Stitch length dial moves when I sew

[DenimHead]

I am repairing an Econosew long arm, and the stitch dial will slowly turn to the left when I sew (meaning the stitch length will gradually get longer).  I have taken off the dial and nothing seems wrong.  I have taken off the top access plate and back access plate, checked the set screws and bolts and all are tight.  The fabric thickness has not changed.  I cannot identify why the dial turns as I sew.  Has anybody had this experience or know why it could be happening?

[DrmCa]

Show the picture of the notches on the back of the dial and the spring-loaded plunger behind it that keeps it from rotation.

I had the same problem until I realized that the tapered end of the plunger was worn/rounded and I turned it sharper on a lathe.

[SARK9]

21 hours ago, DenimHead said:

I cannot identify why the dial turns as I sew.  Has anybody had this experience or know why it could be happening?

Not familiar with your exact machine, but it looks (superficially) similar to the same area on a Consew 206RB4 , which had a similar problem that was significant enough for them to add a thumb-button on the RB5, which now has to be pushed in to change the stitch length. Many of these *clone* machines are nearly direct copies of older designs, so someone who has an RB4 may have a come up with a workaround, if yours IS based on the consew.

-DC

[DenimHead]

On 2/22/2022 at 12:43 PM, DrmCa said:

Show the picture of the notches on the back of the dial and the spring-loaded plunger behind it that keeps it from rotation.

I had the same problem until I realized that the tapered end of the plunger was worn/rounded and I turned it sharper on a lathe.

Thanks for your answer.  I will check the end of the plunger.  There is no spring on the back of this dial and nothing pressing against it to cause pressure.  

[DenimHead]

On 2/22/2022 at 1:55 PM, SARK9 said:

Not familiar with your exact machine, but it looks (superficially) similar to the same area on a Consew 206RB4 , which had a similar problem that was significant enough for them to add a thumb-button on the RB5, which now has to be pushed in to change the stitch length. Many of these *clone* machines are nearly direct copies of older designs, so someone who has an RB4 may have a come up with a workaround, if yours IS based on the consew.

-DC

Thanks for the response.  This dial did hold correctly in the recent past, so something has change so cause it to slip.  You're right, it does look just like a Consew dial.  The Econosew is probably a clone of a Consew.

[DrmCa]

10 hours ago, DenimHead said:

There is no spring on the back of this dial

It is not on the back of the dial. It should be under the plunger, inside the casting, over the thinner step of the plunger.