Constabulary

Your stitch length adjuster is installed upside down. The arrow has to point upward. Also make sure the gib is instilled correctly.

BTW - hope you are aware that is is not a heavy duty leather sewing machine. It was used for sewing garments and maybe some lightweight leather. What leather thickness (all layers together) do you want to sew and with what thread size? Those who think it is a heavy duty machine usually come form domestic sewing machines and think because of size and weight it has to be a "Hevay Duty" machine.

There were pre wound bobbins for barrel hook machines? Can you post some pictures please? Did the machine come without bobbin winder? That surprises me. This one should work: https://www.ebay.com/itm/143422221569

If the needle for your machine is 16x231 then you need a round shank needle. The needle system 16 (as from the Singer 16) is also called System 34 or 287 or 1738. Here you can find different leather needles for the mentioned needle system: https://www.thethreadexchange.com/miva/merchant.mvc?Screen=CTGY&Category_Code=NDL-34

I agree with nylonRigging. Pfaffs are excellent machines - no doubt. But finding gauge sets for different needle distances is a pain. When you are looking for a double needle machine I would look for machines based on Singer, like JUKI, SEIKO, Mitsubishi, Brother (they often share the same gauge sets) or the Singer 212 or 112 it self. On the other hand if the machine has the needle distance you need and you are sure you will need no other then go for it. My double needle choice was the Singer 212G141. To give you an idea of which machines share the same "Singer Type" needle feed gauge set check the description here: https://www.ebay.com/itm/153439679127

True. As Kafka said: Better to have, and not need, than to need, and not have. But this one actually goes on to a new setup.

I finally used the above shown pats for making a box type speed reducer. I have used 15mm coated plywood. It still needs some work.

Patcher machines can become quite handy for repair work or certain sewing operations. if it is cheap and it works and you have enough space for it - why not. My 29K71 does not see much work but I love it and I´ll keep it.

It basically is a shoe and boot repair machine and not designed for really heavy work / heavy thread. 138 pretty much is the max. is can handle. The 29-4 is probably 100 years old and has some (a few) parts in common with the later 29K models. Some parts remained the same bust most of the important wear parts are obsolete. You may find some but they are hard to find nowadays. Its a different story for the later 29K models like 29K71 - the later models are still made in China / far east so parts are usually not a big problem. Servo motor is possible but you have to figure how and where to install it. You may also need a counter spring cause the 29K´s have a heavy cast iron foot pedal. The Adler 30 machines (a similar patcher model but made by Adler in Germany) had optional motor brackets for the treadle stand. I can post picture of one later. Lots of information on the 29 / 29K Singers when you do a google forum search: https://www.google.com/search?client=firefox-b-d&q=singer+29+site%3Aleatherworker.net%2Fforum

I barely need one but I´m using the one fredk shows as well. They are cheap on ebay like 6 bucks or so. Well they all come from China anyway. I have polished / sharpened the blades with jewelers rouge on some scrap leather and I´m actually very pleased with it. F.i. https://www.ebay.de/itm/364005525549

Not sure what the subclass 11 includes but the major difference usually is with what accessories the machine once left the plant. What I can tell form this single picture is that it is a drop feed machine w/o reverse, it has an outdated clutch motor (you will not like it cause it is very fast and most likely not easy to control). This is the 2nd model of the Singer 51w. It has a plain presser foot instead of a roller foot. Some parts are still available but not too many. IMO the 2 plats on the machine bed look kinda odd and I don´t think they belong to this machine. Price wise i think it is too expensive for what it can do but on the other hand post bed machines are harder to find than others. If you buy it make sure the stitch length adjuster is working and nothing it broken on it. Also make sure the timing belt is in very good condition cause AFAIK they are no longer available. The 51w when it came from the factory was set up for a nowadays rather odd needle system 128x3 / 128x4 (or similar) but you can convert the needle bar for using a more common needle like 135x16 or similar. See this link: https://leatherworker.net/forum/topic/96574-singer-51w56-needle-bar-conversion/ I have the 1st model of the 51w and I like it very much but to be honest I´m barely using it. I did a needle bar conversion and a presser foot bar conversion as well but that was cause it still was the 1st model based on a Wheeler & Wilson machine. If you are interested: https://leatherworker.net/forum/topic/86292-singer-51w-sv-2-post-bed-machine-restoration/ Maybe you can give us an idea of what you want to sew so we can try to suggest some other machines. If you need more machine details of the 51w class you can download some 51w manual here:

That is what I was thinking too when I was new to sewing machines. Not that does not work! But you can turn around the product you sew and make the back stitch that way.

looks like 992 00 680 0 - ROLLE (roller) Check with you local dealer or this dealer in Germany. He has a good reputation. https://liersch.com/online-shop/ersatzteile/duerkopp-adler/10222486-rolle-5-49x9-82x7-1-0992-006800 Seems not to be super expensive. If DIY is an option the measures are in the above listing.

Take of the V-Belt and try turning it by hand. Or push down the foot pedal cause the clutch motor has a brake .... just guessing w/o having seen the machine setup.

Just from the picture... Machine has no reverse, not necessary but reverse is a bit more comfortable. Good thing is it already has a speed reducer installed which slows down the sewing speed and adds torque. The oil drip pan underneath the table is missing. It has an "old school" clutch motor. Though it has a speed reducer already the clutch motor may be a little hard to control. So a new servo motor is probably what you want Just test it maybe the clutch motor setup works for you.... See attached file it will gives you some more information 211G165_166_265_266.pdf

I´m still not sure what you mean. There is no need to remove more parts from the arm and I´m sure it is not possible and not even necessary for timing. When you have the hook installed (guessing you have one incl. the parts that hold the hook in place) and the needle plate is not installed (guessing you have one) you have a clear view on the hook and hook tip and the needle sooo....

That seems to the an oil well for the clutch but not for the machine it self.

What do you mean - looks like the bobbin / hook area is open cause I can see the hook driver on picture 2. Pictures are fairly small.... what does the brass tag say? is it 65? If it is a Pfaff 65 then it is a darning machine but not a sewing machine. If the machine is like this (German language website) there is no way to convert it to a 28 cause major parts are missing. F.i. stitch length lever and the rod for driving and lifting the feed dog. But as I said the pictures are very small and do not show the details very well.

You have mixed up the machine Class and the serial number. The G on the serial number is not for Germany. But G for Germany is a suffix of the machine class f.i. 111G156, 211G141. But this only applies for machines made in Germany (in Karlsruhe) after 1954. Machines made in Germany (in Wittenberge, Prussia) until 1945 had a C prefix on the serial number and a D (but not all IIRC) as suffix of the machine class like 45D91, 96D43 and so forth. After WWII until 1954 Singer did not produce sewing machines in Germany. You can get 29K threading wires on Ebay, Amazon, Etsy, Ali Exprsss... for a few bucks Personally I never had problems with 138 thread in any 29K model. They all use the same hooks since for ever. But the size of the needle hole in your needle plate matters. Iif it is too small you may have problems using larger needle and thread sizes. But be aware that the bobbins are fairly small and do not hold much of the 138 thread.

Sorry, I doubt that. What is the serial number incl. prefix and please post pictures from front and rear.

Never have seen this before on a patcher machine. Found this pic a while ago on the web so I cannot provide more details. Seems to be custom made. I don`t think the machine came like this from the factory. Just wanted to share this.

so way way cool How about making the parts from aluminum?

Ebay is your friend - sometimes. Not cheap but he has it: https://www.ebay.de/itm/185107601974 Other than that check with LIERSCH https://liersch.com/ or Zieger https://www.np-z.com/

Singer 211 also came with large hooks depending on the subclass. I think the 666 subclass is a large hook machine.

I would still go with the Singer. I agree with cowboyBob regarding the hand wheel on the 211 (I tried this on my 212 and I had no success) but if you want to change the motor and install a new servo motor you could add a speed reducer to slow down the sewing speed and add more torque. I would check the machines if they have matching forward and reverse stitch length. I know there is a procedure how to adjust F+R stitch length for the Singer 211 and the Adler 167 but I think I have not read anywhere how to do this on a Pfaff 1245 (not saying it is not possible). If the stitch length matters for your projects I think the Adler and the Pfaff have max 6mm and the Singer 5mm.