Help! Ruined my project during stitching!

[Michellleatherworks]

Hello all!

I'm a new member to this site but have been researching topics as a guest for some time.  Mostly since purchasing my CB 4500, since they have a steep learning curve for a beginner.  

I recently was doing a custom knife sheath prototype.  It is a welted sheath about 5/8" thick.  Everything went wrong when I went to stitch it on my machine.  I used 346 thread top and bottom with a #26 needle with fairly high thread tension to sink the stitches into the stitching grooves.  The front stitches turned out beautifully but the stitches underneath were all over the place!  It was enough to make one sick, as any leather craftsman would know.  Also, as a note, I'm using the left harness foot (that leaves unsightly marks on everything) and my machine is a cylinder bed which I suspect is part of the issue.  As I sew, the project tilts side to side slightly every time the front presser foot comes down releases.  There is no way a stitch will be able to stay true through that much material with the amount that it moves.  

My Questions are these:  Is there something I'm doing wrong(most likely)? Would a flat bed attachment help this?  Is there a adjustment on the machine that can help this?  How do I reduce the appearance of pressure foot impressions on the leather, as my presser foot pressure is already set pretty low?

Any help is appreciated!  Thanks for reading!

 

David M

[garypl]

I would cut the sheath 1/4”- 3/8” over size, use the double foot, and then trim to the stitch line after you sew.  With more leather under the feet, it should be less likely to wander as opposed to trying to stitch right along the edge.

Gary

[ComputerDoctor]

Do exactly like garypl said, sewing and the trimming is so much easier and will help keep your intended line.

I started doing just that when I purchased my Cobra 3 and I use a Guide tool that came with the deluxe package I bought.

I very recently installed the flat bed accessories that came in the package and now the machine is much easier to use----for a relatively new person of 1 years experience.

Sewing machine tensions seem to be an esoteric science so talk to people at Cowboy, who are very helpful and watch YouTube video's AND read the instruction book/ DVD that probably came with your machine and things will get better. Practice on LOTS of scrap and not on a finished product until you get good at it:)

Sam

[dikman]

Like they said. Did you stitch after sanding the edges? That stitching is way too close to the edge, so you've got very little support under the leather.

[CowboyBob]

It's a good idea to make a sample of the thickness you want to sew & test it first.It would also help to use #277 in the bobbin,346 is real hard to pull up in stiffer leathers.

Edited January 5, 2019 by CowboyBob

[Michellleatherworks]

Thank you all for the great advice!  And yes I did sand edges before hand, unfortunately.. lesson learned!  I will give the harness foot a go with some extra meat on the edges.  what is the best way to trim material that thick?  I have a trimming knife but am not confident with it by any means.  Any suggestions?

[Wizcrafts]

4 hours ago, Michellleatherworks said:

As I sew, the project tilts side to side slightly every time the front presser foot comes down releases.  There is no way a stitch will be able to stay true through that much material with the amount that it moves.

The side motion as you sew is caused by the bottom feed dog being adjusted too high (and the use of a single sided foot). The specs call for a maximum height of 1mm above the throat plate at maximum lift (with a standard double toe or blanket foot). I set my CB4500 feed dog to half that amount of lift. The needle and inside foot feed fine on their own and only need a modicum of help from the feeder. So, loosen the big screw securing the feeder and push it down at maximum lift so it rises just above the top of the throat plate, then tighten it up. You may have to remove the shuttle to fully access that big screw.

Let us know how this works out.

[Michellleatherworks]

55 minutes ago, Wizcrafts said:

The side motion as you sew is caused by the bottom feed dog being adjusted too high (and the use of a single sided foot). The specs call for a maximum height of 1mm above the throat plate at maximum lift (with a standard double toe or blanket foot). I set my CB4500 feed dog to half that amount of lift. The needle and inside foot feed fine on their own and only need a modicum of help from the feeder. So, loosen the big screw securing the feeder and push it down at maximum lift so it rises just above the top of the throat plate, then tighten it up. You may have to remove the shuttle to fully access that big screw.

Let us know how this works out.

 

I adjusted the feed dog down and that nearly eliminated the problem!  It's sewing like a champ now, even with the left harness foot on.  It just needs minor adjustments and I think I'll have it dialed in.  Thanks again to everyone for the helpful advice!.

Cheers

[Handstitched]

On 1/6/2019 at 3:44 AM, garypl said:

I would cut the sheath 1/4”- 3/8” over size, use the double foot, and then trim to the stitch line after you sew.  With more leather under the feet, it should be less likely to wander as opposed to trying to stitch right along the edge.

I second that with bells on  

I have learnt from machine sewing  simple  knife pouches, sheathes ,  leatherman type cases etc. if I get too close to the edge , my machine makes a totally different sound. We all know the sound of our own machines, so Instead of the nice virtually  smooth noiseless sewing, it will make a ' clack clack clack ' sound ( along with a sudden  drop  in blood pressure and a bead of sweat) . I  know I got too close to the edge. So now , I sew first, trim/ grind / burnish and polish  and make pretty  after.  

HS 

P.S. As for the foot marks,  a technique I use, depending on the job,  I sometimes use a large thick  ' D' ring and rub it along the mark. With a bit of ' elbow grease'  using different parts of the ' D' , and perhaps a bit of polishing,  it does help eliminate it. 

HS

Edited January 7, 2019 by Handstitched

[spurdude101]

presser foot cure! find some oxygen tubing. the 1/8 inch clear tubing old folks use when on oxygen, cut a small section make a small slit on one side half way along the length so it can slide past the presser foot upright and glue on the foot. no more ugly marks on the leather.

[ricroy]

It is a good idea to leave the bottom of the sheath with excess leather 1/4" or so out from the edge. this gives support and helps keep the sheath flat on the machine while sewing. Trim it after sewing . Then dress the edge of the sheath by sanding or how ever you need to. then do the burnishing process.  Also you can groove a stitch line on bottom as on the top.. if you can install  a thread lubricating an oil pot on the machine it will help sew through the leather. i just ordered one for my Cobra 4..