Every so often, the timing between the bobbin hook and the needle in a sewing machine gets uncoordinated. Symptoms involve clicking, getting stuck, etc. We have an old Pfaff Tiptronic 2030 and I couldn't find specific instructions for fixing its timing. Between instructions online for other machines, and figuring things out myself, I got it, I think. But bear in mind that I am a professional philosopher, not a sewing machine repair person.
The instructions probably can be adapted to some other Pfaff models, especially the closely related 2040.
The point of adjusting timing is to make sure that the bobbin hook is at the needle location at the right part of the sewing cycle.
- Two sizes of star screwdrivers -- I am afraid I don't know how to specify the sizes, but you'll see if yours fit or not.
- Medium flat blade screwdriver.
- Something about 2mm in size for measuring needle movement. A feeler gauge is ideal, but I used the blades of small screwdrivers.
Step 1: Remove Foot and Feed Plate
Unplug power plug and pedal from machine.
Remove the swiveling thread / foot holder (carefully lift upward).
Put machine on side on carpet or other soft area.
Remove the foot.
Remove the feed plate (I can't quite describe how to leverage it, but just try and you'll get the hang of it eventually).
Step 2: Remove Base
Make sure machine is unplugged!
Remove the three large star screws (see photo).
The metal base now swivels out. Be careful not to break plastic snaps.
Be careful: there is a ribbon cable and a two-wire pedal connection cable going from the main unit to the circuit board in the base. Keep base nearby so the connections don't get stressed (or else unplug them, making sure to note which way they were plugged in).
Step 3: Unhook Feed Mode Switch Linkage
The machine has two feed mode switches. One is on the left of the machine, hidden behind the bobbin area cover and the other is on the right, on the base, below the buttons. The one on the base is a bit tricky, as it has a fragile plastic link to the feed mechanism.
To avoid breaking the linkage, first slide the switch (the one on the right, below the buttons) to the leftmost position. The switch is connected with a white plastic link to a fragile black plastic link that goes leftward into the machine (to the feed mechanism). Carefully pop the white link off from the black link, being careful not to break anything.
The first time I opened the sewing machine, I didn't know to disconnect the links, and I broke the black one. I glued it back together, but it broke again. (I may eventually try to 3D print a replacement, but in the meanwhile I guess we're stuck using the hidden switch.)
Step 4: Remove Cover From Bobbin Area
Unscrew two (smaller) star shaped screws from the underside of the feed/bobbin area.
Very gently swivel out the cover, as in picture, bearing in mind that there is a very fragile black linkage in there. Look at the picture to see what it's like to prevent breaking it. You might also find that it pops off its slides. If so, pop it back on.
Step 5: Prepare to Adjust
Make sure there is no bobbin or bobbin case loaded.
Make sure there is a needle loaded in the machine, but not threaded.
Turn the flywheel (the manual feed wheel on the right of the machine)towards yourself and observe how the mechanism works. During each cycle the needle goes down once and up once, and the bobbin area spins twice. Make particular note of the bobbin hook that goes round and round. It's used for grabbing thread and aligning it is crucial. See the photo for the location of the bobbin hook.
Step 6: Adjust Timing
Finally, you can adjust the timing. Turn the flywheel towards yourself (i.e., counterclockwise) until the needle is at its lowest possible point.
Now you will need to keep on turning the flywheel a little more towards yourself (i.e., counterclockwise) until the needle lifts up by the right amount.
Unfortunately, I do not know the exact amount for this machine model. Generic information on the web said 3/32" (2.4mm). Information for other Pfaff machines ranged from 2 to 2.2mm. I'd go for around 2.2mm.
To measure out the 2.2mm of lift, you can use a feeler gauge. I used two small screwdrivers, one with a 2mm wide blade and the other with a 1.4mm wide blade. I found that the needle at its lowest point stuck out slightly more than the combined width of the two blades, and so I just rotated the flywheel until the needle tip was sticking out the size of only the small screwdriver.
Now unscrew the black adjustment screw (see the photo) with a flat bladed screwdriver. The bobbin holder area should now spin freely, independently of the needle. (If you do accidentally move the needle, you'll have to repeat moving it to the approximate 2.2mm lift after the lowest point.)
You now need to make sure that when the needle is at this point, the tip of the bobbin hook is right behind the needle.
I found the best place to look at the hook and needle alignment to be from the top, where the feed plate used to be. A flashlight will help. See the photos: I added dotted lines to highlight the hook and the needle.
Turn the bobbin holder area until the tip of the hook is right behind the needle. Then tighten the black adjustment screw.
Step 7: Testing
This is a good point for testing. Keep machine on its side, but thread the needle, load up the bobbin, and make sure the bobbin thread can be pulled up correctly. If the thread is getting stuck, you might want to adjust the position of a black holder plate. Look at how the plate and see how it has a tongue fitting in a groove on the bobbin area. See the photo for the location of the screw that holds it place. Don't remove the screw, just loosen it. Try slightly different positionings for the plate. If you move it too far to the front of the machine, it won't hold the bobbin area assembly in place, and things won't work. If you move it too far to the back of the machine, in my experience thread will get stuck.
Step 8: Reassemble
Reassemble in reverse order. Remember:
- Put plastic cover on bobbin area, being careful that the black linkage goes where it used to. Screw on two smaller star screws.
- Make sure circuit board connections are tight.
- Join black and white linkages again.
- Put base on and screw it on with three larger star screws.
- Plug in.