Instructions for Cobra model JM9160-C servo motor?

[TomE]

I bought a used Cobra Class 29-18 patcher that sews well but is tricky to start up slowly.  Pressing the pedal slowly, the first revolution is sometimes slow and sometimes fast before slowing to an even pace.  Decreasing the maximum speed helps but doesn't solve the erratic behavior.  Q: Can the startup and ramp-up speeds be adjusted on the model JM9160 motor?  Does anyone have an instruction sheet for this motor?

I also considered whether the problem is mechanical/friction when starting up.  The machine was setting for a year or two before I bought it.  I've been oiling it generously.  The previous owner seemed to be good about maintenance.  There is a generous amount of lithium grease on the shuttle driving gear.  The slot on the needle bar cam/flywheel that actuates the needle bar driving lever is also greased.  Q: Should I be greasing or oiling the slot that holds the end of the needle bar driving lever, shown in the 3rd picture?

I did also check the foot pedal for smooth operation and moved the angle of the lever that pulls the linkage chain connected to the servo motor actuator arm.  The actuator has a very short throw and I'm trying to maximize the foot pedal travel over the full operating range. 

Thanks for help and advice.

[CowboyBob]

@TomEGrease will never work into the inside shaft of the roller so only use oil,see attached file for a manual that should work for this motor.Servo motor directions.pdf

[DieselTech]

3 hours ago, TomE said:

I bought a used Cobra Class 29-18 patcher that sews well but is tricky to start up slowly.  Pressing the pedal slowly, the first revolution is sometimes slow and sometimes fast before slowing to an even pace.  Decreasing the maximum speed helps but doesn't solve the erratic behavior.  Q: Can the startup and ramp-up speeds be adjusted on the model JM9160 motor?  Does anyone have an instruction sheet for this motor?

I also considered whether the problem is mechanical/friction when starting up.  The machine was setting for a year or two before I bought it.  I've been oiling it generously.  The previous owner seemed to be good about maintenance.  There is a generous amount of lithium grease on the shuttle driving gear.  The slot on the needle bar cam/flywheel that actuates the needle bar driving lever is also greased.  Q: Should I be greasing or oiling the slot that holds the end of the needle bar driving lever, shown in the 3rd picture?

I did also check the foot pedal for smooth operation and moved the angle of the lever that pulls the linkage chain connected to the servo motor actuator arm.  The actuator has a very short throw and I'm trying to maximize the foot pedal travel over the full operating range. 

Thanks for help and advice.

Tom I got the newer servo motor setup on my Cobra class 26. It is plenty slow at start up. 

Is there a reason your servo motor is loose & missing a nut & washer. 

Here is how mine is. 

Apparently you have yours took apart at the moment. 

[TomE]

4 hours ago, CowboyBob said:

@TomEGrease will never work into the inside shaft of the roller so only use oil,see attached file for a manual that should work for this motor.Servo motor directions.pdf

Thanks so much, @CowboyBob!  I will give the instructions a try tonight.  Thanks also for the advice about the needle arm lever roller/cam.  Will get it cleaned up and oiled.

 

2 hours ago, DieselTech said:

Tom I got the newer servo motor setup on my Cobra class 26. It is plenty slow at start up. 

Is there a reason your servo motor is loose & missing a nut & washer. 

Here is how mine is. 

Apparently you have yours took apart at the moment. 

 

 

I suspect the previous owner misplaced the nut and washer.  If it's metric I probably have one.  The belt tension holds the motor against the one nut I have left - that didn't come out right.   

[1hp]

looks similar to the original motor on my 206rb5.

Consew_CS-1001 (1).pdf Motors-Con-Serv1000.pdf

[TomE]

 

54 minutes ago, 1hp said:

looks similar to the original motor on my 206rb5.

Consew_CS-1001 (1).pdf 376.53 kB · 1 download Motors-Con-Serv1000.pdf 273.51 kB · 1 download

Thanks, @1hp!  Those instructions did the trick. It starts slowly/smoothly now.

@CowboyBob, function S.1 is the start speed on this motor.  I oiled the roller cam and the action is smoother now using the hand wheel. I will be oiling the roller religiously.  Thanks for your help.

@DieselTech, you were right.  The top nut on the belt tensioner was loose.  Probably worked loose after I set up the machine then did some sewing.  That certainly could have affected the startup action.  I installed the missing nut to lock the motor in place.  Thanks for pointing this out.

  

[DieselTech]

9 minutes ago, TomE said:

 

Thanks, @1hp!  Those instructions did the trick. It starts slowly/smoothly now.

@CowboyBob, function S.1 is the start speed on this motor.  I oiled the roller cam and the action is smoother now using the hand wheel. I will be oiling the roller religiously.  Thanks for your help.

@DieselTech, you were right.  The top nut on the belt tensioner was loose.  Probably worked loose after I set up the machine then did some sewing.  That certainly could have affected the startup action.  I installed the missing nut to lock the motor in place.  Thanks for pointing this out.

  

No problem. I thought maybe that might have been affecting your start up speeds. So figured I would mention it. 

Lol I am a newbie rookie when it comes to machine sewing & machine mechanics. 

Thanks to all the great professionals on here that help out.