Old Pfaff Needle Interchangeability And Max Thread Size

[CustomDoug]

I have an old Pfaff 34 (which is very similar to Singer 31-15, but with reverse), that I've never used before and that I need to get some needles for. I took the only needle that came with the machine (a size 100/16, system DPx35) and compared the length to a DPx17/135x17 (size 90/14). The 135x17 was about 6mm longer. Just for giggles I tried to mount it in the Pfaff, not expecting it to fit the needle clamp hole because the needle's shank is a bigger diameter than the Pfaffs original needle. To my surprise it fit just fine. I mounted it, turned the hand-wheel slowly as I thought the new longer needle would hit the hook/shuttle area and try to break... but it did not! However it did not pick up the bobbin thread either. So for the sake of keeping things standardized, would it be a problem to move the needle bar up about 6mm and just use the 135x17 system on the Pfaff?

Also, I read a post here where someone had good success using size 207 thread in a Singer 31-15, as hard as that may be to believe. I'd be interested in doing the same thing on occasion with the Pfaff 34. Are these machines similar enough to assume so?

[Wizcrafts]

#207 thread in a Singer 31-15? I am barely able to get #92 thread around the bobbin case and shuttle (it snaps noticeably as it passes the top of the bobbin case). The slack in the shuttle driver would have to be tremendous to pass #207 thread. This would make for unreliable timing as the position of the hook varied with rotational speed and top thread tension changes.

[CustomDoug]

#207 thread in a Singer 31-15? I am barely able to get #92 thread around the bobbin case and shuttle (it snaps noticeably as it passes the top of the bobbin case). The slack in the shuttle driver would have to be tremendous to pass #207 thread. This would make for unreliable timing as the position of the hook varied with rotational speed and top thread tension changes.

I'm just going by the fact that Singer not only mentions a #23 needle in the operating manual for the 31-15 but also bothers to describe it's uses. A #23 needle would have us in the 207 thread range. Let me say that I understand that this is not the ideal size thread for a machine of this class and I'd assume before trying it that smaller thread in the bobbin would be a given. Anyway, this.. along with what was said in a previous thread has me feeling like it's not out of the question. In that thread, our forum moderator 'Art' mentions that the shuttle needle alignment would possibly need to be adjusted for using a size 24 or 25 needle. BUT I'm talking about using a smaller #23, and would still consider the adjustment might be necessary. Then a couple post down in that thread the original poster named 'AlcoveShop' said of his 31-15 ".. and fyi, 207 sews wonderful in this beast." Here's the thread - http://leatherworker.net/forum/index.php?showtopic=1446 . I can't say how much sewing he actually did with it, maybe not much.

Anyway, do you know about the needles or the question of raising of the needle bar in the Pfaff 34 ?

[Wizcrafts]

Perhaps these folks have newer models of the 31-15 than mine. It was built in 1916, according to the serial number. It won't even sew with #138, much less 207 thread. When I tried to open up the clearance between the shuttle and shuttle driver, it began skipping stitches. The timing became erratic at best and the machine was not trustworthy under that configuration. Your mileage may vary.

Another thing that is weird about the 31-15 machines has to do with variations in the angle of the bobbin case mounting tabs and the opening in the tab plate. I had to bend one tab in and the other out to keep the bobbin cases from spinning around. Again, your mileage may vary.

The needle bar in my 31-15 does not accept #23 needles. It uses a thin stem needle meant for tailoring machines (e.g. 96k40), which line up dead center in the little hole in the throat plate. Anything else would hit the throat plate with the slightest deflection. I cannot use other needle systems without a lot of difficulty (been there, tried that). The biggest needle my machine uses without trouble is a #21.

Finally, these 31-15s use a standard (small) bobbin. If you load it with #207 thread it may sew two belts.

Aside from the difficulties, I like my 31-15 for tailoring, hemming clothing and lightweight leather items. I even use it to sew patches onto vests, right through the lining. I have converted my 31-15 into a roller foot machine, for better feeding of garment leather.

Edited October 5, 2012 by Wizcrafts

[CustomDoug]

Here's a thread at another forum that deals with the same issue of using 207 thread in a 31-15, again it worked for this guy: http://customcowboybootsandshoesforum.com/discus/messages/23/2474.html?1119533753 . BTW, the name Doug in that thread is purely coincidental, not me. So maybe there is something to yours being an older model affecting it's ability to do so. My Pfaff 34 certainly will accept the #23, it's kind of odd that the Singer won't being as they're so similar (maybe it's my Pfaff's subclass). The point about needle deflection is a good one, I'll have to see what happens when I try it I guess. Anyway, the 207 would be the occasional project for me, where I was wanting the thread to be a prominent feature of the piece - and I wouldn't plan on the leather being any thicker than the machine is capable of. That aspect can't be fudged. Good point about the small bobbins too, but I'd only use smaller bobbin thread and these would be small pieces like wallets, coin purses and key fobs mostly. Not that you could get a ton of 138 on that bobbin either, I guess. Can you go two sizes smaller on bobbin thread or is it just one step down only?

[Wizcrafts]

I forgot that this topic was about your Pfaff machine, not the 31-15. Is your Pfaff supposed to use system 134, or 134-35 needles? There is a difference in length and geometry. I can use some 134 LR needles (from my previous Pfaff industrial machine) in the Singer 31-15. However, it cannot use 134-35 unless I raise the needle bar. Check your manual and make sure you use the correct Pfaff needle system. This might mean retiming the hook, or moving the needle bar.

I have experienced movement of my 31-15's needle bar. I used that fact to change the set screw to a new one that I could really tighten down. The original was 96 years old and worn.

As for modding your shuttle for #207 thread; opening up the clearances will allow #207 to pass around the bobbin case and the top tab on the case, then past the tapered end of the shuttle driver. But, the extra slack may mean that thinner thread skips at various speeds, but especially when sewing single stitches (stop/start), or hand-wheeling. The timing of the hook and spacing from the side of the needle (for #207) may render it ineffective for say #69 thread.

If you do anything to the shuttle driver, like bending it, or any other parts on the shuttle assembly, have a spare on hand just in case.

Edited October 5, 2012 by Wizcrafts

[CustomDoug]

I forgot that this topic was about your Pfaff machine, not the 31-15. Is your Pfaff supposed to use system 134, or 134-35 needles? There is a difference in length and geometry. I can use some 134 LR needles (from my previous Pfaff industrial machine) in the Singer 31-15. However, it cannot use 134-35 unless I raise the needle bar. ...

As for modding your shuttle for #207 thread; opening up the clearances will allow #207 to pass around the bobbin case and the top tab on the case, then past the tapered end of the shuttle driver. But, the extra slack may mean that thinner thread skips at various speeds, but especially when sewing single stitches (stop/start), or hand-wheeling. The timing of the hook and spacing from the side of the needle (for #207) may render it ineffective for say #69 thread.

My machine takes the 134-35 needles... but like I mentioned the 135x16 system fit it too, only they are 6mm too long. Which is why I'm asking about moving the needle bar up - I should just give it a try. I thought maybe someone might know whether this would cause a problem of some kind ( like possible 135x16 incompatibility with the Pfaff 34 hook or something like that). I'll try it and see though. I've not used 207 thread up to this point so I have none on hand, will need to order some before I can retime the shuttle or open clearances - or find out if I need to. IF the machine won't do 207 without changes (like some of the 31-15s obviously will) I may just scrap the idea or settle for 138 on top, 'cause I wouldn't want to loose it's ability for smaller thread. We'll see. Thanks Wizcrafts for discussing this with me, I appreciate it.

[CustomDoug]

Needle and Hook - can someone help me figure out the relationship between the two? I tried moving my needle bar up aprx. 6mm for the 135x16 needles to work. Of course it's done a little unscientifically when you're a novice so I'm not sure if I moved the bar enough, or too much. Anyway, the needle will go down and pick up the bobbin thread with the new 135x16 needle (when I've loaded a new bobbin) but it will not do so while trying to sew. Just a series of holes are all I get. I remember a conversation somewhere on this forum where the needle to hook relationship was discussed and described (by sewmun maybe) . It went something like (just for example) "needle tip should be above the hook by [x amount] just before the needle starts to rise.", or something to that effect. I can't remember which machine was being discussed but I was hoping there is a standard for straight lock stitch machines that is bottom feed only as my Pfaff 34 is. here are some pictures that show my needle (the new 135x16 as opposed to 134-35) in it's LOWEST position just before it starts moving up. It's down past the hook about 1/8" or fractionally more. Thanks for any help.

[CowboyBob]

Doug,

Take your needle plate off & turn your machine in the direction it runs & when the point of the shuttle meets the needle the top of the eye needs to be 1/8" below the tip of the shuttle.The problem with the longer needle is if you have a needlebar thread guide on your machine you might need to take it off so you can raise the needlebar enough to get the timing correct for the longer needles.

HTH

Bob

Edited October 13, 2012 by sewmun