Just Got My Cobra 4! Had A Question...

[ericluther]

Let me start by saying I know nothing about machine sewing

I am attaching a photo in the hopes that someone can help me out fine tuning

http://db.tt/V8ZLJmY2

http://db.tt/5nc8XETn

Thanks!

Eric

Edited May 9, 2012 by ericluther

[dbusarow]

I'm still pretty new at this machine stitching but that sure looks like your needle is too big.

The top tension is too high BUT there is a balance between thread size, needle size and the tensioners. Use the thread size/needle size chart in the Cobra owner's manual as a starting point for the thread/needle size pair.

If your thread and needle match then start reducing the upper tension. Make sure that you adjust slowly and adjust both upper tensioners in tandem.

I emptied my scrap box pretty quickly doing test stitches when I first got mine.

Dan

[ericluther]

1336525116[/url]' post='247034']

I'm still pretty new at this machine stitching but that sure looks like your needle is too big.

The top tension is too high BUT there is a balance between thread size, needle size and the tensioners. Use the thread size/needle size chart in the Cobra owner's manual as a starting point for the thread/needle size pair.

If your thread and needle match then start reducing the upper tension. Make sure that you adjust slowly and adjust both upper tensioners in tandem.

I emptied my scrap box pretty quickly doing test stitches when I first got mine.

Dan

Thank you Dan, it did look like the holes were very big. I will try the needle first and see how she looks.

[dirtclod]

How thick is the piece in the picture ? I don't have a Cobra but i have a big machine and they won't sew thin stuff.

[ericluther]

1336525533[/url]' post='247039']

How thick is the piece in the picture ? I don't have a Cobra but i have a big machine and they won't sew thin stuff.

It's 2-3 oz sewn to about 5-6oz

[Randy Cornelius]

Also you may want to check the bobbin tension. It shows how in the manual and the video. there is a small set screw that locks the adjustment screw. I have mine set almost as tight as it will go and it seems to work for just about everything. Then I can us the top tension ajusters to fine tune it.

rc

[dirtclod]

They won't sew 2/3 ounce and look right 5/6 sometimes 2 pieces of 5/6 yes or 5/6 and 2/3 will work to. If you want to sew the thin stuff you need to get another machine. I've had my machine for close to 20 years and i never have been able to sew the real thin stuff and get it to look right. My suggestion is to leave the tension alone and sew what it's designed to sew thicker stuff.

Edited May 9, 2012 by dirtclod

[ericluther]

better uploads

[anester05]

I had the problem with my class 4. I was sewing a wallet which is about 4oz to the insides. All combined it was about 6-8oz of leather. I ended up using a #138 thread with the smallest needle that came with the machine. I had to adjust the top tension down a bit. The lock stitch you have there is probably as thick as the leather you are trying to sew.

[Scary Leatherworks]

Let me start by saying I know nothing about machine sewing

I am attaching a photo in the hopes that someone can help me out fine tuning

http://db.tt/V8ZLJmY2

http://db.tt/5nc8XETn

Thanks!

Eric

needle and tension. I ordered some round point #18 from Steve so I could sew thinner stuff. No they aren't designed for it but I have and still use it to sew thin stuff. I have sewn 2 layers of lamb with my class 4. try smaller needle and thread. When I got mine my smallest needle was a #23 that I used with 138 thread. Also play with the tension to pull the knot in to the middle of the leather

[ericluther]

needle and tension. I ordered some round point #18 from Steve so I could sew thinner stuff. No they aren't designed for it but I have and still use it to sew thin stuff. I have sewn 2 layers of lamb with my class 4. try smaller needle and thread. When I got mine my smallest needle was a #23 that I used with 138 thread. Also play with the tension to pull the knot in to the middle of the leather

thanks Scary, I am going to need to sew two pieces of lambskin, do you recall needle and thread weight you used. how much tension adjustment did you have to do?

Thanks!!!

Eric

[Scary Leatherworks]

thanks Scary, I am going to need to sew two pieces of lambskin, do you recall needle and thread weight you used. how much tension adjustment did you have to do?

Thanks!!!

Eric

I started with the 138 thread and had some ok results but was then reccomended to switch to an 18 round point needle with 69 thread. haven't tried that yet was a bit of tensioning to work out had to back it off quite a bit due to the softness of the leather. make sure you try multiple scrap trials to get it right.

[frmntx]

I started with the 138 thread and had some ok results but was then reccomended to switch to an 18 round point needle with 69 thread. haven't tried that yet was a bit of tensioning to work out had to back it off quite a bit due to the softness of the leather. make sure you try multiple scrap trials to get it right.

I had the same problem with mine, I lightened the top tension, and tightened the bobbin (1/4 turn at a time, lol) and it worked itself out.

Hope this helps!

[PanioloBrian]

use lighter thread for sure and it will help, this means smaller needle also. I sew 2/3 oz to itself folded over on pocket knife scabbards and no problems. Its better on heavier leather but until I have a machine for every leather I build things from its just my Class 4 from Steve.

[Bobby hdflame]

I just got my Cobra yesterday, so I can't give you a lot of advice on it specifically, but from the picture your top tension is too tight. It's pulling your bottom thread all the way to the top.

Using a smaller needle/thread combo like the 138/22 needle will help on your thinner leather. Until you get some more needles and smaller thread, try just backing off your upper tension a half turn at a time on each knob while running a short test stitch. See if that doesn't help get your bottom thread back down inside your leather.

Until now, I've been using a Highlead heavy duty walking foot machine. I rarely have to adjust my bobbin tension. I can just about always get my tension correct by just adjusting my top tension. Unless you know what you're doing, you can really get things screwed up by over adjusting your bobbin.

If you go from the 277 thread down to a 138, you'll most likely HAVE to adjust your bobbin tension.

Good luck. I'm off to play with mine!

[Spinner]

For thinner leathers you can also try using a Tri-point needle instead of a ball or knife. The advantage is the tri is still sharp so it will pierce nicely but it creates a smaller hole than a standard LR needle. Another thing I have learned from looking at other folks work is generally as you go down in thread size you should also consider shortening the stitch length for appearance & strength. The Tri-points aren't as easy to find but usually will have TRI or NW at the end of the numbers. Balls don't add anything and a bladed needle usually has a LR at the end. (ex. 135x17LR)