Shop-made dovetail cutter from drill rod

DaRiddler

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More as an exercise than anything else, I'm thinking of making a dovetail cutter to be used on a project in my mill. Plan to make it out of water-hardening drill rod -- harden & temper it after making it.

I've forgotten where I got it, but the one photo shows the general idea. Seems to me that one could either put the drill rod into a spin indexer and mill out four flats (see drawing #1) OR one could put the rod on end, drill four holes in the end, then turn it down, exposing four cutting edges. One could even mill some relief on it (see drawing #3).

Has anyone here done this? or has anyone seen a write-up by someone who has done it? by the way, yes, that is a napkin on which I made my cheesy sketches . . . cutter.JPGprofiles.JPG

cutter.JPG profiles.JPG
 
More as an exercise than anything else, I'm thinking of making a dovetail cutter to be used on a project in my mill. Plan to make it out of water-hardening drill rod -- harden & temper it after making it.

I've forgotten where I got it, but the one photo shows the general idea. Seems to me that one could either put the drill rod into a spin indexer and mill out four flats (see drawing #1) OR one could put the rod on end, drill four holes in the end, then turn it down, exposing four cutting edges. One could even mill some relief on it (see drawing #3).

Has anyone here done this? or has anyone seen a write-up by someone who has done it? by the way, yes, that is a napkin on which I made my cheesy sketches . . . View attachment 71811View attachment 71812

do a search for diy dovetail cutter here and on Google and you will find lots of post,s on that subject and some will be with index-able inserts:))
 
Here is one I made a couple years ago. It looks familiar ;)

Material is W1 drill rod. There is no relief on the cutter. It did cut, but was pretty slow. I recommend adding some relief. You can do it with just a file if you are careful, and do it before filing.

IMG_6518.JPG
 
do a search for diy dovetail cutter here and on Google and you will find lots of post,s on that subject and some will be with index-able inserts:))
If you make it with inserts, Hardening it wont be an issue. You could probably make it out of mild steel.
 
As Marcel said, an indexable dovetail cutter will save you having to heat treat it. I made this one when I was doing my X2 CNC conversion. The shank is 7/8", for size reference. The pictures pretty much explain the process.
PC230686a.jpg

PC230688a.jpg

The rotary table is attached to the mill table rotated 30[SUP]o[/SUP] counter-clockwise to cut the recess for the insert. The endmill is set to the centre-line of the work, plus the thickness of the insert (below centre), so that the cutting face is on the centre.
PC230689a.jpg

PC230692a.jpg

PC230686a.jpg PC230688a.jpg PC230689a.jpg PC230692a.jpg
 
Let me know how that works. Have some drill rod just begging to be made into one.


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More as an exercise than anything else, I'm thinking of making a dovetail cutter to be used on a project in my mill. Plan to make it out of water-hardening drill rod -- harden & temper it after making it.

I've forgotten where I got it, but the one photo shows the general idea. Seems to me that one could either put the drill rod into a spin indexer and mill out four flats (see drawing #1) OR one could put the rod on end, drill four holes in the end, then turn it down, exposing four cutting edges. One could even mill some relief on it (see drawing #3).

Has anyone here done this? or has anyone seen a write-up by someone who has done it? by the way, yes, that is a napkin on which I made my cheesy sketches . . . View attachment 71811View attachment 71812

I love napkin engineering. Some amazing things have been designed on a napkin.


Sent from my iPad using Tapatalk
 
I love napkin engineering. Some amazing things have been designed on a napkin.


Sent from my iPad using Tapatalk

I like that. I could use that technique to make HSS cutters if I ever get my ECM machine finished. Use ECM to drill the holes, then use ECM or grinding to reduce the diameter and grind with a die grinder in an eccentric fixture to get the relief. Two or three flute would be easier. Might be good enough for low-precision work in aluminum and non-metals.
 
Easiest & cheapest is to just mill a centered flat on the angled end of the bar ..then grind relief on the two two cutting edges .like a a flat wood bit ..if you want to gild the lilly , file some slight rake on the opposite sides...harden in the drill press at 200 rpm ...quench while running by bringing up the brine if w-1 or lite oil if 0-1 ( less warpage bt vertical quench & especiall 0-1 ..i makeing rifle cahmbering reamers my warpage allowandce for grinding was cut in 1/2 this way .....draw at 375 in kitchen oven ofr 0-1 ...put in heated oven for one hour ..shut it & let coll .. Stone edge & u r .done !
Speed is 1/2 of high speed fpm ..always take out as much as possible w/ an end mill before using a dovetail or T slot cutter !
best wishes
doc
PS for multiflute cutters , a square collet block that nolds 5 C collets is th e simplest ..mayv abt $35 ??? fo hex & square ...OR you can MAKE a square bloclk w/ grub screw for the size shank you have ...great accuracy not required ..in fact may be better if a tad off ..irregular flueted cuitters tend to chatter less.....i still have two , nade before the cheap china ones i tempted me to go against my depresion era instincts ...
 
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