Tension Adjustment Question

[particle]

I mostly sew holsters and related accessories on my Tippmann Boss and am wanting to start sewing journal covers too with decorative stitching. I use 277 thread for everything so far. The tension is fine for holsters (two layers of 8-10oz leather), but when I was sewing the journal covers out of 4-5oz leather, the bobbin thread was laying flat on the back of the leather. I probably need to use a smaller needle and thread for journals, but I really like the look of the thicker thread as I feel like it gives it a more hand-made feel, even though it's machine sewn.

So, my question is.... What compromises do I need to make when moving from 16-20oz thickness (for holsters) down to 5-6oz thickness (10-12oz at the folded portions) for journal covers? I'd ideally like to make as little tension adjustments as possible to the machine, but I doubt I'll be able to escape that. In my mind, it seems like once you have the top/bottom adjusted to center the stitch in the leather, it shouldn't matter what thickness you're using, but I don't know enough about how the machines work.

I mentioned this if for my Boss, but I'm hoping to buy either a CB4500 or a Cobra Class 4 very soon if I can afford it.

[Ferg]

IMHO, the 277 thread is way to large for journals. 138 is about as large as I have seen and still look hand done on the lighter weight leathers.

Bob Park uses a lot of #69 thread on his journals etc.

ferg

I mostly sew holsters and related accessories on my Tippmann Boss and am wanting to start sewing journal covers too with decorative stitching. I use 277 thread for everything so far. The tension is fine for holsters (two layers of 8-10oz leather), but when I was sewing the journal covers out of 4-5oz leather, the bobbin thread was laying flat on the back of the leather. I probably need to use a smaller needle and thread for journals, but I really like the look of the thicker thread as I feel like it gives it a more hand-made feel, even though it's machine sewn.

So, my question is.... What compromises do I need to make when moving from 16-20oz thickness (for holsters) down to 5-6oz thickness (10-12oz at the folded portions) for journal covers? I'd ideally like to make as little tension adjustments as possible to the machine, but I doubt I'll be able to escape that. In my mind, it seems like once you have the top/bottom adjusted to center the stitch in the leather, it shouldn't matter what thickness you're using, but I don't know enough about how the machines work.

I mentioned this if for my Boss, but I'm hoping to buy either a CB4500 or a Cobra Class 4 very soon if I can afford it.

[Luke Hatley]

this i know.... when i want to sew thinner leather on my Boss i have to use Smaller thread along with a Smaller Needle.

[particle]

Thanks for the input fellas. Guess I need to clean off the clear fingernail polish from the adjustment nuts on my thread tensioners!

Is there a fool-proof way to keep track of the tension settings so it's quick/easy to go back and forth between two tension settings?

[mlapaglia]

Im not sure if its fool proof but I have a line on my tensioners that I use like a clock face. For 277 thread and 16 oz the primary is at 3 o'clock. when I use 4/5 oz I have to increase it to about 6:30 So I keep a list using 16 0z as the standard. For 4/5 it says increase to 6:30 For 24 oz is says decrease to 11:00. When done with the leather I am doing I always return it to 3:00 making sure to go the correct direction.

Its not exact but the little I have been able to use the machine it has worked for me. Of course due to another situation my machine that was supposed to ship yesterday will now ship today, I hope. So I wont have the replacement machine until at least Monday

Let me know if it helps

Michael.

[Massive]

I don't have a Boss, but I do the thing with the clock face. I use a permanent marker to align with the tension screw. I journal the entries so that if some time goes by I can return to it.

I also just run tests. Once you let go of the safety blanket of not touching anything, the process is simple. When moving down, you drop the bobbin tension way down, you want the lightest tension that will hold the materials together. Of course you have to drop the spool tension also in order to center the thread. The reason you want to drop the tension on the bobbin a lot is just because it tends to be easier to take a big move and find you way up to a starting point that to creep down. It is a lot more obvious when the stitch needs more support that when one has dropped the tension, but not enough.

The other thing I recommend doing is buying a bobbin case for each thread tension. Then you have the Bobbin tension just so for each thread size, type, or job, and can simply leave it fixed. Unfortunately my sewing machine is an oddball and extra cases are a fortune, but if you have one of the commoner types, that is a real nice "accessory" to have. Good thing to bargain for when buying.

[KAYAK45]

Hi Particle!

I don't have a BOSS either, but I did stay at a Holiday Inn last night.

I have my knobs marked with , you got it, fingernail polish at just any point on the wheel. I always keep that straight up. Count, like opening a safe, how many times you pass zero and write it down. write down any variance from there to get to your smaller thread.

Reverse total adjustment when necessary.

I never have changed BOBBIN tension just top side to set the stitches.

If your adjustments are like mine you will be screwing in...why not use you red fingernail polish (you know..the Saturday stuff) to mark your larger outside setting, before you adjust, and just come back out the the paint?

Good Luck!!!

Kevin

[TwinOaks]

Using fingernail polish.....well there's your problem right there!!! I used a paint marker and don't have any problems at all!

Joking aside, I do the 'clock face' thing as well, but I don't touch the bobbin tension. Think of it like this (because this is what's happening):

Your bobbin tension is providing a consistent tension. That stays the same regardless of what sizes you're stitching. Once you have it set for a particular thread size, leave it alone. You're top tension is what determines how high you're pulling the two threads inside the leather. If you have the top tension set at zero, then the needle will move and the tension of the bobbin thread will pull the top thread off the spool with no problems. Increase the top tension and your countering the tension from the bobbin. The result is that you 'lift' the lock stitch by pulling the two tensions against each other. This is also precisely what creates the stitch tension that holds the leather together (yes, I know we glue the leather, too.). Decreasing the tension on the top thread will lower the lock because it doesn't pull as hard against the bobbin thread. Now, here's the key - the 'lift' I mentioned is measured from the bottom of the leather...which is always at the same height...it's (should be) against the needle plate. So all you're doing is increasing or decreasing tension to alter the lift from 'zero' height to anywhere from 1/16th (top of 4oz leather..center of two 4oz pieces) to 1/8th (top of 8oz...center of two pieces of 8oz), etc., etc.

ETA: I'm also sewing on a boss. I suggest trying the following- turn your primary tensioner 1/8th turn counter clockwise and test sew a piece. Alternately.....a quick tension trick I've learned: Some diagrams show a full wrap on both the primary and secondary tensioners for the Boss, some diagrams show a full wrap on the primary and a half wrap on the secondary....this was covered in your thread about the back side of stitches.

If you normally have both with a full wrap, try taking the secondary tensioner to a half wrap and leaving the primary tension adjustment alone. You are decreasing the top thread tension when you do this, and I find it's a very easy way to shift between two tension settings without having to make any adjustments on the knobs.

[Jimbob]

There will be a most constant need to make tension adjustments to most machines and surly for such differet thicknes of leather.....that one said, there is no such thing as the same leather.....some soft, some more dense some seems need more some less tension!

I take a scrap piece of exactly the same leather/layers and run an 8 inch test seam....tension adjusted to just that as it will make a perfect seem for your project....and when 1 or two onces up or down makes no difference!! Just takes a few seconds!

But you have assured that you produce a top quality stitched seam on your work!!

Remove the nail polish and start turning knobs.....the machine will do what you dial in and you soon get a real gut feeling whats needed and what not....you see, you may even feel a little pride in being able to dial it in just right to do top work!! ...........kinda learning how to dial in a carburator....just a little practice!!!

Greetings

James

[leatherkind]

I also like to use thicker thread 270 and up.

It took me a while to set the tension correctly. It sure would take a lot less time if I would have asked Bob to set the machine for 345 thread.

I have noticed that little adjustment to bobbin tension bolt affects tension a lot.

Also thick thread on thinner leather seems to require more attention.

It is not so noticeable with thinner threads.

I did a little test with #346 thread under different tension and recorded the values if you are interested.

http://leatherworker.net/forum/index.php?showtopic=34194&view=findpost&p=214132

Good luck.