Cobra 4 servo motor

[Red Cent]

If this is a repeat, sorry.

I read on some threads that the servo was  little difficult to control. I have read on other sites other servos are difficult to control. So I found a site that will show how to fix the servo.
The Cobra, apparently, is either stop or fast with little room in between. It does not give you the full range of the operating lever but uses the first iinch for it all. This speed on most all digital operated servos is controlled by gradient light. As the pedal is depressed a piece of material is passed over a light/laser. The problem with the material. is the quick "darkening" of the material.
Here ya go.

Scroll down and click on "servo mod"

http://leatherworker.net/forum/index.php?showtopic=41483#entry258131

[Red Cent]

Cliff, is this the problem with yours?

[outrider]

Well I have two servo motors on two separate machines and I don't have a speed control problem with either one of them...but of course they are not digitally controlled.  Mine simply has a dial on the motor which allows me to dial in the speed I want and it stays at that speed until I decide to change it.  These things are getting too technical...

[Cliff Fendley]

Yes Red that is pretty much what mine did when I got it.

The one on my Cobra is digitally controlled and sensitive as all get out. You can control it with a super light touch but it is very sensitive from stop to full speed. That's why I programmed it to only turn a certain rpm (I cant remember what it is set on now) and just go at a slow pace.

If I knew the proper procedure to program the speed it would be no big deal. Small tight turn project I would just slow it down and on belts I would speed it up.

My problem is there were no instructions on programming it, I started pushing buttons and trying to figure it out and had it running backwards and everything else. Once I got it set I didn't know how I did it. I haven't adjusted it in forever because I dread going through that mess again. Every time I do a belt I want to speed it up but figure by the time I have it figured out I could just sew it slow.

Gil Hibbens Adler and it's not hard to control and neither is my Landis. Another guy I know has a Juki and some other machine that looks like one and they are like outrider's. None of those have digital motors like my Cobra.

Now that I've gotten more familiar with the machine maybe I need to set the speed back up and see if I can control it. Keep in mind my Cobra was my first real experience with a sewing machine and I really hadn't got the feel yet when I was having the trouble.

[Red Cent]

If you understand the method, please excuse me for going over it again.

When you depress the pedal that arm rotates moving the paper over the laser. If you used a piece of black paper, you wouldhit top speed immediately. With the front edge of the paper being whte the machine will run slow just because the laser is reduced somewhat. On the other end, when the paper is blck with lead, the machine goes to top speed.

I have watched the video where he attaches the chains to the pedal which turns the vertical arm with the paper. The chain simply turns the vertical arm.





Anybody tried the 4-25 (3600.00)

[Dalton Masterson]

Call Steve at Cobra. They sent the fix out although I have yet to fix mine. It was just a sticker with a gradient on it.
Dm

[Red Cent]

Thanks Dalton. I'm glad to hear that. I waas fixin' to ask Steve if it would screw up the warranty.  See Cliff. Not too technical. A piece of paper with pencil marks.

[Cliff Fendley]

I'll call Steve.

I'm with outrider, what was wrong with the ones with a knob to control the speed?

[Dalton Masterson]

I am so used to mine as is, I may not do the fix anytime soon. Nice to have on hand though. It came with a nice color instruction print out too.