Saturday, February 16, 2013

Sewing Machine Tensions

Lets talk about tensions.  When a machine comes into the shop, no matter what the problem is, the customer will usually say, "it's the tension."  If the timing is off, "it's the tension."  If there's a burr on the hook, "it's the tension."  If the needle is in backwards, "it's the tension."  You get the idea.

I'll do a run through on how we balance the tensions at the shop.

Before we can work with tensions, we clean and oil throughout the whole machine.  It's especially important to clean and oil your bobbin area before working with the tensions.  That's something you should be comfortable doing yourself.

When you thread your machine, the presser foot has to be in the up position, to open the upper tension disks.  If the presser foot is down, the tension disks are closed tight, and the thread can't get into them.  When that happens, your fabric will have loops on the bottom, like this...

You can click on the pictures to make them bigger.

Next, make sure there's no lint in the upper tension disks or inside the bobbin case.  You can sweep the lint out with your lint brush.

Then set your upper tension dial on "normal."  If you don't have a "normal" setting marked on the dial, set it at 3.

Correctly thread your machine, top and bobbin.  Put a light colored thread in the bobbin and a medium to dark colored thread in the top.

Set your machine to do a medium zig-zag (unless your machine is just a straight-stitch machine).  On most machines it's 3 on the width and 2 on the length.

Sew on a light colored, good quality, cotton fabric for about 6." 

If the bobbin thread is pulling to the top, tighten the bobbin case tension by turning the little screw to the right.  Remember, "righty tighty, lefty loosey."  Here's some pictures of  bobbin case tension screws...

If the top thread is pulling to the bottom, that's what you want it to do.  But, you only want the top thread to be a "tick" on the back.  If it's really pulling to the back, loosen the bobbin case tension by turning the little screw to the left.

After working with the bobbin case tension, if you're still not sewing well, try adjusting the top tension.  It works just opposite of the bobbin case tension.  If the thread is still pulling to the top, loosen the upper tension.  If the thread is still pulling to the bottom, tighten the upper tension.

Here's my nearly perfect sew-off sample.

If you're still not sewing well, it may not be the tensions, and you may need to take your machine to the shop.

Saturday, February 9, 2013

Quilt Guild Presentation

This past week, I was asked to come to 2 quilt guilds to give a sewing machine maintenance class.  One guild wanted a hands-on class where they opened their machines and did what maintenance they could on them.  And I took my camera, but forgot to take pictures.  Dang!  The other guild just wanted a lecture/demo.  There were 7 students in the hands-on class, and about 30 at the lecture/demo.  It was great!  I love teaching these classes!

One question that was asked at both classes was, "what gets done when we bring our machine in for a service?"  So, I've made a list. 

When you bring your machine in for a full service, here are some things that get done:

1.  Clean and oil throughout, which can get very deep.  We remove some, or all of the outside of the machine, and use an air  compressor to blow out the lint.  We oil where metal rubs on metal, and put grease on certain gears and tracers.

2.  Service the motor.  Older machines have carbon motor brushes that wear out and may need to be replaced.  We oil the bearings at each end.  In addition, we clean the motor’s commutator (or armature) when it’s accessible.  Then blow the carbon and lint out of the motor when it is open.

3.  Check the belts.  Belts need to be replaced when they start to shred, get deep cuts in them, or get saturated with oil. 

4.  Check the electrical components.  Foot controls and cords on older machines may be a fire hazard.  On newer machines, circuit boards and stepping motors need to be checked.  We also make sure the lights are working properly.

5.  Check for mechanisms that have been gummed-up with old oil.  When necessary, we use a solvent to remove the old oil, then re-oil.

6.  Replace or repair any broken parts.

7.  Polish the burrs and scratches off of the hook and needle plate, if needed.

8.  Replace the needle.

9.  Check and set the timing.  We make sure the needle, hook and feed dogs are working together to make a good stitch.  Never try to adjust the timing yourself!  There are too many variables, and you’ll just scramble your machine.

10.  Balance the tensions and do a sew-off sample.

11.  Clean the outside of the machine.

What To Bring With Your Machine When It Needs a Service:

1.  Foot control and power cord (these need to be checked, too)

2.  Standard presser foot.  This is the foot that can sew all of the stitches on your machine, and has a nice flat bottom.  We need this foot to do a good sew-off sample.

3.  Bobbin case (so we can balance the tensions)

4.  The right bobbin

5.  Thread (if a particular thread is giving you trouble)

6.  Embroidery module and hoop, if it's an embroidery machine

7.  Please write what problems you are having on the service order, and if you’d like to include a full service.

What NOT to bring (because we may loose them):

1.  Accessory case and accessories

2.  Carry case, bag, box or crate

3.  Walking foot or other specialty feet

4.  Thread (unless the thread is giving you trouble)

5.  Snap-on sew table

If you are still having problems after the service, please bring your machine back right away, so we can sit down with you, and figure it out.