Dovetail Cutting

[Anzaniste]

I am planning to make new toolholders for my quickchange tool post on my Leinen lathe.
This is my CoC


Leinen Tool Holder 001 by Anzaniste, on Flickr

I have purchased a metre length  of steel  (En3). I shall cut it in two and make two lengths of dovetailed section from which I can chop lumps off of the appropriate length for the individual holders.
I have never cut a dove tail before so am a bit nervous!!! I am planning to remove the bulk of steel with an facing mill with indexable tips to give me the 40mm wide tongue and then have at it with a 60 degree dovetail cutter .  I need to purchase a new one should I go for the largest diameter I can afford?

Advice from the wise will be greatly appreciated.
I shall be using a rather ancient ~Bridgeport.

[John Rudd]

I'm doing the same, making a qctp and holders for my new mini lathe...

I did the same as you describe, rough out the tong with an end mill or whatever your fav tool is, then I finished to size with a dovetail cutter...mine is only 1/2 in diameter...

Best of luck with yours........

[Anzaniste]

John, What sort of speeds and feeds did you use?
Did you use coolant?
I an scared of chipping the corners off the cutter, did yours stand up OK?

[John Rudd]

I had my mill om a fairly low speed ( around 300rpm ) using coolant and a brush to sweep away the chips..

Feed rate...well I just used the 'feel' technique and avoided overloading the cutter...

HTH

John

[philf]

You'll need at least a 25mm diameter cutter, possibly bigger, to get the 7.5mm step and to finish the flat in one pass.

I would make sure your Bridgeport is trammed as well as you can. I'd also cut both sides leaving the odd 0.1mm and then clean up to the finished dimension without touching the Z-axis. When you rough it out, leave something on the flats to allow cleaning up with the dovetail cutter.

I wouldn't worry too much about the sharp corners. My dovetail cutters all have the sharp corners either stoned or ground off. The mating dovetails (nearly) always have flats instead of points.

Cheers.

Phil.

[DaveH]

There is some info here that may help
http://madmodder.net/index.php?topic=5664.msg60016#msg60016
 
DaveH

[Anzaniste]

Thanks for that. I did try the search facility but did not come up with anything even though I thought I had seen  something in the past.
Time for a little more reading and planning!