A couple of days ago I made my first bag, but I stuggled with the thread tension the whole time. I was getting looping on the bobbin side. What setups of thread tension and needle choice have you had success with? I was using ballistic nylon and 14oz coated vinyl, and in some places nylon ribbon for taping.

It was nearly impossible for me to finish a seam without some sort of a problem when I used a regular machine. I know it's probably not the advice you are looking for, but a more powerful machine will do wonders. Short of that, a heavier needle and more tension might help a bit.

Got any pics?

i've always used denim or leather needles, and both worked fine

Where do you even get a pattern for something like a bag?

I made the pattern myself

Edit: The bag is 100 miles away from me right now, I made it for my mom. She rides a large scarabeo and was using a plastic bag from an Apple store as a purse. I'll take some pics the next time I visit her, but there really isn't much to see.

As for the pattern, I had to make some changes on the fly, so the version I made on my computer, and that I could upload without making changes, doesn't work.

I'm kind of new to sewing, my better half is teaching me, so I don't think me trying to make my own pattern would work out too well. I'll stop stealing yer thread now. cheers

Back to stealing your thread(sorry). Now I'm currious, where does one start with making a pattern?

I started by drawing the completed bag as it would look as a rigid structure. I did this on engineering paper with the standard top-front-left views. Then I unfolded that in my mind and sketched that out.

Then I drew the the unfolded bag in Adobe Illustrator, and added a half inch of material to make my seems. It was rather large, so I had to tile it onto 8 or so pages of letter size paper. I added registration marks all over so that I could easily line things up when I was taping all the pages together.

Attached are scalled versions of my pattern. I made it like this to get the lagest bag out of the 16x60 piece of ballistic nylon I already had. I cut the coated vinyl in one piece, basically just added two inches to the lower half of that pattern.

Sewing order is something like this:

Sew velcro and reflective strips onto material as appropriate.
Sew side pieces to lower half of nylon.
Sew nylon and vinyl together.
Sew and tape lower edge (completed front and side edge)
Sew and tape verticle (side) seems and cover flap.
Sew and tape bottome seems.
Turn bag and attach strap.

if you could take apart a bag you'd be suprised how simple the shape actually is.

the picture is a very rough and NOT to scale pattern, but it can serve as a guideline for a simple bag shape. all of the numbers are in inches. at one point i read "examine every bag you can", and it's true. when you're starting out take a look at all sorts of bags (not just messenger ones), whatever you have lying around, and turn them insides out, stuff like that.

also, muslin is a kind of cotton fabric thats usually white or off white but really cheap. you can try messing around with that first, as not to ruin any of your good stuff.

Cool, thanks a lot guys. I'll keep ya posted.

I've been able to use 92 weight nylon thread in a home machine with some success using a jeans needle (110/18 if I remember right), and jamming the upper tension as far up as it will go. Basically, you should probably have it maxed for using heavy fabric + heavy thread. If it loops, increase the tension.

Also, make sure you have a sharp needle! That ballistic fabric will dull a needle quickly, and a dull needle will cause loops on the underside just as surely as improper tension will. So always check the needle.

quite a good site here about homemade messenger bags.

when i used to make jeans, i would use 18 gauge[?] denim or leather needles. watch out on though, i broke a domestic sewing machine doing that.

fsnl
sparky