Constabulary

You say the thread is resin coated. I have not worked with this type of thread but maybe it needs a certain lubrication. To eliminate a thread issue I´d try an uncoated polyester thread instead just to make sure that THIS spool of thread is not causing the issues. I know you have to use this thread because of certain specs but maybe you have just a spool of poor thread. Sewing machines sometime act different with certain threads. F.I. I wanted to use a pure cotton threads on my DVSG / BUSMC #6 and by the lord it did not form a loop and I have no clue why. I tried different tensions and needles but no change. Then switched to a Polyester thread and it sews like a dream right away. I still want to use the cotton thread but cannot see where the problem is. Sounds stupid but thats how it is. When your machine came from a dealer tell him to setup the machine for the material and thread you want to use.

Depends on the thickness you have to sew and the thread size. I´d at least look for a machine with a wide feed dog like the 20U you mentioned. Another option would an older Singer 140W, Dürkopp 252, Singer 307G2, Singer 457. Or a double needle Zig Zag like the Singer 167W. For something real heavy look for an Adler 166, 266 or the like. Or maybe the Tech Sew website will give you some ideas: http://www.techsew.com/machinery/industrial-sewing-machines/regular-stitch-and-zig-zag.html?limit=all

How it the thread coming off the thread spool? Is it a X-wound cone of straight wound spool? Sometime thread keeps hanging when the thread is not coming off the spool properly . The thread guide arm of the thread stand should be straight above the spool. I´d also leave out the wax pot when you do not sew with waxed / oiled thread. At least worth giving it a try.

What a beast! Congratulations! I guess big oil holes means it needs lots of oil

I don´t know the Class 7 machines but can you try to adjust the needle bar hight or is the needle bar pinned? I would guess you have to lover the needle bar a little bit.

I´m using a Singer 307G2 and a Singer 111G156 in the same table cut out so I bet the 111, 206 and 563 will fit - the Pfaff for sure has a longer flat bed. If I had to choose a machine I´d take the Juki 563

If the parts number is the same it will most likely fit! I have a used original Singer main shaft #82010, always wanted to replace the shaft on my 29K71 but don´t have the time an patience atm. The shaft on my 29K71 is cosmetically not very nice but works w/o problem so I don´t necessarily have to replace it. if you are interested send me a PM and we can talk.

The combination of a speed reducer and servo motor is the best you can do. You can sew slow and have more torque. No it will not sew reverse as the hook will tun in the opposite direction and can not catch the thread loop. This amchine is entirely not setup for sewing reverse - you HAVE to turn around the material to back stitc

Very nice! Is that the original manual on the last picture? Green book seems to be a parts list for Singer, right? What model is it for? Seems even the roller edge guide is included. Right, the bobbin winder the "tub" with lid is missing. Check if is is somewhere around when you pick up the machine. I have restored a DVSG / BUSMC #6 last year (though still not completely finished). In this thread you see the tub: I guess you have to disassemble the machine. However, the heaviest part it the stand with the monster flywheel. I´d also be interested in seeing detailed pictures of the flat bed attachment

NICE! I would like to see some detailed pictures if you don´t mind.

I´m pretty sure they are using the the standard Singer 111 type feet. They are available almost everywhere - Ebay, known dealer.s...

This one once came from Keystonesewing JukiLU-562-3Owners.pdf

The AT335 and other Pfaff 335 clones are mainly used as binding machines, most of the time these machines are setup like this. Meaning they have throat plates, feed dogs, presser feet and other attachments especially for binding operations. You can convert them but if the parts are not included it may cost you some extra $. However, you can use them with the existing parts as a regulars sewing machine as well but he binder throat plate is not entirely flat, they have a cut out on the right side where the binder attachment extents into the throat plate. Also, the 335 type machines are vertical hook sewing machines (you load them from the left side) whereas the 227 type machines like the CB227 are horizontal hook machine (you load them from the top). As far as I know the 227 type machines can handle thicker thread better that the 335 type machines. Guess you are living in the US, right? I ask because I recently have seen and unbelievable cheap offer for 335 machines in Germany. https://www.ebay-kleinanzeigen.de/s-anzeige/freiarm-leder-naehmaschine-mit-3-transportes-mit-ac-550w-motor/519759576-84-7526

Why not - we even have a computer problem section here. We already talked about other sewing machines earlier. As far as I know the German models all have a D in the model number when made prior 1945 and a G when produced from the 1950´s onwards but I´m not much into domestic or semi industrial Singers so there may be exceptions. Still think it is Japanese but not 100% sure.

A cam attachment? I think you mean the foot lift lever on the backside, right? When I look at the machines the only thing that the 807 could have in common with the 217 is the zigzag dial but thats in a different position. The Bernina 217 also is longer. I´d guess the Singer 807 is made in Japan but have no proof - just a guess.The "diarrhea colored" outer is something one has to like but I find it quite ugly. I´d rather look for a Pfaff 230 or the like because you have a better chance for finding parts accessories and manuals. But that does not mean that the 807 is a bad machine as long as it meets your requirements.

If you think the parts are tooo expensive - well you have a Pfaff machine! OEM Pfaff parts are generally more expensive. The machine seems to be not wide spread and so there is no big demand for parts meaning parts are more expensive. If you want cheap parts buy a Singer 111 based machine and you can get parts dirt cheap.

Offensive prices? Too cheap or too expensive?

Check the College Sewnig Website in GB. They ship worldwide and have a section for 1445 parts - they have lots of feet https://www.college-sewing.co.uk/store/Pfaff1445SewingMachineParts

Singer 107 parts are available at College Sewing UK they ship world wide and take Paypal and CC. I´m buying 95% of my parts from them https://www.college-sewing.co.uk/store/Singer107G,107WSewingMachineParts Or Ebay: http://www.ebay.com/sch/Crafts/14339/i.html?_from=R40&_oac=1&_nkw=singer+107

I have linked a HSH-1-1 hook regarding their parts number so I guess the picture is wrong.

Ha - that's the same servo I had before (the 2nd servo I tried actually) - this annoying beeeeeep sound was a pain - I could not stand it.

As I said earlier, I have a CLAES manual in German language. Send me a PN if you are interested. We once collected some pictures of patcher machines in this thread

Pfaff sold machines of other brands (like Adler 5, Class 30...) under PFAFF INDUSTRUIA. I think I somewhere have seen a Adler Class 20 branded with PFAFF INDUSTRIA and I think they also build custom machines, maybe some of them needed 794 needles. Or maybe they just wanted to fill a gap in their needle range.

I have no such machine but a manual in German language of a Claes patcher which is very close to yours. File is too big to attach here and when I reduce the size the file it is of poor quality so if you are interested send me a PM

Just figured there were SV´s in 1913. Copied from ISMCS list: F- 3705085 3706084 46KSV24 1000 January/June 1913 Clydebank, Scotland So I think Singer always had SV´s of certain machines. Also found on needlebar.org http://needlebar.org/cm/displayimage.php?pid=7758 Note the "formerly known as..." So former SV´s machines became later standard machines. Maybe that was not always the case but at least some times.