My old Bernina 1130 has never given me trouble, but today, it seems like the control for the stitch length stopped working. The feed dogs are moving, but the stitch is very, very tiny. Will this be an expensive repair, do you think?

Check stitch length setting. If selecting a long stitch length doesn't remedy the problem then it likely needs maintenance (clean and lube).

If you haven't lubricated the hook lately, now would be a good time. See page 65...
https://www.bernina.com/BERNINA/media/Support/Sewing_Quilting_Embroidery/activa/activa_230/Documents/EN/activa_220_230_240_EN.pd

I suspect the feed dogs are not traveling their full motion. Suggest you drop dogs, run a few stitches and then raise dogs and see if problem goes away.

If not, run a couple dozen straight stitches at maximum length, switch back to previous length and see if it made any difference.

Could be it needs further (deeper) cleaning and lubrication. Comment below and I'll assist further if need be.

Even if you select a longer stitch? Have the feed dogs been dropped for darning? Otherwise, your mechanical machine may be seizing due to old oil that has solidified.


Wheel on right side that controls the needle up and down is very tight...

Yep. These older machines are great but they do love to be treated regularly to cleaning and oiling. Feed dogs are often one of the first to fail due to old oil. Then the stitch selectors will stop working, the handwheel may get stiff, and the needlebar will freeze.

Wheel on right side that controls the needle up and down is very tight...

Not sure what you are asking. The stitch length will determine how far the feed dogs travel (thus pulling the fabric) to create each stitch. There is also the foot (or knee) control that determines the speed that the machine runs.

The page 21 of the manual has that information:

https://www.bernina.com/en-US/Support-US/Machines/BERNINA-artista/BERNINA-artista-200

First, make sure the feed dogs are in the up position and NOT dropped for darning.

Second, check that the stitch length is set to at least a 2 or 2.5 to make sure the feed dogs will actually move the fabric a noticeable distance. The closer the stitch length is set to zero, the closer together the stitches will be until it will sew only in one place because the fabric will no longer advance.

The feed dogs need to move. They should actually rise, move toward the back of the machine, drop down, move forward to the position to again rise--this creates one stitch. If the fabric is not moving, then it is possible that your machine has not been cleaned and oiled recently. Old oil will dry and cause the moving parts to seize.

It was working now it seems to be frozen the needle part wont move


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Manually turn the handwheel. Are the feed dogs still moving but remain below the sewing surface so they do not contact the fabric? Check to make sure the feed dogs have not been set to the darning function. Also set the stitch length to a 10-stitches per inch to see if that makes a difference.

...

have you tried changing the needle

You have to lower the feed dogs and use a darning foot. Use straight stitch setting.

If you cannot lower the feed dogs, this model may use a cover plate.

You can also set the stitch length to zero and tape an index card over the feed dogs with a small opening for the needle.

You will be controlling the stitch length as you move the fabric by hand.

On a Bernina 1130 the power on-off knob and the feed dog raise and lower knob look similar and are next to each other on the end of the machine, making it easy to lower the dog assembly entirely, without realizing it. Make sure you didn't accidentally lower the entire feed dog assembly by turning the feed dog knob: you can tell as you turn it if the dogs are up or down. On the Bernina 1130 the knob, like the power should be in the horizontal position to be working both feed and power.