kgg

You need to increase the speed slightly so the sanding drum acts like a sleeve drum. The rougher the grid the faster the drum needs to spin or it can feel like you are hooking / tearing the material rather then sanding. Just my experience. kgg

Another rivet option maybe to use copper or steel rivets and cover the backside as fredk suggested or use chicago screws with locktight . That way there is less of a rivet head protruding into the clip area. kgg

I haven't had any problems with the Kobe LS-1341 machine. In this class maybe another one too consider would be the Cowboy CB341. kgg

Yes I do have a clone LS-1341. I went to actually pickup a Juki LS-1341 and I said I'll give the Kobe a try. The dealer sells both the Juki line of machines and his branded clones. Compared to other clones in this class it's a pretty good machine and I find the dealer to be excellent to deal with. Most of the clones in this class are in reality clones of the older Juki LS-341. When I am searching for another new machine I set a 4 hour (one way) travel distance. New machines whether brand name or clone aren't cheap so I think you really should at least have some hands on before buying if at all possible. Before I bought my Juki DNU-1541S I thought I had found a nice clone machine with decent machine reviews. So cash in hand I drove about an hour to that dealer / repair shop and gave it a run. The thing sounded like a bucket of bolts banging around in a 5 gallon metal bucket. Shortly after I drove 3 1/2 hours and bought the Juki. Don't be apprehensive about industrial sewing machines this day and age with the servo motor they are quieter and more energy efficient then the old clutch motor driven machines. They are even easier to operate / control then the small foot pedal operated machines like what the old domestic Singers had or the portable walking foot machines. kgg

I do like the Juki machines and yes they are expensive but they are easier to sell and command a higher resale value while parts and accessories are readily available. They are usually the ones that the clones are copied after and the quality is excellent. I like to get my machines shall we say fresh off the boat and the Juki's right out of the box are ready to work. They have the engineering and quality controls in place right down to proper operating and engineering manuals unlike some clones where instructions are to say the least needing or they refer you to a Juki manual. Since this is going to be your main machine buy the best you can afford and invest in a table top attachment if you decide on a cylinder bed machine for things that are better done normally on a flatbed machine. If most of items you are sewing are better done on flatbed get a new flatbed and pickup a good used cylinder bed for the occasions you need a cylinder bed machine or vise versa. Since this is going to be expensive I would take a sample of the thickest material including seams along with the max thread size that you are going to sew and visit a couple of dealers, clone or brand name. Some clones rate there machine thread capacity by what is the largest needle that can be inserted while Juki actually underrates their max thread capacity so it will take the max size thread in both the top thread and in the bobbin in thick stuff. kgg

The motor moves as well as the drive belt and handwheel. I am going to assume the set screws in the handwheel weren't tighten so the handwheel is slipping on the main shaft. So I would check that first. kgg

If you can afford a Juki LS 1341 cut to the chase and buy one. The PFAFF 335 will have limited attachments available, limit your thread size to maybe V92 as well as parts will be more expensive then a Juki or clone. If you decide on a clone machine choose a dealer that you think will supply the best service. kgg

This is what I done which may give you some ideas: kgg

Any software or hardware upgrade is always a royal pain. I just had to change out my C drive and even with a image of the old C drive it was a pain as I also decided to increase the systems memory as well. It's the little things that will get you every time. kgg

I just used my software and doing this using circles gives excellent transition from the vertical lines but using the arc feature can be a problem without using a horizontal guide line to remove a very slight bulge just above the vertical line. I have seen this type of thing occur with my 3 D printers and too solve the problem the printer software needed some tweaking before it gave a nice smooth transition. kgg

It appears that you are doing the arc from the vertical line to the tip of the arc. Have you tried creating the arc from the tip to the vertical line. I don't use your software but use Fusion 360 which is similar. What I would suggest try is to draw a horizontal line halfway between the top of the vertical lines and where the tip of the arc is going to be so as to keep the bend of the arc on the same horizontal line. This also maybe a cause by the laser not being tweaked as good as it needs to be. Just a thought. kgg

Are you sure it is mildew, not mold or a combination of both?? Mold is usually stronger smelling while mildew smells more musky. If it is mildew which grows on the surface and you maybe able to clean it off if it was caught in time but if it is deep within the fibers it is probably mold. My opinion is whether it is mildew or mold get rid of it both can cause health issues. kgg

As Quade said a 550 watt is the smallest size but should be quite capable of doing the work. The first one noted is of a 550 watt brush type servo motors. The second one referenced is a brushless servo motor with electronic controls. Like dikman suggested to get more stitch by stitch control adding a speed reducer or increasing the size of the handwheel is the way to go. I don't use the brushless electronic controlled servo motors as I like to keep my machines a little more basic, hit the go pedal and the machine runs. Motor will not run change the brush's. The electronics for the motor just adds another layer of complexity of trouble shooting when things go south. Depending on what country your in the brush type servo motors may or may not be as expensive or readily available as the brushless electronic controlled servo motors. kgg

I am probably an odd one as I only use synthetic oil in all my machines, new or old. An example is a Singer 29k-71 (1998) that I did own that also had a helper domestic motor installed before being originally sold by Landis. I did do a short video on how it sounded and the ease at which the machine could be hand cranked. https://odysee.com/@SingerSewing:0/singer:a kgg

This maybe not the ideal machine to start out with but for $40 dollars I can't see how you could go wrong buying it. At some point you will find a need for a patcher. These are pretty versatile machines as they can be can be mounted to any flat table surface and hand cranked or mounted to a proper treadle base. Some of these machine were even driven with a domestic style motor mounted to the rear of the base. kgg

I wouldn't get rid of it. If you want or need a different machine and it is taking up valuable space I would grease the Singer up and break down the treadle so you can properly store it. kgg

I would try either a light soaking of the screw with a couple drops of diesel or some synthetic oil for a day or so and then hit the screw with some heat in a safe place. When you have heated the head I would give the screw a couple of light taps with a hammer before trying to turn the screw. I wouldn't be too aggressive as you may shear the head off. If you can get a turn, even a quarter of a turn let it cool then reapply a couple drops of diesel or some synthetic oil again for a day or so. There is probably a proper wrench but as a suggestion if a coin fits in the slot of the screw head I would cut or grind down the coin down too get the most metal into the slot of the screw head and then clamp the coin in a pair of vise grips. Since the handwheel is wobbling I would like Constabulary think it would be best to replace the bent shaft rather then trying to re-straight it once you get the handwheel off. Also check the body for cracks or fractures as a result of the impact that cause the problem. kgg

Since you are in California maybe check out some places like Altas Levy (Atlaslevy.com) or the Cobra Class 4 machine from Leather Machine Company ( leathermachineco.com ). They should be fairly close to you and you could drop by with some of your items and test drive some machines. kgg

The 441 class machines like the Juki TSC-441, Cobra Class 4 or the Cowboy 4500 are designed for sewing heavier items but I think you will need a second machine like a Juki DNU-1541S in a flatbed or a Juki LS-1341 cylinder bed with a flatbed attachment or their clones to cover off your bases for the lighter weight items you listed. No one machine will do everything. If you are mostly going to do really thick stuff get a new class 441 machine and a second hand upholstery class machine and set them up to a particular task or vice versa. kgg

I do agree as I have at auction got good deals and recently got some really nice (600 sq ft of 6-8 oz) leather in approximately 25 square ft hides for 0.70 cad (0.51 cents usd) per square foot as the business owner had recently died. Buys are out there but you need to be cautious. kgg

From you photo's I would say a old long arm Alder 30-1. kgg

I would be very wary. There are a lot of scams around and there was a similar one a couple or so years back regarding sewing equipment. There seems to be a lot of questions that need to be answered. Who referred you, who is he, where is he located, the list goes on and on. If it sounds to good to be true it probably isn't. kgg

All lot is going to depend on i) design / splicing software ii) the quality / type of filament iii) the quality of printer iv) nozzle size v) whether it has a heated bed and most importantly vi) your budget. I use Prusa printers and find them to be really excellent machines. kgg

Why not go to a few tannery's, I'm sure there must be some in Turkey. They would be able to show you leather of various qualities and any defects that occur throughout the tanning process. kgg

Merry Christmas to everyone everywhere. Preparing for the Grinch Storm here in Ontario. Stay Safe. kgg