Tuesday, July 5, 2011

Rotary Hook Drive Shaft Removal

I approached this part of the disassembly with some trepidation, but I’ve run out of all the easy stuff to do.  Before starting I read, and re-read, the Adjuster’s Manual hoping it would be of some help only to find out it was going to be more difficult than anticipated since Ms. Rusty’s gears don’t rotate, making it difficult to access the set screws in most places.
Here is a view of the underside of the Ms. Rusty:  Bottom of machine
I removed the Rotating Hook Shaft Bevel Gear Cover on the by taking out 2 gear cover screws.  This cover is on the front end of the machine, on the left hand end of the drive shaft.
rotating hook gear coverfront gear cover removed
Then I removed the back cover (attached with 2 screws) exposing the back bevel gear.
rear gear coverrear gear cover removed
I then loosened 2 set screws at each of the following points -
Front bevel gear -    front bevel gear set screws
Drive shaft collar -   drive shaft collar set screws
and back gear hub - back bevel gear set screws
At this point the drive shaft was ‘supposed’ to loose enough to be withdrawn.  Not so in my case Sad smileSo I proceeded to removed all the set screws and applied some lubricant to work into the joints and loosen things up.  While that was working, I moved on to work on the removal of the front gear hoping to make some progress there.
I took off the bevel gear front cover – here is a picture with one of the 2 screws removed:
bevel gear front cover removal
Fortunately the front bevel gear was loosened up from the drive gear and I could rotate that enough to access both the set screws on the rotary hook bevel gear.  After those two set screws were removed I was able to pull off the rotary hook bevel gear.
rotating hook gear set screwsrotating hook bevel gear
This exposed the rotating hook shaft that I then removed from the top of the machine
rotating hook shaft exposedrotating hook shaft removalrotating hook shaft
Well, after lots and lots of lubrication, brake release, elbow grease, removal of the bushing set screws, and help from my husband, I was FINALLY able to break the rotating hook drive shaft free!  I first want to point out a few important ‘landmarks’ before pulling out the drive shaft.
Here is the underside with all the set screws removed  all set screws removed
Rear bushing flat area for set screw - left bushing recess
Divot at right end of rear bushing - left end of left bushing
Set screw recess of front taper bushing - right taper bushing recess
Here are all the parts after removal from the sewing machine:  front bevel gear, front taper bushing, left drive shaft collar, right drive shaft collar, rear bushing, and the drive shaft with rear bevel gear still attached at the top.  Theoretically the rear bevel gear should come off the drive shaft, but even after overnight soaking in kerosene, it still will not come off.  At this point, I’ve stopped trying and have decided to leave it on.
rotary hook gear drive and bushings
I can’t really tell the difference between the left and right drive shaft collars, but here are pictures of the left and right hand sides of the them for future reference, just in case there is some difference that I can’t pick up at this time.
left hand side of right and left collarsright hand side of right and left collars
Here is a picture of the bottom of the machine after the rotary hook drive shaft and respective gears are removed.
under machine without drive
I think the next step will be to remove the feed dog shafts.  At that point I should be done with the bottom of the machine and will have to tackle Ms. Rusty’s innards. Oh boy!


  1. Thanks, I have been searching for something like this for days. Doing a 201K at the moment and nothing wants to move!

  2. Nice work! So glad it's not just me;) good luck with Ms Rusty's innards. i'm working on my very first machine, it's a Wertheim Superba "D" S68 about circa 1890-1900 i think, cost me £10, originally just to photograph after a clean-up, i got a little carried away & iv'e striped & cleaned every single little component, except for a drive shaft, gears & anything else that's inside the upper body of the machine,as it's like you, proving difficult, although it's got some lovely detailing (partly worn & worked hard) & nice mother of pearl designs, i think the machines workings are much the same as the Singer 12K new family machine. best of luck!