I've found various discussions on how to sew specific things but I'm trying to figure out if there is one reliable sewing machine that works for most fairly basic do-it-yourself gear modifications. Is there a machine (that doesn't cost a fortune) that can hem a pair of shorts as well as it can sew through a couple layers of flat webbing on a backpack? I realize there are considerations on needle sizes and thread when sewing different things so thoughts on that are welcome too.

I've been using a cheap Brother sewing ( www.walmart.com/ip/Brother-10-Portable-Sewing-Machine/476472>>> ) for years now. Its works fine for occasional use hemming pants, repairing gear, or even box stitching and zig zags on two layers of climbing webbing.

As you mentioned, spend the money to pick up several different needles sizes and points, and some heavy upholstery thread or "E" nylon thread for gear repairs.

Good Luck!

+1 for an older good brand. Easily found for $0- $100. I use an old 60's singer, made in japan, has zig zag and reverse, and a dropping foot for freehand work. A little oil can work wonders, making a dead relic a working machine. An older household model will work easily with flat webbing, like on packs, and tube webbing should be do-able. For extra heavy stuff (haulbags or shoes) I use a $10 speedy stitch hand awl.

I have a Singer 301a and I use it for everything you have listed. My mother has had the same one for many years (30+), I used that when I was younger, and she found me the same model (they're very common) at a sewing shop that was tuned and lubed for $65. They are really great machines.

I have an old machine my mother-in-law was getting rid of. I forget what brand it is, but it's a quality thing which is now almost worthless due to being out-dated. It works well for sewing UL backpacking gear from the lightest fabrics, and I also sew full-strength climbing gear with it, using #92 DB poly thread.

Great info here:
Ray Jardine's Sewing Tips

Juke!

My girlfriend has been through a few Brother sewing machines for her business and now we have two of
THESE

Steel internal construction, super reliable. Runs through my heavy Duck Cloth, webbing, neoprene, denim, and vinyl without any problems.

Juki LU-562