Making a longer chuck key

[WobblyHand]

The chuck key that comes with my mini-lathe is just long enough to do the job, but not long enough to be convenient. By not long enough, I often bust my knuckles, or manage to hit the dial indicator because the handles are not far enough away from the chuck. So I'd like to change that. Handles could be a little longer, but, that's not as important as increasing the body length. I have 2 chucks, a 3J and a 4J. The keys are annoyingly too short.

I have some O1 steel in 0.625" diameter for the key and 0.3425" diameter for the handle. I would turn down the end of the body for the key so that the diameter is about sqrt(2)*key width. Not sure how to make the key square. So far, the only idea I have come up with is a collet in a square collet block to grab the stock. That way, one could then just put the collet block in a vise and file the section. Then rotate the block 90 degrees and file again, etc. Is there a better approach? Don't own any collets, nor a collet block, so I'd like to know if there is a better way, so I can minimize my cost, and maximize the likelihood of two properly fitting chuck keys.

Should I attempt to harden the square key afterwards? They are not that big, only about 0.25" across the flats, for one of them and about 0.3" for the other.

 

[brino]

Okay, so without a mill and without a collet block.......

Could you use the 4-jaw chuck itself for indexing?

Maybe
i) in the lathe, centre the stock in the 4-jaw chuck
ii) do any required reduction in the bar diameter
iii) remove the chuck from the lathe (with the bar still held tight)
iv) put the bar in the bench vise jaws aligning the sides of two opposite horizontal lathe-chuck jaws with the tops of the bench vise jaws
v) file away
vi) rotate in the bench vise for the four flats
Viola!

-brino

I noticed when making mine here: https://www.hobby-machinist.com/threads/just-a-simple-lathe-chuck-key.81492/
that I also had to remove the corners of the square end. The lathe chuck pinion holes did not have square corners.

-brino

 

[ErichKeane]

You could 'face' it square, but just on the bottom. Put it in the 4 jaw perpendicular to how it usually goes (like this: http://www.mini-lathe.org.uk/turning-square-part-mini-lathe.shtml) and turn 'face' a side flat. Rotate 90 degrees, repeat,etc.

 

[WobblyHand]

That's an interesting perspective. Might be interesting balancing the chuck and trying to file. I'll look into it.

I was expecting someone to try to spend some of my money. You're not trying hard enough I'm not adverse to spending some cash on the collet blocks. I just wasn't sure it would work.

 

[WobblyHand]

You could 'face' it square, but just on the bottom. Put it in the 4 jaw perpendicular to how it usually goes (like this: http://www.mini-lathe.org.uk/turning-square-part-mini-lathe.shtml) and turn 'face' a side flat. Rotate 90 degrees, repeat,etc.

I've seen that before. Was hoping I could do that squaring on something. I'll think about it again. Might be possible... The chuck size would limit the length of the key. More to ponder.

 

[brino]

.....following along with @ErichKeane 's great idea, if the shank is too long to be held perpendicular in the chuck, just square a small block using his method and then press it into a hole on the end of the chuck key handle.
(yep, square peg and round hole.....that's the kinda guy I am)

I was expecting someone to try to spend some of my money. You're not trying hard enough

Sorry to let you down ...... hopefully they don't take away my membership for not upholding the values of the site!

-brino

 

[ErichKeane]

.....following along with @ErichKeane 's great idea, if the shank is too long to be held perpendicular in the chuck, just square a small block using his method and then press it into a hole on the end of the chuck key handle.

-brino

Thats a really good idea... no reason it has to be one piece! You could always just do a theaded joint and red loctite it.

 

[brino]

You could always just do a theaded joint and red loctite it.

Great Idea!

To me that's what makes this site so useful.

Three of us across North America just had a brain storming session (a kinda white board session, but with typing) and came to an elegant solution.

I guess we have to find another project for @WobblyHand that requires the collet block and collets though......

-brino

 

[darkzero]

Sorry to let you down ...... hopefully they don't take away my membership for not upholding the values of the site!

Ooh, you're sooo getting an infraction!

 

[mikey]

I was expecting someone to try to spend some of my money. You're not trying hard enough I'm not adverse to spending some cash on the collet blocks. I just wasn't sure it would work.

These guys are just trying to be helpful. I, on the other hand, am going to tease you about being "mill-less". I am going to try to spend your money!

If you buy a mill, hair will suddenly grow on your chest and maybe even the top of your head ... you will be a manly-man!!! When other mill-less guys have issues, you can step up and speak with pity and disdain. You may not ever make parts for NASA but you can tell yourself you could if you wanted to. Heck, with a mill and a collet block, that wrench is 10 minutes away from being done and if that doesn't make you puff up your chest, I don't know what will.

I fully expect @darkzero and @higgite to back me up on this. We help each other spend the other guy's money and we are hereby including you!