Help Timing A Pfaff 335

[Andrew Chee]

Hello all. I recently had to replace the needle bar on my Pfaff 335. In order to do that I had to remove the hook assembly and needle bar and put them back on. That necessitated a retiming of the machine. I have a pfaff service manual but it's useless to me because it mentions things like the lower needle bar bearing and I have no idea what those parts are. Futzing my way through things I think I have it almost there. The stitching look ok but the knot is but super consistent. The upper thread tension seems very sensitive now. The weirdest thing is at the end of the stitch, the extra top thread looks like it has been unravelling or something. There's something weird going on here.

Earlier on I was having problems with the hook splitting the top thread but I set the hook to engage a little later and that seems to have solved the problem.

Can anyone give me the proper way to time this machine? I'm just doing this by trial and error at this point so any pointers would be appreciated.

Andrew

[Tejas]

Would this link help?

http://www.pfaff-industrial.com/pfaff/en/service/downloads/technicaldocu/pfaffdocument?doctype=technical&classid=335&is_submitted=1&submitselect=Show+Results#ergebnis

[Andrew Chee]

I have the manual. Page 12 says to put a 1.8mm thick feeler gauge with its cutout close under the lower needle bar bearing. What does that mean?

Andrew

[Anne Bonnys Locker]

Set the feed to zero.

Neele bar goes down and rises. The manual will tell you how much.

When the needle bar has risen the specified amount the hook should be smack bang in the middle of the scarf. Adjust the needle bar and hook to suit.

I use a business card to give the right separation between hook and scarf.

[Andrew Chee]

Does 1.8mm sound about right to you?

Andrew

[Trox]

Hello,

First you must pre adjust the needle bar height (needle height) ,see the manual: to be 15 mm. over the needle plate at BDC. Its all wrong now when you changed it. Perhaps you already have adjusted its height, just make sure you did.

"Page 12 says to put a 1.8mm thick feeler gauge with its cutout close under the lower needle bar bearing. What does that mean?"

This is related to the needle raise, the needle bar has to raise with 1,8 mm after BDC ( bottom dead center). The hook has to be set to the needle when the needlebar is in this position.

They do this with some special tools described in page # 5 in the manual. A gauge 1,8 mm thick and a clamp called needle bar clamp, that lock the needle bar in the right height (1,8mm after BDC and stitch length set to 3, with the desired needle size that should be your medium size needle).

In absence of that I always use a caliper to measure its proper height and a tubing clamp to lock it if necessary (first the needle bar height at 15 mm. bdc and then add the 1,8 mm to find the correct raise after bdc; where the hook has to be timed, 16,8 mm. in your caliper).

When the needle bar (with the right size adjusted needle in) is set to the right height I loosen the screw in the hook shaft and turn the hook to set it to the needle.

If your machine is pretty new and the hook gear move freely on the hook shaft (after opening its screws), you can probably manage to adjust it with out the aid of an needle bar clamp.

However, if its an old machine and you must use some force to move the hook gear you can use a tube clamp etc. instead. Lock the needle bar from advancing (in its right height 16,8 mm over the needle plate, thats 1,8 mm after BDC) with this around the needle bar. Use some thin leather inside the tube clamp not to damage the needle bar.

Then turn the hook gear and adjust the needle hook timing as described in the manual. Do not forget to set the right distance between the hook and the needle sharf too (0,05 to 0,1 mm= as close as possible with out hitting the hook).

When your machine is splitting the tread etc, its related to improper adjustment. It will be fine when you adjust it like described above.

Good luck

Tor

[Andrew Chee]

Awesome. I had adjusted the needle bar to 15mm above the bed at bdc but didn't understand the 1.8mm rise after bdc at stitch length 3. I think I got it now. Thanks.

Andrew

[Trox]

Thats good, sometimes the hook shaft on these machine have damages after the gears setting screws. From being adjusted allot. Then a clamp will be of good help to lock the needle bar when you move the gear. I had to remove the hole hook shaft on my Pfaff 345 to loosen the gear, it would not turn on the shaft. It can happen to all old machines.

When you do these adjustments, then do them all. Start with the first one and adjust the feed, stitch length everything at once. They all are connected to each other. For best result control them all.

Andrew, is that an goat in your picture, do you live on a farm?

Tor

[Andrew Chee]

I don't live on a farm. I was at the petting zoo with my son and there was a goat just standing there with its head against the wall. Just thought it was funny and said something about life.

Andrew

[Trox]

Yes, sometimes my life feel that way too. It a good picture, it deserves a bigger column space.

Tor