Will a post-bed, (driven) roller foot machine let me sew thin veg tan?

[tozafoot]

Having been hand sewing footwear for 7 years, I’m researching my first sewing machine. Many thanks to folks on this forum for all the excellent advice that helps newbies like me learn.

I make minimalist shoes, boots and sandals with thin, very flexible soles (no raised heels). I am now looking for a machine that ideally will let me: 

1. Assemble uppers: sewing two or three layers of 2-6oz chrome tan or very soft veg tan leather. Up to 6mm (1/4") in total thickness, but mostly around ~3-4mm (1/8" to 5/32")
2. Assemble flat veg tan soles: sewing two flat pieces of 4-8oz fairly dense but flexible veg tan together. See photo 1 below for an example. Total thickness is typically ~3mm (=1/8" or 8oz) to 6mm (= 1/4" or 16oz) 
3. “Stitch down” uppers to soles: I stitch one to three layers of 2-4oz chrome tan or soft veg tan upper “down” flat around the perimeter of a flexible 4-8oz veg-tan sole. See photo 2 below for an example. Total thickness is typically ~3mm (=1/8" or 8oz) to 6.5mm (=1/4" or 16 oz). This is similar to what I think Jarakoko is doing.

Since I often want to stitch close to the edge of the leather on tight curves, I figure a (driven) roller foot machine might be better for me than one with a walking foot such as a Juki 1341 clone. I have been considering whether an inline walking foot would work, but I am not convinced it will, because there simply won’t be enough material in line behind the needle on some of the tightest curves I want to sew.

Most of what I stitch is 3-6mm total thickness, which many of these post-bed machines should be able to cope with according to their posted specs. But it seems there are relatively few capable of sewing with V138 or V207 thread; many seem to max out at V92. I would like to use V138 or even V207 thread at times, so I have been considering:

• The TechSew 830: can apparently take #22 needles and V138 thread. The TechSew site says it can sew up to 3/8” (9.5mm) thickness.
• The Artisan 4618LBB: Artisan apparently modify the normal 4618 (which appears to have the same instruction manual as the Consew 701) to take up to #23 or #24 needles and V207 thread. But the total thickness of material it can cope with under the roller foot is only 6mm, or 1/4”.

My question is: can I sew up to 6mm (= 1/4" or 16oz) total thickness of flexible but fairly dense veg tan leather on either of these machines, using a #22 needle and V138 thread? If not, what is the maximum thickness I might expect to be able to sew? Sadly I haven’t found anywhere near me (NJ, southern NY, eastern PA) to try out either of these machines in person, so I’d be very grateful for the experience of folks on this forum as to what, in practice, they are capable of. Many thanks for any advice you can give!

[kgg]

20 minutes ago, tozafoot said:

using a #22 needle and V138 thread?

In my opinion the #22 needle is good for V92 in thicker items or V138 in thinner items. A good cross reference for needle size to thread size table can be found at ( https://www.tolindsewmach.com/thread-chart.html ).

I would call / email the vendors and ask them directly if their machines can sew what you want.

kgg

 

[tozafoot]

 

On 2/10/2023 at 12:09 PM, kgg said:

In my opinion the #22 needle is good for V92 in thicker items or V138 in thinner items. A good cross reference for needle size to thread size table can be found at ( https://www.tolindsewmach.com/thread-chart.html ).

Thank you, kgg, I have been relying on that very useful needle/thread chart for weeks, while I have been drawing up a shortlist of possible machines. From your comment here, I guess the "minimum" is a more important part of the "minimum needle size" column heading than I had previously realized (I would have looked at the chart and decided that a V92 thread required a #19 needle...). For my uppers, I think V92 will be fine, but I do wonder whether it will be strong enough for stitching down uppers to soles, and for sewing sole components to each other.

On 2/10/2023 at 12:09 PM, kgg said:

I would call / email the vendors and ask them directly if their machines can sew what you want.

Yes, thank you, I have had conversations with helpful folks at Artisan (Chester) and TechSew (Ron) about each of these machines. As far as sewing tight curves, and close to edges, no question either machine would be a good choice. Regarding thickness of what can be sewn, and whether or not the machines would work for what I want: it seems that the number of layers matters, as well as the type of leather, total thickness and needle size/type (I believe these machines both take 135 x 8 needles, the TechSew 830 up to size #22 and the Artisan 4618LBB up to size #24). The TechSew 830 can be fitted with a speed reducer before shipping; the Artisan doesn't have that option: apparently the (specific to Artisan) servo motors are highly controllable making a speed reducer less necessary. Much to think about.

If anyone reading this has one of these machines (Artisan 4618 or TechSew 830), I would so appreciate it if you could let me know what types and thickness of leather you are successfully sewing with it!