My yankee screwdriver

[Daydream believer]

They fit a brace and bit or a drill though.

Too slow & no good against a wall or an obstruction for a brace, as one has to keep using the ratchet

 

[dancrane]

I think you have the biggest Yankee which is a 131...You don't need to grind anything - just buy the right sized adaptor.

Ah, but there's the rub. I haven't worked out which model mine is, so I can't be sure what is the right size adaptor.

Mine is 618mm, maximum. That's substantially shorter than the quoted length of the 131.

So I'm prepared to guess and adjust the adaptor if it's wrong.

 

[penberth3]

Ah, but there's the rub. I haven't worked out which model mine is, so I can't be sure what is the right size adaptor.

Mine is 618mm, maximum. That's substantially shorter than the quoted length of the 131.

So I'm prepared to guess and adjust the adaptor if it's wrong.

You already have a driver bit that fits? Measure its diameter.

 

[dancrane]

The bits that came with it, seem to be fractionally over 7mm thick. I don't have a micrometer but they're about that.

I assumed that the "1/4-inch Hex" reference is to the diameter of the bits that fit in the hex-socket...

...not the chuck-end of the adaptor that fits in the yankee.

 

[dancrane]

You don't need to grind anything - just buy the right sized adaptor.

It arrived, and it fits.

I still don't feel sure what model Yankee I have, but the adaptor for the 130A and 130B fits, so I suppose it's one of those.
.

 

[penberth3]

It arrived, and it fits.

I still don't feel sure what model Yankee I have, but the adaptor for the 130A and 130B fits, so I suppose it's one of those.
.

Lovely!

 

[Scotsailor]

I was taught by my Dad, who used to be a RN shipwright, that these are called an “Archimedes screwdriver”

 

[georgebertie]

The ring that locks and unlocks the spiral extension will often crack, or break.Putting a small hose clip around it saves the day,and also stops the screwdriver rolling away when you put it down on a sloping surface. Especially useful when working at height or on a scaffold.