Pfaff 345 / Bringing it back from the dead

[Trox]

I try to explain this again. You do not need to change this lever (pic 1) Just run a chain from the lever true the hole in the base, see arrow pic 1. Drill a corresponding hole in the table and run a chain to the pedal.

Pic 2:

I don't know where you found this underlined part, it looks like it fits so it's probably the same. If you find it that's great, if not it's simple to make. If it's to long or to short, modify it. I would just make it, that would be much faster than even write a post about it.

Pic 3:

You see this isn't the same presser foot lifting lever/arm as on our machines, so you can't use the angle iron part from this one without changing the arm/lever to. The design is changed, I would think the one in my part list is a later design; because it allows a height adjustment. Just use the arm in pic 1 you already have.. You don't need the geared linkage who's probably there to making it easier to lift with a knee lever lift. It's not necessary! Not even if you have a knee lifter, it's not a heavy lift.

There is nothing wrong with your presser foot lifting lever/arm!? You don't need messing with that geared assisted linkage, there are plenty of Pfaff machines that didn't come with that extra feature.

 

[Trox]

45 minutes ago, DonInReno said:

I’m more familiar with brass/bronze brazing so that’s what I’ve used in the past.  After beveling the joint and grinding out any small cracks, you’ll want to heat the area well to burn out oil that is hiding in the pores and small cracks you didn’t catch originally, then finish prepping the area before fluxing.

In general there is no big advantage to either brazing brass/bronze or welding with nickel welding rods - I’d use what you’re most familiar with.   On larger parts there is an advantage to welding with nickel since gas welding setups have a hard time producing enough heat in deep grooves and inside corners. 

Sewing machines are often made with ductile iron so it can bend a little before cracking - before sinking a lot of time and effort into fixing the small bits, I’d carefully check the alignment of the arm - it might not be worth fixing if you have to cut the arm off and reattach to fix an alignment problem due to a bend.

edit:  What do you mean by bed extension is broken?   Maybe I just missed that in the photos.

Thanks but he don't need that part fixed, it's just a extra feature for handicapped people who can't lift more than 200 grams. Nothing wrong with handicapped people, but it's not worth using time fixing; this the machine will work just fine without it. Most machines doesn't have this feature, anyway. I won't use anymore time on this. 

Edited June 13, 2023 by Trox

[karmazine]

7 hours ago, DonInReno said:

I’m more familiar with brass/bronze brazing so that’s what I’ve used in the past.  After beveling the joint and grinding out any small cracks, you’ll want to heat the area well to burn out oil that is hiding in the pores and small cracks you didn’t catch originally, then finish prepping the area before fluxing.

In general there is no big advantage to either brazing brass/bronze or welding with nickel welding rods - I’d use what you’re most familiar with.   On larger parts there is an advantage to welding with nickel since gas welding setups have a hard time producing enough heat in deep grooves and inside corners. 

Sewing machines are often made with ductile iron so it can bend a little before cracking - before sinking a lot of time and effort into fixing the small bits, I’d carefully check the alignment of the arm - it might not be worth fixing if you have to cut the arm off and reattach to fix an alignment problem due to a bend.

edit:  What do you mean by bed extension is broken?   Maybe I just missed that in the photos.

Thank you for the info. I am more used to welding, but not much on cast iron. Some variants are almost unweldable (high graphite content, so only brazing possible). I was hoping someone (you!  ) had experience or information about it.

If the iron is bendable, it is for sure weldable. I was also thinking about welding the lowest spot of the "valley" created by the grinded bevel with TIG, and contiue with nickel electrodes, but it is usually done on engine blocks and similar complex stuff. So for now I am up to grind all the paint with wirewheel and pre and post heat it in the electric furnace and use just the nickel stick electrodes.

The crack is clean "snap" with no bends, and even if it warps during the proces, It is no big deal since the linking part is the lever with ball joint on each side which should take care of possible slight missalignement.

So the only concerning part is that the crack goes thru one of the mounting holes. I think welding over the mounting hole and re-drilling is safer and more clean way.

 

Broken part of the bed extension is visible on the attached photo. I think I will leave it as is and drill a new mounting hole as close as reasonably possible to the corner/crack.

Maybe even three bolts should hold it enough — only stress is during maintenance  when using the massive hinge to inspect/service the lower parts which is not that much often done I think.

 

 

Edited June 13, 2023 by karmazine

[karmazine]

5 hours ago, Trox said:

I try to explain this again. You do not need to change this lever (pic 1) Just run a chain from the lever true the hole in the base, see arrow pic 1. Drill a corresponding hole in the table and run a chain to the pedal.

Pic 2:

I don't know where you found this underlined part, it looks like it fits so it's probably the same. If you find it that's great, if not it's simple to make. If it's to long or to short, modify it. I would just make it, that would be much faster than even write a post about it.

Pic 3:

You see this isn't the same presser foot lifting lever/arm as on our machines, so you can't use the angle iron part from this one without changing the arm/lever to. The design is changed, I would think the one in my part list is a later design; because it allows a height adjustment. Just use the arm in pic 1 you already have.. You don't need the geared linkage who's probably there to making it easier to lift with a knee lever lift. It's not necessary! Not even if you have a knee lifter, it's not a heavy lift.

There is nothing wrong with your presser foot lifting lever/arm!? You don't need messing with that geared assisted linkage, there are plenty of Pfaff machines that didn't come with that extra feature.

 

 

I understood partly but now I finaly got how you meant it. I thought that the spring attached to the arm cover is more important than really it is (not at all).

I was thinking about attaching the chain or steel bar directly so I was a little bit confused by your sugestion of changing the whole arm. 

I understand that the time this repair (welding of the broken cover) kills is not worth it, but I like welding and take this as a challenge and possibility to learn a bit about welding cast iron. If I succeed I have a new ability and a bonus is that assisted lifting for which my wife would surely be grateful since she is tiny.  

If I screw it I can always revert to linking it directly as you proposed. And I can skip the hand lifter — it is not necessary.

 

Manufacturing of the angled linkage (your pic 2) is no problem.

I would not be hunting for it if it was the only part missing. Since there were more I was tending more towards sourcing the donor machine or used parts. I was too naive to think there could be enough of them floating around.. :-D Now I know I was wrong. The machine is possibly much older than I thought. 

Again thank you for your replies and patience! If you in the future come into (unlikely) situation of needing something from my home bannana republic, let me know.

 

 

[karmazine]

If I didn't annoy you totally with my silly questions:

How easy should this machine go handcranking it with no threads/materials and feet lift up? For now it is  sprayed all over with WD40 (to dissolve all the remains of old oil) and It rotates fine, but If I spin the wheel it stops almost instantly.

I am used only to the Singer 66 which spins at least one, maybe more revolutions if I give the handweel a strike. I think this should go similary nice. Or the aditional friction of the compound feed, etc. eat it?

No moving part feel like blocking/grinding. I plan to let it sit for while, maybe spin it a bit with the motor and flush/change the oil for real oil and grease. 

 

[DonInReno]

54 minutes ago, karmazine said:

Thank you for the info. I am more used to welding, but not much on cast iron. Some variants are almost unweldable (high graphite content, so only brazing possible). I was hoping someone (you!  ) had experience or information about it.

Sounds like you know what you’re doing and shouldn’t have any problems welding it!

I’m always surprised by the amount of oil that can soak into cast iron, and sewing machines are always covered in oil, so it definitely helps to get it hot enough to burn up any oil - automotive stuff must be the same.

[DonInReno]

Machines with a walking foot won’t spin much so that’s normal.   I also just use wd40 and rags with a small brush to clean most parts then oil everything well.   There’s no need to ever take the machine apart to clean.   Normally every day it’s used, just one drop of oil in each oil hole and every place two pieces of metal rub together is all it needs, but on a dirty machine I’ll maybe do 5 drops each day knowing it’s going to drip oil so place extra rags under it.   

[karmazine]

20 minutes ago, DonInReno said:

Machines with a walking foot won’t spin much so that’s normal.   I also just use wd40 and rags with a small brush to clean most parts then oil everything well.   There’s no need to ever take the machine apart to clean.   Normally every day it’s used, just one drop of oil in each oil hole and every place two pieces of metal rub together is all it needs, but on a dirty machine I’ll maybe do 5 drops each day knowing it’s going to drip oil so place extra rags under it.   

Thank you for reasuring..

[shoepatcher]

On 6/9/2023 at 4:20 PM, karmazine said:

Hello Trox,

Thank you for the reply! I was out and had only a few minutes in the workshop to take the pictures and go.

I had the subclass list but only in text form and less detailed. I try to decipher the 913/52, it should be hidden in the new pdf somewhere.

Anyway, I saw the machine only few minutes today, but found out that the feed dogs are definately not from the binding version (they have ribs, and number 44080 C).

As always it could be usefull to double check if and/or to what extent the machine relates the name/type plate. Someone could swap part in the past.

 

The part list I have is originaly from your upload here (I think. filename 5ao8mf6d ). It seems to be general, not H3 specific.

The parts around the lifting lever that I need are not there at all. Could you please upload it too?

 

Photos attached. If you need me to shoot something specific I can take it tomorrow.

 

Thank you!

 

 

 

[shoepatcher]

I would have the piece in the back welded first to see if it will work. 

Strima in Poland carries a lot of older parts. 

 Check with them since you already have the part numbers. 

I you contact Pfaff in Germany and see what they have. 

There is also a guy on eBay in Lithuania that sells a lot of older Pfaff parts.

glenn

Edited June 18, 2023 by shoepatcher
grammar