Good morning! I'm currently working on a lift motor that I'm having issues with. When pushing the up or down arrow to raise/lower the treadmill, the motor will engage, make 1/2 a revolution, then stop. I thought it may be a damaged gear, those look fine. Motor smells fine (not burnt). I can tap on the back of the motor assembly and it will take off. It does the same thing on the bench. The motor is single phase, 120V. There is a capacitor attached, which I am beginning to think is the suspect here, and then the gearbox and lift cylinder. Unfortunately, the identification for the capacitor has worn off. All that is on there is Yuhchang 10% 250VAC. The manufacturer (Jaeger Industrial) has nothing on their website with regards to this assembly. Best I can tell is the date of manufacture was 2004. Their part number is MJ8245. In closing, the motor does operate, just stops under any type load. It has a 1,400lb thrust rating.
Replacement cost is around $325, so if it's something simple I'd like to try to fix it. It also has a rheostat which should have nothing to do with this issue as the rheostat just tells the treadmill what position the cylinder is in.
Thanks in advance, ob_one

 

is it by any chance a brush type motor? runs after tapping on the end sounds like bad brushes.

 

Can you post a pic and dimensions of the cap?

 

No brushes. Straight up single phase, 120V motor, not converted to DC.

 

 

Hi Alec, the cap is perpendicular to the motor. It's a special application as the cap is molded to it's housing which then clips on to the motor shroud. If it is the cap, I'll have to end up cutting the wires from the old, splicing or soldering in the new, then clamping it to the motor. Fun...

 

By the look of the web examples it appears to be a G.B. operated ball-screw linear actuator, it could also be a dry mechanism sticking, lack of lube etc.
The motor is only very fractional H.P. by the look of it.
Max.

 

1.4A, 1/8HP. Lube does look good. My wife asked me the obvious though, and that was if I checked the gears for damage. I did not, however when bench checking, I did get it to run for over 1 minute non stop. This of course with the actuator unattached and just spinning with no load on it.
I do know for a fact it's not the machine. My friend owns a gym and we swapped out a lift unit with another one that does work. I put this one in the other machine and same issue. It had blown the 2A fuse in the other machine. This machine when I slaved it in it did not blow the fuse, although the second it stalled, I killed the power.

 

When you tried it on the bench did you supply it with 120vac direct?
If so, did you try applying direct AC when it is on the T.M.?
Also, is there any way you can load it when it is on the bench?
Max.

 

Well, I just took it apart again. Found two teeth on the plastic gear torn off. So, electrically, we're good. Now to find a gear. Thanks to everyone for their help/input. Best regards, ob_one.

 

Well, I just took it apart again. Found two teeth on the plastic gear torn off.

So basically she said "I told you so"
Max.