Pfaff 345 sub base needed

[barclay]

345 h3 cast iron sub base, the part that holds the head to the table.  The one I have is from a singer I think and is too tall and not the right width for the pfaff.  The singer is about 6" tall and I would like the lowest base possible, maybe 2".  Where can I get such a cast part.  If all else fails I will cut this one down. But I will search first.  thanks

[barclay]

the black base is the wrong size and not a Pfaff.  Machine is too tall and need a lower base.  Any ideas?

[Handstitched]

All the pics I've seen of the 345's don't have that extra black  bit with the clip on . Can that be removed? Or get another bench with adjustable height ? It would be  quite a tall order to modify the Singer base. 

HS

Edited May 7, 2023 by Handstitched

[kgg]

 

@barclay

I would:

i) call around to the repair shops and try sourcing one as they may have a donor machine.

ii) get a new one from a PFAFF dealer if they are still available. The parts you need can be found on page 4 of "Housing Sections" of the listed in the following topic as a downloadable manual "parts5ao8mf6d.pdf". The base part number is: 91-014 200-75/995

iii) have a welding shop fabricate a support frame probably using 3" angle iron

iv) as you suggested cut down the one you have.

 

kgg

Edited May 7, 2023 by kgg

[barclay]

thanks for the wisdom.

[barclay]

I decided just to cut and weld.  Its ready to weld tomorrow.  I can weld it from the inside to hide the weld , paint it and its done. I took out almost 4".  Hinge and latch holes are still intact.  No drilling no tapping.  Now waiting for a servo to show up.  At that point I will need to reduce the speed etc.  onward.

[kgg]

5 hours ago, barclay said:

I decided just to cut and weld.  

That is what I would have done. A few cutting disc later and the basic job is done. Are you planning on modifying the existing Singer treadle table to accept a servo motor or building a new table? With the servo motor I would install it first before putting a speed reducer on as you may find it not necessary, depending on what you want to sew.

kgg

[barclay]

one disk and a jig and the 2 cuts went better than expected.  I will keep the singer table as it is cool.   The servo goes down to 300rpm and with a small pully and a 5.5" handwheel pulley I will get about 100 spm i think. could be slower for the thick leather so reduction may be in order..

[barclay]

base done, much more acceptable height.  On to the next issue.. a bigger handwheel pulley, to slow things down a bit.  Back to the lathe for that.

[kgg]

5 hours ago, barclay said:

base done, much more acceptable height.  On to the next issue.. a bigger handwheel pulley, to slow things down a bit.

Nicely done. As a note if you want the base color to be a better match, try your auto supply store for a tin of spray paint. I used one for a Toyota to match the base color of a PFAFF flatbed.

A good pulley size calculator to checkout before you hit the lathe is: https://www.blocklayer.com/pulley-belt

Example A:

Small pulley at servo motor with a 5.5" hand-wheel pulley with a motor speed of 300 rpm will give you a hand-wheel rpm of:

i) 2" pulley at servo motor: 109 rpm

ii) 3" pulley at servo motor: 163 rpm

to get those speeds down to say 40 rpm at the hand-wheel the new hand-wheel pulley would have to be:

i) 2" pulley at servo motor: 15 inches in diameter

ii) 3" pulley at servo motor: 22.5 inches in diameter

Personally I would suggest putting a speed reducer in, double bearing shaft or canter lever style, and leaving the existing 5.5 inch hand-wheel pulley for a couple of reasons. Leaves the machine in original condition, helps reduce startup jerk and provides a more uniformed torque range.

Example B:

Small pulley at servo motor with a 5.5" hand-wheel pulley with a motor speed of 300 rpm and installing a reducer pulley (6 inch /2 inch) will give you a hand-wheel rpm of:

i) 2" pulley at servo motor  36 rpm

ii) 3" pulley at servo motor: 55 rpm

kgg

 

[barclay]

Thanks for the info.  My hand wheel pulley is only 3.5. I will turn a pulley that goes around the 3.5 and screws to the handwheel, leaving the original handwheel.  Or I  may reduce it further as you suggest.  already repainted it, the gray was ugly.  

[barclay]

decided to use the Pfaff brown color, like the decal.  Matching the machine would never be right so I went with the contrast, looks fine.  Its a singer base ro start with so originality means nada at this point.  Top plate and needle bar cover plate are now brown too.  Almost ready for the servo and table etc.

b

[kgg]

17 minutes ago, barclay said:

Almost ready for the servo and table etc.

Looking good.

kgg

[Trox]

On 5/12/2023 at 2:23 AM, barclay said:

decided to use the Pfaff brown color, like the decal.  Matching the machine would never be right so I went with the contrast, looks fine.  Its a singer base ro start with so originality means nada at this point.  Top plate and needle bar cover plate are now brown too.  Almost ready for the servo and table etc.

b

Nice work! I have a 345 H3 myself, with a binding feed. Feed dog goes back and forth only, it's for propelling a synchronized binder. If your machine has the same type of lower feed, just adjust the feed dog so it doesn't prolong above the needle plate. (About 1 mm. under the level of the needle plate). If it's above the needle plate, it will just interfer with the material feed anyway ( If your machine has a binding feed, that if). These machines have no hook safety clutch, that means big trouble if you get a birds nest in the hook. They don't like coarse threads that much,  with a speed reducer/bigger handwheel it's easy to knock it out of timing. If it jams, the hook will turn out of position on the hook shaft. The needle bar might also move out of position, so take care! My hook has moved on its shaft so many times,  the hook's set screw's has made grooves in the hook shaft. I had to remove the shaft to repair that. That made me more aware. I can't emphasize this enough; no clutch= big trouble if it jams. My machine have a strong servo motor and a speed reduser. It's there to control the speed, but that's more power than these are design to be used with. I make sure not using too heavy threads in it. As I'm blessed with two heavier class machines, I don't need to be doing that. I look forwards to see you finishing this project, and to see the new handwheel. A bigger handwheel is always a better solution than a speed reduser. Because the extra belt and pulleys makes much more friction. And you can't use a needle position motor with a reduser, it will not work well. Good luck with your project!

Tor 

[barclay]

new handwheel, from 3" to a new 5 -7/8".  Now the motor mounting and reducer .  This set up gets me down to 100spm, would like to go slower, so some more pulleys underneath.  The original handwheel is still intact.

b

Edited May 21, 2023 by barclay

[kgg]

8 hours ago, barclay said:

new handwheel, from 3" to a new 5 -7/8".  

Nice top pulley. As @Trox has mentioned be very aware of the additional torque this the hand-wheel has created and by installing an speed reducer the even higher torque that will be available which could over stress internal parts. Your 335 does not have a safety clutch to prevent damaging those internal parts. Before you install a speed reducer I would try the machine on a project first.

What are you planning on sewing? How thick? What size thread?

kgg

[Trox]

15 hours ago, barclay said:

new handwheel, from 3" to a new 5 -7/8".  Now the motor mounting and reducer .  This set up gets me down to 100spm, would like to go slower, so some more pulleys underneath.  The original handwheel is still intact.

b

Nice work! You would not need s reducer on this setup, just a small pulley on the motor.

[Trox]

100 rpm is the slowest maximum speed. You can go slower on the pedal, I would not recommend using a speed reducer. Use a needle position instead, needle position will not work with a reduser. And the motor setup will be way to strong with an reducer, you can break the hook (there are no safety clutch) The extra belt and tension with a reducer makes it sometimes harder to control. Because you need more power to start turning the machine.  I think it will be perfect as it is now. I have a reducer on mine, that's just to much for such machine. That's the setup for s 441 type of machine.

[barclay]

the motor slowest speed is 300 rpm  750 w.

[Trox]

2 hours ago, barclay said:

the motor slowest speed is 300 rpm  750 w.

What about needle position? Then you can go stitch by stitch 

[barclay]

I hooked up the machine temporarily.  Running a 2.5" motor pulley and the 5.875" handwheel pulley i stitch 127 spm at 300 rpm, (i counted them!).  If I go down to a 45mm(1.75") at motor I will get 89 spm.  I have not hooked the needle positioner up but will take your suggestion and do that to see if I can get better stitch by stitch at the start up.  The machine runs smooth, but I don't have a upper tension spring for the thread to run through, waiting for that to be shipped.

[barclay]

needle positioning helps get one stitch at a time, but still kind of fast without doing a bunch of foot work.  I think I will give it a go like this.  thanks for the advice.

b

[barclay]

Got the machine sewing again.  It is sewing at 8 stitches and inch.  Can I get it to make fewer? would like a longer stitch length.  Rated at 6mm per stitch but not getting that.  Is there internal adjustments I can make? Pfaff up top Singer below.

[Trox]

On 6/7/2023 at 8:11 PM, barclay said:

Got the machine sewing again.  It is sewing at 8 stitches and inch.  Can I get it to make fewer? would like a longer stitch length.  Rated at 6mm per stitch but not getting that.  Is there internal adjustments I can make? Pfaff up top Singer below.

 

On 6/7/2023 at 8:11 PM, barclay said:

Got the machine sewing again.  It is sewing at 8 stitches and inch.  Can I get it to make fewer? would like a longer stitch length.  Rated at 6mm per stitch but not getting that.  Is there internal adjustments I can make? Pfaff up top Singer below.

Nice job! I was going to ask you about the weldability of the Pfaff cast iron, but you didn't weld that; it was a Singer part you welded.  Related to you questions about the stitch length, I assume you know there must be an "N" in your subclass number if it's a 6 mm max stitch length machine. N=6 mm maximum stitch length. There are plenty of pictures of your subclass plate but their resolution are to bad, I can't read it. If you do not already have the 345 H3 service manual I can share that with you. I has no pictures and they use some special "gouge" parts for adjustment, these are listed in the last pages of the part list. When you adjust this machine you got to do control all adjustments in chronological order. About the special Pfaff adjustment gouge parts we do not have access to: To measure the needle bar lift I use a caliper and the needle bar lock just a hose clamp etc. Let me know if you need the service manual, I've shared it here before.

[barclay]

All is well, 5mm per stitch is good enough for my purposes.  Some lighter material it pulls 6mm stiches.   The singer cast iron welded fine.  Tacked it every 2" around the base watching not to heat it asymmetrically. let it cool very slowly.   Used a nickle rod in my arc stick welder.  Not a mig. What is the reason a needle positioner and speed reducer will not work together?.  How can the controller 'know' what pulleys you have on it?  Still would like it to go slower sometimes.  But one stitch at a time does work.

thanks for your ideas.