Leather needle problem - Consew 206rb

[buko]

Let me first start by saying that I know very little about sewing machines. This is the first one I've ever used. I've been researching for months and finally bought a used Consew 206rb-2 from a local sewing machine mechanic that restored it. To use it for leather, I replaced the motor with servo, put a 50mm pulley on the motor and replaced the wheel on the machine with a 145mm pulley which has slowed the machine enough that I can control it.

Now the problem: any time I try to use a 135x16 size 22 needle the top thread comes unwound and breaks. I've tried both #138 thread and #92 thread with the same results. When I use a 135x17 regular needle it sews fine. I've checked the hook timing (after watching videos) and it appears to be ok. I've adjusted the tension and it doesn't seem to affect anything. I've attached a photo to show what I'm getting. The stitches on the brown leather are with the normal needle and the ones on the black leather are with the leather needle. The blue thread is #92 and the black is #138. What am I doing wrong?

[Wizcrafts]

This could possibly be caused by an improperly adjusted check spring. Try lengthening the stroke of the spring. This will keep the top thread taut until the needle has fully passed through the leather and comes out the bottom layer. Too short of a stroke may allow the thread to be too loose as the needle makes contact. This is where the thread splitting begins.

[mikesc]

I'd be interested to see how you are threading the top thread ( thread path ) , you may be missing a step, or winding the thread around somewhere that you shouldn't be ..

[buko]

  On 10/27/2017 at 2:07 AM, Wizcrafts said:

This could possibly be caused by an improperly adjusted check spring. Try lengthening the stroke of the spring. This will keep the top thread taut until the needle has fully passed through the leather and comes out the bottom layer. Too short of a stroke may allow the thread to be too loose as the needle makes contact. This is where the thread splitting begins.

Expand  

Ok, this sounds like what is happening. I see the thread go really slack as the needle makes contact. When you say "lengthen the stroke" do you mean adjust the tension or do you mean rotate the check spring counter clockwise? Or both?

[Pintodeluxe]

Just noticed you're in Vancouver, I'm in Camas.  Small world.

I'm sure you'll get it fixed up with the expert advise of Wiz and others.  You had asked me on another forum where I found Schmetz special order needles, and I think it was just direct from the company at Schmetzneedles.com  

Good luck with it.

Edited October 27, 2017 by Pintodeluxe

[brmax]

Just the check spring.  As the needle touchs the material is when check spring tension is no longer needed. So adjusting as mentioned either direction as required. Best to stick with one adjustment at a time, or its what I have found best. 

 

Good day

Floyd

[buko]

It appears that adjustment worked. At first when I tried it the thread was still fraying so I took the plate off and noticed that the hook was splitting the thread. I replaced the needle and it started sewing fine. I guess I must have bent it at some point.

The thread I have seems to fray very easily though. Its bonded nylon from Superior Threads but I'm not sure if I'm really a fan of it.

[Wizcrafts]

  On 10/27/2017 at 3:08 PM, buko said:

Ok, this sounds like what is happening. I see the thread go really slack as the needle makes contact. When you say "lengthen the stroke" do you mean adjust the tension or do you mean rotate the check spring counter clockwise? Or both?

Expand  

I mean that you could lengthen the distance down that the spring travels. The check spring assembly has a movable bottom stopper for the spring. It is locked down by a screw that is on the lower right side of the assembly. Loosen the screw then tap or pry down from the spring side and the stopper should rotate CCW, letting the spring bottom out farther down. Lock the screw down when you reach the point where the thread is still taut as the needle goes through the leather.