Tejas

Not precisely on-topic, but here is a link to a service manual for the singer 66, 99, 15K and 201. Since the manual was created by a non-profit, I made a contribution. http://www.tfsr.org/publications/technical_information/sewing_machine_manual/

I'd rather have a really good user and service manuals, and then someone to help talk me through the issue.

Chapter 4 of the manual in the following link might be helpful. http://militarynewbie.com/wp-content/uploads/2013/11/NAVEDTRA-14217-Aircrew-Survival-Equipmentman-1-C.pdf

I started with a 111W155 and no experience, and was intimidated by the speed of the clutch motor. After switching to an FS-550 servo-motor with a 50 mm pulley, and at the lowest top-speed setting, I could single-cycle the needle.

As an alternative to holding the threads upon starting sewing, stick a quarter with butyl tape toward the back of the bed and wind the threads around once. As for sewing and pulling the material back to lock the stitch, that worked for me on my 111W155 if tension was kept on the threads.

Perhaps were people to learn the value of quality, there might be much higher quality products at more reasonable prices. Just an observation, but I lived in Japan for about 10 years and traveled frequently to Western Europe, and the typical quality of most consumer products seemed higher than in the US. I'm annoyed not infrequently to be unable to even find a quality product of a type at any price in the US that were readily available in Japan, where not only were the products higher quality, the customer service was higher.

You might want to read this article on screwdrivers for sewing machine maintenance. I bought a Chapman set from Amazon. http://vssmb.blogspot.com/2011/07/screwdrivers-part-3-which-set-do-i-or.html

Folks more knowledgeable than I can clarify, but I don't think you need to spend $450 for a good variable speed servo-motor for slow speed and control. I have a Family FESM-550S Variable speed servo-motor and can single-cycle the needle. As for power, among the considerations are motor horse power and mechanical advantage of the delivery of the power.

Chapter 5 includes disassembly instructions. http://militarynewbie.com/wp-content/uploads/2013/11/NAVEDTRA-14217-Aircrew-Survival-Equipmentman-1-C.pdf As does starting on page 164. https://archive.org/stream/TM10-3530-202-24#page/n171/mode/2up

Here is a very readable copy of the manual. Thank Gregg at keystone.com. JukiLU-562-3Owners.pdf

The Consew 225 seems to be a Singer 111W clone, and similar to the the 111W it's a compound walking foot machine and lacks reverse. Here's a link to the manual. I couldn't find anything about the b model. If it is more or less a clone, there is lots of documentation about 111W that should mostly be applicable. http://www.consew.com/Files/112347/InstructionManuals/225.pdf Depending upon the condition, $800 might be a bit pricy. I had a 111W155 and liked the machine but it lacked features -- no reverse, small bobbin, a hassle to change stitch length, ....

The Juki Juki DNU-241H is the same machine as the Nakajima 280L which I think was bought out by Juki. I think I recall reading somewhere that all the parts are still available but the most likely needing replacement are. Here is a link to the manual. http://raichert.com/adobe/dnubook.pdf

If you decide on a Juki 1541, there is also a 1541S that has a safety clutch that protects the hook in case of a jam. The price of the S model is only about $100 more.

Gregg's picture shows the upper feed arm at the lower marker line for the least amount of alternate vertical movement. My Juki 1508 came adjusted the same way. This thread describes the ability to walk-over humps as an advantage of increasing the vertical movement. According to the manual, the vertical movement adjustment can be varied from about 3 mm (lower marker line) to about 5 mm (upper marker line). I'd like to know if there are disadvantages to increasing the vertical movement and what those disadvantages might be.

I have encountered what I thought was the same or similar situation as the OP with my walking-foot Juki 1508 being unable to walk-over a bump and stitching in-place. The spacer solved the problem, including hemming jeans. I sew up to the bump with the needle buried, raise the foot and insert the spacer behind the needle and manually and sew up onto the bump. To sew off of the bump, while still on the bump I raise the foot with the needle buried, insert the spacer in front of the needle and manually sew over the drop-off before removing the spacer.

You might try a Dritz Jean-a-ma-jig. I've never used one on leather, but not infrequently on fabric and webbing. I've used it behind then the needle sewing over thicker materials and also in front of of the needle sewing off thicker materials. Joann's also carries them. http://www.amazon.com/Prym-Dritz-915-R-Jean-A-Ma-Jig/dp/B000J4IH0M I've read that the hump-jumper was the original and can be gotten in a set of one or two thicknesses. http://www.thecolorfulworldofsewing.com/The-Hump-Jumper.html I also have this set of five pressor foot spacers of various thicknesses. http://www.threadstandhero.com/Presser_Foot_Spacers.html

There is a safety clutch according to the Consew 227 manuals that are too large to attach. Send a PM and I'll email the manuals.

You might consider getting a different servo-motor. For about the same money you could get a Family FESM-550S Variable speed servo-motor. At the slowest dial setting I can single-cycle the needle.

As you suggest, lifting the presser foot enough to move the material back a couple of stitches back and sew over again is a suitable way to lock the stitch. Another way is after sewing a seam is pull the top thread at the ends end of the seam to the underside and tying the top and bottom threads together. A surgeons knot is probably the most secure.

http://bits.blogs.nytimes.com/2015/02/15/slice-and-carve-the-next-wave-in-computer-aided-creativity/?_r=0 The page also has a video. "The wave of new machines is bringing a new level of precision to people who make physical objects — from leather wallets to lamps to circuit boards — as a career or hobby." " ... he placed a piece of cowhide inside the Glowforge and sent a design for a cover for a Moleskine notebook from an iPad to the machine. Pulses of light began to glow inside the laser cutter as it burned stitch holes into the leather, followed by a rectangular cut that formed the outer edges of what would become the notebook cover. "

The most detailed service manual I am aware of for the Singer 111W155 is TM 10-3530-202-24. I bought a copy via ebay. Here is a link quite readable online copy. https://archive.org/stream/TM10-3530-202-24#page/n1/mode/2up

Tha Thanks for posting the link. I'm really interested in visiting sewing machine museums. There don't seem to be very many. I'd have thought that manufacturers would have museums but apparently not.

I don't think so. I have to press real hard on much thinner leather. I also have an Allstar model AS-100K powered rotary cutter that might. I've cut other materials that thick, but not leather. I use the Olfa cutter with a straight edge and can get straight, vertical cuts. The powered cutter has a foot that runs about 3/8" under the material, and getting real straight cut would be difficult, at least for me.

A good resource for Singer 66, 99, 15K and 201 sewing machines is the TFSR Sewing Machine Manual. http://www.tfsr.org/publications/technical_information/sewing_machine_manual/ Since this resource has been made available by what seems to be a worthy charitable organization, I think folks who use the resource should consider making a contribution. I have no affiliation.

Here is a link to a DVD I've wondered about and would like to know if anybody has an opinion about the DVD. http://www.canvastraining.com/sunshop/index.php?l=product_detail&p=452 Chapter 4 of the following manual might be helpful. http://militarynewbie.com/wp-content/uploads/2013/11/NAVEDTRA-14217-Aircrew-Survival-Equipmentman-1-C.pdf Attached is a pdf of the 1508N Engineer's Manual. LU-1500N Engineer's Manual.pdf