Myford gear problems steel and Tufnal

When turning my Super 7 lead screw by hand I noticed the quick change gearbox was making lots of chatter and cyclic ticking noises, and on inspection found a number of dings on the gear teeth both inside and outside of the box which I filed off with a fine grain diamond needle file, washed them in WD40, and bingo! quiet box.

Happy at this I then set the meshing of the quadrant gears, and was turning the chuck by hand to listen to the outer drive train, when a tooth came off one of the Tufnal gears! which I either put down to fatigue or a historic event.

But my Tufnal gears don't have any grain in them and I don't know if this means they are old or third party gears? and thought Tufnal was like it's name tough?

Edited By C J on 27/03/2018 01:50:41

Edited By C J on 27/03/2018 01:51:46

Looks like someone in the past has been changing gears with the motor/spindle running and gear train moving. Tsk Tsk. Tufnol may be tough but it's still the weak point in a train of iron/steel gears, which is not a bad thing if it saves the other gears from major damage.

Bottoming of gears?

I think Hopper's analysis of gear-changing whilst moving could be correct; it doesn't look like foreign object ingress to me.

Tufnol gears are original and are there to reduce the noise of the gear train as well as provide an easily-changed (but expensive) weak link in the gearing. RDG Myford still sell the gears, but I think third parties also sell them in Nylon and other similar materials.

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If they don't have any grain, then they are [most likely] injection-moulded 'third party equivalents'.

Here's a link to Tufnol's page about gears: **LINK**

http://www.tufnol.com/technical/tufnol-gears.aspx

MichaelG.