Originally Posted by
Velocivixen
Could someone tell me what type of sewing machine you're using? Just a good quality traditional machine or something specifically for heavy duty sewing?
Originally Posted by
nashvillebill
A traditional old Singer will work for denim or medium ballistic nylon, and perhaps it could do a simple two-layer seam in very light leather. For heavier leather or multiple layers of thick material, a heavier duty machine will work better. Note, old industrial sewing machines usually aren't good for this--though they are sturdier, they operate at blinding machine speeds, typically with an on/off clutch that requires considerable skill to master. A slower sailmaker's machine or leather-purposed machine is better if you want to sew thick materials. (Although you can slow down the old industrial machines with a modern variable speed motor, that cuts back on the power available, which sorta defeats the purpose)
Note that the 600 series Singer and newer (from the mid 60's on) uses some plastic components in the drive train, not as good for heavy materials as the old Model 66 or 15's or the 300/400/500 series. I've made several amplifier covers with medium weight vinyl on my Model 66 and 503a machines.
One key is to use the proper needle for your material--leather needles and vinyl needles have different tips than general-purpose needles. Also set your thread tension properly for the thicker seams. I've found the old machines often have their thread tension mechanisms gummed up from old solidified lubricants, so they won't work properly until that little mechanism is properly (thoroughly) cleaned and oiled.
I use an old singer 15-125. (Almost identical to the 15-91, but it's... green... and updated?) It's a potted motor, no belts or chains. Runs strong. I bought some 3/16" thick leather straps to attempt to use on a bag (didn't turn out well) and the machine sewed straight through it. No problems whatsoever. (Disclaimer: You you coax ANY domestic machine to sew through leather... it's the longevity that becomes the problem.) That's like belt thickness leather. I got it for ~$60 at a pawn shop. It's a straight stitch only machine, but it has one of my FAVORITE accessories ever. I have the buttonholer attachment. It basically attaches to the foot and needle and sews PERFECTLY IDENTICAL buttonholes every time. Unlike the modern 4 or 5 step buttonhole, these buttonholes are virtually indistinguishable. Plus, the way it works is just so cool. Anyway, rant over. I made a frame bag at one point, was surprised I didn't post it to this thread.
My machine is identical to this except not NEARLY as nice.
Oh and my singer 5050c doesn't like to sew through that leather.
The problem I run into when sewing thick things isn't that the machine can't sew through it, it's more that I can't fit the material under the foot!
If you are going to be sewing thick leather consistantly, you really need an industrial machine with an external motor. Compare the motors from a 15-91 (often considered an "industrial" machine) to an actual industrial.. external, motor.
From this page.
The Vintage Singer Sewing Machine Blog: The Difference Between Domestic & Industrial Sewing Machines (or, How Not to Get Swindled on eBay & Craigslist)