Boring bar to fly cutter

[Alberto-sp]

Hello. I have a boring head and I want to use it as a fly cutter in this way



I would use this boring bar but the base of the boring head touch the piece I want to face (sorry my english if this doesn´t make sense)



So I´m going to bend it in this way (putting it red hot)



The angles before the bending are these



I supose the 14º angle is OK, but th 5º how much can it go bigger (obtuse, open)? Because the more I´ll bend the boring bar, the more obtuse it will be than angle.

Thank you

 

[mmcmdl]

Why ? A 6" flycutter ? You won't have support to cut anything other than possibly plastic and I'm hoping you have a drawbar for the TS .

 

[Alberto-sp]

Thanks for your answer.

I'll cut it. I wont keep it so long

What is TS?

 

[Winegrower]

I think it’s worth messing around with stuff like this just for the learning experience. You are going to know a lot about both boring bars and fly cutters when you get through with this.

 

[Alberto-sp]

Nooo I prefer to know before having the boring bar encrusted in my cranium

 

[extropic]

The 5° is OK for light cuts. The lower the angle, the more of the insert is into the cut meaning higher cutting forces.
The 14° worries me because that implies it's a Negative rake bar/insert.
I'm assuming you have a relatively light hobby mill so I would suggest a positive rake bar/insert to keep the cutting forces lower than negative rake.

TS = Tail Stock

 

[Alberto-sp]

Thanks for your answer

So if I bent the draw bar the 5° angle will became for example 7 or 8° and the cutting forces will be softer right?

And yes I have a 750watts mini mill.

I can reduce the 14° angle if is good for the purpose.

And I thought ts stands for tailstock but I wasn't sure because I din't see the connection with the milling machine

 

[extropic]

Thanks for your answer

So if I bent the draw bar the 5° angle will became for example 7 or 8° and the cutting forces will be softer right?

And yes I have a 750watts mini mill.

I can reduce the 14° angle if is good for the purpose.

And I thought ts stands for tailstock but I wasn't sure because I din't see the connection with the milling machine

I think you're missing the main point regarding the difference between positive rake and negative rake inserts.

Start a new thread to discuss the significance if you like.

I think you are wasting your time and money, but that's up to you and why they call it a hobby.
The interrupted cuts, typical of when using a fly cutter, will be hard on the boring head.
I think you're staring with the wrong kind of bar/insert.

Look at these accessories:

BORING HEAD ACCESSORIES | mesatool

www.mesatool.com

 

[extropic]

So if I bent the draw bar the 5° angle will became for example 7 or 8° and the cutting forces will be softer right?

Less insert edge in the cut = lower cutting forced (all other factors being equal).

I can reduce the 14° angle if is good for the purpose.

Based on the flat on the shank, I assume the 14° angle is compatible with the intended insert geometry. If you change the 14°, what insert are you going to use?

 

[mmcmdl]

I was actually referring to the Taper Shank of the holder in my above post . Fly cutting with that long and weak of a tool might cause a few issues . A fly cutter is a cheap and readily available tool to acquire .