general timing question

[fibersport]

Should the "hook washer" or needle guard actually touch the needled at any point in it's rotation?  For that matter, should anything actually touch the needle enough to move it?

[shoepatcher]

Answer to both questions is yes   It normally touches the needle just before the hook gets there.

 

glenn

[Wizcrafts]

4 hours ago, fibersport said:

Should the "hook washer" or needle guard actually touch the needled at any point in it's rotation?  For that matter, should anything actually touch the needle enough to move it?

Technically, it is a needle deflector. I usually bend them so they only touch the needle if it gets deflected to the right by something I'm sewing. The problem is that I use a variety of needle sizes. So, I can't have the deflector actually touch a #18 needle knowing that I may be installing a #23 needle for the next job. I have to split hairs and set the deflector to just brush a #23 needle, but miss a #18, unless that needle gets deflected hard right by thick seams. The goal is to prevent the hook tip from hitting the needle square on.

Obviously, if one rarely changes needle sizes, one can set the deflector to brush that needle aside ever so slightly. There's a lot to be said for keeping separate machines optimized for different sizes of needles and thread.

[fibersport]

Thank you both.  Currently it looks like the needle guard may have been damaged with a prior owner.  The top edge was all chewed up so I dressed the rough edges but noticed that after setting my clearance between the needle and hook, the needle guard really pushed the needle over.  When I first got the machine running smoothly, I had adjusted the clearance so that the needle just barely moved, now when I tried to set things by the book, my stitches are now a little erratic and the needle guard pushes the needle over quite a bit- hence my question regarding clearance.  I'll keep playing with the clearances and see how it performs.

[DonInReno]

On 3/18/2023 at 10:12 PM, fibersport said:

…now when I tried to set things by the book, my stitches are now a little erratic and the needle guard pushes the needle over quite a bit…

That sounds like the tip of the hook has been bent inward.   Cheap replacement hooks aren’t known for having the best steel or heat treatment.  You’ll probably be breaking needles from the large amount of deflection.

Replacement hooks from Amazon or eBay aren’t going to be great choices quality wise.  Even the moderate quality Japanese replacements are being faked with inferior Chinese knockoffs.   It would be worth it to get a new hook from Cowboy Bob.

Once upon a time I had a bent hook - since it was already screwed up a little experimenting wasn’t going to screw it up more - it bent out even with the needle deflector pretty easily - it was definitely a low quality replacement part with soft steel.

 

 

 

 

[fibersport]

You could be right about a bent hook, however I just got the machine last week and had it sewing perfect stitches,  only until I tired to clean it and adjust it did my problems show up.  I do know that originally I adjusted the clearance so that the needle guide just touched the needle, now it actually bends it to the left.  I just recieved an order of new needles and should be able to try them out along with some adjustments tomorrow.  I do think that either the hook or the needle guard are bent.  The machine sat for years in an unheated garage and accumulated a lot of rust, dirt and old dried grease.  Maybe I should have left it alone?  All I can find is a manual for a Pfaff 1245 which i understand is close to the 145 which is what I have.  I'll keep trying with all the suggestions - thanks to all for the help.

[DonInReno]

That’s a nice solid machine.  I think you did the right thing - many functioning machines are put out of commission by “cleaning and adjusting”, but in your case even if it seemed to be sewing perfectly it was probably just on the edge of skipping stitches.

  I must have assumed you’ve adjusted the guard already - it can be bent as needed for clearance - the hook is only a problem if the needle guard is adjusted in as far as it will go and the tip of the hook is still too far away from the needle (needle hits the non adjustable part of the rotating assembly).

Even without a manual for the specific model, most of it is very close to a copy of the other major top bobbin models - Juki lu-562, Singer 111w155, Consew 224, etc.   Having said that, there are some adjustments that will stop the machine dead in its tracks if not done correctly, so it’s always a good thing to know exactly what an adjustment is before turning that screw.   Industrials don’t normally need fine tuning on a regular basis.

One major difference is instead of a clogged belt going off the main shaft you have two sets of bevel gears and a drive shaft - on old crusty machines the grease gets hard and should be changed.  It doesn’t have to be anything special - just take off the gear cover, scrape out the majority of the old grease and replace it with automotive grease.

[fibersport]

Quote

 

You have given me more great information to try out maybe tonight - thanks again.  I have not done any adjusting yet, I didn't realize the needle guard was adjustable.  I do believe the hook is good because there is another one facing the opposite direction that seems to be almost in line with the main one.  This backwards hook is called the hook gib in my parts manual.  The needle guard also was chewed up on the top edge so I wonder if some needle decided to commit suicide on it at one time.  The manuals I have been able to find are for newer models and seem to cover mine pretty well.  With your help, the manuals and a little mechanical engineering logic I should be able to figure it all out in time.  Will update as things progress.

[fibersport]

DoninReno - I wanted to let you know that I figured out my problems with the machine.  I took it all apart last night and found out that it is not s 145-H4 as the tag says but has been downgraded to an H2 for fabrics.  All that really doesn't matter since it will sew what I need it to but it was a little disheartening.  Anyway I went back tonight determined to get it working again.  I reset everything both according to the book and by gut feel.  I had to use the original needle but figured it worked before so it should work again.  I got it all back together and made some test stitches only to find out it was still birdnesting on the underside.  I adjusted the tension with only about 80% of the stitches coming out good.  I then started thinking about the odd sounds it was making and then opened up the cover plate over the bobbin.  My stitches seemed to be better.  I adjusted the tension to even things out and all was good until I closed the cover.  It made a sound like the bobbin was spinning very fast and I had birdnesting again.  That's when I noticed the cover plate over the bobbin had a pice of metal on the underside that had some curved sections.  I tutned the cover plate around after realizing I had it in backwards.  I was then able to sew without any birdnesting at all.  The good thing ios that i was able to learn a whole lot more about my machine and how to clean and time it.  I appreciate your comments and assistance with this problem which turned out to be a mistake on my part.

[Uwe]

50 minutes ago, fibersport said:

has been downgraded to an H2 for fabrics

I’m curious how you determined that, especially the H2 bit. The H1/2/3/4 are increasing lift height designs that involves a bunch of parts that are not easily exchanged, especially on the H4.  The fabric(S) vs. leather(L) designations likely just indicated if the machine initially shipped with toothed or smooth feed dog, throat plate and feet - this can be easily changed over in just a few minutes.