Nothing is frozen and dial turns well. Too well! The dial turns and turns, something is too loose in my opinion. It is not engaging something inside enough to change the stitch length, the reverse lever works OK. I took some pics but will have to take some more as they did not turn out well enough to post. I will take the machine outside to have better light for pics and will post pics.

Update to Stitch Length Selector problem
 

I did some more fiddling with the Stitch Length Selector this afternoon. There is some kind screw in the center of the dial that sits behind the set screw in the center of the dial. By taking a small screwdriver and turning the center screw I was able to move that pointy end that juts out of the back. It is the pointy thing that engages with the mechanism inside and adjusts the stitch length. The first stitches were six to an inch, nowI am now getting a respectable 10 stitches to an inch and am not going to mess with it any more.

I also had to spend some time adjusting the upper tension. That was a chore because the upper tension dial is not numbered. I also decided that the first bobbin case that I tried was not going to defeat me either. I played with it's tension screw. Voila, both upper and lower tensions are balanced and providing a perfect stitch.

Caroline, it is gunked up inside... I can see it.

Gorgeous! Let us know how she sews!

She is a beauty! I think you did very well.

Did it come with a book? If not, you could find a singer 15 book online, free, and go to town with the oil and grease. It is close enough to be of help, as your machine is configured like a 15. Joe says to use Singer oil and grease, but not the old stuff. Be careful not to oil where it say grease or it won't stay. Grease to grease and oil to oil. You can't go wrong, just done't use too much oil only just enough to lubricate, otherwise it will make a real mess. Good luck.

Wow I was just gifted one of these yesterday. My friend's grandmother machine passed down to her mother and she gifted to me. I was on line looking for a manual as it came with a box full of parts. it looks like it was used maybe twice it is so new. The bottom is clean and the mod number is R3L Ta 157628 and the motor is a Morse as well. Dial o matic. I will grease it up if it needs it and oil it today and sew on it. It has all it's original parts. I am tempted to change the wiring even tho it looks like new but the plug is so outdated? Does anyone know where I can find a manual?

Rosy, I'm thinking that if it has the tension on the face plate like the one in this thread that the manual found at https://ismacs.net/singer_sewing_mac...al-rotated.pdf should work. The stitch length is different, but the rest of it should work.

If the tension is on the front above the needle, there is probably a different manual that would work. A picture of your machine would help.

We like pictures. In order to post pictures on Quilting Board, you will probably need to reduce or compress the picture to a file size that is smaller than 2MB. How to post images can be found at https://www.quiltingboard.com/attach...020-01-17-.pdf
Don't forget to scroll over to the far right to find and click on the "Upload" button.

I have found that only the big red "Reply" button or "Quote" work to give me the paper clip icon to work for adding pictures.
https://www.quiltingboard.com/attach...p-location.jpg

Some additional info regarding reducing images at post #4 and images for the scroll and upload button can be found at #5 of https://www.quiltingboard.com/main-f...d-t312607.html

Another way to post pictures can be found at https://www.quiltingboard.com/showpo...postcount=1143
And how to use an ipad to post pictures can be found at https://www.quiltingboard.com/qb-hel...s-t318147.html

Or simply - Make sure pictures are smaller than 2MB
Click on red "Reply" button
Click on the paper clip icon
Click browse - choose picture/s. (only 5 allowed per post)
Once they show up as being loaded, Scroll over to the right side and click on "Upload"
After the pictures show up as being attached, you can close that window and go back to the screen to finish posting your post.

Janey - Neat people never make the exciting discoveries I do.
Not affiliated with off-site link(s)

mercury sewing machine dial o matic
 

Wow, time sure flies. Thank you for all that info here are some pics of the machine. I had put the machine on the back burner as I couldn't fine a manual for all these parts. I have searched everywhere for a manual.

I'm not sure what you mean by "a manual for all these parts" as the manual found at https://ismacs.net/singer_sewing_mac...al-rotated.pdf will give you threading instructions. As for the stitch length regulator my best guess is the knob turns to lengthen and shorten the stitch length and the lever is for reversing the direction of the stitches which would be locked to the length set by the knob. Unfortunately the OP that has this machine has not been on QB for over five years.

There is a Morse and an Admiral that have this stitch length regulator, but the upper tension is in a different position than the Mercury.

Janey - Neat people never make the exciting discoveries I do.
Not affiliated with off-site link(s)