A Catch Plate Fly Cutter

[Anorak Bob]

In Glen" BrianLara400" 's thread on machining a bedding block, Chris "Jack620" mentioned using a boring head, mounted in his lathe spindle, as a fly cutter. Chris was looking at buying a boring head to achieve this task. Back when I wouldn't have really known what a boring head was, let alone what a Wohlhaupter was, I made up a simple flycutter for my old '58 Hercus. ( There is a touch more clearance behind the spindle nose on the plain bearing lathe than there is on the latter roller bearing model ). The cutter is a piece of 1/4" round HSS and the holder was machined from some 1" 1214 hex bar. The catch plate required a bit of flattening on the rear.

I have used this on my little No. O mill with acceptable results. Hercus made a 3 Morse arbor with a threaded nose that facilitated mounting the catchplate in the vertical spindle.

A simple little thing to make that could be useful and a lot cheaper than a boring head.

BT

[jack620]

Hey thanks Bob! I've got a Hercus catch plate that I've never used. There is a fly cutter similar to yours in Tubal Cain's book. Unfortunately the photo is very poor and the description very brief. Now I have some details I'll make one myself. Thanks for the info.
Chris

Edit: what sort of RPM do you run it at?

[pipeclay]

That would generally depend on what you are cutting.

[jack620]

Sure, but roughly?

[Ueee]

Just treat it like any turning or milling speed calculation. If you are cutting MS and the tip is 2" off center treat it like turning a 4" dia, so you would want about 100rpm.

Nice idea Bob, when i first saw the thread i read it as "A catch plate fly catcher" and i thought what the, there must be a real fly problem in WA at the moment...

[jack620]

Thanks Ewan.

[Anorak Bob]

Just treat it like any turning or milling speed calculation. If you are cutting MS and the tip is 2" off center treat it like turning a 4" dia, so you would want about 100rpm.

Nice idea Bob, when i first saw the thread i read it as "A catch plate fly catcher" and i thought what the, there must be a real fly problem in WA at the moment...

The flies are out in force over here Ewan. A couple of warm days and the bastards are everywhere. :no:

And Chris, when I used that fly cutter it would have been at the slowest of the normal speeds on the old Model A. I only used it a few times.

Bob.

ps. Chris, if you are considering purchasing a boring head, have a look on US Ebay. There are often good quality heads from makers such as Flynn, Criterion, Craley etc, selling for less than those of oriental or subcontinental origin. Here's a link to a post about a too big Flynn I bought and later sold to a forum member in Darwin. http://www.woodworkforums.com/f65/too-big-130210/index2.html#post1269611

[jack620]

Thanks Bob, but I will make a cutter the same as yours. I've been going a bit crazy on Ebay recently and it's been noticed. :rolleyes:

Besides, I enjoy making my own tooling.

[simonl]

Hi Bob,

Excuse my ignorance but is this tool used to cut a disk in a piece of steel plate, analogous to trepanning on a lathe?

Nice work BTW.

Simon

[jack620]

Simon,
here's a demo of what it is used for using a slightly different design of fly cutter:

Lathe Workshop for Beginners. Part 2 making a flycutter. - YouTube (http://www.youtube.com/watch?v=I-iVLgILSFY)

[jack620]

I made a modified version of Bob's fly cutter today. The tool holder is 4140. The nut is just a construction grade 12mm nut. I'll get a proper one later.

The cutter is made from the butt end of a 6mm drill bit. I realised after I'd ground it, it wasn't hardened. :doh:

I'll mill a couple of flats on the holder when I get my milling attachment sorted.

[Anorak Bob]

I made a modified version of Bob's fly cutter today. The tool holder is 4140. The nut is just a construction grade 12mm nut. I'll get a proper one later.

The cutter is made from the butt end of a 6mm drill bit. I realised after I'd ground it, it wasn't hardened. :doh:

I'll mill a couple of flats on the holder when I get my milling attachment sorted.


Good on you Chris.:2tsup:

[BrianLara400*]

Good work boys, I recall seeing a similar facePL set up in one of those workshop practise series books, "Milling operations in the lathe".

For a period of time that little book was my bible;- I had nutted out several attachments for the topslide of my Colchester Mascot, @ 10hp & rigid it was going to be the most serious improvised hobby milling/lathe arrangement ever devised:U, but alas I purchased a dedicated mill and this kind of killed off the need. May still do something but it wont be as grand.