Lathe broaching a keyslot

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stomp10

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Using Mr Pete's you tube video on this:

I happen to have a blank of both what I call tool steel or, I can use the other end of an HSS parting tool.
I tried it with a blank 3/32" HSS bit but it had WAY too much flex as it was pressed into the piece. And still not wide enough to make a 5mm keyslot.
I want to use the tool steel blank to make the cutter as it should have a lot more rigidity than the HSS.
The tool steel is super hard to my mind.

(Dont laugh.... )
I ground down an old Armstrong knurling tool clamping tang so it would fit into my Enco stock toolholder. It took FOREVER!!! But it also allowed me to creep up on the final grind dimensions. That old knurler looks pretty cool now too.
It also seems to me that this stuff is super rigid.
This is why I want to use this blank instead of the HSS one but, I have no idea if this will work for the cutter as I have never heard of this being done.

Can I use the Tool steel or should I stick with HSS for making the cutter?
 
stomp10 said:
Can I use the Tool steel or should I stick with HSS for making the cutter?
Click to expand...

HSS didn't exist until after the turn of the 20th century, around 1910, and wasn't in really common use until the 1930s. Before everything was tool (high carbon) steel. Yes, it will work fine.
 
Wow, That makes perfect sense, Jim.
Lots of messy black nasty powder in the process.
This from My Grandfather's tool box, so the time frame you mention fits perfectly.
all his ground bits in the drawer are HSS which would have been early to mid 20th century for his working years. A remnant from his apprenticeship perhaps.

Not expecting ANY problems cutting this slot!
This is for the DC motor upgrade pulley on the lathe, so I can't wait!

Thanks a million for that answer!
 
Do not worry about using hard steel for non cutting tools. ridgidity depends on modulus of elasticity, heat treatment and alloy have nearly no effect on modulus, only carbide is stiffer than HSS, you could use a HSS tool bit in a soft steel boring bar to cut keyways.
 
Ben, the boring bar method is actually my plan B with a single tooth cutter, as to me grinding the cutter seems an easier solution based on my meager shop. Until I get the drill\mill thing running again I am quite challenged in drilling holes for a boring bar. I am hoping to change that soon though.

I'll have to take your word on what you just said as understanding the modulus of elasticity is way outside of my wheelhouse.

Its hard to believe that HSS and tool steel have the same flexability cuz in my hand tool steel just feels harder\stiffer. I realize that isn't any reliable test, but just my feel for it.
I'll gladly soak up any shreds of wisdom anyone wants to share though.
Is there a way to briefly describe what that is for me?
 
These tools are available as inserted tooling, you will not have to stop it every 10 parts to grind a HSS tool.

Rev Broaching Tool - Home

New patented tool system for broaching and slotting processing on lathes, milling machines and cnc workstation, with symmetric adjustment. Ideal for traditional slotting machines.
www.revtool.eu www.revtool.eu

If you have a live tooled lathe then this will broach from the turret. This is for low production/prototype work as no manufacturer would actually produce parts in this manner.

In the past I have produced blind internal keyseats with a manual lathe, this is the exact opposite of "efficient".

If however you choose to do so here are a few tips, drill a hole from the outside of the part to the bore at the end of the keyway, this is where the tool will stop without hitting the back of the last cut. I realize that this hole may ruin the appearance of a part but must be done.
Lock the spindle if your lathe does not have a C axis drive, placing a manual lathe in back gear is not enough so you must find other means of locking it.
Good Luck

 
Warren. this thing is amazing.
Who said German engineering is dead?
Thanks for sharing that!
Apologies... P.Waller... I thank you!
Trying to read without my glasses again.
 
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I suspect that there is a limited number of home machinists that have live tooled lathes that will operate such a device (-:

I could be wrong however, Grizzly may have a line of live tooled turret lathes that they keep a secret.
 
P. Waller said:
I suspect that there is a limited number of home machinists that have live tooled lathes that will operate such a device (-:
Click to expand...

My lathe would, but I suspect there are not many others. :)
 
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