In this Instructable I will show you how to adjust the bobbin timing on your machine. For my example I will be using the Handi-Quilter at TechShop San Jose.
You will need:
A pair of thread nippers
A screw driver
A metric hex key set (if your machine happens to use it. It might be all screws)
Step 1: Take It Apart
Step 2: How a Bobbin Works
There are 2 main parts that I will be talking about today
1. The Bobbin Case
2. The Shuttle Race/Shuttle Hook
The Shuttle Race is made of 2 parts. The part on the inside is stationary, and the part around the outside rotates and grabs the thread as you sew (aka. the hook).
On the Handi-Quilter, there are 2 lock bolts which you can access through the access points on each side of the machine. You might have to turn the wheel to get to each.
Once you have the needle down, rotate the outside of the shuttle until the point of the hook is just above the eye of the needle.
It is very important that the inside of the shuttle stay stationary during this alignment. It should be held in place by a prong coming out of the machine.
Again, you may have to carefully turn the wheel to get access to the bolts, but be sure the shuttle is turning with you.
There should be an opening between the top of the pin and the back of the shuttle slot. It varies between machines, but should be somewhere around 1/16" or less. You really just want enough of an opening do the thread can come up through after going around the bobbin.
If you do need to adjust the distance of the pin, there should be a bolt underneath the machine you can loosen.
I suggest you thread the machine, insert your bobbin, and run the wheel to make a stitcth at this point to make sure you have the shuttle hook and your pin aligned properly.