bunching thread, help needed

[Sorethumbs]

Hi, I'm totally new to this heavy-duty sewing stuff and I'm having a problem that I'm hopping I can get some help with..

I dove into this by buying a Pfaff 238 industrial sewing machine, oufitted it with  a brand-new size 16 needle, and t-90 bonded polyester thread. I got some heavy duty 900 denier waterproof camo material to complete my first project, a hunting blind that I've wanted to make for the last 10 years. I should also say that I'm banned from using my wife's machine after ruining it during my last blind-making attempt.

Anyway, that's about as far as I got before the project ended, why, because the thread kept buching-up underneith the fabric. LOOSE loops down there, really a mess. Now, I'm not a complete idot so after consulting my manual I quickly realized that the upper tension was too loose, the lower tension was to tight, or both. Adjusting both did help, up to a point. Now I have the upper tension as tight as it will go, the lower as loose as it will go, but still the problem remains. No longer a bunched-up mess, but still loose on bottom. The interlock still dosn't occur between the layers of fabric. It lies on the face on the lower layer. I'm really bummed. Can anyone help me out???? I'm not sure what to do next. Thanks!!!

[RocketmanMH1]

First, take your tension discs off and clean them,  then thread your machine by the manual EXACTLY  like the manual says, READ IT CLOSELY.      If that does not  work then youtube is your friend!

[JDUpholstery]

A lot of issues come from not threading machine right, youd be surprised how much one missed thread point can cause....also needle size plays a lot in the mix, T-90 thread should use an 18 or 20 needle....when was your machine serviced last, timing adjusted, if its a new-to-you used machine, it never hurts to have it professionally serviced before using it

[needles eye]

hey hey

first adjust the bobbin case adjusting screw on the bobbin case with a loaded bobbin

grab the loose end of thread from bobbin and case and together they should fall about a coupla inches or so when given a slight jerk

that's if it doesn't fly apart on ya ..

the bobbin adjusting screw is real small you'll need a cheap jewelllers type screwdriver

it goes "righty tighty" in adjusting up ..

check that the bobbin is rotating freely in the bobbin case too

this is real important

sometimes there's a little spring flat washer in there missing or jamming

or fluff and lint and gunk binding up free spoolin' from the bottom thread

or you got a wonky bobbin or wrong sized bobbin or need oil in bobbin case

bit of silicone spray never hurt anyone either

anyway then you're set to play around with the top tension

yo make sure it's threaded up properly around the tension take up spring too bro

stick with and soon you'll have a sweet concord of stitches

note get the bottom set up nice first so you're not a rudderless boat dead in the water

make small incremental changes to top tension as you go

check that thread is running nice from spool thru all guides no snags

check out the rotating shuttle hook that spins around to catch the thread from the bottom

it can have crap on the pointy bit or slight damage there even, clean with emery and it brush out

slight possiblity timing has shifted so check your manual for alignment marks too

make sure the hook to needle placement on the horizontal plane isn't grabbing only a coupla strands of the v92 instead of all three ie hook may need to move closer to needle via adjustment to shuttle hook holder (usually 3 screws to adjust)

most importantly try a new needle first and make sure it's offered up dead straight such that hook can get a nice bite of the cherry however note some stichers like to put a slight twist on the needle especially when using a leather type needle ..

good luck
have another gin if all else fails

[Sorethumbs]

hey hey

first adjust the bobbin case adjusting screw on the bobbin case with a loaded bobbin

grab the loose end of thread from bobbin and case and together they should fall about a coupla inches or so when given a slight jerk

I can tell you that mine is adjusted WAY, WAY looser than that. If I held onto the thread and let go of the bobbin & case it would fall slam to the floor by gravity alone. I have the little screw on the bobbin case out pretty far,  its putting no tension on the lower thread whatsoever. Yet still the stiches are too loose under the fabric - above looks perfect. The bobbin sits very loose in its case.

As its adjusted right now (max tension upper, min tension lower) when I raise the foot  and grab the thread it takes a good pull to get thread from the needle but the lower thread comes out very easily. I had to set it this way to eliminate the loops and mess from under the fabric. This is a new to me machine. I know it was serviced professionally 2 years ago and has had very light use since then.

I  have ordered some larger needles I'll try that first. It will be a few days before I get them but I'll let you know what happens. I might not get to it untill after labor day.

[RocketmanMH1]

Your issue is on the top thread if you are having the results you said in your first post. Get your top set up right and  you will see.   You should be able to sew with your 16 needle, you may have some fraying issues though. Once you get the top right you will be able to bring the bottom or bobbin thread tension back to normal range not loose like you say. MAKE SURE YOU ARE THREADED AROUND YOUR THREAD TAKE UP SPRING LIKE THE MAN. SAYS.     You can tighten your top tension all you want and if the discs have something trapped in between you wont get the tension to the thread.

[needles eye]

cool bananas

have a great labour day

hey champ dissasemble the upper tensioner assembly from the front screw facing you in

making most careful note of where everything goes

ther'll be fluff and dust and crap everwhere therein

wash the steel washers with alcohol

and all the years of binding gunk out

check out singer site, say model 291 u3

oldie but a goldie

there's a good illustration there of how to adjust thread tensions, like wow it's got three examples of bottom loose, good and top loose man

just what you needed

note thread pulled from top should be firm like a reasonable pan sized fish

with consistent pull to tension no grabbing or binding

also check that your standard feed dogs are in good nick pulling job thru nicely

you can change to heavy duty feed dogs real easy and worth doing mate

coupla screws and parts are cheap as chips

well anyway good luck

have a great day

[JuneC]

I'm with the "top tension too loose" group.  Ok, so you've tightened it all you can.  Something in the thread path is not working as designed.  Your take up spring may not be heavy duty enough. Or the needle is too small for the thread diameter.  Or your tension spring is sprung.  Just for fun, grab a spool of your wife's dressmaker thread and test it with your setup - placing it on the top only (leave the bobbin as-is).  If you don't get bunching underneath, you probably have a too-small needle.  The top thread, via the needle, penetrates the fabric multiple times, each time getting more frayed.  If the needle hole is so small that the take-up spring doesn't pull it back through the fabric to the upside, you'll get bunches underneath. 

To illustrate, use a white top thread, take a red Sharpie and put a mark somewhere on the the top thread - maybe 3 inches above the needle eye.  Sew by hand, slowly and watch the red mark to see how it goes through the fabric multiple times.  Each time it gets harder for the thread to come back up topsides, through the needle eye because it's getting fuzzy from so may passes through the fabric.  The thicker the fabric, the more difficult it is.  Eventually, the friction is so great that it exceeds the tension from the discs on the topside.  End result is too much thread UNDER the fabric. 

There are a couple of fixes - heavier take up springs (the "U" shaped thing on the left side of the tension discs) or a bigger needle.  When you manually pull the thread from the spool on the topside, via the needle, it should be quite difficult (with the presser foot down).  If it pulls through easily, then your tension disk spring is too weak for the thread you're using.  You might try expanding it so it presses harder when you tighten up the tension nut.  Or, order yourself a new heavy-duty tension spring or take-up spring.  Sorry to be so wordy...  I'm no mechanic, but I've certainly had my share of tension problems. 

June

[needles eye]

sorethumbs
what's happenning
give us an update mate
how'd your needle shopping go

anything else springing around??

make sure the bobbin holder reasonably tightish
being not as loose as you have implied
make sure the tensioner threading is correct too!
the thread goes out the tensioner assembly to an arm and then back to tensioner  and up ... check 238 manual

[Sorethumbs]

make sure the tensioner threading is correct too!
the thread goes out the tensioner assembly to an arm and then back to tensioner  and up ... check 238 manual

I don't follow this, could you explain more. My threading procedure goes like this: 1) off the spool, 2) up to an over-machine arm, 3) down to a metal pin of top of the machine, twice trough, 4) down to a bracket, thrice trough, 5) down and around the tensioner clockwise,  6) through the litte spring retainer on the tensioner, 7) over to a small downward pointing arm, 8 ) up and trough the large osillating arm (take-up lever), 9) down to and through a small thread retainer near the needle, 10) through the needle.

I do have some updates, good news and bad. Good news, I got the machine sewing. The thread is interlocking between the layers of fabric! I changed the bobbin case & bobbin. I think the machine came with the wrong ones. I also changed to a size 20 needle.

The bad news: there is a part completly missing from the machine. The final threading step is to pass the thread through a "thread retainer." That is the missing part. It is a small arm that extends from the machine to a position in front of and above the needle. It has been replaced by a small bracket that sits on the shaft above the needle. I think the original "thread retainer" probibly adds a small amount of tension to the thread. I called several industrial machine shops but none had the part. Oh well, I guess if the machine keeps going I can't get that bummed.

[needles eye]

the last thread retainer isn't all that important really and there's nil tension from there, just functions as a guide

could try try a google search for "threading pfaff 238"  or search on youtube, there is one on there for threading a 430 which is probably similar ..

http://www.youtube.com/watch?v=HgRHBxMV3_8&feature=related

[DBR1957]

My first thought was the "U" shaped take up spring like June said.

My other thought was the release pin on the tension guide plates.
On my Consew 206 when you lift the presser foot there is a pin that
pushes on a lever and slightly separates the guide plates that the
thread runs through. If the pin isn't returning the plates will stay
"open" and there won't be any tension on the thread.

Your Pfaff may not operate the same way but there has to be a similar
mechanism.

[Sorethumbs]

This weekend I ran 140 feet of seams/hems and made 4 bimini straps for my boat blind. Things went pretty good. I think switching to the larger needle really helped. That incorrect bobbin was really screwing things up too. I think it was binding within the case.

Here's a question for you. This is a duck blind being made of camoflague material. After each panel of fabric is made (60" x 60") there is a layer of raffia grass (like from a hula skirt) that is sewn at the top. This gives the blind complete camoflague when out in the marsh. I completed one panel with the raffia grass sewn along the top, so it hangs down. It looks great! However, I can still pull individual grass strands out of the seam. If you had to do this how would you set-up your machine? Needle size? Thread size? stitch length? Zig-zag or straight stitch?

[baileyuph]

What stitch length setting?

Never sewn grass but intuitive it is going to likely take a very short stitch length.

I assume the machine pulls the grass through the needle acceptably?

Doyle

[Toledo Mach. Sales]

However, I can still pull individual grass strands out of the seam. If you had to do this how would you set-up your machine? Needle size? Thread size? stitch length? Zig-zag or straight stitch?

Shorten your stitch length so you catch each blade.
Bob