reconic Report post Posted November 5, 2015 Hello, I have a question in regards to understanding how sewing machine specifications translate to what I actually need the machine for. The machine I am looking at is a Singer 20u73 zigzag. The first question I have is about the needle and thread size range. In the manual (linked below), page 3, shows a chart on what needles the machine can take. With this information in mind I look at the chart found from the thread "Needles And Threads" from this forum (chart linked below). So to me, it looks like the needles range from, 10-19, which I can only assume is the Singer needle number. Now I look to the chart, and the range of thread this machine can handle is Tex (I'm assuming Tex) size, 12-92? - Anyone who understands what these numbers mean can probably see I am stuggling to understand what I am looking at. I have been trying to understand needle sizes and thread sizes for months now. I just can't seem to grasp needle sizes to the appropriate thread sizes, then how that looks in real life. If anyone can help me to understand how to read these numbers and get a unquestable answer I would be greatful. Manual, http://parts.singerco.com/IPinstManuals/20U73_73B_83_83B.pdf Needle and Thread Chart, http://raphaelsewing.com/blogimg/techsew_ndl_thread_chart.pdf - The second question I have about this machine is about what it can sew through. I sew with denim to make jeans. One of the reasons I wanted to look into this machine was because I could make a version of a bartack (and it was in my price range, I found a good deal locally 500ish). I need this to make a bartack on the belt loops. So that means dense material folded, so all in all going through about 8ish layers of denim. How can I tell from looking at the specifications of this machine if it can do this successfully and repeatedly, or not. I have searched many articles/forums on google, watched every youtube video I could find of this machine and no one has shown an example of what this machine can do. Basically all I have seen is this machine going through a piece of thin leather and a double stack of thin apparel material, which tells me absolutely nothing to what the limit of this machine is. - I hope someone out there can shed some light on my problem. Thank you for your time, Quote Share this post Link to post Share on other sites
SARK9 Report post Posted November 5, 2015 I have a 20U33, a gold painted one, still made in Japan, which I bought in like-new condition. I don't think I've had occasion to sew with T-90 thread on it as yet...I almost exclusively use T-70, with a number 18 needle. The way mine behaves, I am a bit dubious about your prospects with folded-over belt loops in jeans material. This is a plain single needle bottom-feed-only machine, and is pretty fussy about the initial feeding of material just under the leading edge of the hinged presser foot. To use the ZZ function for a bar tack, you'll have to install the ZZ needle plate, feed dogs and presser foot, which pretty much will make an issue with visibility on something as narrow as a belt loop. I mostly use mine for hemming 2 to 4 layers of 1000D Cordura fabric, which it does well pretty well, but even using the T-70 thread, its a bit snarky about tensioning the upper thread consistently. You may find them a little hit-or-miss if asked to punch through really hard layers of folded fabric, since the design of this machine is essentially a slightly more robust version of the domestic type home machine, with the same "stop motion washer" bobbin winding release on the handwheel, which *will slip* if asked to get too serious. I'd consider it quite a gamble for your application, though mine may just be an oddball. I suppose you could take some samples of your item with you and see if the seller can demo it? Take several to set up with. -DC Quote Share this post Link to post Share on other sites
gottaknow Report post Posted November 5, 2015 I would not use that machine to set belt loops on jeans. It will have a short life. You'd be better off using a regular lockstitch machine with a reverse and going back and forth numerous times. A machine like a Singer 211W157 is a needle feed and easily sews through 8 layers of denim. It also has a reverse and takes the longer 135x17 needle. The machines can be found for a few hundred dollars. Levi's are sewn with a variety of thread sizes, anywhere from T60 on the loopers of chainstitch machines up to T105 depending on the style. A 211 will handle the T105 just fine. The thread is polyester core, cotton wrap which is a very common apparel thread. Have fun! Regards, Eriic Quote Share this post Link to post Share on other sites
