Originally Posted by J Miller

We have a slant stitch monogrammer that I wanted to try. Since our 401 has a needle plate lift lever I thought it would be simple to try it on that machine.
I hooked it up and got to trying it out. But I had problems from the start. As I was trying to figure the thing out I realized the top tension was way tight. I could not reduce it. It didn't take long to see that the presser foot was not releasing the tension. It had worked just the other day when my wife put some decorative stitches on some jeans pockets so I knew something had gone wrong.

To make a long story short I got back to it and looked inside the hole the tensioner fits in. I saw some shiny silver bits. Then I had an epiphany. When I had originally cleaned this machine I had to remove the tensioner to clean the area around it. It wouldn't go back in the I thought it should, but it did work.
I removed the long set screw cleaned and oiled it and put it back in snugly.

Today I removed the set screw (first pic) and slipped a very small long shanked screw driver into the hole. It would not protrude into the hole the tensioner passed through so I gave it a push. A bunch of metal chips came out (second pic).

I cleaned all this debris out of the set screw hole and everywhere else, reassembled the tensioner and put it back in the machine.
Then I printed out the top tension instructions to the TFSR site and adjusted it.

Put everything back together, threaded it up and proceeded to test sew with it. Works great now. (third pic )

So, if you have a machine that has tensioner problems and yet the tensioner is in good working order, check the set screw hole. If it's full of aluminum chips from when the threads were cut, the tensioner may be working loose as you sew with it.

As I'm doing this post my wife is sewing up a storm with our 401A. (last two pics)

Joe