Back stitching Biothane Beta w/Cowboy 4500

[Parott1]

Purchased a CB 4500 with a slotted plate to make biothane beta dog leashes.  I'm using 138 bonded nylon thread with size 24 organ needles. 

I have no problem sewing with the machine IE going around corners etc, my only dilemma is back stitching.  It seems almost next to impossible to get the needle to feed back in the same holes.  I tried lifting the presser foot to align the needle, but then I get loose thread/loops on the bottom side.  Sometimes they align, but most of the time they are just slightly off.  Every now and then when back stitching, the thread on one or two stitches looks to be slightly frayed and I'm worried that this will weaken the product instead of adding strength. 

 

I included a few pics of the test pieces I made

[Wizcrafts]

Biothane is not leather! Did you send a piece of Biothane to the dealer so he could setup the feed to match in both directions? This would have eliminated the problem before it came up in your shop.

Assuming you didn't and the dealer wasn't aware of Biothane's stickiness and density, you need to make an adjustment to change the reverse stitch length, to get it to match forward stitching. Here are some simple things you can try without any dealer interaction.

1. Set the inside foot to meet the top of the slotted plate just after the needle.
2. Set the inside foot to meet the top of the Biothane with the tip of the needle
3. Loosen the bolts on the stitch length/direction nacelle. remove the top bolt. Pull outward on the very top, insert a washer, push the top bolt into it, and screw the bolts back into the body. This will change the stitch length in reverse. It often compensates for mismatched stitch lengths on these machines.
4. Loosen the pressure on the feet. Don't back off to the point where the 'thane lifts with the needle though, or you'll get skipped stitches.
5. Try a diamond/triangle point needle.

If none of the above correct the stitch length problem, call the dealer for instructions on adjusting the internal parts that control the directional stitch lengths (not simple or trivial). The dealer should walk you through the procedure. Don't attempt this on your own!

[MADMAX22]

Good luck with using the slotted plate and back stitching. Even with leather and making as many adjustments as I have scene it still wouldnt work worth anything. Using the feed dog and normal plate with a silly washer installed on the ramp and still pushing up on the lever then pulling it back down about half an inch I can get them to line up correctly with leather. Ofcourse it could just be my machine or one of the many who have started threads on the subject. Pretty sure even Wiz said it doesnt work properly with the slotted plate. 

reverse stitching is not one of these machines strong suits. 

[Wizcrafts]

I had better success sewing Biothane with the feed dog and standard plate.

[Wizcrafts]

Personally, if I'm having a problem matching stitches in reverse, I spin the work 360 degrees and stitch through a few stitches in the forward direction. That way the holes always line up. I use the same system on some of my old machines that don't have any reverse.

[MADMAX22]

Agreed, I either flip it or saddle stitch back by hand. Depends on what I am making and how nice I want it to look. The saddle stitch back stitch looks nicer and  I can pull both threads to the back, but it takes way more time then just flipping my work around. 

I went back to using the standard plate. Seems to work the best out of all of them as long as it meets the sewing needs.

[Parott1]

I didn't send a sample of the biothane to Bob before I purchased the machine.   The feed dog that came with the machine wouldn't let me sew as close to the edge as I wanted, so I had to purchase the slotted plate, 

Wiz, when you say, you spin the work 360 degrees and stitch through a few stitches in the forward direction.  Do you mean you spin the work around and sew 2-3 stitches forward and then spin it 180 degrees and sew in the direction you normally would?

[Parott1]

I followed all the steps above with the exception of #4.  I think the needles I have are triangle point.  The washer seems to have shortened the back stitch.  It looks half decent from the top, but the thread on the bottom side is slightly frayed.  I just bout a pack of 1/4' washers from lowes.  Here are a couple current pics.  The first one is the top and the second is the bottom side

[Wizcrafts]

12 hours ago, Parott1 said:

I didn't send a sample of the biothane to Bob before I purchased the machine.   The feed dog that came with the machine wouldn't let me sew as close to the edge as I wanted, so I had to purchase the slotted plate, 

Wiz, when you say, you spin the work 360 degrees and stitch through a few stitches in the forward direction.  Do you mean you spin the work around and sew 2-3 stitches forward and then spin it 180 degrees and sew in the direction you normally would?

That is correct. I sew backwards a few stitches, spin the work 180, drop the edge guide if needed, then sew to the end, where I reverse and sew back again to lock the stitches. Sometimes I opt to just lift the feet and pull the material towards me, two or  three stitch lengths, drop the feet and resew through those stitches. On other jobs, if the back side won't be seen, I may just hold the threads and start sewing to the end. Then I pull the top thread through the back side with a seam ripper and tie the starting threads together in a knot. Ditto for the ending stitch. This is especially useful of large projects, like bomber jackets, where spinning the work isn't trivial (I sew in zippers and patches all the time).

[JLSleather]

On 7/3/2016 at 4:23 PM, Wizcrafts said:

 

Loosen the bolts on the stitch length/direction nacelle. remove the top bolt. Pull outward on the very top, insert a washer, push the top bolt into it, and screw the bolts back into the body. This will change the stitch length in reverse. It often compensates for mismatched stitch lengths on these machines.

If none of the above correct the stitch length problem, call the dealer for instructions on adjusting the internal parts that control the directional stitch lengths (not simple or trivial). The dealer should walk you through the procedure. Don't attempt this on your own!

When you see someone familiar with sewing machines as Wiz clearly is making statements like "often compensates for mismatched stitch lengths", then you can REASONABLY assume the this is fairly common (which,it is).

So, I "get" it.  This is an adjustment which has no 'fine tuning' set screw.  And to further complicate things, you're trying to make a LINEAR change in stitch length with a ROTARY control.  While that can be done, it's not 'zip, zip, done' (probably).

Has there ever been one delivered that showed up stitching back in the exact holes? Probably.  Throw enough poop at the wall, as they say....

But it does "grate" me a bit that they are ADVERTISED "stitches back in the same holes", if they DONT.  What they mean, apparently, is that is "could be" made to do that.  So that's probably what they should say.  $2500 isn't life-altering money, but it's not pocket change either (at least, not to me).  For $2500, it should show up ALREADY doing what it's claimed to do. If not, it's like buying a new car, which runs GREAT once you tune it up....