Wizcrafts

Here is a topic from 2009 about Yamata portable walking foot machines and modifications

I meant to say Thompson started making portable walking foot machines, for light upholstery and sail/boat seat repairs. I have been looking at search results on the forum and I think that the best phrase to use is: "portable walking foot machine". There are a lot of posts going back to 2010 from people who tried to make these things sew leather. AKAIK, the Monster wheel can replace the existing wheel. You will need a longer belt though. Sailrite also sells their motor and presser feet and some attachments.

That type of machine is not really used in serious leather work, which our forum is all about. You might have better luck finding answers at a sail makers forum. That's what the target audience for these dual feed mini-walking foot machines is. It all began a long long time ago with a Morse portable walking foot machine. But, if memory still serves me well enough, if you search the forum for "mini-walking foot machine", or "sailrite" you will find some old topics dealing with efforts to improve these portable machines.

Check your private messages. I sent you a PM earlier tonight.

I already posted links to those Adler machines on the first page on this topic.

I recommend getting a real industrial walking foot sewing machine, in this case with a cylinder arm. The linked-to machine is a medium duty waling foot machine, rated at up to 3/8 inch thickness, with #138 bonded thread. It looks like you are using #69 (T70) bonded thread, which is best sewn using a #18 needle. I'm sorry that you got duped into buying that domestic sewing machine that was advertised as being a leather sewing machine. Not even close! Ebay sellers who advertise domestic sewing machines as "Industrial Strength" (often misspelling Strength) are lying. This is the place to learn about real leather sewing machines. I wrote an article about the type of sewing machine you need to sew leather, that is stickied on the index page of this forum, Read it and learn. Prepare to pay between $1,200 to $2,500 for a real leather sewing machine that is for medium duty work like your sandals. It will have a compound feed walking foot system, plus it will use industrial system 135x16 (leather point) or 135x17 (fabric) needles, available in sizes all the way up to #25. The bobbin and shuttle will allow it to sew with #138 thread, which is twice the capacity of any domestic machine. Finally, most of them are rated at 3/8 inch thickness. I refer to these machines as "upholstery grade machines."

I was actually going to mention that you might want to look into a long body machine. Go check it out. Bring some thread and material. I have a 20" body Singer walking foot machine and it is used almost every day to sew patches onto the back of Biker vests. A 30" body is even better. It can sew banners, awnings, quilts, bedspreads, and all kinds of wide items. The machine should be capable of sewing with #138 bonded thread, top and bottom and uses the same needle system as the Juki 1541 you already own. Here is the official specs page.

By "backup machine" are you worried that your Juki is going to fail under the load? That would not normally happen unless the machine is not properly maintained and runs out of oil in critical places while she is sewing at a high speed. Every sewing machine owner has the responsibility of oiling his or her machine. as often as needed (using Lily White or Juki Defrix sewing machine Oil). Further, they must make sure that any frayed thread segments are cleared out of the bobbin case race and from the bobbin tension spring. Ideally there won't be any frayed thread in the bobbin case/basket. But, shit happens and you will eventually need to remove some thread from the bobbin case and the race surrounding it.

Here is an Adler to die for; a model 869 cylinder arm walking foot machine.

Member "StickAndTin" asked about an upholstery grade sewing machine that is heavier duty than a Juki DNU-1541s. Here is one that I have seen and operated it in person and it is awesome: Adler 867 complete from one of our advertisers, Weaver Leather. I would love to have one of these machines!

Juki machines are made to work hard and hold up. Once your wife's business gets moving she will appreciate the higher quality machines they build. The Consew 206RB-5 is a Japanese design that is now assembled in China. FWIIW, I have a modified Singer walking foot machine that is based on the 111 design. It has been modified to use a Juki LU hook and large bobbin system. It takes a myriad of presser feet made for this ubiquitous type of machine. It is the second most used machine in my shop (next to a Cowboy CB4500). It features Poor Man's Reverse and stitch length adjustment via a knob on the handwheel. It is straight out of the 1960s and works like a charm. It is, however, way to easy to jam the top thread in the bobbin case. My next walking foot machine will have a horizontal shuttle, a stitch length knob on the front and a push down reverse lever, like the Consew 206RB-5 has.

Bigger diameter needles are deflected less than thin needles, for any given length. The longer the needle system, they greater the deflection. Needles get deflected by the thread pulling on the way down, as well as by the last stitch on the upstroke. The more tension you have on the thread, the greater this effect will be. As I said before, when sewing Naugahyde, you should back off top and bobbin tensions. It shouldn't take much tension to bring the knots up between the two or four layers. Move up one needle size if necessary.

Warning about high lift walking foot machines using system 190 needles I modified my previous National 300N walking foot machine to this spec. While it did allow me to sew thicker material, it was hell on thin needles sewing thinner leather. I used to break #18 and 19 needles every day I sewed with #69 thread, into 8 ounce hard leather belts. The extra 3/16" length made the thinner needles easier to deflect into the side of the feed dog. The problem resolved itself with #21 and larger needles. Of course, they left a hole that was too big for the thread. I came to the conclusion that this setup is best used with a #23 or #24 needle and #138 or #207 thread. I later restored the original timing and system 135x(16 or 17) needles and it worked much better with #69 thread

The Juki LU-1508 NH is the next step up. It is still an upholstery grade machine, but uses system 190 needles and the body has been modified to allow the feet to lift and alternate higher (almost 1/2 inch).

Accessories will have to be custom fitted to this machine. It is way bigger than 99.99% of standard walking foot machines (it weigh well over 100 pounds!). Bear in mind that the 132k6 is a primarily buffing wheel sewing machine. Yes to the servo motor change, as long as the original clutch motor uses the standard 3 mounting bolts. Note, the flywheel pulley is much larger than a normal walking foot sewing machine and it runs slower already. Mine had a 2" motor pulley and ran at a top speed of about 6 or 7 stitches per second.

You should be looking at industrial walking foot machines with either a servo or 1/3 HP clutch motor. I am guessing that slow speeds won't be required too often for upholstery work. Mind you, a servo is easier to control at slower speeds than a clutch. The real issue will be how much body depth do you require to sew these items? Portable walking foot machines (made for use on boats) are usually well under 9 inches deep, from the needle to the inside of the body. Some have a fairly low inside height as well. A standard Consew or Juki walking foot machine will have more width and height. The only way that the LS or LZ will work better for you is if space is limited and your vinyl projects can be either edge stitched only, or folded up inside the smaller harp area. If all your material is other than leather, a dual feed walking foot machine will do just fine. These machines have a driven outside foot that follows the driven feed dog. They also have aggressive teeth on the bottom of both feet. If your total thickness exceeds 3/8 inch, a Juki LU-1508NH or equivalent will be a better choice. It has a longer needle and is cut out for higher lift.

The SInger 132k6 is made to sew buffing wheels and webbing, up to 1/2 inch thick, with #346 thread, using a #26 needle. It seems to be a good match for your projects. I used to own one of these beasts and know its limitations and advantages. As for reverse, you can either spin the work around to backstitch, or just sew over the starting thread for a few stitches. I have a SInger walking foot machine without reverse and overstitch all the time. Four or five stitches should do the trick.

Sure. #92 thread has 15 pounds test, as opposed to only 11 for #69 thread. If you do that, use #20 round point needles.

The intermittent "tiny balloons" on the bottom would be thread knots or even top thread loops on the bottom. There would be two things that would account for this. The top thread is twisting up in the upper tension disks, out of the primary pressure zone, causing it to lose tension The bobbin was wound incorrectly, or is warped and is binding intermittently Check the spool of thread to see if it comes off the spool like a coil spring. If so, place a funnel on top of the spool and feed the thread through the spout, up to the thread guise on the stand. Then, when it gets to the three hole thread guide near the top tensioner, go through all three using a wrap around technique. This may counteract the twisty thread. The opposite can happen if the bonding on the thread is sticky in some areas and loose in others. Examine the cone and see if the thread sticks too much intermittently. Wind a fresh bobbin load, using a fairly strong amount of tension on the disks on the far end of the winder assembly. You want the bobbins to be loaded tightly and evenly all the way across. As the bobbin is loading, check it for out of roundness. If the sides are bent the booin may bind inside the bobbin case. Check the bobbin case tension spring and slot for thread pollution. A ratted piece of thread can cause intermittent tension changes. You don't need a lot of bobbin tension. Use just enough to get a decent lay on the bottom, with the knots buried between the layers. Then you won't need as much top tension either. Finally, make sure that the top thread is feeding through the check spring and adjust its travel to see if it makes any improvement, or worsens the issue. The adjustment should be set bey a little screw in a curved slot on the disk facing forward, over the check spring. One direction lengthens the travel and vice-versa.

Colt; The check spring is on a second split shaft under the top tension disks. It is the small coil spring with a turnback on the end, which you pull the top thread through, before it feeds up to the take-up lever. Its purpose is to maintain tension on the top thread during the take-up and downstrokes. It must keep the thread taut until the needle penetrates the top layer and must let go before bottom dead center is reached. Everything in between is optional and can make a difference. The amount of movement of this check spring is determined by a bracket under it. The bracket is movable in an arc on the housing that holds the spring. Loosen the screw going through the bracket and move it one way or the other to change the distance the spring travels, from a resting position. Instead of a bottom stop bracket, rour check spring may have a sliding block facing outward and behind a knurled nut on the lower shaft. It is secured by a little screw inside a curved slot on the forward facing round plate. These allow a certain amount of fine adjustment of the travel. Here is a link to one on eBay, with a good photo of the spring and mounting assembly. http://www.ebay.com/itm/CONSEW-206RB-WALKING-FOOT-INDUSTRIAL-SEWING-MACHINE-THREAD-TENSION-ASSEMBLY-/270962678983

Stop using leather point needles on webbing. It frays the strands and makes a slit, rather than a round hole. This change alone may improve the bottom appearance. #23 round point needle with #138 thread, top and bottom. Lengthen the check spring travel some.

This proves the age old adage that less is more! Or something like that.

Kelsey; Try backstitching three stitches and hold both threads taut as you do so, until you pass the starting stitch. Make sure that the knots are as centered inside the material as is possible. Finally, use a smaller needle if all your stitches are loose (experiment). The travel of the check spring has an influence on the stitch tightness. Longer travel makes for tighter stitches all around. But, too much travel can dissolve the loops before the hook picks them off.

If a #20 needle breaks and she isn't pulling hard on the material, then needle deflection caused by thread tension is a possible cause. Reducing both top and bobbin tensions, rebalancing the position of the knots, should help alleviate this deflection. Also, check the feed dog and make sure it is not moving at a different rate than the needle. The Juki may be equipped with an adjustable rate feed dog control, used to ruffle curtains. This would be a bad setting for flat work. If she is trying to force the work around the turns, the needle may be deflected into the feed dog surface. If she has to move up to a bigger needle,she may have do the same with the thread. Otherwise there will be huge holes with tiny thread. The normal needle-thread combinations for upholstery grade walking foot machines are as follows. #69 thread: #18/110 needle #92 thread: #20/125 needle #138 thread: #23/160 needle

Apparently, you already have a large enough needle. The 125/20 is the "size" designation or width indicator. The 125 is the European size and the 20 is the American/Singer equivalent size. The 135x17 or DPx17 are the needle "system," with the x16 being leather point and the x17 round point. I get most of my thread from Bob Kovar (Toledo Industrial Sewing Machines), including #92. I only buy elsewhere if he doesn't have a color I am looking for in a particular size. Most of his bonded thread is the Cowboy brand and it matches colors across multiple sizes. So, if you buy an 8 ounce spool of a certain color code in #92 and 16 ounce spool of the same code in size 277, the colors will match. You can see the colors and codes of the Cowboy thread here The color codes are listed in the right sidebar on the Thread page.