McKay 77 Stitcher - Initial Questions

[Ogoki]

Hi all,

I recently picked up an old McKay Champion 77 stitcher, and I have a few initial questions.

First, thread.  The fellow from whom I purchased the unit mentioned that it should take a left twist thread.  Can anybody confirm this?  Also, what should be used in the wax pot?  The local supplier has thread lubricator and stitching wax.  Or, is there a thread that can be used without liquid?  I used to operate a Rapid E outsole stitcher, and we used heavy bonded nylon thread without any wax or lube.  Something like this would be preferable (just in that I assume it is less messy).

Second, I have a problem with the cast-off in that it sticks in the upward position and the needle consequently drops the thread loop.  The little cast-off block is sticky on its shaft, and I need to push it back down into position with a screwdriver.  I assume it should slide around freely on that shaft when the return spring is removed.  Any thoughts on this?

Thanks for any responses.

[CowboyBob]

The linen or cotton thread with lube(we've even used sewing machine oil) is all that will work,the nylon doesn't make a good loop & gets caught in the needle eye when sewing.You probably need to put some wax cleaner or kerosene down the shaft where the cast-off runs in, it might have some old wax in it & then oil it too.You could have a weak spring too.

[Yetibelle]

That replacement "Cast-Off Screw" looks a little out of place?  So that was a trouble area already on the machine I suspect.  Here is the guide

 

77 McKay_Stitcher.pdf

 

 

 

 

[Ogoki]

Thanks for the responses, guys.  I do have an old hard copy of the manual, as well as that pdf.

The cast-off screw is a 6mm bolt, and the threads in the block aren't pretty, but I will need a bottoming tap to clean them up properly.  In any case, it does its job of holding the cast-off in place as is.

The spring is probably weak, but that little spring couldn't push the block back into place even if it were in good shape.

I would like to remove the block and its shaft, but the manual doesn't exactly have step-by-step disassembly instructions...  Unfortunately my workshop is in my apartment and the upstairs neighbours wouldn't appreciate kerosene.  Is a wax remover less smelly?  I have tried heating the shaft, hoping to wick away any wax that might remain, to no avail.

Thanks again.

[CowboyBob]

You might want to pull it out,it could be bent on the inside.It's been quite a few yrs since I worked on one so I'm alittle rusty on them.

[Ogoki]

It turns out that cast off screw was very close to the problem.  I managed to remove the cast off assembly, and the block was bulged out, presumably from years of over-tightening that screw against the cast off.  I sanded the bulge flat and cleaned and oiled and reassembled and managed to stitch a couple of boots.

Now it is sticking again but the block is fine and the problem seems to be a bent cast off.  For the time being I will try to straighten it, but is there a supplier for parts for this thing?  I see needles around, but what about cast offs?  This one has probably seen more than its share of use.

And what kind of thickness can these things handle?  I can't imagine that I am pushing it in that regard, but who knows...

Thanks again.