Wizcrafts

Not really. The motor affects punching power and the running speed. An underpowered machine can be custom fitted with a more powerful under the table motor. But it will still have a certain needle, thread and thickness handling maximum that cannot be safely exceeded. The main things that determine the thread handling capacity are the design and clearances of the hook and shuttle and the strength of the take-up and tensioning components. If a certain sewing machine was built to sew light weight cloth, it won't do well with leather, or with thick thread, or large needles. You simply cannot sew with very thick thread on a sewing machine made for cloth and light upholstery. It requires a holster, or harness, or a shoe sole stitcher. BTW: sewing with #346 thread calls for a #26 needle. That is beyond the capacity of walking foot machines, except for the big Juki 441 and its clones and the Adler 205 and its clones. These machines run in the mid $2ks through the high $6ks.

Puritan Industries, a US builder, makes a transverse feed model with a 36" arm, called The Alligator. Like all Puritan machines, it has no bobbin and sews a chainstitch, meaning you'd need to sew across, or glue down the starting and finishing inside chains to lock them in. One advantage of this type of machine is that it easily handles waxed linen thread of just about any size (with the proper needle and awl combo).

If you actually need a transverse feed, order one. CowboySew/Hightex makes a transverse feed machine, as do several other major brands. Here it is in action.

The Sailrite LS1 maxes out with #138 thread and a #23 needle. To use them you'll need to upgrade to the Monster II balance wheel.

This dealer sells the Family Sew FS-550 with a 50mm pulley attached. He also has type 3L v-belts. You are going to need a shorter belt after you replace the clutch motor (with its bigger pulley).

@prbush The shaft on the Family Sew motors is not a standard diameter (as pulley mounting holes go). The 50mm pulley is custom fitted by the dealer. If you buy one from an online seller who is not a specialist in leather sewing machines, it will probably have the 75mm pulley installed (standard for high speed upholstery and garment sewing). This will not be a good size for slow sewing. The machine could start up like a jack rabbit. As for your question about the machine pulley, measure the diameter of the pulley across the top. If it is at least 4 inches, keep it. That way a 2" motor pulley will yield a 2:1 speed reduction/torque multiplication.

I think what's throwing RJ and others off is the fact that you can hand sew with 2 needles to do a running stitch with very heavy thread and have no knots to hide. The stitches are always perfect on both sides in 2 needle hand stitching. Lockstitch sewing machines have an overlap where the top thread grabs up the bottom thread and draws the resulting knot into the material. Lighter threads form tighter knots that are easily buried inside the work. But, thicker thread, especially anything over 1/2 mm, forms a very big overlapping knot that requires a very large needle to poke a hole wide enough to clear at least 3 times the diameter of the largest thread. In the case of .8mm - which equals #554 bonded thread - the thread is not only wide, but not very flexible. It will create a lockstitch knot about 4 times the diameter of the thread. This would require a 3.2mm hole, which is about 1/8 inch diameter! The knot would be so big that it would need to be locked inside 5/16 inch of leather, or more, to totally conceal it. The minimum needle size for sewing with #554 (.8mm) thread is #30. The largest needle that a 441 or 205 type machine uses is a #27. That leaves one having to look into needle and awl harness stitchers, as I previously mentioned. I used to own Union Lockstitch machines that could handle 1/8 inch awls. I called them roofing nails.

I have a trick to pass along to people with loose bobbins on bobbin winder shafts. Feed the thread stub through a hole in the inside of the bobbin, then tuck it through the center post to the front. Find a position where the thread is in direct contact with the shaft, not the split area, and push the bobbin all the way in. This locks the starting thread stub in place and helps keep the bobbin from freewheeling.

If you can't find the lamp clamps for your machine, you can buy a new LED flex light with a magnetic base that holds to the body of the machine. I have several now and like them.

I have 2 Family Sew FS-550 servo motors in service at this time. One feeds a 3:1 speed reducer (on a CB4500). The other is direct drive to the machine. I can set the speed limiter to minimum and still punch through leather without the motor bogging down. Both are equipped with a small 50mm pulley that adds torque. The standard pulley is much bigger and would run too fast and lose power when you try to sew slowly. The pulley size matters on leather sewing machines.

First, verify that you are using a proper combination of thread and needle sizes. Second, if the top tension is as loose as can be and the bobbin has reasonable tension and the knots are still visible on top, the top thread is binding somewhere along the way. This could be the thread spool itself, or thread twisting over the guide on top of the thread stand. It could also be caused by the take-up lift adjuster barrel being set too far in, forcing the take-up to pull too much thread through with each stroke. Last, the timing could be too far advanced or retarded, adding unwanted pressure. But, that is unlikely to affect the knots so drastically.

The only machines I know of that can handle 1mm thread are needle and awl harness stitchers and curved needle shoe sole stitchers. I invite the O.P to read about the Campbell-Randall Lockstitch machine. These machines sell for thousands of dollars, whether new or used. The issue here is that the O.P. doesn't understand how lockstitch sewing machines form a stitch, thread sizes, or machine builds and mechanisms. There is no $200 sewing machine that can sew with 1mm thread - unless it is in a barn or storage locker sale. The smallest sole stitcher that can handle that size thread is a German Junker and Ruh hand cranked, curved needle sole stitcher.

I did get one push button servo from you in 2011 that had a cutout at a certain point of movement of the pedal. It eventually died altogether. The Family Sew servo motors you now sell are so much better and easier to control. The Sew Pro was also a very good servo motor while it was in production. Too bad they folded.

That turned out to be caused by warped or misaligned v-belts. You sent new belts that laid flat and that fixed the vibration.

Check all of the screws, nuts on bolts under the table to ensure that they are as tight as possible. This includes the screws or bolts for the reducer. Also, check the horizontal plane alignment of the belts. The motor pulley should line up with the large reducer pulley. The small reducer pulley should line up with the machine pulley. Youi may need to reposition the motor, reducer, and/or machine to get all three inline. Finally, watch the motion of the belts while the machine is in slow motion. Some belts are twisted, or welded off center from the factory and may give a rough ride at some speeds. Replacing those belts often smooths out the action at all speeds.

Different needle bars and clamps are bored for specific upper shank diameters to center the needle in the hole in the throat plate of feed dog. Different machines have different needle height settings from TDC to BDC. Tailoring machines typically use much shorter needles than upholstery walking foot machines. Holster and harness stitchers have even longer needles. A needle system defines its entire geometry. Some sewing machines that take a system 135x16/17 needle system are physically limited to a #23 or less needle. Others have bigger holes, clearances and different types of shuttle that allow for the use of a #24 or 25 needle. If your machine was built with an upper limit of a #23 needle and you try using a #24 or 25, something is going to jam or break. I have had #26 needles in system 135x16 or 17. But, I didn't have a machine that would actually sew with them.

You never told us what size and type of thread you want to sew with. Perhaps if you consult this thread/needle chart you can choose a combination that meets the minimum required sizes. With those stated we can recommend machines that are able to handle that combination. How's that sound?

A lot of newbies to sewing machines, coming out of hand stitching land, are used to the same stitch appearance on the top and bottom. They have trouble Grokking why the bottom looks so different from the top. They are strangers in a strange land until they come to grips with the fact that especially walking foot machines push down hard directly around the needle holes - causing the bottom leather to take the shape of the hole or slot in the feed dog or throat plate. In order to obtain a top/bottom stitch appearance that almost matches hand stitching requires a needle and awl harness stitcher, like a Union Lockstitch, or Campbell Lockstitch, or Landis 3 machine. These machines have a jumping presser foot and needle or awl feed. There is no inside foot like on a compound feed walking foot machine. The wound from the stabbing top awl tends to heal as the awl comes back up, quickly followed by an ascending barb headed needle. I used to get very nice bottom stitches on the Union Lockstitch machines I owned and let go of. But, nothing I've sewn on beats a Campbell Randall for top/bottom stitch appearance.

It will sew belts, guitar straps, rifle slings, chaps, vests, zippers in jackets, wallets and upholstery, with up to #138 bonded thread (22 pounds test). The maximum seam it will climb over and sew without skipping stitches is perhaps 3/8 inch. But, with #138 thread and a #23 needle, you might need to crank the pressure spring down almost all the way to keep the leather from lifting with the needle. As for holsters, I wouldn't recommend using under #207 thread in a 16 ounce pancake holster, with #277 being much stronger per stitch (44 pounds test). I think that #138 thread is just too weak to hold the leather together under the strain a gun can place on the stitch lines. FYI: Many commercially produced holsters are sewn with #346 lubricated bonded nylon thread, or else with 6 or 7 cord Barbour's Irish linen thread run through a bees wax pot. The former requires a Cowboy, Cobra, Techsew, Weaver, or Artisan, etc 441 clone, or an actual Juki TSC-441, or an Adler 205-370, or the newer Adler 969 Eco harness stitcher. The later calls for a needle and awl harness stitcher or a shoe sole stitcher.

Basically, avoid home style (aka: domestic) sewing machines. They are not good at sewing leather, except for about 5-6 ounces (chaps). All of them are bottom feed only, via feed dogs. Leather is much denser than cloth and takes much more foot pressure to hold it down as the needle and thread ascends. If the pressure spring isn't strong enough to hold down the leather you'll get skipped stitches. The added pressure needed to hold down the leather often causes to top layer to drag out of sync with the bottom layer. Also, the largest commonly sold needle size for domestic sewing machines is #18 (aka: 110), limiting the machine to no more than #69 (T70) bonded thread. This is strong enough for thin leather goods, like leather skirts and wallet interiors, but is a little weak for 1/8 inch thick hand bags. While buying a vintage domestic sewing machine for leather is at best iffy, getting an industrial walking foot machine is just about a sure thing (up to its thickness and thread handling limits).

Cowboy makes a smaller version cylinder arm machine, with compound feed walking feet, named the CB227-R. It fills the gap between light and heavy duty machines. The specs are in the right sidebar on the page.

Have you contacted some long time industrial sewing machine dealers? Some who have been in business for 40 or more years could possibly have that type of machine on a steel shelf in a back room where old machines go to die or get resurrected.

I use these Family Sew motors, equipped with a non-factory, dealer installed 50mm pulley. I also have a speed reducer between the motor and some of my machines.

The post you replied to is from January 6, 2015. Chayne has not logged onto this forum since December 4, 2015. Still, I wish you luck in your hunt for unobtanium parts.

The OP lives in Bucharest, Romania, if that helps.