If your machine justs runs on while you wind a bobbin

Posted by Dave McCallum on Nov 14th 2013

I can't resist it!

A gentleman wrote to say his Featherweight just keeps runnin'-on when he tries to wind a bobbin. I suggested he take the hand wheel off and clean the bore and the bushing it turns on, with 220 grit wet and dry sand paper and oil. He did and the machine still didn't behave. So I suggested;

I think you will find that if you take the motor drive belt off it will take no effort at all to turn the hand wheel on your machine
compared to a machine that doesn't have "the problem". I suspect your
machine is so well "broken-in" that all of the parts are working in
perfect concert with each other therefore there is no resistance to the machines being
turned and however slight the tug of a well oiled hand wheel there isn't enough internal resistance prevent the machine from "running-on". Your machine probably runs fast compared to some Featherweights.

To induce
a little internal resistance to the machine's turning I suggest this. Gain access to the underside of
your machine and locate the set-screws that secure the bushings for the
lower high speed shaft. The bushings and their set-screws are in the
"aluminum blocks" cast into the base of the machine that support the bushings. These two blocks have the oil holes drilled through their side to oil these bushings.
I'll pick on the bushing at the hand wheel end of the machine that has
the lower high speed shaft's gear next to it. The other end of the shaft
has a block with a bushing in it also. In both blocks is a set-screw pointing
out the bottom of the machine. But for now we pick on the bushing in the block at the hand wheel end.

What I am suggesting is
that you induce a little resistance into the free turning of the machine
by over-tightening the set-screw near the gear to the point that we
deform the bushing a tiny amount. I have done this several times and it
has worked well. Before you do anything, take the motor belt off of the
machine and turn the hand wheel a whole bunch and remember the effort needed. Get use to the feel of how much
or how little effort is required to turn the machine without the motor
connected. Get/find/steal a good quality screw-driver that fits the
set-screw quite well and tighten the set screw
more/excessively. If you detect/feel that the screw has tightened a tiny
bit, check to see if you can feel an added resistance to the machines
turning. If by chance there is a bunch more resistance, back off on the set-screw a
bit and things will go back to normaler. Keep it up until you feel some resistance or until it appears this
might not be getting what you wanted and you fear it is getting to be a bit much. Lets try something else.

Plan "B", if the above didn't work;

Remove the set-screw near the gear completely. Using a "nail set" punch
(or something of the kind) reach down to the bottom of the hole touching the bushing
(which is the bottom of the set-screw's hole) with the end of punch and tap it
with a hammer. Feel for resistance to turning again. If the resistance to turning hasn't increased, tap it
again just a little more firmly, and again until you do get some
resistance, testing between each progressively heaver tap. Baby steps. At no time should you
let yourself get impatient to get things done and clobber the punch
hard. Just a little harder each time until it works, replace the
set-screw and go off telling your self that you'll never tell anybody
what you just did to your Featherweight. Especially that I said to.

I have done this before also, and it does work.

Source: Dave's Blog