How to setup a Cobra Class 4 for holster sewing?

[JMWendt]

I have a Cowboy 4500, and use it for everything from thin wallet innards to thicker bags, beefy holsters and straps.  

I do a lot of holsters and belts.  I have the stirrup plate, holster plate, slotted plate, and the blanket set, as well as the roller feed (material) guide and the table top attachment.

I use my machine with thread ranging from 69 to 277, with an assortment of needles that I match up with thread size (with some variation).

The stirrup plate is useful (sometimes) for very difficult items (obvious example is stirrups, or some holsters, or sharp box corners on totes that you should have put a round gusset on instead).  Using the stirrup plate requires removing the feed dog, and because the feed dog is removed, you have to help with the feed a bit.  This takes some getting used to, but is easy with some practice.  It is a ten minute job setting the machine up to use the stirrup plate.

The holster plate is useful slightly more often than the stirrup plate.  Although some people seem to be under the impression that the holster plate requires the removal of the feed dog to be used, this is not the case (at least with the holster plate I have, which I believe is the standard Cowboy holster plate).  It fits on the machine without removal of the feed dog and does not interfere with the feed dog.  The feed dog does not touch the material being sewn when the holster plate is being used, so you could remove the feed dog, but you don't have to do so.  Like the stirrup plate, using the holster plate takes a little experience to get used to helping the feed process, but it is a useful plate for some holster situations where you are trying to get close to an edge.  I find it very useful for holsters that are formed first, then sewn-- where you are trying to follow a bulging region on the backside or get around an installed piece of hardware (clip).  In cases where you are sewing first, then forming, you won't find the holster plate as useful as the regular plate-- if you have a flat pancake holster and sew it up, then wet it and form the holster into it, the holster plate is not worth putting on the machine.

For both the stirrup and holster plate, I find myself using the right foot only most of the time.  

With either the stirrup or holster plate, you'll have to greatly increase the stitch size to match up with what you normally set the stitch arm to . . . the thickness of the plates decreases the stitch length.  Stitch length is a variable that is based primarily on your own aesthetic preferences, but the plates will change your stitch length.  6 is no longer 6 (if it ever was) when you use the holster or stirrup plate.

I tried using the material guide (roller), but found it to be cumbersome.  I prefer freehand work.  There's probably a time I might use it, but don't usually.  I wouldn't sell mine, but it may gather dust.

The slotted plate is nice for very thin straps or softer material where the item may tend to get partially sucked into the feed dog itself.  The slotted plate can help make a nicer finished backside on an item.  It does require the removal of the feed dog to be installed.  It also requires you to help with feeding, since the feed dog is removed to use it.  Like the stirrup plate and holster plate, it has limited usefulness, but if you are willing to take the ten minutes to set up for a job specific to it, it can improve your quality for those jobs.

I also have the table top attachment and use it 40% of the time overall.  I don't bother to screw it down, just set it in place and it stays just fine, so it is easy to remove and put back on when I need to.  It's great when you need it for larger items or flat work.

I have found that I have had to adjust tensions very little for all the various items I sew.  I have never had to adjust the bobbin tension.  I have only adjusted the primary and secondary tensions on the upper for use with 69 thread.  138, 207, and 277 sew very well at the same tension settings.  They all appear to sew wonderfully no matter what leather I am sewing, and sew perfectly on canvas and cordura as well.  From my research, I assumed I would be adjusting these to sew thinner materials, but this has not been the case.  I had though I might even need another machine to sew thinner materials, but at this point, the only reason I am still considering getting another machine (like a Consew 206 or the equivalent) would be due to the heavy duty marking on thin / soft materials from the feet on the monstrous Cowboy 4500, not due to limitations on what thinness of material the machine sews properly.  It appears to sew anything I throw under it, no matter how thick or thin, even items well under 6 oz in thickness.  It even sewed a patch on a judo uniform without issue-- basically thick fabric.

Even if I found I had to adjust tensions for different thread sizes and thickness of leather, it would be just fine . . . it may vary from machine to machine, but don't be afraid to tinker.  You are the boss of your machine.  Experiment.

If you are broke/cheap/miserly, you could easily not have a stirrup plate, slotted plate, material guide, or holster plate and still manage to do a hell of a lot with the machine nonetheless.

If you can only afford one or two adders, I'd recommend the table top attachment and the holster plate, and don't bother with the rest (especially given how spendy they are).  With just the table top and holster plate, you cover most of the situations you'll see.  You should also have the right foot only as well as the double foot.  If you were to only use one thread size, I'd probably recommend 207, but I highly recommend having 69, 138, 207, 277 on hand in black, white, and brown.  You can just do more that way.  Adjust needle size based on the standard chart, but even this can be fudged.  Changing the machine per job to do what you want it to do is a chore, and gets a little repetitive, but when the only other option is to have two or even three machines, each configured specifically to a type of job, well, it's just fine.

I hope this helps.  I asked a lot of questions when I first started using my machine, and tried a lot of things.  Still more to try and to ask, but this is a fairly decent summary of what I've learned so far.

Edited May 2, 2016 by JMWendt

[Red Cent]

That be the only reason?  And how is it working out for you?  No issues with anything at all from customers on prior builds?

 

None that I know of. And I have made a lot for locals and I would think the word would get back to me. And there is a bunch scattered around the United States.

Nylon or polyester have their pros and cons. From what I have read and learned they are about equal other than the poly seems to be more supple.

[Ed in Tx]

I noticed in one of the posts that you are using a size 25 needle with a 277 thread, that isn't the correct needle size for 277. You should be using a size 24. The size 25 needle is too large, The manual that came with my Cobra has a sheet showing proper thread to needle size. The best thing you can do is practice, you aren't going to be a master sewer in a few days. It takes time an patience to progress. You will find times when a left foot works better than a right depending on what you are sewing and where the seam is. Practicing sewing curves and turns is also a good idea. There are numerous YouTube videos that were made specifically showing how to sew with a Cobra 4.

[Red Cent]

.

"The recommended needle size is a #24 or #26.  The larger eye is necessary because of the large diameter of the thread."

  http://www.superiorthreads.com/superior-bonded-nylon-277/

"277 top and 207 bobbin use a #25/200 needle"

http://ferdco.com/content.php?page_id=27

"Hey all. There is a needle and thread reference guide in the back of the instruction book. It will tell you what size needle, and thread to use for many different thicknesses and applications. It is nothing written in stone because of the variances in leather, but it is a good starting point. Steve"

 

[klaykrusher]

15 hours ago, Ed in Tx said:

I noticed in one of the posts that you are using a size 25 needle with a 277 thread, that isn't the correct needle size for 277. You should be using a size 24. The size 25 needle is too large, 

I actually was running into an issue this weekend when sewing double 8oz layer belt using #24 needle with 277 top/207 bottom.  Randomly, the loop would not be formed for the shuttle to catch the thread and would skip stitches.  It was recommend for me to try a #25 needle.  Once doing that i no longer have the issue. 

[schwebel]

Thank you all for your input. Slowing the motor down really helped me to learn how to use the machine better. Also watching about every youtube video I can find. I really wish there was a video on tension adjustment though. I have done a couple things where the stitches look great top and bottom. I have also done some where the bottom stitch looks way to tight and I can't figure out the tension adjustment for the different thicknesses. I guess practice, practice practice and I'll figure it out. 

[JMWendt]

There are a couple vids on tension adjustment.  See Al Bane's instructional video for the Cobra, right around 32:54.  Also, there is the video for tension adjustment on the Cowboy 4500 which is identical, really.  That's at https://www.youtube.com/watch?v=udRtllp0TAo.

 

[JLSleather]

Re: needle size to thread size.  Keep in mind that not all needles are created equal.  Two different manufacturers (or even the same manufacturer) may make - for example - a size 24 needle with a different hole size, point geometry, etc.  Two needles can BOTH be 794 series and size 24 yet be considerably different.  I wouldn't carve needle sizes in stone.. just a place to start - like how hard do you strike a punch (answer:  hard as you need to).

Red has been on about poly thread for a while now.  I tried poly thread (and still have some) but I prefer the nylon.  From what I have read, the "advantage" of poly thread seems to be a bit more resistant to UV -- other words less likely do decay due to direct sunlight.  This is not a new concept -- my monofilament fishing line has the same issue -- but it doesn't disintegrate over night.  So, I largely (not exclusively) use nylon thread.  This week I had opportunity to see a tooled handbag I made over 25 years ago -- does NOT need re-stitched   Having said that, I've always liked Red's holsters, which appear to me to be both solid AND attractive.

Incidentally, my post above must have been 'fat-fingered'.. it should have ready that i prefer LL point needles.  The stitch is much straighter, and tighter with the same tension setting.

QUICK PIC of the difference, both stitches were done without changing the stitch length or tension... Note that the black stitch on the right (LR point) appears longer due to the angle - it is the SAME stitch length as the left side.

 

Edited May 6, 2016 by JLSleather

[Red Cent]

http://www.schmetzneedles.com/learning/pdf/leather-needles.pdf

[CowboyBob]

The #24 needle w/277 is very marginal,it will work sometimes W//some threads BUT can give you problems so we always recommend #25 w/277.