One of our readers asked how to reassemble the stitch-length adjustment knob on her 503 Rocketeer. She took hers apart to clean it and then encountered a problem getting the pieces back together. I didn't know the answer either, so I went and asked the resident expert. He explained it to me and I went and tried it out for myself and took some pictures and videos to share.
Without further ado, here's how to reassemble the 500/503 stitch-length adjustment lever knob. First we'll look at taking it apart and then we'll look at putting it back together.
The lever has a knurled knob on the end that tightens up against the face plate to select the desired stitch length.
There are two wings on the lever that slot into the notches at the "fine" selection and the "6" selection to lock those settings into place.
To disassemble the knob, use a standard screwdriver to remove the screw at the end of the shaft. Then pull the whole knob assembly toward you. It will slide off along with the small washer that sits on the end of the shaft between the screw and the knurled knob.
The winged piece screws up inside the knob and will have to be unscrewed for proper cleaning and lubricating.
When you've finished disassembly the knob, you'll have four pieces as shown at left. Next, a light application of lubricant on the inside the knob will aid in reassembly.
Putting the knob back together can be a bit tricky because threading the winged piece back into the knob works opposite from the old "lefty-loosey, righty-tighty" principle.
Start by holding the winged end in your left hand. Then take the knob in your right hand and screw it onto the end of the winged piece, turning it toward you. This is best shown in video:
Next the winged end will be inserted into the slot on the lever and the washer and screw put back in place. Again, this is best demonstrated in video:
As you can see, it only took a little bit of fumbling to get the pieces back together. Believe me, it will be a lot easier if one hand isn't tied up holding a camera!
And there you have it. Make sure everything is firmly tightened and your knob will be good as new.
Happy Sewing! Barbara
OldSewinGear...dedicated to helping you get the most out of your old sewing gear.
OldSewinGear is the collaborative effort of retired repairman Gary and daughter Barbara. We love old sewing gear and enjoy sharing what we've learned in our vintage sewing machine adventures. We are located in Roseburg, Oregon.