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Russ Walling
Social climber
from Poofters Froth, Wyoming
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A few more thoughts off the top of my head:
If you are doing thick or really dense webbing, you will need to slow the machine down and lube the thread with a thread lube device.
These things generate a lot of heat at the needle and will melt the thread if they are going too fast. Slow them with a different set of pulleys on the motor.
With thread lube (silicon based?) you will see smoke coming off the needle as it sews and spills some heat. I did some tests and cooler needles will give about 10% more strength to the tack due to less thermal thread trauma.
I have seen a small air line, from an aquarium pump, set up to cool the needle also. I think this was an old Gramicci trick. Peater might know?
Also, this was pretty important for our stuff: You will need to set the cam timing a bit retarded (I think?? It's been a while) to give the cycle enough time to clear the needle on the final up stroke. If not you will break a ton of needles since they do not clear the thick material in time to let the machine index.
And the bad math method to determine the approximate strength of your tack is:
(A+B) X (C) X (.90) = S
A= top thread breaking strength
B=bottom thread breaking strength
C= number stitches in cycle
S= final strength of tack in webbing
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Peater
Trad climber
Salt Lake City Ut.
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To add to Russ's comments and add few more of my own:
Thread lubes and air cooling the needle does help but they're messy and a hassle. The lube can stain your material and the air cooling is annoying.
Experiment with thread brands. They're not all the same and higher cost is not always better. I used generic thread from John Howard Co in Monrovia Ca. It was cheap and worked great.
Use titanium oxide coated needles. (from Groz Beckert) The titanium coating has less friction to keep the needles cooler and they are stiffer so they don't break as often or skip stitches from needle flex. Cost is a little more but well worth it.
The needle length the machines use can be 135 x 17 or 135 x 5. 135 x 5 is better because it's a little shorter and flexes less. It's still long enough to sew thick stuff.
Slowing the machine down a little is good but not too much. The cam goes a little slow during the first few stitches of the cycle and if sewing thick stuff it can jam at the start of a tack.
If you splurge you could buy a machine with a DC motor. The motor is attached directly to the main shaft and you will have no problems with the torque you need to sew your materials. They make no sound unless you are sewing something. Plus they don't use a cam. And you can have a choice of sewing patterns built into the memory. Just dreaming here. You don't need all that.
Something important that I forgot before. You need to make sure the machine you buy will do the 7/8" wide tack. A lot of machines 42 or 28 stitch will only do 3/8".
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Ferretlegger
Trad climber
san Jose, CA
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Topic Author's Reply - Dec 3, 2016 - 07:38am PT
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Peater, Russ, and all,
Thanks a million for the tips!! I am going over to see Larry's machine here in Moab this morning. It is apparently an old "Levi Strauss/ Singer", so probably a fairly simple machine. I hope! Larry has had it overhauled, so it probably isn't a museum piece, but I know nothing else yet. Perhaps I can post an update.
Peater, if you have some sources for the needles you mentioned, I would love to try some. I have a Sailrite Ultrafeed LSZ-1 walking foot machine that is fairly burly (although probably on the light end of a true industrial machine). I bet that the needles would work on that also.
Thanks again everyone! I am learning a lot.
Michael
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john bald
climber
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Just stopped at Yates over Thanksgiving for new draws. Blaine knows them inside and out.
If you are shopping, check NickO for bunches of used and new.
Like Peater says....DC motor is the way to go. Slowing it down on thick is key.
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NegativeK
climber
Chicago
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If you end up finding a three-phase machine, look into a variable-frequency drive. You'll be able to find a lot of info from machining/metalworking hobbyists: industrial motors are happier on three-phase, and lots of people want a lathe or a mill that's worth a damn (plus, used industrial machine tools often cost the same as their newer and usually flimsier consumer cousins.)
Upside: VFDs can change phases and voltages, all in a little box. Downside: they're not plug and play. They often have features like continuous speed variation, motor braking, and other sh#t, so you have to program and wire everything up.
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Peater
Trad climber
Salt Lake City Ut.
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Gros Beckert needles are widely available. I haven't needed to buy needles for quite a while so I don't have a current recommended source for them,just google it.
If possible while shopping for your machine bring some of the materials you'll be sewing and try it on their machine.
An old Levi machine might be a 28 stitch 3/8" tack and set up for lighter thread. Not what you want. But check it out anyway. I'm imagining an old black painted Singer that uses leather belts with animal hair still on them (for real). Actually the leather belts with fur on them are better than the ones without fur.
3 phase motors are better but make sure you have that power where you'll be running your machine.
John Bald: Good to see your name pop up.
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