Boring Head - another approach

[Anorak Bob]

Below are photos of a Sandvik modular boring tool. A neat way of achieving a wide range of cutting diameters with only a small range head. I'm tempted to have a go at a smaller derivative.

[azzrock]

looks nice. do you mean a smaller Sandvik model . is it expensive. do these tip tools like to spin fast like lathe and other milling tip tools. just thinking about the balance.

[Stustoys]

azzrock,
Think about the Dia of the "cutter" . At a guess thats about 6" so my maths says it should be run at about 120rpm.

Stuart

[Anorak Bob]

Having the thing flailing around at high speed would be scary. I imagine it would try to shake the head off my mill, Azz. I haven't used carbide inserts with my boring head. I have used brazed carbide tipped boring bars though and they have worked O.K. The boring heads on their own are usually high priced items. It would be disappointing to throw money at something that wasn't going to work.

Stu, do you reckon the carbide would work at 120 rpm?

[Stustoys]

BT,
I'm not sure, I do find carbide more forgiving then I've been lead to believe on interrupted cuts.
I was just pointing out that 120rpm was the rpm for carbide at that diameter in steel(twice the HSS rpm). So if anything you would want to be running it slower than that.
I don't believe (on my mill) it would be "flailing about" at that rpm.

Stuart

p.s. that's not one of yours is it BT?

[Anorak Bob]

No. That will be at least a 40 taper on the set up. From memory, it had a "buy it now" of around 900 bucks.

BT

[RayG]

Hi BT,

What would the advantage of that arrangement be over the boring heads with the option to mount the cutter at right angles?

Like this..



Regards
Ray

[Anorak Bob]

Maybe a touch more rigidity Ray, but in reality I'm just playing with myself. I like the look of the thing. How do you find your boring head? A Hong Kong purchase?

Wohlhaupter use the same outrigger boring bar set up as you have. If it works at both ends of the scale, why complicate it. I should just chuck the money at a CTC metric head and move on.( and save up my play money, on the side, for a Wally)

BT

[RayG]

Hi BT,

I bought the boring head at the same time as the mill, and I got extra sets of the brazed carbide boring bars. I've used it a fair bit in normal mode, but not with the cutter at right angles.

It's the 75mm head with 18mm cutter shaft diameter.

I bought it from H&F, but now I know better, i would get it from CTC for about 1/3 the price I paid.

It's the same as this one
75MM BORING HEAD WITH NT ARBOR & 12PCS 18MM BORING BARS #H56

Regards
Ray

PS.. It comes in a nice yellow plastic box too!

[Anorak Bob]

Thank you Ray.

Any chance of a favour? When you are looking at it next, could you possibly measure the height of the head? I have the same arbor.

Bob.

[RayG]

Hi Bob,

The head is 81mm from the bottom of the arbor. I hope that's enough clearance?

Regards
Ray

[Anorak Bob]

That was quick! Thank you again Ray. I will have a look tomorrow though I'm low on optimism. With a boring bar in place, I imagine things will be tight.

[Dave J]

Ray,
That looks similar to the case that mine came with. I bought mine off a guy on ebay (now Dezza in Tas) new for $280 with all the bars. Did you get the boring bars for HSS?

Dave

[RayG]

Hi Dave,

I think I paid a little more than that, I think it was around $400-$500 during one of the sales. That's for the brazed carbide boring bars, the head, and the arbor. In a kit.

I can't see the equivalent kit it in their current catalog.? But the kit from CTC is the same as I got last year, maybe they don't carry them anymore?

I did buy some extra boring bars, with HSS cutter inserts that I could use either on the lathe, or the mill, like a fly cutter. But I don't have any HSS boring bars as such.

Regards
Ray

[Dave J]

Hi Ray,
The one I have is Taiwanese and is written on it, yours would probably be as well, because when I bought mine 3-4 years ago he said they where the same as the ones sold at H&F's.
How much difference there is between these and the Chinese CTC one's I don't know because I don't have a Chinese one to compare it to.
The HSS bars are I have are 18mm, and it was only the other day I suggested to Stuart to use lathes ones cut in half instead.

Dave