Thread: Full dia hand wheel for Y axis

Some time ago I made two full circle hand wheels for the table on the mill. ( I really don't like the 3 ball design) I re-purposed some wheels I had that had come off a bit of old equipment that was scrapped at work.
Anyway, I only had the two so I didn't make a wheel for the Y axis. So recently I was looking for something to do that I could generate a bit of enthusiasm for, and decided to re visit the Y axis hand wheel
I had a disc of Aluminium which was 12mm thick and 250 in dia. It too came off a bit of dumped equipment and I’d been hanging onto in case I needed it.So I thought "stuff it I'll use it". It had to be machined down to 190dia.
The other wheels I used had three slots in them from their previous life and this disc was solid. I started thinking about putting slots in so that it looked similar to the others.
Easy to do on the rotary table, but then I got to thinking about my rotary table. It has an input shaft at the back running through two dog clutches and gears so it can be power driven from the machine. So theoretically if set up correctly it should be able to do spirals.
So I thought some spiral slots would look cool if I can get it set up.
I didn't have any gears but I did have a couple of sets of push bike sprocket clusters. I worked out that I need around a 1:2 ration between the table lead screw and the Rotab input shaft to give me the curve I want.
These sprocket clusters appear to be put to together so that they are permanently fixed.
So I set up a cluster in the four jaw and very gently gnawed away at it until I was able to unscrew the smallest sprocket. The part I had to machine was where the balls for the ratchet ran so it was pretty hard. Took a couple of inserts to get through it but I eventually ended up with 7 sprockets.So a 36 tooth and a 19 tooth was the closest to the ratio I wanted(its not critical).
I was able to fit the big one to the back of one of the hand wheels.
handwheel sproket 01.jpg

Then I had to make a shaft to connect it to the Rotab input shaft. I found an old mill machine arbor that I've had for years that was about the right length. So set it up in the lathe and drilled/bored an 18mm hole in the end X 80mm long. That fits over the input shaft. I didn’t go to the trouble of putting a key way in it,. I just put a couple of grub screws in. Machined a spigot on the other end for the small sprocket to fit over.
As it turned out I didn't need an idler. Was able to fit chain reasonably tight without.
I ended up tack welding the sprocket to the old arbor.
So anyway, managed to get the chain drive working ok.
chaindrive 001.jpg
I stuck a bit of cardboard onto the rotab and put a marking pen in the quill to check if it was going to work.
Turned out fine so then I set up my disc and got stuck in.
cutting slot 01.jpg
It turned out ok. I would have liked a bit more curve on them but I was limited to what sprockets I had.
slots done.jpg
I just set it on the face plate and trepanned the excess off to get down to the required dia.
trepanning 001.jpg


I also had to machine a bush with a keyway to suit the leadscrew.
cutting keyway 001.jpg
All in all I was pretty happy with the way it turned out.
done 001.jpg

I've since painted it so that the colour matches the others.
Peter

Nice work Peter. I seem to have seen that before from you, or maybe I'm physic or is it physco???
Something really original

Originally Posted by KBs PensNmore

. I seem to have seen that before from you,
Something really original

You got the sneak preview.