Screen showing broken thread when using double needle

Edge Stitching Foot? Or 1/4" guide foot? Piecing foot?

1 4 Edge Stitch Foot
or
http://www.husqvarnaviking.com/accessories#1814

In actuality, almost any flat presser foot will work that is wide without any ability to roll edges, pintuck, etc. You can attain the 1/4" seam by measuring exactly 1/4" from the needle and mark with a strip of painter's tape, or some other movable material. Then just use that painter's tape as your 1/4" guide. Somewhere I saw someone recommended using 1/4" inch graph paper as a guide--set the needle on a line and use the 1/4" line for the fabric guide.

Generally, you would use a straight stitch. Trying a decorative stitch or zig-zag with a twin needle is tricky because the twin needles will hit the presser foot or needle plate if the stitch width is set too wide. Be sure you are using a presser foot with a wide opening.

Stitching Odyssey How to use your twin needle

How to Use Twin Needle on Your Sewing Machine

A twin needle makes neat pintucks if you have a pintucking foot.

Your owner's manual should have instructions for using a twin needle.

Most machines can use a twin needle. However, some machines have two tension disks so one can separate the two threads and get equal tension. (The Bernina 930 has two tension disks, so am assuming your newer machine does also.) Look at the top of your machine where the tension mechanism resides and see if there is a right and left side. In either case, do NOT thread both threads at the same time as the threads can become twisted. When threading the machine, ALWAYS RAISE the presser foot, thread one thread completely. If threading the left side of the tension disk, also thread the left needle. Then thread the second thread, making sure to use the other side of the tension disk and needle.

Just a reminder to be careful using any zig-zag or decorative stitches since a twin needle requires a narrower stitch width to avoid broken needles.

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Stitching Odyssey How to use your twin needle

How to use twin needle So Sew Easy

Bernina Instruction Manuals

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It appears that there are two issues: skipping stitches, and, loose stitches. Let's deal with them individually but first some general points to check.
1. Change both needles for completely fresh ones out of the package. Make sure that they are inserted all the way up, this is very important. The right needle should appear longer than the left one. Make sure also that you are using the correct needles for your serger.
2. Use a good quality thread with very little stretch, almost no fuzzies, and in pastel colour. Dark thread ages quicker, therefore has a shorter shelf live. A good quality sewing machine thread is also acceptable.
3. Make sure that the tension dials are clean and free of lint or other debris.
4. Re-thread the serger in this order, keeping the presser foot in the down position at all times
a) Upper looper. Ensure that the thread is securely embedded inside the tension discs. Place the thread tail under the presser foot to 11:00 o'clock and place the presser foot down again
b) Lower looper. This is the difficult one to thread but make sure that all the thread guides are properly threaded as well as the upper looper elbow. Check that the thread is lodged between the tension discs. Once the lower looper eye is threaded, place the thread in front and over the upper looper and then under the presser foot to 11:00 o'clock and place the presser foot down again.
c) Right Needle. Thread the right needle path, again ensuring that the thread is between the tension discs. Place the thread tail under the presser foot to 11:00 o'clock and lower the presser foot.
d) Left Needle. Proceed as with left needle.
e) Double check that all tension dials have their respective threads embedded between the discs by pulling firmly up on each thread above the tension dials.
f) Check that the stitch length is set to between 2.5 and 3.0, differential to normal, blade position to middle, blade is engaged, and upper looper converter not in use.
g) Set tensions to recommended setting for 4-thread overlock.
g) Make a test stitch out. How is it? Still having the same issue/s?
If yes, continue with the items listed below, otherwise have a great time serging.

Skipping Stitches:
1. Check that the looper tips are smooth. Burrs will cause problems.
2. Check that the needles match the type of fabric being sewn.

Loose Stitches:
1. Double check threading.
2. Debris caught between tension discs will also manifest itself in loose stitches. Take an 8" X 6" piece of medium weight clean and lint free cotton fabric, fold it in half length-wise and pass the fold only firmly between the tension discs from top to bottom (with the presser foot up and no thread in the tension dials).

Re-thread and test stitch. How is it now?

Something here may help:

How to Sew Pin Tucks Threads

Try removing the top threads from the machine. ALWAYS RAISE the presser foot and rethread both threads. Could be possible your threads were not seated in the tension disks.

if you want to sew pin tucks, then yes, you could use that foot providing the hole is large enough for the two needles to pass through. Twin needles come in 4mm gap and 2.2mm gap so just check that it will fit. When using a twin needle, there is a lot of heat created so it is always important so sew slowly, going too fast will cause the needles to break.

Also, you should check on the twin needle type, modern machines now using a twin which is slightly offset, the block colour is usually a dark brown/red colour. Your machine may have come with a twin needle in the needle selection so take a good look at it and see if it is an offset one, then make sure you buy replacements of the same type.

THe pin tucking foot allows you to keep rows of pintucks lined up, it will have grooves in the base that you can run the previously stitched pintuck through to keep even distances. Best on lightweight fabrics like cottons, lawns, batiste etc. You'd probably go for the narrow 2.2mm twin needle to get a nice fine tuck. I like to press each seam after stitching too to give a sharp tuck.

Hello,

The Pfaff 7570 Creative Designer is a computerized sewingand embroidery machine that has the ability to connect to the computer, andhave embroidery designs sent to the embroidery machine. The sewing andembroidery machine has many features, including hundreds of general sewingfunctions, a separate embroidery module, and on-screen editing features. TheCreative Designer 7570, manufactured in the 1990s, was the first sewing andembroidery combination machine ever made by Pfaff.

1. Usingthe Sewing Machine
1 Turn on your sewing machine using the "On"button located just below the turn wheel on the right side of the machine.Thread your Pfaff 7570. Note that Pfaff sewing machines thread from left toright, not right to left like other sewing machines. The upper tension discsshould be raised at their highest position while threading, and the presserfoot should be raised up until you thread the needle. Drop the presser footright before you thread the needle. The prevents thread problems during use. 2 Insert a full bobbin and retrieve the bobbin threadthrough the thread plate. Raise your sewing foot and needle to its highestposition; hold the needle thread taught with your left hand, lower the needleinto the thread plate using your right hand, and then raise the needle. As youraise the needle, the needle thread will catch the bobbin thread, and pull itup. There should be a loop of thread intertwined with the needle thread. Usetweezers, your finger, or a straight pin to retrieve the bobbin thread that isvisible through the thread plate, and pull it through the plate. 3 Place the fabric under the presser foot, and drop thepresser foot. Choose the stitch you want to use from the top stitch display,right above the top thread feed. Press the '0-9" button located on thesewing machine's front panel, and a display screen will come up. Input thethread number, and press the 'OK' button located on the sewing machine's frontpanel. The stitch will display, and you are ready to sew. Repeat Step 3 foreach stitch you want to use.

2. SettingUp the Embroidery Unit
1 Turn the sewing machine off. Take out the embroiderymachine unit, locate the connection bushing on the back of your embroideryunit, and match it up with the connection bushing on your sewing machine. Theconnection bushing should be located next to a yellow sticker on yourembroidery unit, and somewhat resembles a serial port on a computer. Slide theembroidery unit onto the sewing machine with the sewing machine turned off. Connectto the bushing carefully as you slide the embroidery unit onto the sewingmachine. Use your embroidery unit manual if you need assistance. 2 Insert an embroidery card. Your embroidery unitshould contain an embroidery card labeled embroidery card 1. Use that or useanother Pfaff 7570 card that you own. Turn on the sewing machine. 3 Open the bobbin case area just below the threadplate, and lower the feed dogs by pushing the feed dog switch to the right.Press the card button located on the front face of your sewing machine. Adisplay with pop up; choose embroidery designs or monogram and a new screenwill pop up with your design choices. Choose the design you want, and press"OK." A checklist screen appears. Do everything on the checklist, andpress "OK." Use your embroidery unit manual if you need help. 4 Start embroidery by pressing the foot pedal. At thistime, your hoop should already be attached to the embroidery unit becauseyou've already gone through the checklist. Your embroidery manual displayscolored picture diagrams that are very helpful in understanding everything inyour checklist menu.
Thanks for using fixya

If you want the bottom of the T to look like RTW with the double row of stitching, you cannot do this on a serger.

You can achieve the effect by using a twin needle, two spools of thread, bobbin and a straight stitch.

Make sure the double/twin needle will pass through the presser foot and opening in the needle plate below the presser foot.

Practice on a double layer of a scrap of the T shirt material as the tension may need to be slightly looser than the normal setting.

Re thread the machine with the presser foot up.

Use a heavier stabilizer - double what you used before.

Change to a new needle.

Solution taken from "Handbook for Huskylock Sewing Machine Models 1001L/1000L/1000"

1. Raise the presser foot by using presser foot lever. When the presser foot is raised, the two thread tension discs in the thread tension control panel are released so that thread passes freely between them. Otherwise thread tension may not be correct.

Important! When threading the needle, always be sure to lift the presser foot lever, and also take care to thread in the proper order.

Threading order:
1. Upper looper thread (green)
2. Lower looper thread (blue)
3. Double chain stitch looper thread (purple) in case of 5 thread stitch or double chain stitch
4. Right needle thread (red)
5. Left needle thread or double chain needle thread (yellow)

Caution!
Because the left thread tension dial (yellow) is used for either the left needle or the double chain stitch needle, these needles will never be used at the same time.

Upper looper (green) sequence:
1. Thread holder (silver triangle openings attached to thread holder stand)
2. Thread guide (flat silver clips just behind thread tension disc)
3. Thread tension disc (circular knobs with numbers for tension setting)
4. Pull thread around upper looper guide and upper looper
5. Pull thread into hole of upper looper

Lower looper (blue)
Repeat 1, 2, 3.
4. Pull thread around guide (see color coded chart inside front serger cover).

Easy threading mechanism (for lower looper)
1. Pull out the lower looper threading lever
2. Thread the lower looper and position the thread on hook of the lower looper
threading lever.
3. Push the lower looper threading lever back to its basic position while
holding the end of the thread.

Caution:
When returning the lower looper threading lever, always make sure that the two
blue triangle marks (directional arrows) meet each other.

Right needle thread (red)
Left needle thread (yellow)
Important: Thread the needles after threading of lower looper and upper looper.
First raise the presser foot lever, and then thread the needle threads in order shown in color coded thread guide.