Pfaff 145 h3 reverse stitch length shorter than forward

[ThomasBH]

Hello,

My “new” Pfaff 145 has a couple of issues, namely the reverse stitch length is significantly shorter than the forward. Any tips of fixing this?

I found this forum thread, but the answer was not listed: 

 

My other two lesser issues are:

1. The screw holes in the bobbin cover/plate don’t seem to work with the thumb screws I have from my Mitsubishi DY350 binding attachments. Is this not a standard size, or should I order a new plate? (Anyone know of a decent priced North American supplier of these parts? I’m in Canada)

2. The needle bar will strike the outside foot on thicker fabrics. Unfortunately this machine only came with a welting foot and I do not have other ones to test on. 
 

Thanks!

 

[DanishMan]

Hi Thomas

The mismatch between forward and reverse stich length is most likely due to the lower transport not set correctly.

• Set the stich length to zero
• Rotate the hand wheel in the normal sewing direction and take the needle to bottom dead center (all the way down). Now continue rotating the handwheel and raise the needle slightly less than one millimeter.
• When moving the stitch length lever up and down, the feed dog should not move (or just very little). If is does move, adjust the eccentric on the main shaft (close to the handwheen).

If this does not solve the problem entirely, you can play a bit with the eccentric. 

Regarding the two additional questions, I am not sure about the size of the screws going into the metal cover.. May be it is easier to find new screws than a different cover.

I am not sure, what you mean with the second question. Could you possible take a few photos?

Brgds

Danishman

[ThomasBH]

Thanks for the detailed reply!

1. I will try again when I get home from work, but trying yesterday the stitch length screw seemed to bottom out around the “2”. Like the screw in the reverse leave cannot go to zero. 
2. I will take some photos later today, but basically the needle bar smashes into the outside of the welting foot and actually bends it out of the way which causes the screw to loosen, not to mention probably damages something. This only happens on very thick material, such as ~1/2” foam.

[DanishMan]

I made this video two years ago. At that time I used bottom dead center as reference for the feed dog not moving. Now I changed it to 1 mm up again.

Regarding the piping feet. Are they original?

[ThomasBH]

8 hours ago, DanishMan said:

I made this video two years ago. At that time I used bottom dead center as reference for the feed dog not moving. Now I changed it to 1 mm up again.

Regarding the piping feet. Are they original?

Since I got home I’ve been fiddling with the eccentric screw. I’m finding it difficult to get it to stay put after getting the feed dog to not move in the needle down position because the two screws aren’t exposed until you rotate the hand wheel a bit. I’ll keep trying! Thanks for the video and reply!

and looking at this piping foot in comparison to the parts catalogue and it must not be original. Here you can see it striking the needle bar. 

[ThomasBH]

After fiddling with the eccentric screw in micro adjustments for about 3 hours I found a decent enough balance that it will at least match the stitch length closely for about 8 reverse stitches before going off, so this was promising…however this was all done at the longest stitch length and as soon as I reduced the stitch length it is completely off! I will keep fiddling to see if I can fix this for any stitch length. 
 

Any tips would be appreciated!

[Constabulary]

I have not worked on Pfaff machines for quite a while but what I would probably try is to set the stitch length 1/2 way of the longest factory stitch length (if 6mm then to 3mm if 4mm then to 2mm....) and try to balance the F & R stitch length equally. The idea is that the amount the stitch length is off is approx. the same in shorter and longer stitches and probably not as significant as when you adjust it from the longest stitch. Not sure if this is what Pfaff recommends and I have not tried this by my self (have nothing to work on atm) but may worth giving it a try.

Makes sense? Maybe, maybe not.

I know a lot of folks prefer Pfaffs but I (obviously) do prefer Singer (or Singer based) triple feed machines cause they are fairly easy to adjust F + R stitch length like on the 111 and 211 models - the later 211 (at least the 211U) even have a screw for hat.

 

Edited February 2, 2022 by Constabulary

[Michiel]

5 hours ago, ThomasBH said:

I’m finding it difficult to get it to stay put after getting the feed dog to not move in the needle down position because the two screws aren’t exposed until you rotate the hand wheel a bit

What i do is rotating the exentric just a litle bit, fix it, and than rotate the handwheel to check the feed

(and repeat that a few times) 

most of the times i put the needle at the hook point ( the position you use on timing the hook - needle) but i think it depends on the model / make of the machine

[ThomasBH]

Thank you all for your replies. I will try halving the stitch length, which is a bit of guess work on this machine (it’s not entirely clear when you’re at certain lengths) then adjusting the eccentric screw in micro-adjustments. I’ll post my results after some fiddling. 

[ThomasBH]

Still cannot get this to work. I can’t even get it back to the best point I had it at last night. I feel like I have done hundreds of small adjustments. I can easily get it to that “no movement 1mm above dead bottom centre on the feed dog ” but this doesn’t help. Neither does doing incremental changes in either direction. Eventually if I keep going the thing starts going in reverse, but never matches forward and backward stitch length, especially at the shorter lengths. Lowering the stitch length seems to make the issue exponentially worse. 
 

Is there anything else that may be out? Timing?