What to do ...

[SpaceCadet]

I have a question ;D

I have just made a spindel hand wheel for my Super 7 to the design by GT. I am very happy with it apart from one thing.

The screw shaft that pulls the cone into the main body, thus expanding it and locking it in the spindel, has a grove cut into it and a dog ended screw runs in this. The purpose of this is to make sure the cone ejects automatically when the screw shaft is losened, thus not having to give the screw shaft a tap with the hammer to eject it.

However, there is quite a bit of side force acting on the grove and after only a few uses has resulted is the shaft being deformed. The grove has curled outwards. thus now rubbing on the main shaft. Both screw shaft and screw are mild steel.

Should I:

a) Replace screw with one made of brass so that it deforms rather than the shaft ?
b) Replace screw shaft with another (harder) material ? Which would be ?
c) Case harden grove?

Thanks

/Ian

[Tel]

I should think that a screw bearing on the side of the slot would be a particularly bad bit of design in this instance as the contact area is tiny, allowing the distortion. Much better, perhaps, to cut a groove (keyway) in the outer part & fit a key at least 3/16" long in the shaft. My mandrel handle dosen't have any anti-turn provision at all (but then, I 'made it up' as I went along). I just hold the handle, give the nut a tweak with the spanner & then tap the nut with the spanner. Works every time.

[IP]

Tel,

Same here, I made my own mandrel handle no anti turn and just like you one quick turn and hey presto.

Regads, IP

[Tel]

Well, I gotta 'fess up that I made mine outta various bits & pieces, the actual handle is a speed control handle from a Mono pump & the bolt & nut are out of a masonry anchor. All I actually made was the adaptor to fit the handle to the mandrel, with the tapered hole & slits.

It was just a rough, temporary job to get me out of trouble & since it will have been in use for 25 years in a month or two - it's probably nearly time I did a 'proper' one.

[Phil Sutton]

Tel,remember the old saying"If it ain't broke,don't fix it",works for me every time.(done too much'fixing'in my impetuous youth)

Phil

[IP]

Ian,

Thinking on a bit, do away with the pin altogether what is ow mine works.......to release after use a very light tap with an ommer will do the trick.

Regards,

IP