kgg

This formula can very misleading as it was develop mostly for fabric and indicates that by increasing the number of stitches per inch increases the seam strength it leaves out the practical factor before you damage / weaken the material, fabric or leather. As a note the strength factor would be 1.7 if you were using a Chainstitch machine. Using the formula in that article for Lockstitch machines: i) 6 stitches per inch x V92 having a breaking strength of 14.5 lbs x the strength factor= 130 lbs / inch ii) 20 stitches per inch x V92 having a breaking strength of 14.5 lbs x the strength factor= 435 lbs / inch The stitches per inch is stitch density and for leather it is recommend the stitch density should not be more then 3 to 4 per cm which converts to 6.35 - 8.46 stitches per inch. The reference article for this is Schmetz, Sewing Focus Technical Sewing Information -- Section 3.3 ( https://www.schmetz.com/mm/media/zh/web/7_tochtergesellschaften/bilder_18/schmetz/pdfs_4/sewing_focus/SewingFocus_20_3075-22_Lederbekleidung_D.pdf ) kgg

In Canada a major consideration is that with customer 3 phase service drops is the billing. A lot of companies charge the customer on their 3 phase peak so they pay that demand for the whole year even if their peak is never again reached throughout the year. So for the small or individual customer 3 phase is not a viable option from a cost point of view let along trying to contend with typical 3 phase voltages, 4.16 kv, 12.47 kv and 25 kv. In Canada distribution is similar except that a 3 phase trunk feeder with small 4.16 kv, 12.47 kv and 25 kv will have a ground wire travelling along with the phase conductors from the electrical substation. Single phase taps necessary to feed single phase customers like small business and housing subdivisions a phase and ground are tapped along the 3 phase trunk feeder route. The single phase voltage is then further to reduced to 120v / 240 volts at 60 hz by either pole mounted or pad mounted transformers. Large customers are usually feed at line voltage ( 4.16 kv, 12.47 kv and 25 kv). kgg

I guess it depends on how large the bag is and how much stuff it will be loaded with as well as your stitch length. It comes to a point where if your stitches per inch are to small the seam will act like a perforated paper tear off strip like you see with a cheque book. As a comparison the V69 you used to attach the handle has a breaking strength of 11 lbs and is about 0.012 thick versus the 6mm thread you are use to having a diameter of 6mm and a breaking strength of about 50+ lbs. If you want to use thinner thread as V69 is really in my opinion a domestic size thread. Typically the domestic sewers refer to that size, V69, as heavy duty as it is the largest size most domestic sewing machines can take. I would move up to V92 with a breaking strength of 14.5 lbs and probably a stitch length of 6 stitches per inch. As a note: i) B69 is basically the same as V69, Tex 70, M40, Tkt 40, D236/3 just a different designation standards. In North America the two typical standard ways of referring to a thread size is either by the US designation, " V " and in Canada the metric " M " and the US " V " designation. ii) The Consew 206RB-3 uses system 135 x 17 x (needle size) needles for fabric and 135 x 16 x (needle size) needles for leather. When sewing leather use the 135 x 16 x (needle size) appropriate for the size of thread. Here is a good cross reference chart for thread size and the corresponding needle size that should be used. ( https://www.tolindsewmach.com/thread-chart.html ) kgg

I make my belt with two layers of 6.5 oz glued back to back and stitched with V138 on the edge. I like a heavier belt and it holds it's shape better. Also looking at your photo's I noticed the wriggling starts at the holes you wear the belt at. The holes you punched are round rather then oblong but the holes will sorta go oblong which maybe contributing to the wriggles which are I think caused by the leather stretching. Also doing a stitch line about 3 or 4 mm in from the edge will help the leather from stretching. kgg

In North America the standard residential / small business electrical service is single phase 120 / 240 volts at 60 Hz on a 200 Amp service drop. There are smaller older service drops, old 60 Amp, 100Amp but typically 200 Amp is the norm. Over 200 Amp service drops do require a different metering installation but in rural areas a single phase 300 Amp service drop like mine is not that uncommon particularly if there are other out buildings like barns / garages on the property. Most commercial applications, at least in Canada, will have three phase service drops but usually peel off 120 Volts for small motor usage like what is used with sewing machines. kgg

On my cylinder arm I use a my flatbed attachment then use a edge guide. I prefer a standard bolt down type edge guide rather then the drop down style. The edge guide gives me a consistent stitching distance from the edge. kgg

Typically top tension issue. This also crops up when using dull, incorrect needle size, thickness of leather, worn hook, incorrect tension on bobbin tensioner spring. The correct needle for leather in the Sailrite is a 135 x 16, the max thread size is V92, the max needle size is #22 and the max thickness is about 1/4" in chrome tan leather. Are you doing a drop test on your bobbin / bobbin case to get the tension correct. Keep in mind these machines were designed for sewing sail cloth on the open water. What needle are you using??? What thread size you are using??? What type of leather and in what thickness??? kgg

Keep in mind that the strength of the stitch will be of the smaller thread size where V138 has a breaking strength of approximately 22 lbs and V92 has a breaking strength of approximately 14.5 lbs so the stitch strength would be limited to 14.5 lbs. Most times I think this is done for top stitch appearance. kgg

I agree with @dikman there are just to many possible machines available from brand name machines to clones in both flatbed and cylinder bed configurations then add to that the class of machine capabilities. To further muddy the waters it also depends on where you live with Europe being more accustomed with machines like PFAFF and Adler type machines while North America tend towards the Juki type machines. If you find a machine just post and I'm sure someone can give you an idea as to it's capabilities. kgg

Your clutch motor is probably a 1 hp (745 watts) and with a typical speed of 1750 rpm. That motor on startup could have a inrush current draw of 6 times that of normal current draw (~6amps) on initial startup. Anytime you reduce the input voltage on a motor the motor will run hotter and it will draw more current in order to keep it's wattage rating until it blows the motors inline fuse or circuit breaker in the main electrical panel. My opinion is that you have done almost all the normal mods except for reducing the size of the pulley on the motor. However until you master feathering the clutch you got what you got or until you install a servo motor which will set you back about $150 USD.

I missed or skipped over that point and I do agree with @fredk. If you want to almost eliminate aggravating your arthritis you are going to need a motorized machine. The Juki LS-1341 and older LS-341 as well as their clones will handle up to 7/16" of material with V138 thread and if you need / want to sew thicker or use heavier thread close to what is normally used when hand stitching then you are into a Class 441 machine. A couple of 441 clone machines that you might want to consider would be similar to the Cowboy CB 3200, CB 3500. It really comes down to what you normally sew, what thread thickness you want to use and how thick your pocket book is. kgg

The problem with buying used is like buying a used car, you have to be careful. My rules of thumb when buying a used machine for myself: i) is it has to be in impeccable condition or as close to new condition, ii) not have been used in an industrial setting iii) the price is 70 percent, max. of what a new one lists for. Example: The Boss you mentioned for $850. A new Boss is $999 x .70% = $699.30. The max price I would pay would be $700. Yes those machines use the 794 needles. A typical 135 x16 needle used in the Juki LS-341 has a shank diameter of 2.0 mm while the 794 has a diameter of 2.5 mm. As a note a 2 1/2 " finishing nail has a shank diameter of 0.099" or 2.51 mm. kgg

A few photo's would be helpful in showing the overall condition of the machine, asking price and most importantly what you want to sew. My main concern is the parts and accessories for the PFAFF machines can be expensive. Unless you are use to using a sewing machine with a clutch motor you need to add to the selling price somewhere between $150 and $200 for a servo motor to get controllable speed control. kgg

It would be if nothing else the little road trip to see if the machine would work for your needs and the owner my drop her price once you arrive. I still would wonder whether the cost saving of $150 USD would be worth the no warranty and no extras versus a new machine with warranty???? kgg

A new Boss is $999 USD plus shipping plus any accessories. Does the machine come with anything extras? The 341 has probably been used and abused in a factory setting and is old. There are no photo's showing the drive belt or the internal head parts or what parts were replaced. Also there has been a lot of machines imported from overseas. IMO I would stay away from the 341 and would consider the Boss but that may not be the machine for your purses as the hole the needle will make is going to be very large. Think of the size a 2 1/2" finishing nail will make. I would take a sample of your stuff and test out the Boss. Keep in mind the Boss will be better suited more for doing sheaths and holsters then purses. kgg

It really doesn't matter on how long the rivet shank is. The shanks are all the same diameter for a given rivet size whether they are 1/4" or 1 1/2" long. Procedure normally in a nut shell is punch the appropriate size hole in the leather, put rivet through, put burr over the shank and with a the correct size rivet setter set the burr down over the shank to the leather, cut the rivet off slightly above the burr and then dome the rivet shank with the rivet setter doming part. kgg

Just to add to @AlZilla comments. when you stop to do a 90 degree turn: i) bury the needle to the bottom and then raise the needle about 1/4" ii) raise the presser foot up slight to take the tension off the material and the turn the leather. iii) drop the presser foot back down and continue. Some of your problems are probably being cause by not holding the threads for the first three stitches and then back stitching to your starting stitch that will lock the so the threads don't get pulled. I am going to assume you meant 135 x 16 needle not 136 x 16. For V138 thread the range is #22 to 24 depending on the thickness and type of leather. Veg tan I find grabs the thread more then chrome tan. Here is a link to a good thread size vs needle size chart ( https://www.tolindsewmach.com/thread-chart.html ) Looking at your photos the leather looks very thin which means there is very little thickness to constantly bury / hide the bottom knot in. I would suggest: i) you try again with either thicker leather or a few layers of thin leather to give the needed space to burying the knot. ii) you lock the starting stitches. kgg

Just watched this youtube video about you make those fancy very expensive ladies bags and thought it might be of some interest. Is it true or misinformation I don't know but it does make one wonder. kgg

Basically sanding the edges of leather sorta like those various shapes of sanding / honing cones used on dremel machines but on a lot larger scale. kgg

Nicely done on the 3D printed template forms. My suggestions: On the 3D printed templates. 1) Increase the nozzle end temperature and filament compression. 2) At your direction changes in the template "Cutting" and "Marking" templates at the four corners do a 0.25 mm fillet so the filament is laid down as a radial turn rather then a 90 degree turn. That way the head speed doesn't have to slow down as much to make the turn which will decrease your print time. 3) I would change the "Cutting" and "Marking" from being indented to being raised markings which would decrease your print time. 4) If the bed of the 3D printer is to small to allow you to print say the "Cutting" and "Marking" template as one unit change you design slightly by putting in joining slots or shapes. I would try: 1) cutting the ends of the sandpaper so they join together at say a 45 degree angle. 2) Then super gluing some thin 1" nylon binding tape to the back side of the sand paper so 1/2" is glued to each end. Then the other end is butt ended to the first part and supper glued to the other side of the 1/2" binding tape. That should eliminate the overlap ridge / bump and as it rotates you don't have the whole joining edge of the joint striking the leather at the same time. It may or may not work but maybe worth a try. kgg

Probably because China is such a large market. I know they make the Juki DU-1181n walking foot machine in China. I have one and it is NOT of the same quality as my Juki DNU-1541S made in Japan. kgg

The Juki DSC-246 is made in Japan. Also if you zoom in the nameplate indicates it was made in Japan. kgg

You also might want to check wawak.com for needles 135x16 x size 16 needles ( https://www.wawak.com/sewing/sewing-needles/industrial-sewing-machine-needles/schmetz-leather-industrial-machine-needles-135x16-tri-dpx16-d-10pack/#sku=smnl135116 ). I would not advise you to use a thread larger then V69 with #16 needle. My personal option on the Vinymo thread is yes it can be used in sewing machines but really is meant for those with Class 441 machines like the Juki TSC441 as well as the clones like the Cobra Class 4 and the Cowboy 4500 or the one arm bandits like the Cowboy Outlaw or Tippman Boss to name a few. kgg

What I would do is vacuum the machine with a throated down (1/2") shop vac, wipe the exterior of the machine of with a damp cloth, inspect the internals and if you think there is sand in the internals I would then do a couple of complete flushes of the machine with diesel and then with synthetic transmission oil then wipe dry and oil everything. kgg

From their website ( https://artisansew.com/cylinderarmandpostbedmachine.html ) " Fabrics: 135 x 17 Size(14 to 23). Leather: 135 x 16 TRI Size(14 to 23) " Using undersized needles for your thread my cause problems depending on the thickness and toughness of the leather as the hole the needle makes has to allow for not only the top thread but the twice the thickness of the bobbin thread. If the material is sticky or the needle hole is to small you can get skipped stitches. Here is a good cross reference of recommended needle sizes for various thread sizes. ( https://www.tolindsewmach.com/thread-chart.html ). According to this website ( https://districtleathersupply.com/products/vinymo-mbt-size-5-0-6mm-polyester-thread-full-spool ): Sizing Size 8: Comparable to machine thread size 92 Size 5: Slightly thicker than machine thread size 138 Size 1: Slightly thinner than machine thread size 207 #8 - 0.5mm #5 - 0.6mm #1 - .75mm #0 - 1.00mm When you compare those thread generally accepted thread dimensions to the chart I referenced something is way off. I would strongly suggest contacting both Artisan as the 246 appears to be rated for up to V138 thread and the manufacturer of the thread ( https://nagai--yoriito-com.translate.goog/eng/pages/13/?_x_tr_sl=ja&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=sc ) or the US distributor ( www.districtleathersupply.com ) V92 - 0.337mm V138 - 0.414mm V207 - 0.508mm V277 - 0.586mm Also here is a pretty good review of the Vinymo thread from a previous discussion in 2022. kgg