Flat felled seams on a tube tent

I don’t think you need professional machine unless you’re making a lot of tube tents and you really want to squeeze out every penny of labor for sewing

Any machine will do fine

Sew the two pieces together, then spread out, fold over twice, and sew through the fold.  Or sew an extra row of stitches just to make sure.  So you do three rows of stitches.  With the professional machine you only need one pass through the machine so it takes less time.

Thanks for your response; I do want to reduce the time and the labor.

Just wondering; have you called them? They probably know their machines better than we do. I’d also ask how a machine made for denim will handle light slippery synthetics.

You need to be aware that the link is to chain stitch machines, not lock stitch which is what I expect you actually want.

You’re right. I havn’t been able to find an off the arm, double needle, lockstich (301). They are all chain stitchers (401) whether they are light duty or otherwise. Does anybody know how the big guys make their flat felled seams? Do they use a chain stitch?

For most gear other than some clothing you would only use lock stitch.  The issue with chain stitch is that if a thread breaks then the whole seam can unravel.  For something like a tube tent you do not need an off the arm machine, a regular flat bed machine is fine.  It may be easier if you have a longer arm than normal but the size of the opening in a tube tent won’t cause any problems that an experienced industrial machinist would have to wrestle with.