Breaking needles

[BurkBags]

I wanted to see what needles everyone suggests for heavy leather.  I have a Durkopp Adler 8967 which uses 134/35 needles and I'm using 138 bonded nylon thread.  Curious what point everyone is using as well as what you consider maximum thickness for that needle system.  

I'm currently using 140/22 with D/TRI point.  But I'm having trouble with breaking needles.  But I am trying to sew some pretty thick leather.

 

 

[Uwe]

Quite often a needle breaks because it's being deflected as it's going down and it hits the feed dog instead of the hole in the feed dog. At the right speed this will break a needle every time, no matter what size or tip.  Make sure your needle points at the center of the feed dog hole when no material is in play (check service manual for specifics.)

You need to support your workpiece so that it does not pull or push in any direction as the machine sews - that's often not easy to do. If you're letting a heavy bag, or a whole saddle dangle from the end of your cylinder arm, your needle is doomed. You also need to make sure your workpiece lays perfectly flat on the throat plate so that the needle does not hit a slope as it goes down.

According to the Durkopp Adler 8967 manuals, your machine uses needle System 2134-35, which may not be the same as System 134-35.

The slim cylinder arm machines are usually designed for light to medium duty work. If your "pretty thick leather" is a couple layers of 10 oz. veg tan, your needle (and eventually the machine) is doomed.

For "pretty thick leather" you probably need a Juki TSC-441 or Adler 205 class machine.

Edited February 14, 2017 by Uwe

[dikman]

I can only agree with Uwe, as I have broken a few needles through deflection and hitting the feed dog. The thicker the leather the easier it is to deflect the needle. Even if it doesn't break the needle it can easily damage the point.

[BurkBags]

I think you are dead on with the deflection, when I think about the way I was holding the pieces and their shape, this is most likely exactly what happened.  As far as the type of leather I am sewing, I have some 1/8 inch thick oil tanned.  And I also have some much thinner purse/bag leather.  Sounds also like this particular machine might be not quite beefy enough for the 1/8 inch although a bit surprising as its a beast.

[shoepatcher]

That machine was a high speed version of the 69 class Adler.    1/8 " leather should be no problem for that machine at all.  That is only 8oz. leather and an oil tan is not a hard leather at that.  The problem may be the needle.  I would check with Durkopp/Adler  in Georgia and see what the difference is between a 134-35 system and a 2134-35 needle system and I mean the needle specs as length, size, etc.  I am not familiar with the 2134-35 system at all.  It had to be something special for that machine. 
Also, get us a few pics of the shuttle and hook area if you can.  I would want to see the hook in relation to the needle and how it looks thru a seam cycle with the balance wheel turned by hand.

glenn

 

[BurkBags]

Looked up needle systems and consulted my local shop.  Apparently 134-35 and 2134-35 are the same.  The machine was used in a blue jeans factory for high speed hemming before I got it and they had a ton of needles in the drawer which were all 134-35  I ordered some diamond point needles though so we'll see how that goes.  Also will properly support the work, I've never worked with leather until my recent experiments and its defnitely a humbling experience compared to even the toughest synthetics.