Pfaff 345 sub base needed

[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.

[shoepatcher]

Y The speed reducer screws with the sensing in the synchronizer.  You can use a servo motor, synchronizer and  speed reducer but not all three.  I would get rid of the speed reducer.  

glenn

[kgg]

On 6/15/2023 at 1:10 AM, barclay said:

How can the controller 'know' what pulleys you have on it?

My take on needle positioner:

The controller is basically factory set so when it receives a input signal of a certain time duration in milliseconds from the needle positioner that is basically monitoring the position of the hand-wheel shaft. From the position of the hand-wheel shaft the position of the needle can be determined as it goes though it's up and down cycle. From the position of the hand-wheel shaft the controller then knows the distance that the motor has rotated and where it needs to be for the needle to be in the up or down position. When you throw in a speed reducer it changes the distance the hand-wheel has traveled (rotated) in a certain time frame (msec) so the input signal back to the controller from the needle positioner now is off as compared to the factory settings. When that happens the controller assumes the hand-wheel is in certain position hence the position of the needle but in reality the hand-wheel is in another position which means the needle is also in another position.

Some people love the needle positioner and others not so much. I happen fall into the not so much group myself but that will depend on what you feel best suits your needs.

kgg