The pattern selection dial on my Brother LS-2160 is turning but isn't changing the pattern. The needle won't change stitch or size, I have the front off but not sure which part is missing, but not sure what to do next. Nothing from the dial moves anything near the arm

Hi Maureen-
I found this link.
https://help.brother-usa.com/app/answers/list/st/5/kw/stitch%20lengthen/p/6359/page/2
Item #13 How to change the stitch length
The stitch lengths are preset. - To select a stitch, simply turn the pattern selection dial to the desired stitch length.

I also found this link.
https://www.brother-usa.com/virdata/content/en-us/had/consumer/usersmanual/um_ls_2125i_multi_1144.pdf

If you would like to contact Brother.
https://www.brother-usa.com/contact-us

Hope this helps.

What size needle are you using. Maybe a larger size will help.

Here's a manual for your machine:
Brother XL 3010 Operation Manual

It appears that your machine does not have the ability for the user to change the needle position. Instead, it seems that the selection of the specific stitch pattern determines where the needle is positioned, ie #1 appears to set the needle in the left position but other stitch and width selection will move the needle position.

you probably wont find it listed anywhere as it is from experience and changes with different material thickness and needle size
SO how to set tension
thread the machine and adjust the tension until you feel a drag on the thread
now thread the needle and sew a piece of scrap material
if the thread bunches up underneath then increase the thread tension until it sews properly
if the bottom thread is pulled to the top or the thread keeps breaking loosen ti off a bit
when the stitch is being properly formed , both bottom and top threads should meet at the center of the two materials being sewn

You may need to use a walking foot with your machine as stretchy fabrics are hard for the feed dogs to 'grip' and pull the material through under the needle.... you will probably need to change needle as well... there should be a helpful video on YouTube that will tell u all about sewing with stretchy fabrics and how a 'walking foot' works... hope that helps.

Hi there Kathryn... when you load/thread the top cotton through the machine.... and then through the eye of the needle.... do you also load the bobbin case... or is it already in there and loaded as per instructions... ? What I normally do... is load up the bottom and top threads first.. making sure to put the top thread through the needle and make the thread end go through and behind the 'foot'... when placing on fabric to try... I make sure to load the fabric... with the top thread's tail going out through the presser foot and behind your foot.. sometimes.. if its the thread (some machines don't like certain threads)... I will manually (wind the right hand wheel) so that the machine does a few stitches.. before I use my foot pedal!.. I have both a serger/overlocker... and a Brother 8500 (sewing/embroidery machine).. I have been sewing for over years now...
You will need to change your needle... when you've used it for more than 6-7 hours continuously.. OR you notice that the stitches are not as they should be... in your fabric...

take the machine back & get another one

Are you certain that the pattern selector is set for straight stitch and not buttonhole?

Turn the handwheel so that the needle is up and the take-up lever is in it's highest position. Then turn the pattern selector knob through all of the patterns back and forth a few times. Finally, select straight stitch and see if the length works. If not, need to take it to a repair person to determine the course of action.

The brother website has a users manual for it that can be downloaded. Use this link to get it:

http://welcome.solutions.brother.com/bsc/public/us/us/en/doc/manual_index.html?reg=us&c=us&lang=en&prod=hf_ls2125eus&type2=5&flang=English&dlid=

To select stitches 11-21 you position the stitch length dial on the "SS" setting , and the pattern selecting dial on the desired stitch number.