"Recycling" a lathe chuck key

[craig9]

Hi folks,

This is more of a home "recycled" tool than a home made tool, but a lot of the steps would be much the same.

I start by showing a mangled worn out chuck key which still just about works. I was given an oversize spare chuck key by a friend called Ted (Thanks Ted). This gets machined down using the mill and lathe, into a suitable key for the chuck. Simple stuff, but hopefully entertaining and interesting for some.

I intend to do a quick and dirty job of hardening and tempering the working surfaces, but I didn't show that in the vid.

Thanks,
Craig

[DIYer]

Thanks craig9! We've added your Lathe Chuck Key to our Lathe Accessories category,
as well as to your builder page: craig9's Homemade Tools. Your receipt:

Lathe Chuck Key by craig9

tags: lathe, chuck key

[garage nut]

Liked the video.
Watched it just to see how you were going to do the set up to go from one face to perfectly square to the next.
Then i see you have a fancy "vice"...did you make it or is something one can buy? never seen it before.

Then a request/suggestion/wish call it what you like. I am a total self tough machinist. what I know is what I have seen on YouTube
and watching clips like this. Any chance you guys can add info to the video such as the type of cutter you are using and the rpm you are using.

[craig9]

Hey Garage Nut,

Thanks for asking. I think you're referring to the collet block. That's a device which is often available with 4 or 6 sides, which give you some good ways to get to 2, 3, 4 or 6 sides of a part. This particular one is an unusual one (12 sides) and comes from M&G Productions (in Melbourne, I believe), and was invented by an Aussie.

To use the collet block, you need a set of collets, and they're the expensive component. I've standardised on a particular external size of collet called ER-40 which suits my mill size. I use them for holding cutters in the mill spindle, and I use the collet block which you've seen, and I also intend to create a collet "chuck" which threads onto the spindle of my lathe, for workholding.

Hope this is helpful. Not sure where you're starting from, so I hope I'm not teaching you how to suck eggs. If you want more info though, please ask - I am always happy to explain.

There are lots of ways to skin a cat though. You could mill one flat, with the part held in a v-block, then use a square off the mill table to index round to the next flat and so on. Hope that makes sense too.

Also - apologies, I keep forgetting to add the cutter type, and RPM and so on. Folks have thanked me before when I've included this, but that slipped my mind until you mentioned it. I'll do what I can to include some detail in future to help out. For now, I will add a note below to explain what I did.

All the work on the lathe was done at either 500rpm or 800rpm (I forget which, but either would work fine, and the faster would would work better). For turning the cross-drilled boss down, to fit in the back of the collet chuck, I used a CCMT cemented carbide insert in a 12x12mm right hand holder. The end mill I used in the mill to trim the length down, and create the flat driving faces was a 10 or 12mm carbide four-flute endmill ran at about 1000 rpm. The radius/cove I turned with a home-ground 1/2" HSS bit shaped to approximately a 1/2" diameter. I went back to the CCMT insert to take the corners off the square, and also to produce the chamfer on the end. Chamfer tool would be better but I haven't made one up yet.

Cheers,
Craig

[garage nut]

I thought that end mill was going at some rate and a fairly decent cut as well.

I battle to afford a HSS 12mm end mill, I am sure a carbide end mill will cost what my whole Chines Lathe/Mill cost.

If it was to be a HSS end mill, what speed and size cut, working with mild steel, would you suggest?

All hand fed, no auto feed on my machine.

[craig9]

Plug the basics into a speed and feed calculator (like this one: https://goodcalculators.com/speeds-feeds-calculator/ - or find and print yourself out a wall chart with the materials you like to use - this is what I use).

That website gives 600-1000 for 1/2" (12mm) and 800-1400 for a 3/8" (10mm) HSS four flute cutter. So it looks like I could have gone much faster than I did with a carbide cutter (approx 4 times the RPM - not that my mill can do that).

You don't have to try to hit those numbers though, and if it's easier on you or your machines, you can run at lower RPMs, and just feed more slowly. Remember to use lubricant for max tool life, even a drop of engine oil (steel) or a squirt of WD (Aluminium) is better than nothing. Try not to go above those numbers though or you'll ruin tools very quickly.

Cheers,
Craig