Cowboy 4500 Won't Stop. Servo Problem?

[greyleatherco]

Hi all,

I was doing some spring cleaning/maintenance on my Cowboy 4500 today. I got everything dusted and cleaned, back on, put together, and oiled. I turned it on to test without a needle/thread installed and it ran great, the only problem is it runs so great that it runs even when I'm NOT pressing on the foot pedal.  I don't think I changed anything, but I suppose it's possible I may have bumped or adjusted something unknowingly while moving the machine. 

-I can push lightly (about half way) on the pedal and the machine will work normally with the speed reducer function. When I let off the foot pedal, the machine will stop as expected.

***The problem comes when I push all the way down on the foot pedal and then let off, the machine keeps running (needle, feed dogs, foot moving etc.) like it's on the slowest setting. It also makes a fairly obnoxious squealing noise while moving very slowly.

I tried moving the link on the chain up and down to change the amount of slack and tension- that doesn't seem to be it. If it's too tight it will run too fast and I don't get the speed reduction. Too loose and it doesn't matter. I even had the chain completely unhooked from the pedal and it kept running. 

I've narrowed it down (I think) to the black plastic arm on the servo motor that is attached to the foot pedal by the chain. 

It's not going all the way back up to stop the movement of the machine. I can gently push up on it momentarily with a finger and the machine will stop normally. If I let off the pressure with my finger, it will keep running. I also can apply a little more pressure and the whole black plastic arm will "click" or "snap" back up to a locked position and the machine will remain off. It will start up and run normally when I press the foot pedal, but again when I put it all the way down and release it will not stop completely. I have to manually push this arm up to stop it completely. Again, that's why I thought it might be the chain tension, but had not luck when moving the link and tension.

Is there anything you can think of that would fix this? What could I have done to cause it? Could the problem be coming from something else? This machine is only 2 years old, hasn't seen excessive use, and it is well taken care of. I bought it from Toledo Sewing Machine and have never had any problems with it before. I'm really hoping I don't have to replace the motor since it's so new.

I took the cover off the servo motor to see if there was anything obviously wrong and couldn't see anything. I'm not super mechanically inclined, so I thought I'd start here with the experts before doing anything. I didn't want to start chasing one problem and create a handful of others. 

Any help you all could provide would be greatly appreciated. Fingers crossed it is something simple and I can get it back to normal. 

Thanks in advance,

-Hannah

 

[Wizcrafts]

See if there is a return spring on the motor control arm that pulls it up. Tighten that spring. Otherwise, you may have bent the plastic control arm. The bend would be obvious. Try straightening it out. Also, make sure there is slack in the chain from the motor to the pedal.

[greyleatherco]

Hi Wiz,

My dad is helping me look and we aren’t seeing a spring on the motor control arm. Should I unscrew the plastic cover again? 

I also don’t see an obvious bend in the motor control arm. For some reason I can’t upload photos from my phone.  

There is definitely slack on the chain from the motor to the pedal. I marked it with a sharpie when I first set it up when I got it. I tried moving it up and down today after discovering the problem and it didn’t do anything to help, so I put it back in the “sweet spot” that had the sharpie mark. 

If I can figure out how to reformat my phone photos I’ll try adding them so you can see the motor control arm, but like I said, it looks straight. 

Thanks!

[Wizcrafts]

Open up the motor end cap and see if something is binding or the brake cork is not engaging with the lever up.

[greyleatherco]

I’ll have to get back into it tomorrow. I’ll check it out and report back. Thank you!

[greyleatherco]

Hi Wizcrafts,

We took the motor cover off and nothing is binding up inside. Everything seems like it's in the right place and as tight as it needs to be. It runs very smoothly, it's just stopping it that seems to be the issue.

The brake cork WILL engage and stop the machine when I push partially down on the foot pedal and let up. If I push the foot pedal all the way down and then let up, the brake cork will NOT completely stop the wheel from turning and the machine keeps running. I have to manually push that black plastic motor control arm all the way up until it makes a fairly loud noise, clicks back into "place" and then everything will stop. If I apply some upward pressure with one finger it will temporarily stop and the brake cork will fully engage, but if I let off the upward pressure with my finger it will continue to run without pressure on the foot pedal. Nothing about the brake/cork looks odd or concerning.

The squealing noise mentioned earlier when the machine runs and won't stop seems to be coming from the wheel and cork contact. 

The plastic arm is definitely not bent and there is plenty of slack on the chain connecting the foot pedal to the motor, so it is not preventing it from going all the way up.

I'm just really confused what would cause this because I didn't touch the motor while sliding the machine (on castors) out of it's usual spot to clean the machine and surrounding area. I also never removed the cover until the problem was discovered, so nothing has been changed or adjusted. Previously, I could push all the way down on the foot pedal, let off, and the machine would stop completely. So it all seems very odd that this happened.

I made a short clip and uploaded it to youtube. I thought that might help if I'm not clear in my description. The only thing I forgot to film is that when I say I am pushing the pedal part way down and everything "looks fine", I forgot to let up to show that the brake will stop the wheel completely. 

https://youtu.be/Ihuox5y8lSs

The video is "unlisted" so you need the link to view it. Hopefully it works for you. Please excuse my voice, I'm sure I'm not the only one who hates the sound of their own voice on camera. 

[Wizcrafts]

There is a spring inside that motor that is supposed to lift the lever all the way up. Something happened to that spring. You can call one of the Cowboy dealers for assistance with your motor. Your closest dealer is Solar Leather in Texas, then in Toledo Industrial Sewing Machines in Toledo, Ohio..

[greyleatherco]

Ok, I ordered the machine from Toledo Sewing Machine, so I'll start there. Thanks so much for your time!

[Wizcrafts]

Let us know how this turns out for you.

[greyleatherco]

Will do. Hopefully it won't be an expensive and/or time consuming fix.