Cobra 4...presser Foot Marking Leather

[bushpilotmexico]

Hi everyone,

Still practicing with my Cobra 4, getting reasonably competent with most sewing but now it's time to close down a couple of holsters and sew the welts in.

I made up a test piece just to practice with and you can see the presser foot is leaving an imprint on the leather.

If I hadn't dyed my actual holster leather before hand and was just dealing with the leather you see in the photos I could probably using some water and burnish the marks out.

My problem now is that I have dyed the holsters and I'm going to see the track of the presser foot after I am finished.

Any suggestions as to how to prevent it?

[JLSleather]

Is your holster really that thick?#@!@#!@#$!!

There's a few ways to git around that if ya hafta. Simplest one is to make the holster 1/2" wider at the stitch line, stitch it up, then trim off the marks from the feet.

Beyond that, a fella could move a couple bolts --- but I hate to be crowding the guy who "stands behind" those, so I'll let him answer that.

[Colt W Knight]

Hi everyone,

Still practicing with my Cobra 4, getting reasonably competent with most sewing but now it's time to close down a couple of holsters and sew the welts in.

I made up a test piece just to practice with and you can see the presser foot is leaving an imprint on the leather.

If I hadn't dyed my actual holster leather before hand and was just dealing with the leather you see in the photos I could probably using some water and burnish the marks out.

My problem now is that I have dyed the holsters and I'm going to see the track of the presser foot after I am finished.

Any suggestions as to how to prevent it?

I wish my machine sewed that thick.

I am sure the folks who work with those big machines can help you reduce the marks, but I don't think anything will sew that much leather and leave no marks at all.

The teeth were ground off my smaller machine, and it still leaves some marks.

Edited October 9, 2015 by Colt W Knight

[Red Cent]

I never use a welt in my holsters. No matter, I still get tracks. I don't think we can get rid of all the marks. Wet down the leather real good and flex the leather. It will stretch a lot of the marks out of the leather. May not do it with 3/4" of leather tho.

[Wizcrafts]

There is either a sharp edge on the presser foot, or it is tilted up one way or the other. I would expect to see a smooth tract that is the width of the outside toes, but not those stab wounds. Remove the outside foot and feel it to see if there is a sharp edge. Use Emory cloth to smooth out the offending edge and polish it on a buffing wheel with green rouge.

If the foot has too much slack on the presser bar, it might shift up or down from true horizontal.

[bushpilotmexico]

I never use a welt in my holsters. No matter, I still get tracks. I don't think we can get rid of all the marks. Wet down the leather real good and flex the leather. It will stretch a lot of the marks out of the leather. May not do it with 3/4" of leather tho.

I was hoping I wouldn't have to wet the leather down but I guess if I do I will have to give the whole holster a dip because it's already dyed and if I just sprayed the stitching line and burnished I think I would get a water stain.

I know the samples that Steve sent with the machine showed presser marks, especially the chunk that was 7/8" thick.

I was kind of wondering if I could use a couple of layers of that green or blue painters tape and lay it along the path of the presser foot, might soften the blow? I'll experiment a little bit.

I know from Googling I found out that if you start off 6 stitches per inch as the leather thickness increases so does the tension and you'll have 8 stitches to the inch at the top.

On my third line once I started to sew up hill I manually increased the stitch length one full turn and the stitch length proved to be fairly consistent through out.

[Wizcrafts]

I was hoping I wouldn't have to wet the leather down but I guess if I do I will have to give the whole holster a dip because it's already dyed and if I just sprayed the stitching line and burnished I think I would get a water stain.

I know the samples that Steve sent with the machine showed presser marks, especially the chunk that was 7/8" thick.

I was kind of wondering if I could use a couple of layers of that green or blue painters tape and lay it along the path of the presser foot, might soften the blow? I'll experiment a little bit.

I know from Googling I found out that if you start off 6 stitches per inch as the leather thickness increases so does the tension and you'll have 8 stitches to the inch at the top.

On my third line once I started to sew up hill I manually increased the stitch length one full turn and the stitch length proved to be fairly consistent through out.

The change in stitch length is due to the pendulum effect of the needle bar pivoting from the top of the machine head. The longer the needlebar and needle combination, the greater the loss of stitch length as the thickness increases.

One other workaround is to sew these projects on a Campbell Randall or Union Lockstitch machine.

Edited October 9, 2015 by Wizcrafts

[Colt W Knight]

The change in stitch length is due to the pendulum effect of the needle bar pivoting from the top of the machine head. The longer the needlebar and needle combination, the greater the loss of stitch length as the thickness increases.

One other workaround is to sew these projects on a Campbell Randall or Union Lockstitch machine.

How much do those cost?

[Wizcrafts]

How much do those cost?

The Union Lockstitch sells for about $5,000 and the Campbell Randall for about $6000, base price. Accessories will drive the cost up considerably. I have owned two Union Lockstitch machines over my career as a leathercrafter. Like a fool, I sold them.

These machines have square drive.

[Art]

Campbell, $4k Used to $6k New with accessories. Union Locks are all over the place (price wise) depending on condition. Unions are nice machines, but more of a factory item where there is a maintenance staff. Wiz knows the UL pretty well, but there is no substitute for hands on experience. Campbells are a little less of a maintenance problem, but you would be wise to leave them setup for whatever you do the most of and not fiddle with them.

Art