Sew #69 Thread On My Cobra 4?

[Squilchuck]

I assume I can sew #69 thread on my Cobra 4, but I am not sure of the correct needle - something like 110/18 or 120/19? I usually use 794S or LL points with larger thread and needles, but I cannot seem to find a source for this needle system and smaller size. Any suggestions on size and supplier?

[Art]

Chuck,

You will be trying to do something that machine was not designed to do. The smallest 794 system needle in a leather point is a 160/#23 and the smallest I know of in a round point is a 140/#22. The smaller the needle diameter, the farther away the hook is from the needle. This can be adjusted (with some work), but you really shouldn't go screwing around with those adjustments over and over. The good thing is that you will wear out before the machine. The 160/#23 needle will work fine with Z-138 and Z-207/Z138 for a tighter stitch. You could use Z-69 with the 160/#23 needle, but the holes will be huge.

The best way to solve the problem is to purchase a CB-227R.

Art

[pcox]

I have sewn with 69 thread on that class machine. I use 7x3 # 18 needles but I had to change lots of adjustments . Needed lighter tension springs and change bobbin tension. Those long skinny needles flex a lot as you go over seams etc so you are going to break some needles. I didn't think it was worth the trouble. As said above maybe time for another machine.

[Wizcrafts]

The practical lower thread limit is really #92, top and bottom. Use a #20 needle with it

As mentioned already, there are no leather point needles in stock below #23 in system 7x4/794. Getting smaller leather point needles would require placing a very large minimum order with the needle manufacturer.

If your Cobra is already set up for #277 thread and sewing normally, you will have to reduce the tension to almost nil on the top disks and the check spring. Balance the knots using the bobbin tension spring. The travel of the check spring may also need to be dinked with to get a suitable loop at the eye of the needle on the upstroke. Of course, the top pressure spring will need to be adjusted almost all the way out.

Sewing things that look best with #69 thread may indicate that some of the material if very soft and thin (4 ozs and under). Such materials tend to get shoved into the huge slot in the throat plate and feed dog. So, it is best to remove the feed dog and standard plate and replace it with the optional flat slotted plate (with a narrow slot).

[Darren Brosowski]

You are using a sledge hammer to break wallnuts.

[Squilchuck]

Thanks for all the good feedback. You all confirmed my suspicion that the Cobra 4 is not designed to sew such lighter leather, which I rarely do anyway. I definitely don't want to have to fiddle excessively with tensions etc., not to mention deal with broken needles, then try to get back to my normal working settings. I'll work on a different solution - machine etc.

[Cobra Steve]

We sew with thread sizes 69-415 on all Cobra Class 4 machines, yes you will need to change the needle to a size 20 and adjust tensions, but it will do it.

By the way, I am back from my 3 surgeries in 10 weeks and I'm as good as new!

[Wizcrafts]

We sew with thread sizes 69-415 on all Cobra Class 4 machines, yes you will need to change the needle to a size 20 and adjust tensions, but it will do it.

By the way, I am back from my 3 surgeries in 10 weeks and I'm as good as new!

Welcome back, Steve! I'm glad you survived the butchery.

[Cobra Steve]

Thanks Wiz!

[Wizcrafts]

To be fair, I have managed to get a Cobra 4 to sew with #69 bonded nylon thread. I used a #19 needle, which was the smallest I could get at the time. I reduced all tensions, including the check spring. Finally, I had to remove the feed dog and throat plate and install the narrow slotted plate in its stead. With minimal top tension, I was able to sew a canvas bag and a zipper in a vinyl jacket.

The time it takes to transform such a machine into a light duty stitcher is only worth it if you only do it once in a great while. It is simpler for those in business to acquire other medium and light duty machines for thin, soft materials.