Union Lockstitch? Yes ? No? Or?

[catskin]

I surely would not want you to try to modify your machine just to see if it could be done. What I was wondering is if you thought the awl and needle would be long enough for that thick of leather in the event someone like me was to try making a foot a looper and guide that would let that much leather pass under and still make the stitch. For example would the barb on the needle clear the leather so as to allow it to hook the thread.

I had to switch to a modified presser foot to sew over 3/4 inch. In order to sew 7/8 inch I would have to perform Voodoo on the looper and thread guide, and grind away more steel on the right side and top of the foot. Since I am happy with being able to easily sew 3/4 inch, this is not anything I look forward to doing.

[Wizcrafts]

I surely would not want you to try to modify your machine just to see if it could be done. What I was wondering is if you thought the awl and needle would be long enough for that thick of leather in the event someone like me was to try making a foot a looper and guide that would let that much leather pass under and still make the stitch. For example would the barb on the needle clear the leather so as to allow it to hook the thread.

Why don't you pick up a Union Lockstitch and see if you can get it to sew 1 inch? My ULS is for sale! The needle and awl will probably be long enough, or almost there. The biggest problems are the top and right side of the foot, the looper (which has to revolves around the barb in the needle) and the thread guide and the thread slack arm (I forgot to mention that part). My guess it that once you have modded a ULS to sew 1 inch, it will no longer sew 1/4 inch as well as it did before.

You may also have to replace the top pressure spring with a motorcycle grade coil spring, to exert enough pressure to hold down 1 inch of leather. Further, the take-up arm may need to be altered to allow it to pull the knots up into such thick leather.

There will be no wiggle room allowed in the feed mechanism. You will need to tighten all moving parts affecting the needle bar and stitch length arms. The position of the shuttle ring gear will be critical to eliminate slack. The heat generated on the awl will be stupendous. It may stick inside the leather unless you spray it with silicon as you stitch.

It will be an interesting project Catskin. Let me know how it works for you.

For anybody following this topic and wondering if there already is a machine capable of sewing an inch out of the box, there is. The Campbell High Lift sews 1 1/8 inch.

Edited February 4, 2012 by Wizcrafts

[catskin]

The problem I have with the machines I have is getting the last few stitches near rings where the leather is doubled back.

The traces I sew are 2 ply that amounts to about 1/2 inch but when I turn the ends back so there is 2 ply through the rings after skiving a slope I can still end up with near an inch for the last few stitchs. This is where I wondered if the ULS could be made to do that thick for a short distance. Maybe I am thinking something that can't be done. I would also slow the machine down to a crawl to make control easier and near eliminate heat buildup.

[Wizcrafts]

The problem I have with the machines I have is getting the last few stitches near rings where the leather is doubled back.

The traces I sew are 2 ply that amounts to about 1/2 inch but when I turn the ends back so there is 2 ply through the rings after skiving a slope I can still end up with near an inch for the last few stitchs. This is where I wondered if the ULS could be made to do that thick for a short distance. Maybe I am thinking something that can't be done. I would also slow the machine down to a crawl to make control easier and near eliminate heat buildup.

I suspect that Campbell-Randall Company could give you a better answer about modifying a Union Lockstitch for higher lift. They may even offer to modify one and sell it to you. But, for only a few thousand more you can buy a Campbell High Lift.

It would cost me about $200 for extra parts to experiment with this on my own machine. I can't afford that right now.

[Wizcrafts]

Well, out of curiosity I ground down the right toe on my Union Lockstitch machine, to a height af about 1/8 inch. I also extended the straight edge on the right side of the presser foot body. This gave more room for the thread holder arm to move at extended heights. I also had to reshape that arm to not only clear the right side and top of the foot, but also the looper/thread guide.

After all that dinking around the machine still only wants to sew 7/8 inch. The lift on the presser foot can be varied somewhat, with lower lift making it more likely to sew thicker leather. But, the stitch length is reduced when the foot lifts later and comes down sooner. I try to keep the lift at about 1/8 inch, at all thicknesses. I can compensate for the shortened stitches by lowering the stitch length regulator bar.

Geometry came into play at 7/8 inch and the thread wanted to miss the pickup arm's slot, due to the severe change of angle the thread has (to the left) at such altitudes. The solution is to make a new pickup arm with special shaping that will grab the thread at great thicknesses, yet clear the right side of the presser foot body and also clear the bottom of the looper/guide tube.

My advice after all this fussing around is to buy a Campbell High Lift to sew 1 inch or above. The machine is already designed to do so and won't need to be modified.

Edited February 4, 2012 by Wizcrafts

[catskin]

I am NOT asking you to spend time or money trying to modify your machine in order to get answers for my questions.

I only expected you to look at your machine to see if you thought there was room for the modifications to be done. But thank you for all the advice you have given me.

I suspect that Campbell-Randall Company could give you a better answer about modifying a Union Lockstitch for higher lift. They may even offer to modify one and sell it to you. But, for only a few thousand more you can buy a Campbell High Lift.

It would cost me about $200 for extra parts to experiment with this on my own machine. I can't afford that right now.

[Gregg From Keystone Sewing]

Wiz,

Thanks, good info. I don't know or claim to know much about this machine. No excuse, but it just does not come up often enough for me to get involved with it.

[Wizcrafts]

Wiz,

Thanks, good info. I don't know or claim to know much about this machine. No excuse, but it just does not come up often enough for me to get involved with it.

Gregg;

The Union Lockstitch machines are like the Indian Motorcycle of harness stitchers. Fast, temperamental, powerful, built in the USA and totally awesome!

I found it relatively painless to eek out a little more working clearance from my old gal. A 6" grinder, a strip of Emory cloth and a buffing wheel, working on the right side of the presser foot and some bending of the thread check arm (still needs work) got me just over 7/8 inch. I suspect that if I put in some more time on it, I can get it to sew and feed a full inch of anything I put under the foot. That includes plywood lined with leather.

I'm toying with the idea of shooting a few short videos on my Canon digital camera, showing how to thread, time, change stitch length and perform basic adjustments and maintenance on a Union Lockstitch.

[Gregg From Keystone Sewing]

Gregg;

The Union Lockstitch machines are like the Indian Motorcycle of harness stitchers. Fast, temperamental, powerful, built in the USA and totally awesome!

I found it relatively painless to eek out a little more working clearance from my old gal. A 6" grinder, a strip of Emory cloth and a buffing wheel, working on the right side of the presser foot and some bending of the thread check arm (still needs work) got me just over 7/8 inch. I suspect that if I put in some more time on it, I can get it to sew and feed a full inch of anything I put under the foot. That includes plywood lined with leather.

I'm toying with the idea of shooting a few short videos on my Canon digital camera, showing how to thread, time, change stitch length and perform basic adjustments and maintenance on a Union Lockstitch.

Good deal, not may folks running around with personal useer experiece on this this machine.

[jsmith]

Wiz

Your vast experience with the uls is so rare I'd love to see you do some videos. It would have saved me years of re-engineering parts and functions on my machine.

Jeff.

PS I'm waiting for the truck to drop my new Cobra 4 , the uls won't get as much use now.

Jeff