Super 7 spindle crank handle

My take on a spindle crank handle for my Super 7 lathe who's bore was more like 16mm than 19/32". I made the main shaft from bar so had to push a 6mm drill bit through 210mm which took a bit a bit of clearing!

Edited By C J on 06/07/2018 20:26:39

Edited By C J on 06/07/2018 20:29:44

CJ,

I made something similar a long time ago but was always fearful of forgetting to remove it after use. I bought a spoked wheel off an exhibition junk stand and fitted it to a spindle like yours but shorter so easier to drill out. I still have to remove it before turning but at least I feel safer, should my sieve like brain let me down. There is a small lever handle on the rim and I think that it causes a small out of balance load resulting in chatter when turning. That is why I still remove it.

John

Hi John,

I get distracted very easily so I'll have make a big "Check for handle" sign next.

I made the handle for cutting short threads instead of playing Russian roulette with the clutch!

Regards,

Colin

Edited By C J on 06/07/2018 21:46:00

Hi Colin,

Maybe you need a "REMOVE BEFORE FLIGHT" streamer as used on aircraft, for your handle!

http://www.aircraftspruce.ca/catalog/pspages/ljrstreamers4604.php?gclid=Cj0KCQjwpvzZBRCbARIsACe8vyLfFzqBbdaRUpiwMQ2TTefltfxdFzgxoOSA4MDwVspvnZnc1XtXQssaAp08EALw_wcB

Great job on the handle BTW.

Ha ha

And I cut the slots with a hacksaw too.

Edited By C J on 06/07/2018 22:26:00

Why does it need to be so long it would drive the spindle from the end without having to be so difficult to make?

David

The bore of my spindle tapers slightly towards the middle so I thought to position the expanding part at the point but as an aside I suppose a longer shaft helps the he handle to run true.

Edited By C J on 07/07/2018 00:12:08

There was a beautiful one with balanced ball handle in probably MEW, 10 or so years back. I just had a quick flick through looking at covers but it might not have been on the cover. The lathe ran smoothly with the handle attached, just for testing and not recommended. Might have been David Piddington ??

if you had a DEWHURST type reversing switch, you could remove the lever handle from the switch and use that as the handle for the crank.
BobH

That's a nice looking handle. I made mine from the Hemingway kit, I wonder how I ever got on without it.

Now that's a clever idea...

One with a sprag bearing might be safer

The the handle only turns when the operator turns it

Like a motor boat starter

The proper solution is to find or create a universal form of safety interlock that positively prevents a motor start when the handle is in position

Speedy Builder offered an ingenious idea on just the right lines but it would only work of course on lathes equipped with Dewhurst switches.

Brian

I made one for my mini-lathe and very useful it was too. For some reason I've not felt the need to make one for my bigger lathe, probably because it can do 30rpm rather than the mini-lathes minimum 150.

Anyway, rather than attach a permanent handle, I put an nut of the end and drove it with a ratchet spanner handle.

(My version gripped the spindle with sliding angled blocks tightened by a threaded rod. (Wish I had a photo - it was based on the way handlebars are fixed to a bike if that helps.)

The advantage of a detachable handle is being able to safely leave the gripping part fitted inside the spindle when doing other work. The disadvantage is it's easy to power up the lathe after forgetting to remove the handle. Quite scary!

You could always make a stowing receptable, that makes an interlock that only allows motor start when handle is in its righful place.

One of my “to do” jobs but have managed for 40 years without one ! However I always had in mind to make spring loaded dog clutch for the drive, just 2 pegs on the handle and 2 slots on the spindle part, similar to the ones on the knee/table on milling machines. Thus you need to push in and engage the handle when in use, when you let go it disengages . Not a get out of jail free card but if the machine was inadvertently started with the handle in place it’s only friction that could drive it and that’s unlikely I think?

The sprag clutch is a good idea but it will drive only one way.

John

The article I referred to above was in ME

https://www.haythornthwaite.com/4341%20Mandrel%20Handle.pdf

Sorry, I don't know how to make the link live

Thanks for the reference, Simon

... Here's your **LINK**

https://www.haythornthwaite.com/4341%20Mandrel%20Handle.pdf

MichaelG.