Help with my Singer 15-91, there are many like it, this one is mine.
 

I am brand spanking new to the sewing world in every way. I have my first ever sewing machine, and it's a Singer 15-91. I've managed to learn how to thread it and hem a pair of work pants, which is a huge accomplishment. I'm still trying to find the sweet spots for my settings, and how to get the machine tensioned right so my stitches are tight and right.

I noticed my underside stitches are longer than the top, and are loose, in some places they are not even really a stitch like the machine stopped stitching at the rate I set it for for a second or so.

Well, anyway, I'm so new. I want to eventually use my machine to make shoe uppers. First I must learn to sew! long ways to go for me. Hope I can meet some really smart nice people here that would like to help me. I'll be happy to share my projects and progress with learning to sew with everyone. chao for now!

The best suggestion I can make for you at this point...take at least 2 layers of fabric of the type you are planning to use for your projects. Say about 12" square. Sew some straight seams the length of your piece. In each case, mark where you have your tension setting. Only adjust your tension a bit at a time; make a test seam with a pen/marker; repeat for each setting. If you are ultimately looking to do projects with multiple layers, follow the same process with that number of layers. This will give you an idea of what settings you need for different projects. Also note the type/weight thread you have used for each as well as needle size.

There are some great discussions here regarding thread weights/needle sizes. If you do an advanced search on 'thread weight'; 'needle chart' that might give you some helpful information.

Go up and google for 15-91. You can get a free manual to print. If you don't have a printer, sit and read it over and over. Bookmark it for your reading .

In addition I would mention to match needle size and thread weight (thickness) correctly. Since you are hemming jeans you might be using top stitch thread, I suggest upping the the neede size to 18 (110) right away.

Double check for needle insterted correct way, if it's not it will mess up the stitching. Loops under the fabrics generally means you need to tighten the upper tensioner; loops on top means you need to loosen upper tensioner.

That said, you might have to set bobbin tension for the thread you use, but often you can get by with adjusting upper tension to get a balanced stitch.

If the machine is new to you, remember to cleand and oil it, take off faceplate, throad plate, round plate in the back, bobbin case clean out any dust and lint you might find. Detect all oil points and give them a drop or two.

Thanks for all your replies!!
 

Thank you so much. Such a breath of fresh air getting these replies so fast. I've pretty much been on my own with my 15-91 since I purchased it off ebay. Initially when I got my 15-91 it powered up, but the needle would not move. This Singer was an estate find, and then my find on eBay. I had it shipped to my door all for 120.00 and I thought I did pretty good. It came with everything original, with the Singer electric foot pedal, and nothing looked to need rewiring. I knew so little I actually thought the motor was bad, but come to find it was just the whole machine was parched everywhere.

I ordered up some vintage Singer oil and Motor Lubricant, and tried my best to put the oil in all the little holes and, yes, I did download a singer manual and gave it a once over skim to see how to lube it up. Basically, I got it going again with just oil. The way I applied the motor lubricant is questionable.

I found the two oversized screws and removed them to access the cylindrical ports where the motor lube is to go in. I clumsily squished about a 1/4 tube of the motor lube in each port, but I don't see how it's supposed to lubricate anything or go anywhere. The motor lube is like a vasoline consistency, but I figured whatever, I followed the instructions and I used the right stuff so far as I know. I removed the wheel (pardon my not being hip with the sewing machine lingo) and used my finger to lube up the gear teeth under it. I removed the face plate near the light bulb and the one near the needle and used oil in there. It's running pretty good.

The sewing I did was on a pair of polyester work pants, using some pretty simple black thread, nothing heavy. I had trouble really seeing if my bobbin tension was right. I saw a video where a lady shows letting the bobbin dangle, and if it plum drops really fast the tension is too loose, and if you bounce it a couple times and it doesn't let any thread out, then you are too tight. I couldn't do this test, because the darn bobbin kept falling out of the bobbin casing, so I sort of winged that part.

I'm pretty sure I had the top tension at about 7 or 8 while I was sewing the pants and it did ok. I wanted to do more practice, so I grabbed a pot holder and stuffed that under the pressure foot and gave it a go. That's when I started getting a mess on the bottom stitch. It was like the stitches either tangled up on me, or the stitch on the bottom was loose, and way longer than the top stitches. I haven't a clue how to adjust the tension right for thicker material. I also have not a clue as to what thread thickness vs. tension vs. needle I should be using. I will definitely take advice and look into those write ups you spoke of. My ultimate goals is to be able to stitch shoe uppers together with this machine. So, we're talking moderately thick leather material, which isn't as thick as I've witnessed the machine handle. Anything thick I'll be sewing by hand. I'm not trying to abuse the machine, and then have a motor go up on me.

Thank you both for your input. I appreciate it greatly. I just did a big long response, but didn't have you quoted. I'm just getting used to this forum and how it jives. That's great advice, and what I too was thinking. I'll just get a scrap piece and go by trial and error until it's just right.

No. If it's shoe uppers you're set on sewing this is not the machine for it. I'm guessing the Ebay ad told you it will handle leather. For once in a while things like light weight garment leather this is a great machine but a steady diet of anything heavy is asking for an early demise. This is a domestic(home) machine, what you want is an industrial designed for leather work.

Cari

Hi Cari, I've heard this before, and I respect it. I've watched a guy on YouTube walk a needle down a 3mm thick piece of leather over and over again with no problems with a well serviced 15-91, but I don't think I'm going to be using material quite that thick. Definitely not thicker than that. The 15-91 is just my answer for doing what I want to do until I can shell out $500.00 for an industrial Pfaff leather sewing machine, ya know. It's sixty dollars worth of fun while I'm learning a new craft, as far as rebuilt replacement 15-91 motor being sold on eBay all day long is concerned. Thanks for your reply here. I hope I can learn a thing or two. The feedback on this forum is really plentiful, I am so glad I found it!

Congrats on your 15-91! I love mine! You mentioned you bought Singer motor lubrication. It's not a good idea to put the new motor lubrication that Singer now makes into the 15-91 grease pots. It has a higher temperature melting point, vs the old grease. If you have a vintage tube, great! If not petroleum jelly works, I heard. I'm sure someone hear knows more than I do.

Cari is correct about continual leatherwork on the 15-91. While it's a great machine with a lot of power, if it is sewing thick leather all the time, you run the risk of burning out your motor or stripping your gearworm. The motor and mechanics were designed for light/home sewing. If you really want to sew leather, I have seen vintage industrial Singers, like the 96-80, for sale on Craigslist for about $300.

ETA, Leather sewing bags is light and all not hard a machine, but shoe leather is far thicker. I know of a man who sees leather bags on vintage machines, so maybe that's what you saw on YouTube?

There are many and this mine- am i the first one to recognize the quote? Do I get the movie nerd prize? That's one of my favorite movies, btw.

As for yourvtension: clean out around the feed dogs and bobbin assembly first, then set the tension. If you are too far toward either end of the tension range on top, it's time to turn the screw on the bottom bobbin 1/8th turn, so you get more towards the middle of the range on the top tension array. I am frequently guilty of giving inexplicably abbreviated directions because I assume a shared base of understanding which does not exist. If I have done this again, please ask for elucidation.

And remember, one is for fun. ;)