Questions About Post Bed Machines

[jjodrey]

Hello,

I make leather bags using chrome tanned leather on my refurbished, flat bed Singer 211 U566A. Though the machine is fantastic and serves me very well, being a flat bed, it has its limitations. I'd like to add some decorative top stitching to various hard-to-reach area of the bags (bottom/base, and sometimes the side seams), but it's very difficult to do so easily - and in many cases is actually impossible.

I *think* I should be in the market for a post bed machine, but though I've looked for more information online about these machines (I live in a small town, and there aren't any shops here that I can ask), I can't find a definitive source of information and have been reading machine descriptions (which appear to be written in a foreign language - ha) such as the following:

This post-bed industrial sewing machine is equipped with vertical hook, spring return reverse lever mechanism with slider thread take up.

This compound feeding machine works with upper roller, lower wheel and needle feeding synchronizing, ensuring smooth sewing at all time,even when joining other materials for overlap sewing.

With extra large rotatable shuttle bobbin, both time saving and efficiency can be achieved.

If any of you can answer my questions below (and also answer any questions I don't know enough to ask), I'd be incredibly grateful. :-)

1. Should I indeed be looking for a post bed machine? A cylinder machine?

2. I notice that there are many different heights and thickness's for the posts. Ummmmm.... help? ;-)

3. I believe that a single needle machine will do, but what type of feed should I be looking for?

Thank you in advance for any assistance and guidance you can provide.

Kind regards,

Jill

[Art]

Hi Jill,

If you make or repair leather bags of medium weight (heavy weight mould be messenger or "lawyer" bags made of veg tan where you need to use large thread in construction), a post machine is not a necessity, but pretty darned near so. A cylinder arm is ok if you plan the construction of the bag around the machines limitations an do decorative sewing while the bag is deconstructed (or not yet constructed would be a better term). Some construction jobs on shoes or boots just can't be easily done without a post bed, but any bespoke shoemaker can sew everything by hand if required. Answer to need? Yes, of course you need one.

Post machines typically can use 92 thread and down, they have smaller hooks and 138 is really pushing it. The good thing here is that sizes 69 and down have a lot more colors available. If size 46 thread can hold shoes together, it can hold most things together, so size is just not that important.

As far as posts go (and there are a lot of configurations). I've never used one with a horizontal hook shaft (that means the bobbin stands-up vertically, confusing as hell, but just know you want the bobbin and hook to lay flat and the bobbin to "drop-in" and this is usually called a vertical shaft bobbin), so get the vertical shaft. You want a single bobbin to the right of the needle, this gives you a drop-off to the left of the needle, here again, you can get the bobbin to the left, but to the right works and the parts are easier to find. A 7" or so inch post height will be sufficient, more is not necessarily better as the cost skyrockets the higher you go.

For feeding, there is the standard undriven roller foot and a lower wheel (driven) or feed dogs. A good example of this machine is the Cowboy CB-810 from Bob Kovar at Toledo Sewing Machines. These machines have a roller top foot that allows you to sew very close to the edge. There is a reverse lever on this machine.

Then there is the triple feed or the version I have. If you don't buy this one, you will hate not spending the few extra bucks. This machine is a dual roller foot machine where both wheels are driven AND the needle feeds also. This is more complicated and more expensive, but for leather, it just works better. If you run the edge off the rollers, this machine still feeds with the needle 'till you get back on course. This machine is a copy of the Pfaff that was and still is used in industry, the Chinese didn't try to re-engineer it on the cheap, it is all ball and needle bearings and with care will run forever. This machine DOES NOT have a reverse lever, typical German design, always advance never retreat. Honestly, sewing machines got away without reverse for decades, I don't miss it on mine. A good example of this machine is the Cowboy CB-8110 from Bob Kovar at Toledo Sewing Machines. I've had confidence to take-on a few handbag repair jobs and knew I wouldn't have to spend hours either deconstructing a bag or hand sewing in an unfavorable spot to get it done. All around, I like this machine and recommend it highly.

A note; when sewing leather, short stitch lengths are not so good for construction, for decorating, a smaller needle and thin thread can and do work. If you go too short with a larger thread and thick needle, your sewing machine will sometimes cut the leather or make a very weak seam.

Art

[jjodrey]

Dear Art,

Thank you very much for your detailed reply. This is exactly the kind of information I've been looking for (but would never have been able to find through a Google search). I use a size 92 nylon thread now for my bags, and it's perfect, so it seems that a post bed is just the thing. I think I will spend the extra bucks and look for a triple feed machine. I rarely use the reverse feed on my Singer (and never with leather), so the advance, not retreat design should also work well.

Thanks again. It's really comforting to know that there are many people out there like yourself, who are so generous with their time and knowledge.

Kind regards,

Jill

[MG513]

This was a great read as I am currently looking for a post roller for shoe uppers. Thx art!

Edited July 1, 2016 by MG513