Kitebuilder.com's

woodpekr · Joined: 25 Nov 2003 Posts: 71 Location: USA Oregon Portland

I need some fabric expertise/experience . . . .

Just got my machine (Pfaff 1222) back from a tune up. I left a bag of Ripstop scraps and a spool of thread (Kite Studio #33 Nylon Bonded Thread) so they could tune it for the materials and thread that I'm using.

Everything looks great on .75 oz Ripstop. I went throght a bunch of scraps and all is good.

I'm currently starting work on a spikey windsock. The material for the spikes is Ripstop with a very heavy coating on it. This coating looks like the coating that you find on the inside of a nylon rain jacket. It has a soft almost rubbery feel to it. I'm dropping stitches, about 30% of them, when I try to sew this stuff. I go back to my regular Ripstop and no dropped stitches. Back to the heavy coated stuff, dropped stitches.

Any Suggestions?

Thanks -- Rich
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Rich Durant
Portland, Oregon

Kitesquid · Posted: Mon Dec 01, 2003 4:14 pm Post subject:

first thing when you are dropping stitchs is to unthread and rethread your machine!!!!

If that does not fix it try a slightly largre needle,

Then play with tension...

whenever you change one thing in the sewing system:

Thread
Tension
Fabric
Needle
and beleive it or not, the speed that you sew at

all can affect stitch quality......

test on scraps and retune the system if nessary whenever you change any of the above!!!!!!!!!!!!!!!!!!

Read Gary Engval's and Kevin Shannon's sewing machine set up guides

Also read your owners manual.

If you dont have one I belive you might be able to download a copy from Pfaff for free, or ask your dealer

Did you take the free class that most reputable sewing machine dealers give wiht the purchase of your machine???????
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VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA

P.S. The wind is like the air, only pushier.

stevef · Posted: Mon Dec 01, 2003 4:42 pm Post subject:

Try changing your needle to a brand new one. Ripstop actually dulls needles fairly quick... When you sew the regular kite Ripstop, do you hear a "popping" noise? If so that is a sure sign of a dull needle. Be sure to replace it with a SHARP point or even a SHARP JEANS point. Do not use a Ball Point needle.

I also would do what Squid suggested.... rethreading the machine often solves the problem.

Let us know what happens....
-S
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Go Build a Kite!
A very big, public applause to kitenerd and his Della Porta project. Great Job Arnold!

Stan · Posted: Mon Dec 01, 2003 5:03 pm Post subject:

Rich,
The points made above sound right.
I had the same problem when I would use too much Fabritac glue to join seams or sewed urethane-coated Ripstop. It would work fine on plain fabric but drop stitches on the grippy stuff, especially on zigzags.
The trouble was caused by the thread tension being affected by the grip of the rubbery fabric. A larger needle may help, but tension adjustments may also help. Watching the behavior of the thread bubble at the bobbin case while turning the handwheel will give you an idea if the grip of the coating is preventing the bubble or loop from forming properly so the revolving hook will pick it up. You might try this with different fabrics.

With skipped stitches, watchiing the hook miss the bubble can help in the diagnosis.

Just my two cents.
Stan

woodpekr · Joined: 25 Nov 2003 Posts: 71 Location: USA Oregon Portland

Kitesquid · Posted: Tue Dec 02, 2003 8:19 am Post subject:

I dont think it is on the web, as IIRC it was printed in a MKS winter retreat binder...

I will e him and tell him about these forums and to see if he would be willing to share it here or at his web site...

It is basicaly what Gary said, but in diffrent words, so it provides a slightly difrent point of view.

We also need Joe Tricarico here. IIRC he is a 3rd generation industrial sewing machine mechanic/shop owner.
_________________
VR/
KiteSquid
AKA TakoIka
AKA Harold
King George VA

P.S. The wind is like the air, only pushier.

Gary · Posted: Tue Dec 02, 2003 11:21 am Post subject:

Yup, Joe T. would be a great addition to this Forum.

I agree with everything that has been said so far.

Given that the machine was sewing fine on 'normal' Ripstop scraps, but started dropping stitches on the 'grippier' stuff, it is probably best fixed with a larger needle. It sounds like the loop left by the needle is just not quite large enough for the hook to grab on its way by.

Another thing to try would be one of the thread lubricants.
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good heavens;
Gary E

woodpekr · Joined: 25 Nov 2003 Posts: 71 Location: USA Oregon Portland

finally got it to work! tightened the tension on the top and bottom and life is much better. I did all of the checks that you guys reccommended and finally decided to adjust the tension.

The tension was set such that when you held the bobbin case up by the thread that it would barely slide down without wiggling or jerking the thread. I tightened it so that it doesn't slide until I make an ever so slight hand movement.

Thanks for the suggestions and help.

--Rich
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Rich Durant
Portland, Oregon

stevef · Posted: Thu Dec 04, 2003 8:46 am Post subject:

woodpekr · Joined: 25 Nov 2003 Posts: 71 Location: USA Oregon Portland