kgg

If you mean you bought them from Vergez Blanchard as new I would have expected them to be in a lot better condition. They should have been presentable, sharp and ready to work with maybe a minor touchup on the sharpness. I would contact the Vergez Blanchard company and express my disappointment with photo's of how they arrived. kgg

I stand corrected , sorry. kgg

I would say the problem lies in your speed reduction. I am going to assume you have a 2" pulley on your motor, you increased the diameter of the hand-wheel from 4 to 6 inches and with a motor speed of 100 rpm's. 1) The original speed of the hand-wheel would have been 50 rpm's. Changing the hand-wheel to 6 inches would increase the torque and reduced the hand-wheel speed to 33.3 rpm's. 2) Installing a standard intermediate speed reducer (6" large pulley with a 2" small pulley) between the machines i) original 4" hand-wheel and the 2" motor pulley you would increase the torque and further reduce the hand-wheel speed to reduce the 17 rpm's ii) if you keep the larger size diameter hand-wheel (6") you already installed you would again increase the torque and further reduce the hand-wheel speed to reduce the 11 rpm's I think the problem of the belt slipping maybe poor sidewall contact or belt type not matching both pulley profiles. Other things could be incorrect size of hand-wheel pulley, glazed motor pulley, incorrect distance between hand-wheel and motor pulley and / or undersized motor or a bad motor. I think installing a intermediate speed reducer would probably solve your problem as long as the proper belts and pulley distances are done. When sewing are you just putting the doubled leather under the presser foot and going for it or are you hand-wheeling the needle down through both layers to let the machine have a run at it? kgg

A good place to get bobbins / needles with fast delivery is Wawak.com Leather needles: 135 x 16 (DPx16), www.wawak.com/sewing/needles/industrial-machine/schmetz-leather-industrial-machine-needles-135x16-tri-dpx16-d-10pack/#sku=smnl135118 Bobbins: metal Class 15, www.wawak.com/sewing/sewing-machine-accessories/bobbins-cases/singer-class-15-metal-bobbins-1pack/#sku=bob8 Thread size vs needle size reference chart: www.tolindsewmach.com/thread-chart.html kgg

Why not give one a try. If they work great. Not sure if you get caught you don't windup in the dog house. kgg

That's good news the machine is working. If you have a sewing / fabric shop in your area the bobbins are the same as you would use in a domestic sewing machine. kgg

Looking at your video again and it maybe the angle of the lighting but it appears that you have the groove of the needle on the Right side and the scarf on the Left. If so the needle is insert backwards. kgg

I think you need to take the bobbin thread and have it exit by the thumb size recess on the front side and slide the cover close. Then hold the end of the top thread and move the needle down holding the end of the top thread. With my machine I cheat and just thread the bobbin thread up through the hole in cover then slide the cover over. A caution is that make sure you use the correct hole in the cover as there is a different size needle hole on each end. Also a standard class 15 domestic sewing machine bobbins are really available and cheap. kgg

Like Constabulary I use the tension mounted on the side as a guide for threading my bobbins. I have not seen any video's on using a 29K for darning but all the manuals I have seen have instructions of how to thread the needle for darning using the side mounted tensioner. Anyone have a video, love to see how that works. This is a manual for the 29k-71 but if you refer to pages 9 and 10 you will see the top threading path. This is how I set up my 29k for the top and bobbin threads. kgg 29k71-2.pdf

This link to Aliexpress my help with finding odds and ends for your portable walking foot machine. The Chinese versions of the Sailrite are called 106-rp, the quality???. I just type in 106-RP in the search line: https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20221118042012&SearchText=106-RP&spm=a2g0o.productlist.1000002.0 kgg

This link to Artisan manuals may help: www.artisansew.com/manuals.html This link to the youtube video Cowboy 8020 may also help as it appears to be a similar leather splitter: www.youtube.com/watch?v=V8XSHI2X--0 kgg

If the needle striking problem disappears it will prove that those are incorrect and made maybe for a PFAFF 1245. If the original presser foot work great, if not hopefully they are also incorrect otherwise you may have problems like a bent needle bar. I would checkout the golden wheel page for their CS 335bh manuals www.golden-wheel.com/en/product/product_detail-370 kgg

The 341 class machines should be good for your bags / wallets / knife sheaths but probably not for gun holsters. Another option that you may want to consider is the 441 class machines like the Cowboy 3200 /3500 /4500, Cobra Class 3 / 4, Techsew 4100 / 5100 / 5200 with the needle plate that RockyAussie developed to be able to use them on thinner items. kgg

They are clones of the Juki LS-341 with the three more common clones on this forum being, in descending price point, are Techsew 2750 (~$2749 USD), Cowboy CB341 (~$2395 USD) and the Cobra Class 26 (~$2390 USD). The shipping cost will of course depend on how far away you are from either of them. Flattop attachments can be purchased for any of them from either the dealers or third party attachment suppliers. I would go with who you feel confident in supplying the best support, before and after the sale. The question really comes down to what you want to sew and is the 341 class clone machines the best for your items. kgg

What size of needle are you using with the V60 (T70) thread. The # 100 (#16) needle is made for sewing thin soft material with V69 but is more for V46 in thicker material. Using V69 move up to at least #19 and in thick or tough material a #21. You maybe having some needle deflection and the thread rubbing on something. Also check and see if there isn't a burr on the thread guides, presser foot or feed dog. If you haven't passed the thread through the needle guide on the needle bar just before the needle you will also get fraying. A good view of this guide hole is at 7:12 of the Sailrite video. Also the type of hardback coating as well as how thick the items being sewn are will also to be factors. These machines were design for flat sail material 1/4" thick and can struggle with fluffy stuff. This can sometimes come down to whether the fluff is towards the feed dog as it maybe catching or being compacted into the needle plate or feed dog. Sometimes this can be solved by using a thin piece of paper between the fluff and the feed dog. A good cross reference of thread size to needle size can be found at www.tolindsewmach.com/thread-chart.html kgg

The Techsew appears to be a closer clone of the Juki LS - 1342 then the Juki LS-341. It has the adjustable presser foot climber mechanism which the Juki LS-1342 and LS1342-7 have that is not available on either the Juki LS-1341 or the old Juki LS-341. The Cobra class 26 appears to be a clone of the Juki LS-341 except able to take a #25 needle and not having the adjustable presser foot climber mechanism also with a slightly smaller max sewing thickness. The Juki LS's are rated for a #24 needle and a thread size of V138 in thick material. The Juki machines specify their arm measurement as the distance from the needle to the body and their arms 255mm (10.04 inches). It is unclear as how Techsew or Leather Machine Co. measure the length of their arms, from the needle or from the end to the body of the machine?? I think the Techsew claim of being able to use V277 in a #24 needle is an error as I think a #24 needle would be good for V138 in thick material or V207 in thinner material. Something to check with Techsew. Besides the price, the question really is the climbing feature a need or a want item for you items? If not then the Juki LS-341clones would be a cheaper option like the Techsew 2750 (~$2749 USD) or the Cobra Class 26 (~$2390 USD) or the Cowboy CB341 (~$2395 USD) and of course the shipping cost will depend on how far away you are from either of them. kgg

I'd say tough love, but it maybe a gem in the rough. A good winter's project as it is a walking foot machine. kgg

To get the bobbin tension probably close enough do the drop test. A good method is shown in this video by Gymnast in his video called " How to adjust Bobbin Thread Tension of Sewing Machine " ( https://www.youtube.com/watch?v=kINRgj42GnI ) at about the 4:21 mark, he calls it the "yoyo". Once you get the bobbin tension roughly set you can concentrate on the top tension as long as you have the top thread properly threaded through the main tension disc like in the Sailrite video at 5:50. Remember the bobbin tension needs to be checked / reset every-time you change the size of thread or install a new spool of thread. Also note the stitch length will not be maintained as you increase the thickness / toughness of the material under the pressor foot, the stitch length will decrease. kgg

That video is incorrect starting at 5:50 when he threads the top thread around in an "S" pattern in the top pin (can be done this way if you need addition top thread tension) then he continues with another mistake by going under the tension disc before going through the twisted part of that guide. The tension disc is only used when you are winding a bobbin. I stopped viewing the video stopped at this point. The best video to view are the ones made by Sailrite. An example would be Start Sewing with your New Ultrafeed Sewing Machine https://www.youtube.com/watch?v=c_TC4bztXVo&list=PLAbM539i4biWOFtdRlX6JE0F_Y9uLPO-z&index=3 even thought this is for the LSZ-1 they are threaded the same. Your guide that you have just before the main tension disc is incorrect and should be turned 90 degrees towards the head. The top thread needs to be pulled up above the little thread guide in the tension disc just above the thread spring. kgg

Yes. I do like how you also included the drop test at about 4:21 in the video which you called the "yoyo". Since most people don't use a gauge for measuring tension knowing how to do the drop test can be very helpful starting point. I can only imagine some of the tensions you would measure using a non brand thread. kgg

That is good price as it does look like it's in good cosmetic shape with a nice table setup from the photo. No, it is a clutch motor with a box of tricks and needle positioner. For a servo motor check out Japan Sewing Machine & Supply Co. (146 West Beaver Creek Road, Unit 5, Richmond Hill, Ontario, Canada L4B 1C2. Tel: (905) 764-0100 ). If you want to keep the needle positioner ability I know they carry a 1 HP brushless servo motor with a needle positioner. I don't know if their 1HP will work if you decide to put a speed reducer on. For now you could put a brushed servo motor on, 550 watt or 750 watt, with or without a speed reducer. I use their 550 watt brushed servo motors on all my machines as they are nice simple motors with no electronics. kgg

For my limited needs I use just your regular old LePage Heavy Duty Contact Cement. kgg

My understanding is a skiving machine will do a nice job on veg tan but not on chrome tan leather. So if most of your leather chrome tan I would suggest other methods. kgg

The instructions are good basic instructions. When doing the bobbin tension as the method shown in the video their method is a good starting point but the drop test will provide a better method or you could use a bobbin thread tension gauge to be even more accurate. To check the top thread tension a top thread tension gauge can also be used to adjust / set the top tensioner. In the end it is really going to come down to what and how thick/tough a material/leather you are trying to sew and choosing the right thread needle combination. kgg

Once you get the other photo's sized down please post so we can see the full thread path. We maybe able to offer some more suggestions. What I see so far in the photo: i) The top thread needs go in the top hole of the pin as you have done but it also needs to wrap around the pin and come out of the bottom hole so as to make a "S" shaped wrap around on the pin. This will help in getting the coils out of the thread and add a very slight top thread tension. It appears you are using a 8oz spool of white polyester thread and I assume the little 4 oz spool on the top cover is your N66 bonded nylon. ii) Are you trying to use the little 4 oz spool of thread on the top of the machine or are you replacing the white polyester thread with the black N66 bonded nylon? iii) The base of the top thread spool needs to be better secured so as not to move around on the table from machine vibration or accidental bumping of the spool. The center of the thread spool should be directly under the thread support arm. As the amount of thread on the spool reduces the easier it is for it to wander off and explore the floor. kgg