S.e.w. Line Sl-29 Timing

[Ole South]

I dropped into a local alteration shop today and found one of these SewLine SL-29 patchers with a servo motor. A knock off of a 29k71 I'm assuming. The little lady that owned the shop said she'd had it over a year (ebay purchase) and had never been able to get it to sew. Breaking top thread, dropped stitches ect... She said she'd had three sewing machine repairmen out but all were unsuccessful.

I got it sewing, incorrect threading, bad bobbin, wrong tension everywhere. Had to slow the motor down as slow as it would go and jury-rig an actuator limiter. It won't do anywhere near 500 stm... 200 max as near as I can tell before it begins to drop stitches.

Okay here's where I need our experts advice:

The timing is marginal at best, eye is scarcely ascending as the hook centers on the needle scarf. I've never worked on a patcher before but it seems pretty straight forward except... I can't get the timing screw to turn!!! This is the screw head visible through the hole in the base... yes/no? I spoke with an experience industrial sewing machine repairman (the last guy to work on it) and he said he couldn't get it to budge either. Am I missing something here?

Also, the handwheel has a v-belt size groove in it... is there a tire that is supposed to go in there? Other patchers I've seen all have been solid, no groove.

[Constabulary]

On 29K71´s - "the real ones" - you can see and access the screw from the hole when the arm is almost down on the front end. But you may need a flash light to see it and you have to loosen a nut on the opposite side first. I don´t know the Chinese variants but maybe some (I don´t know) don´t have this timing screw. I remember I have restored an 29K1 last Christmas and it also had no timing screw but it worked w/o it.

Regarding V-Belt grove - do you mean the detectable hand wheel or the fixed pulley on the right?

Usually the hand wheel has no grove but maybe the rubber wheel of the bobbin winder is meant to run in it.

Edited December 2, 2015 by Constabulary

[Darren Brosowski]

The current Chinese machines do not have the belt groove on the hand wheel which is a good thing. On the older ones with the groove I put a spacer behind the bobbin winder assembly so the winder tyre runs on the wheel.

There is usually a "turnbuckle" arrangement on the rod that drives the shuttle.

[Ole South]

Yeah today I found the nut on the back of the adjustment screw and it was locked down hard . Yep Darren, It's a threaded rod terminating in a turnbuckle and an eccentric screw. I'm having trouble relating the timing instructions for the 29-71 to this machine. When I drop the needle to bottom dead center it stops and starts to rise I bring the hook to it and then it drops and sits there before it rises again. By this time the hook is well past the needle scarf and breaks the top thread. I finally timed it dynamically and it only drops a stitch occasionally and stopped breaking thread.

I'll go back tomorrow with some 69 bonded and try again.