amuckart

Thanks You're right. I've been taking things apart and (mostly) putting them back together again since I was about 3 (when I took a wall clock to pieces). It's not a job for the less-mechanically inclined who just want a machine that sews, but a 45k is a piece of cake once you've done an Elna TSP zigzag machine.

If you want a good straight-stitch only domestic sewing machine for lightweight stuff the 201k is a much better bet than the 15k. The 201 is fully rotary and geared throughout, so it is both smoother and more robust than the 15k which is an oscillating hook machine. The 201 has a higher and wider clearance than the 15k too. Neither, though, are designed for sewing leather but if you're doing really lightweight stuff then you can put a teflon foot on them which will help the feeding. It won't help with the foot pressure though.

I'll offer an alternative viewpoint to Constabulary's with respect to disassembling the machine. I completely disassembled my 45k25, down to the last screw and taper pin. I found it very rewarding because the process taught me a lot about how the machine (and sewing machines in general) work. I was not the first person to have done so. A lot of the screws in my machine had damaged heads from idiots with the wrong size screwdrivers going at them and some of the external parts on my machine are not original. The foot lifter bar in particular is held on with a very jerry-rigged assemblage of nuts and spacers. Once I had it apart, I had the head stripped and powdercoated and had the relevant external parts nickel plated. IMO Powdercoating gives the closest finish to the original japanning and it's extremely durable. I'm fairly mechanically minded to begin with, and I was extremely systematic about how I took my machine apart. I took photographs of every single bit I removed, before, during, and after removal, and I put all the screws and small parts through numbered index cards, which I then photographed as well. This gave me a complete sequence consisting of several hundred photos I could refer to during reassembly. If you want to learn how machines work, and you've got the right set of screwdrivers and spanners, completely stripping a machine and reassembling it can be quite rewarding, and on a machine the size of a 45k it's a hell of a lot less fiddly than on a domestic machine.

I'll explain the principle for the benefit of the archives, then the process for a 45k, which is basically the same for any oscillating hook machine. To time a machine you need the point of the shuttle to pick up a loop of thread coming off the needle. This loop is then pulled around the shuttle (and bobbin) to pass the top and bottom threads over each other. The loop is formed on the side of the needle that does not have the groove in it. Many modern needles have a scarf or indent above the eye on the side opposite the groove. This scarf allows the needle to be closer to the shuttle and gives the shuttle point a bit more space to pick up the loop in the top threads. This allows a more reliable stitch formation. The loop is formed when the needle has gone all the way down and then risen slightly from bottom-dead-centre. What happens is that the thread in the groove of the needle is held in place by friction with the material, so when the needle moves up, the thread slides in the groove, leaving excess under the material. This excess slides through the eye of the needle and forms a loop on the scarf side. When the loop has formed, but before the needle rises too far and either squishes the loop against the underside of the material or pulls the top thread back up through the material, the point of the shuttle catches the loop and pulls the top thread around the shuttle to make the stitch. Here's a quick and dirty diagram showing the loop formation: Shuttle to needle timing is critical because if the shuttle point passes the needle too early the loop won't have formed and if it passes too late the loop will have moved up above the shuttle point and there will be nothing for it to catch. The general process for timing an oscillating hook machine is as follows: Remove the needle plate and feed dog. This usually involves removing the shuttle race and shuttle, but put them back when you're done removing the feed dog. Put a new needle in. Schmetz size 230 are good for this size of machine Turn the machine until the needle has gone all the way down and keep turning until the needle has come up about 4mm/3/16th inch (the exact height varies by machine, but I think this should be Ok for a 45k. The main thing - and the reason to use a Schmetz 230 needle - is to have the middle of the scarf align with the point of the shuttle. At this stage the point of the shuttle should be in the centre of the needle, exactly in the middle of the scarf. If it does, you're good. If not, you need to either move the shuttle so it is in the correct position (do this if possible) or cycle the machine until the shuttle is in the right position and adjust the needle bar height so that it all lines up. In this picture the shuttle timing is delayed, the shuttle point has not reached the needle yet. Sorry I don't have one with the timing correct. On old machines like my 1919 one, the shuttle timing is fixed and you adjust it by adjusting the height of the needle bar. To adjust the needle bar height, remove the face cover and loosen the two screws in the rectangular block the needle bar passes through: On newer machines, there is a screw where the shuttle driver attaches to the back end of the shaft. Loosen this and you'll be able to turn the shuttle by hand without the rest of the machine moving. It needs to be just tight enough for the shuttle to stay where you put it. The screw you want to loosen is accessed through the hole in the base of the machine that's facing you when you are using the machine. In this picture I'm pointing to the screw (which is missing in my machine) The shuttle driving bit is the rectangular part with two rivets in it in this picture (taken looking up into the machine from underneath). Watch that part move as you turn the machine and it should become clear where the screw is you need to adjust to fix the timing. I hope that helps.

What do you want to know? There are treadle machines that you can sew leather on but they're treadle powered industrial machines. The vast majority of treadle machines you'll find are domestic fabric machines. Even the best of those, such as the Singer 201k, won't sew leather well. As a general rule of thumb, if it takes standard 15x1 domestic sewing machine needles, it is a fabric machine, not a leather machine.

Yep, it will.

The best thing to do is read Wiz's thread on the type of machine you need to sew leather, which is pinned at the top of the sewing machines board and can be found at this link http://leatherworker.net/forum/index.php?showtopic=25239

You might want to experiment with reducing your presser foot pressure at well.

Most small sewing machine motors are universal AC/DC motors and can be reversed. The easiest way is to open the motor and swap the brush housings around and it should reverse the direction.

Is there a particular weight/type of leather you're interested in? Can you post pictures of what you're getting out of your machine at the moment? That might help get suggestions on what to adjust.

Glad my blog is useful 5-6mm isn't too difficult to turn at all provided you get the right stuff. Avoid sole bend, it's hard rolled and far too stiff for turnshoes. The stuff I have is "48 hour" tanned (normal 'vegetable' tan is 6-12 hours) and it's nicely flexible. I can't get any more though. Regular thick veg tan still turns easily.

I use 2.5mm veg tanned double shoulders and it works very well. I use 5-6mm veg for the soles, which is borderline too thin but works Ok.

It's a needle and awl machine. The biggest limitation of it is that it has a throat depth of about 4", so the shapes of things you can feed through it are quite limited. If you search the forums I think they've been discussed here before. Here's a video from Lisa Sorrell showing how it works.

It looks like an American straight needle stitcher to me.

A New Zealand site called TradeMe http://www.trademe.co.nz about four years ago.

Nice find Wiz. That looks like a really useful feature!

I don't know what the market is like where you are, but to put your budget in context, but here in New Zealand I bought a Pfaff 441 for NZ$250, and a Seiko STH-8BLD2 for NZ$300, both with motors etc. I had to replace the motors on the Seiko because it was set up for upholstery work and was much too fast for what I wanted but a new servo motor was $150.

What's your definition of "medium weight"? 6oz or 18oz? It's handy to be as specific as possible because my definition of "medium weight" coming at this from a different area of leatherwork might be very different to yours. In my book, 24oz is "medium" but if you're doing garment weight stuff then I suspect your definition of "medium" is a lot less than that. Are you particularly set on a Juki machine? They're good, but you pay a premium for that brand. There are older models of machine that will sew garment weight leathers really well that you can probably get for a lot less than $1000. That money might be enough to get you a second hand Seiko TE/TF-6, which are cylinder arm roller foot machines designed for lightweight leather sewing. The TF-6 is a left handed machine, meaning it's arm points to the right instead of to the left like a normal machine and the presser foot and feed are on the inside of the arm. This gives excellent visibility of the seam lines. Both can have a flat table attached. The TE/TF-6 are modern clones of the Singer 16 and 17 class machines. Another machine that's popular amongst people sewing things like boot tops and shoes is the Singer 31-15, which is a flat-bed roller foot machine. It's a straight-stitch only, and has no reverse, but there are modern versions that do. The Pfaff 441 (not to be confused with the Juki 441) is another flat bed roller foot machine for leather that can be had second hand. There's a post-bed version too, but I can't remember the model number. For someone working outside of a factory setting without maintenance staff, the advantage of machines like these compared to more modern self-lubricating direct-drive ones is that they are much simpler and far easier to service and unless you need really high production speeds they will probably serve you just as well. My recommendation would be to look at the advertisements on this site and talk to Techsew, Toledo Industrial, etc. about what you need and see if they have a machine that will do what you want inside your budget. I've also heard very good things about Melanie Machine Co. in Ohio.

I didn't, but google found it quickly enough. Thank you for the pointer. It looks like a rework of the Juki engineers' manual.

When you say "lambskin" do you mean wool on, or thin lamb leather? The sort of machine you need to sew garment weight leather and the sort of machine you need to sew thicker leather are quite different. I think that for lighter weight leathers a roller foot machine (ideally with a roller feed) is a good idea. A post or cylinder bed machine will allow you to sew complex 3D shapes as well as flat things. For heavier leathers, you'll want a walking foot machine. For medium weight work a Seiko STH-8 or Consew 206 (both clones of the Singer 111) is a good bet. They're common, easy to get feet and parts for, and reliable. I don't know if they can be adapted to sew thin soft leathers like lambskin though.

Mostly, but not 100%. Interestingly adjusting it in accordance with Steve's video did not work. I don't know why, I thought Cobra and Cowboy machines were mechanically identical. The video gave me what I needed to stare at the mechanism while cycling the machine which let me work out what bits did what. Along with the engineering manual I've got the machine sewing cleanly forward and backwards into the same holes but the stitch length is out by about -10-15% across the board. At 11mm I get just under 10mm stitches, and it stops feeding by a needle width at about the 3-4mm setting. I think I know why this is but I need to play with it some more to be sure. The correct point for zero on my machine is the centre of the adjustment bar.

I think this video of Cobra Steve going over the whole machine with all its adjustments makes a useful addition to this thread:

I was wrong. I found Cobra Steve's video and it showed me most of what I needed. Thanks for the pointer Constabulary!

This great video from Cobra Steve answers the question

None taken. It was a calculated risk, and one I'm happy with. I'm not a professional who needs the machine for production work and I fix machines for fun so sinking time into getting it sorted isn't an issue.As it was I got the machine with a full set of feet & plates, for less than half what it would have cost me to import a machine from the USA. That's thousands of NZ$. For that money I'm willing to spend some time sorting it out and deal with a certain amount of mucking around with the local importer. I'm setting the machine up from scratch so I'm a bit beyond the basic tension and stitch length stuff :-)