Slow Down A CB4500

[1Poet]

Hey All,

     I apologize for not having a profile up, but it doesn't load for some reason. Anyway, I have a new to me CB4500 and I have a problem with the speed, especially starting up. I do not need anything fast, but would like to start slow and keep it slow. However, the foot pedal is something that requires a lot of pressure to start and does not seem to be very sensitive to my foot input. I am doing short length stitching on smallish items, 4" to 8". Is there any way to make the servo start slow and stay slow? I have tried everything I can safely try, but no solution. Advice greatly appreciated.

[kgg]

14 minutes ago, 1Poet said:

I have a new to me CB4500 and I have a problem with the speed, especially starting up.

A couple of questions:

i) does your machine have a speed reducer or just one belt from the head directly to the motor??

ii) does your machine have a clutch motor or a brush servo motor or brushless electronic servo motor???

iii) what size of motor?

A couple of photo's would help clear up your particular setup and narrow down possible solutions.

kgg

[Wizcrafts]

15 minutes ago, 1Poet said:

Is there any way to make the servo start slow and stay slow? I have tried everything I can safely try, but no solution. Advice greatly appreciated.

First of all, what type of servo motor is installed on the machine? Does it go directly from the motor to the machine? Or, is there a speed reducer between them?

In the early days of the CB4500 and Cobra Class 4 machines (e.g., 2011 - 2013), they all had digital servo motors with a readout display and push buttons to change functions. these motors started spinning at about 200 rpm. Sometime after that, they began to ship with analog servo motors featuring a simple knob to limit the top speed, plus a 3:1 speed reducer to triple the torque. My analog servo and speed reducer lets me sew so slowly that it's like watching grass grow if I just slightly engage the speed pedal.

[1Poet]

Wiz,

My machine has the analog servo with a single knob for speed. I have it set on the lowest setting. It has the 3:1 speed reducer. My issue is do I have the pedals and connections set right or is it something else. On start up I have to push on the foot pedal a little too much and then try to slow down to a slow speed. I would like to adjust it where I start slow and it will run slow. I currently don't have it running fast even with the pedal all the way down.

BTW, thanks KGG, I think Wiz has nailed what I have.

[dikman]

As mentioned, photos will help, particularly the foot pedal linkages and where they connect to each end.

[Northmount]

7 hours ago, 1Poet said:

I have a new to me CB4500 and I have a problem with the speed, especially starting up.

Moved your post to leather sewing machines.

[1hp]

i put a 40mm pulley on the motor. made it a lot easier to get used to the machine.

https://www.ebay.com/itm/124309601543?var=425199910545

in addition to having speed reducer. no expert here.

 

Edited July 12 by 1hp
more info

[1Poet]

Hey, y'all! I don't know how to add photos! DUH! Any guidance appreciated!  

[bladegrinder]

I have a CB4500 and notice a big improvement as far as pedal reaction to foot pressure by removing the brake pad in the back of the motor. you could try that and if you don't like it just put it back.

 

 

[bladegrinder]

To add a picture, it has to be resized for this forum to take it. I resize mine to 650 as the largest size, then save that resized photo, come back here click add a photo and choose the one you just resized.

anything bigger and it won't post.

[Wizcrafts]

3 hours ago, 1Poet said:

Hey, y'all! I don't know how to add photos! DUH! Any guidance appreciated!  

This article explains how to post photos on our forum.

[1Poet]

Bladegrinder,

     I tried your tip on disconnecting the brake and it worked! I adjusted the linkage and it starts slow, runs slow, or I can speed it up. Only downside is making sure to stop stitching you have to push the pedal back to the starting position!

     There must be also be a  way to slow down the startup besides removing the brake! Anyone have any ideas?

[bladegrinder]

It sounds like your pedal it hanging up, it should return to the stop position when you let up on it.

[ASAuLTCases]

Hi, I'm not sure how your machine pedal controls the motor, so I am going on the 2 modern style industrial tables with clutch motors that have basically the same set up, one I think original to the Singer 211G166  compound feed flat bed, the other a union special (flat bed) table that has got my old Singer 17-8 cylinder arm machine fitted on it,  but I might swop that with my Adler Patcher I have on a Singer treadle base for the Patcher style machines,? 

But back to what I found years ago on how to slow down and get more control over the machine is quite simple but quite clever as well, 

The lever that is at the bottom of the motor, it pulls down and operates the motors clutch, at the end of the lever is a hole, the Rod links into, with a bolt in the end of it, the lower end of Rod fits on the pedal. That's what it does, 

What will give more control is making the distance between hinge of the lever and the Rod link at the other end, in the same way as it would give more force for less energy,  it allows increased control because eg the pedal control movement of 1 inch changed the motor speed from 0 to maximum speed,  when the distance between the hinge and Rod link are increased the control movement can be greatly improved doubled plus quite easily to do by bolting a length of bar, angle alli, I think it's uni strut with holes in it,  Channel rail, the Singer table pedal was connected to the Rod on the motor side so I just moved the connection on the pedal to the other side and extended the lever with a bar, I've just noticed the other table pedal is in the middle for a normal flat bed machine and I will probably move it across to suit where the action is and more comfortable, 

I hope you understand what I mean? It does work and when you think about it is quite logical, 

I keep thinking about turning the cylinder arm machine around so the arm is clear over the end of the table,  but I am not sure whether the motor will be OK wired the other way round so it runs opposite direction, DC AND 3PHASE motors do, not enough room to turn the motor round, 

Anyway hope this helps, 

 

[Wyowally]

Most of the brakes are adjustable or modifiable for when they engage and how much they engage - with a little effort. Others on this forum might have the best ways of doing that. They can be set to stop movement especially if wanting to stitch slowly. Adjusted that way, it won't dead stop things if stitching fast though.