Beautiful_Sound

What do I do?

66-1 from 1911 on a treadle, but I put a side clamp presser bar from a 127. So while it looks like a 66-4 it's not.

My Machine Sewing book says it should sew a straight line and until I saw it in writing in that old book I never really thought about it.

Glenn

Make sure the presser foot is ligned up square with the feed dogs. If not need to make the adjustment on the presser bar. Do you have the right sewing foot for the 66?

Beautiful_Sound

Yes I think so, I've got several. I'll adjust the presser bar

sewbeadit

Also if the presser foot is down too far or too much pressure you can have trouble with straight seams.

SteveH

define "not sewing straight"

do you meant that the stitch line is curved? or that the end of one stitch is not in line with the next stitch.

like this:

/
/
/
/
/


If it is like that it could be from a slightly rotated needle and not the foot at all

KLO

Ah, I always wondered what made those "leaning stitches" happen. Now I know. So glad that I am fortunate enough to be a member here and get to read the Vintage Machine threads. I have learned so much!

Beautiful_Sound

Well it does that as well (the ///), but 95% of the stitch line curves or arcs away.

Farmhousesewer

Even a straight stitch only machine will have some degree of ///, because of how a straight stitch is formed. Sure sounds like the needle bar is crooked.

J Miller

If the needle is good, the presser foot is good and the fabric pivots as you sew, the most likey cause is a misalignment of the presser foot and feed dogs.
To fix this I use a pair of metal 6" rulers. I place one along the feed dogs then lower the foot and place the other along side the foot. You can easily see if there is a misalignment by doing that. Then adjust the shaft at the locking screw so the foot and dogs are in alignment.
Also relieve the presser foot tension before you do that and make sure the foot is down far enough to rest on the needle plate when the presser foot is all the way down.


Joe