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kenc
02-18-2005, 05:28 PM
Guys,
I'm making some plane-making floats out of 3/16" thick O1 (unhardened). A float is basically a single cut coarse file with a triangular profile of about 12 degrees.
The teeth need to be cut like a rip-saw with a 60degree angle between teeth and the cutting edge vertical.

I cut the end float where the teeth are cut on the 3/16" edge on my mill with the head tilted to 30degrees and using the end of a 60degree included angle countersink. This was barely do-able using multiple passes and gave a ragged result as you might expect.
By the way, my angle blocks are wider than 3/16 so I had to tilt the head.
There's no chance that this would work on the side float which tapers from a point to almost an inch across. This time I tilted the head again and used an end mill just to kiss th surface to mark the steel every 1/8" e(oh yeh, spacing is 8tpi). Currently I am half way through filing each and every tooth
and since I started at the pointy end and still have the wide end to go, it won't be done till doomsday.
If I had a horizontal mill and a cutter with a 60degree included angle profile it'd be easy but I don't. Just have a lathe and a vertical mill. I guess I could use a fly cutter and grind an HSS bit which would give me curved teeth but that'd be OK I guess.

Any advice? Darin? Forrest? Other smart machinists?

Ken


Link to pics of floats:
http://www.norsewoodsmith.com/img/float/Floats4.htm

[This message has been edited by kenc (edited 02-18-2005).]

Allan Waterfall
02-18-2005, 05:38 PM
What about using a 60 degree dovetail cutter?

Clamp a piece of flat bar wider then the float at 30 degrees in your milling vice.Clamp the float to it with toolmakers clamps.You can always move the clamps if they get in the way.

Allan



[This message has been edited by Allan Waterfall (edited 02-18-2005).]

dkochan
02-18-2005, 07:35 PM
Dovetail cutter would do it, but they're expensive and fragile!

How about a fly-cutter with a threading-tool-sort-of-shaped cutter? I have done checkering of steel, which is a very similar operation, with good success this way.

Dave


[This message has been edited by dkochan (edited 02-18-2005).]

wierdscience
02-19-2005, 12:57 AM
Ken,dovetail cutter,preferably an insert cutter that way you can spin the crap out of it.You can also use the fly cutter just fine,same idea involved with any of the cutters mentioned.

You say the pitch is 1/8",would it be possible to use .100" instead?After all thats just one full crank on the b-port dials,no math for each step that way.Makes for less scrap and profanity http://bbs.homeshopmachinist.net//biggrin.gif

The redneck alternative would be to take one of those dull 3/4" two=flute endmills you have laying around and freehand grind it into a dovetail cutter.

Ever seen what a babbit file looks like?

wierdscience
02-19-2005, 01:08 AM
Better yet,here is a link to a curved tooth,flat body file.8tpi,might could be made to work.


http://www.cooperhandtools.com/brands/nicholson_files/index.cfm?model_list=1&att_id=NFI012&att1=Files&att2=Milled%20Tooth%20Bodifile

kenc
02-19-2005, 02:24 AM
Thanks Guys,

After seeing the word "dovetail cutter" a few times I remembered I have one of those suckers still in the box sitting in my tool chest! 60deg included angle too.
Don't you love this board?
I will crank the head back over to thirty degrees tomorrow and finish that bloody float! Lots o' cutting oil!

Darin,
I have a DRO on my mill so I can do .125 although as you suggest .1 would be probably just as good.
That Nicholson file has a good cut but it needs to be pointed at (e.g) 12degrees - the angle between the bed and breast (?) of a moulding plane -square profile wopn't do it.
Thanks to you I have enough Lignum to box about 1000 moulding planes if ever I make that many ;-)

Ken