After several disappointments, an inexpensive industrial sewing machine has finally fallen my way. Buying from Gumtree can be sooooo frustrating, when you email about an advertised item, only to get a 'sorry it's sold' email several days later. Worse when sellers don't even offer that courtesy!
I have been looking for a good, heavy-duty, sewing machine for some time now. The positive side of such delays is that knowledge increases with each potential purchase. For example, I found that although the machines im looking at are 'industrial', they are not automatically suited to doing heavy materials. In fact, the high speeds that industrial machines run at, make them quite unsuitable for thick material such as canvas, vinyl, and leathers. The High speed places undue stress on the needle, and friction can heat the needle to failure or bending. Heavy/thick materials often have feed problems with the standard teeth sets, or can jamb if pressure not correct.
This is the machine I bought. It cost me $250, and required another all-day sortie to go get it. Unlike home machines, industrial ones are driven by a much larger motor, usually located under the bench. Standard motors are designed to run really fast, and that speed needs to be greatly reduced. This can be done cheaply, by swapping the pulley on the motor for a smaller size. Smallest I found was 40mm. You can see the size difference, in photo below. Another drive belt is required with change in pulley size.
With speed significantly reduced, it's time to improve the ability to handle thick materials. Once again, this can be done easily and cheaply. Installing a heavy duty feed dog (set of teeth) and cover plate is quick and only cost $15 in parts! You can easily see the dramatic difference in size between STD and heavy duty sets. Lots of extra grip gained here!
I want to do a couple more mods, and then I will start using my new toy.