a tippmann. i was comfortable with a little more speed. hope you find a answer . i sew at around 600 rpm on holsters. little higher on belts i am sure steve will help you

How do you adjust it to 600 RPM? I'm using the S3 setting of 4 to sew my holsters and belts, but don't know what RPM that is.

[particle]

FYI - I elongated on my experience in this thread:

http://leatherworker.net/forum/index.php?showtopic=40168&view=findpost&p=249753

[Techsew Ron]

Is the light sensitive control how all these servo motors control the speed via the foot peddle? Specifically is this what i would get if purchasing a CB227R or Techsew 2700....or is this a issue only with the motors Cobra use?

Never heard of this light sensitive control issue before, though I can't speak for other motors because not all are the same!

Ron

[mwebert]

1338076777[/url]' post='249803']

Never heard of this light sensitive control issue before, though I can't speak for other motors because not all are the same!

Ron

Thanks for the response!

Mike