What machine to make this bag?

[Spyros]

8 hours ago, Matt S said:

I agree with you about how the handles were constructed (machine sewn single thickness w/skinny thread then hand sewn to the bag w/ chunky thread) but there are reasons to sew single-thickness: appearance (to give an increased appearance of completeness, finishedness and matching with other stitched parts), and to reduce stretch. I often stitch single-thickness keeper loops for both these reasons. I'm not too keen on how it was executed here with the thread mismatch, would have been more elegant riveting the handles on IMO.

It just does my head in Matt, the engineer part of my brain throws a tandrum when I see stitches and rivets that don't hold anything together.  I guess customers don't think like that, so yeah, maybe, ok.

But don't think it will reduce stretching in any meaningful way, the thread will also flex and stretch overtime.  If you're going through the trouble of stitching it, why not line the damn thing, and that really reduces stretching.

Edited November 20, 2021 by Spyros

[RockyAussie]

7 hours ago, MtlBiker said:

What part of that bag says to you, "post" bed machine?  Is it the side seam which might be hard to reach near the bottom with a flatbed?  I make a similar bag using both flatbed and cylinder arm machines (for different parts) but I'm drooling over getting myself a post machine.  Please... give me more reasons to get one! 

(I'm actually thinking of the Techsew 860 or equivalent, as it uses the same needle system as my other machines plus has a compound walking foot, and takes thread up to 138 and needles up to size 24.)

Because of the height of this bag I would not want the Techsew 860 as it has a low height post. For the ease of stitching the base in and getting down low on those long sides I would be looking more at the Techsew 85017 which has a 17" height post compared to the 7" height of the other. Doing this form of side seam and base is quicker than other methods if you have the right machine . This machine can do a very wide range of applications but just a word of caution all the same for the OP ....if I were just starting off with out any other machines I would be looking more at a cylinder machine. You can easily make tote bags with them as well but not with this construction method. If the leather you use is soft and floppy you may get close to doing it but you would want to be pretty desperate to try.

[RockyAussie]

10 minutes ago, Spyros said:

why not line the damn thing

Time and money and sometimes skill..

[Spyros]

55 minutes ago, RockyAussie said:

Time and money and sometimes skill..

false economy IMO... a strap of liner leather costs nothing, and you're already wasting time by stitching leather with air, how much more time is it really to cut a same size strap and hold it underneath while you're stitching?

Different story if you decide to go with plain unstitched straps, that does save time.

[Matt S]

On 11/20/2021 at 3:33 AM, Spyros said:

It just does my head in Matt, the engineer part of my brain throws a tandrum when I see stitches and rivets that don't hold anything together.  I guess customers don't think like that, so yeah, maybe, ok.

But don't think it will reduce stretching in any meaningful way, the thread will also flex and stretch overtime.  If you're going through the trouble of stitching it, why not line the damn thing, and that really reduces stretching.

The engineer part of your brain is running with insufficient data Spyros!  Stitching single-thickness leather will reduce stretch over time. It also increases stiffness which, in this case, might be lacking in the handles. Judging by the rest of the bag I'd estimate that they wouldn't stand erect like that without the stitching. That stitching definitely has a purpose.

From a leathergineering PoV I have a lot more problem with the postage stamp stitching of the shoulder strap clips.

On 11/20/2021 at 4:49 AM, Spyros said:

false economy IMO... a strap of liner leather costs nothing, and you're already wasting time by stitching leather with air, how much more time is it really to cut a same size strap and hold it underneath while you're stitching?

Different story if you decide to go with plain unstitched straps, that does save time.

Having a practiced operator run those handle straps through a machine will take a couple of seconds max. Pennies of labour and an almost incalculably small cost in thread. Lining with leather you have the cost of leather, the cost of the die cutter, the material and labour costs of gluing the liner in place, the drying time, and maybe trimming. Some of those costs reduce with scale (the die cutter will, within its service life, ameliorate to virtually nil) but others (like labour and drying time) are per-unit costs that largely don't scale down with volume.