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.

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.

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.

Ya, I'll have to have a look at that. It is a VERY complex machine! I was excited that its automatic in terms of auto-backtack and threadcut as I have a flatbed with those options. But the DA is on another level. Like there's something like over 300 parameters you can program and you can dial in certain functions to the millisecond. I have been going over the service manual but I might end up having a local tech come out as some things are a little over my head. I did figure out the thread cutting mechanism is a circular rotating disc with a knife on it so possibly its a timing issue with the needle like yours was. I also noticed when going to "home" position, the motor is currently setup to send the needle home, but then reverse a tiny bit so the needle is at its highest position so its above the foot to prevent snagging material when pulling it out. I might try to turn that off and see if it helps thread cutting. Thanks!

I recently picked up a DA 8967 cylinder bed machine that used to be used in a blue jeans factory for the cuffs. I am going to use it for some heavy multi layer cordura projects as well as leather. I got it running and with a new needle got it sewing with my bonded 69 nylon thread really well in terms of making a nice stitch. However, my issue is with the thread cutter and also auto backtack. When I use auto backtack, the stitch length knobs both jump to maximum (6) when its used. They jump when the machine shifts from rev back to fwd. I also noticed they will do the same thing if I manually push down the lever and let it spring back. If I gently move it down to reverse and let up gently, stitches stay the same length. The thread cutter seems to try to work, but when its used, the top thread remains uncut and when I pull the piece out, there are 3 threads coming from the bottom also uncut. Very strange. Attached pics of bobbin, maybe I'm threading wrong. Pics in manual aren't terribly clear.