Rotary hook wear

919Embroidery

So I am not a newbie to machine maintenance by any means. I have several Melco AMAYA's and have always maintained them myself. Over the years, I have pretty much removed every part possible on one or another of my machines. I've bolted on motors, belts, sensors, and disassembled heads to replace needle bar packs (mostly because my employees destroyed something, not because it was worn out). I've even thwarted Melco's attempt to sell me an $1100 circuit board by soldering on a new 50 cent part from Digikey (I think it actually totaled up to $10 because I ordered 10 of them plus shipping). All this without a single minute of tech training but using a heap of common sense.

That being said, there is one question I haven't been able to satisfy with simple experience and I need some advice. I have a couple machines approaching 500 million stitches and one sews great while the other sews like crap. I've cleaned it, oiled it, retimed it, checked every possible setting and adjustment to no avail. It just doesn't sew well. It likes to skip stitches and break thread under the needle plate. Its not unbearable but its obviously not operating properly either. Do rotary hooks wear out? I've been all over the net reading websites and blogs with no definitive answers. Machine manufacturers are quick to recommend selling you a new $100 hook but I prefer to keep my $100 if possible. The problem is, at this point I may be shooting my business in the foot with lost productivity over a simple $100 part. I have already ordered the part (in fact I ordered two so I have a spare on hand) but at this point its more curiosity than anything.

Do rotary hooks wear out? Do they have a recommended replacement interval? I know they're technically a consumable part but is this something I should be looking for more regularly? Are the teflon coated hooks really better than the standard hooks? Do they sew better? Do they last longer?

Someone with more tech experience than me come to my rescue. Satisfy my curiosity please!

919Embroidery

Incidentally my question isn't limited to my embroidery heads only. I recently acquired a Pfaff 130 manufactured in 1953. I also acquired a Singer 111 circa 1920. Both of these machines currently sew like a dream but I'm hoping the answer to my rotary hook question will help KEEP them sewing like a dream.

Flint54

Yes, rotary hooks can wear out. But most of the time problems will be caused by nicks in the hook itself. If a needle breaks the piece can nick the hook, if sewing thick items you can use a needle that is too small, it can deflect and nick the hook. As part of your maintenance kit get some 800 grit wet dry sandpaper (Black), use this to polish your hook.

If you get a teflon coated hook and you put a nick in it you will need to get a new hook. They do not appear to be worth the extra $$. Three of the hooks in our 4 head are original from our start in April of 06. Keeping your machine CLEAN & PROPERLY LUBRICATED will allow for many hours of run time. Oil the raceway of your rotary hook at least every other bobbin with one small drop of oil, this is the area that wears on a rotary hook, ALSO, if you have a multi head machine but only use one head at times. REMEMBER TO OIL THE ROTARY HOOK(S) OF THE HEADS NOT BEING USED WHEN YOU OIL THE HOOK BEING USED, ALL HOOKS RUN WEATHER YOU ARE ACTUALLY SEWING ON THE HEAD OR NOT! The hook rotates twice for every cycle of the needle.

Eric

I run Barudan & Tajima's, and I have never seen a recommended hook replacement interval from either of them ... however, I find that replacing the hooks can fix a TON of "quirky" problems, so, in my opinion, yes definitely they do wear out.

We don't have a set time for replacement of the hooks, where it is an "expensive" part (in relative, consumable terms) we only replace them when we feel necessary, or if like you said, damage occurs due to operator error.

I've seen the teflon hooks, but have no experience with them.

Its all situation based I guess.

To me the $100 would be worth it, and if nothing else, you have a spare on hand incase of a real problem.

919Embroidery

I appreciate the feedback. I've handled the "knicked hook" problem with 2000 grit. I never considered that I won't be able to do that anymore when I ordered the Teflon hooks. Oh well. I could have gotten the regular hooks for $30 less each. I guess I screwed up on that one. Live and learn.

minimalist

Well you've got it fixed already but I'll add this. I spent a number of years with the industrial machines and found a couple of things that help. One is to lightly polish the hook using a dremel at low speeds with the cotton buffing wheel and jeweler's rouge. Two, the throat plate might have a nick on it from a needle breaking so I polish the inside of the plate where the needle goes through it only lightly with corded sandpaper.

Remember that the thread passes over and sometimes slightly under the hook. There are many places the thread will pass over and break or fray from a burr. I'm new to the embroidery machines but I've seen what happens with the lightweight thread used. It doesn't take much to break.

Teflon is a coating and I don't see any reason why you couldn't polish it later on. I always used Koban replacement hooks on my smaller machines (adler 167,267, consew 225, 206rb juki 341, lu563) and never had any problems.