Why .................... does our 778 do this?
 

Our Touch & Sew 778 sews great. It will work just fine with ALL of the black cams, and three of the six white cams. The other three it spits them out.

CLICK ON THE PIC TO VIEW THE VIDEO. ( Hope it works.)
http://i119.photobucket.com/albums/o...-June13016.jpg

We have two sets of the white cams and it does the exact same thing with both sets. Three are good to go, three get ejected right quick. And if we leave the trap door closed it still ejects the cam only it tilts and jams up the machine.

Anybody have any idea why this machine would work with some cams and not others?

Joe

Have you looked very carefully at the cams to see if there might be some difference in those that work and those that don't work?

Yep, even measured them with calipers. All the same.

Joe

Joe, I have no idea what does this. I have a 750 here, it runs beautifully until you put a cam in, then it runs in reverse. The problems may be similar or related.

You just know it was the last thing I tested after oiling, disassembling and cleaning, and everything. Ugh. Another clean and oiled parts machine unless I figure it out. In the meantime, I took its throat plate pins as punishment.

Tammi,

I have three theories:

A: The little three fingered spring that holds the cams in is either week or the wrong one. It holds the black cams fine, but not the white cams.

B: There is something causing too much pressure on the follower that works with the cam release lever. So it causes it to shift around as the top follower rides the cam and then pop out.

C: There is something binding in the cam release, rear follower parts. Sometimes the cam release lever works easily, sometimes it binds and won't go all the way to the rear.


I'm working on something else now, I'll have to get back to it later.
I might take it to my LSMG, I'm sure he needs a laugh.

Joe

I enjoyed looking at all your pictures online. I don't have a clue about the ejecting cams, though.

I have to admit, I sort of giggled when it jumped out.
It seems like it has to do with the eject lever. Does the lever move as a symptom of the escape, or a cause?

ETA: It moves down up ejects the cam then down all the way... it -seems- causative...

Re: A, wouldn't they all jump out then? or do you think the white cams exert more pressure somehow?

B: Plausible.. Could be leftover goo somewhere...

C:, I've never liked that release lever, it's too variable. The 2 I've had here (the 750 languishing in the basement and the 758) both have had variable release lever tensions. Neither ejects a cam though.

I'm thinking if I can't diagnose this one it just might go to my LSMG. Last thing I was to do is mess it up.

Joe

Eh... it's a good learning experience. If you don't have too much into it, it's cheap education. Worst case, it's not like it doesn't share parts with other things. That's why I wasn't too upset about that one landing in the basement.

Tammi,

We took it and three others in trade. Other than the problem with the three white disks it works pretty good. So I think this one will be worked on as time and inclination allows.

Joe