Ulma Doctor

Infinitely Curious
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Feb 2, 2013
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Now that i have a big lathe (Victor 2040) with a lota motor (7.5hp, 3 phase),
i'm collecting tooling large enough for the scale of the machine.
that means 3/4",7/8 &1" tools for the enormous CA sized toolholders.
(for size comparison- i didn't buy Aloris :apologize:
[https://www.aloris.com/aloris_cat/31e970.pdf])

i have not ground lathe bits larger than 5/8" before, but the same basic principles should apply to larger tooling as it does to small tooling.
{i say the same principles should apply, because i'm hoping my speculation is correct :grin: }
this experiment has continued from small machines, and will extend to this larger machine.

my first victim is a lovely HSS blank marked only PURPLE LABEL , a 7/8" square blank with 5° ends pre-formed
my thought was to use my 12" grinder to remove most of the metal in the relief areas,
and then use the 618 surface grinder and an angle jig to precisely grind the largest lathe tool i have tackled yet!

the simple tool took about 35 minutes to grind, the time was split between the rough grind and the surface grinder.
i flipped the tool and reset the jig often through the process to ensure i would hit the cutting edge at the same height.

although his tool was ground as a left hand tool, it will work as a right hand tool also, if the tool is rotated 90° in the toolholder ! :big grin:

here is the finished 10° tool- 1/16 nose radius
top view left pic , front view right pic
IMG_4010.jpg IMG_4011.jpg



and for size comparison....


Left AXA toolholder with 3/8" tool installed- Right CA toolholder with 7/8"tool installed

IMG_4008.jpg

IMG_4009.jpg

i'll be grinding a couple more varied geometry tools very soon to do a Pepsi Challenge.
come along for the ride, if you like this kinda stuff!

chips be flyin' soon
 
Wow, BIG tool!

Your tool is essentially a knife tool so it should face really well. Might not be as good for turning because it has no end cutting edge to contact the work and that end edge is what produces a finish. Still, its fun to mess with geometry to see what it does.

Let us know how it goes, Doc.
 
thanks mikey,
the 3/8 tool in the last picture is the same 10° grind, in essence. (it looks better in the real world than in picture)
i use that tool mostly turning on 303,& 304- i can take substantial cuts in the 1236 and retain a very nice surface finish
i also use the very same tool to work delrin to a very fine finish
this is the same tool that i use in the Unimats, but instead of 10°, i made their angle 8°.
i'll see if i can make some comparison chips to illustrate, when i get in front of the 1236 lathe tomorrow
 
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let’s see this new machine too :)
 
Jeepers, that thing looks like a wooden model used to illustrate the angles to grind on a small tool!


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Likewise. My 10K feels like a mini lathe!


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