Grinding a has bit

[DPittman]

Hi everyone, Merry Christmas!

I have very little experience ( none really) grinding effective hss tool bits.

I'm wanting to grind a 1/8" bit for broaching out a key way slot inside a aluminum wheel.
I hope to do this broaching with bit mounted in tool post on my lathe.

I'm thinking this is pretty basic but so am I.
Any tips or pictures on how to achieve this.

Thanks.
Don Pittman

 

[DPittman]

Also...any good ideas on how to hold lathe spindle in one spot. The lathe has no back gear or mechanism to lock.

 

[Dabbler]

what lathe is it? I've never seen a lathe without a spindle lock...
usually you engage the back gear with the pin in, and that locks the chuck.

 

[DPittman]

what lathe is it? I've never seen a lathe without a spindle lock...
usually you engage the back gear with the pin in, and that locks the chuck.

It's a craftex 10x22 lathe. Yup previous Atlas lathe had both the pin and back gears but this one does not.

 

[DPittman]

Ha ha! I just watched a Tubalcain video that showed me exactly how to do what I want! He used a cut off blade.

However I'm still looking for help on how to hold my spindle in place.

Don

 

[Dabbler]

yes mrpete222 is a great guy.

I'd have to guess that you would C clamp on one jaw of your chuck to a vertical bar, then c clamp to a horizontal bar across the ways. (for good measure , you could bar clamp it to the bridge, but that's for the paranoid) Good enough to hold to a couple of thou. If I had pictures of your gears in the head or the banjo, there might be an easier way there.

 

[PeterT]

I have to do this eventually too. But I don't think I have a spindle lock on my 14x40. Wait a sec, I'll ask John. HEY JOHN! Do We Have A Spindle Lock!?

I've seen guys make up a friction clamp on one of the idler gears or exposed shaft under the hood. I've also seen kind of a plunger finger arrangement that detents in a gear tooth opening. Probably fine but just don't ever brain fart on the power button or it could be expensive. I've also read to take very light keyway cuts on small lathes, its not that great on the carriage traversing gear assembly. Some guys make these lever handle plunging accessories that mount to cross table which is locked down to take the duty load off the carriage motion.

 

[DPittman]

I have to do this eventually too. But I don't think I have a spindle lock on my 14x40. Wait a sec, I'll ask John. HEY JOHN! Do We Have A Spindle Lock!?

I've seen guys make up a friction clamp on one of the idler gears or exposed shaft under the hood. I've also seen kind of a plunger finger arrangement that detents in a gear tooth opening. Probably fine but just don't ever brain fart on the power button or it could be expensive. I've also read to take very light keyway cuts on small lathes, its not that great on the carriage traversing gear assembly. Some guys make these lever handle plunging accessories that mount to cross table which is locked down to take the duty load off the carriage motion.

Peter,

I did my broaching without locking spindle (mostly because I couldn't figure out how to) and it worked ok.

I was only doing a 3/32 slot in aluminum and only took .005" at a time. I also had a make shift indexing plate that would show me if things moved.

That gizmo you showed would definitely be a good thing as I could feel the strain on my little lathe with just a small aluminum slot.

Don

 

[John Conroy]

Nope we don't have a spindle lock Peter. I've never found need for one but then I've never broached a keyway either.