Boring Bar Tool Sharpening

[ianmac]

Hello All,

I am building a Gauge 1 36 Class loco and ive started in the cylinders and i have drilled my way throught the cylinders but was advised to bor the cylinder to make sure it was perfectly concentric.

What is the best way to sharpen the tool?

Ian

[houstonceng]

The "smart-ass" reply is "on a grinding wheel !". But I'm sure you're not asking for that.

If it's the profile of the tool you're after, I'd suggest you read up on some of the many descriptions in books like "The Amateur's Lathe" by Sparey and "The Model Engineer's Workshop Manual" by Geo Thomas.

You don't say if you are using a tool in the tool-post or a betwen centres boring-bar (BB) or what material your cylinders are made of (Bronze or Cast Iron).

Personally, I do most general boring on my lathe (almost any material) with a set of indexable tip tools bought from Chronos. I have them in 6mm, 8mm, 10mm, 12mm and 16mm all of which take the same tips. I get a very good finish by repeatedly running the tool in both directions (without adjusting the cut) using self-act - and, of course, no need to sharpen them.

For boring my 5" gauge Sweet-pea cylinders, I'm using a between the centres BB with a modified carbide tip honed on a diamond lap.

[ravensworth2674]

As you are working with Gauge 1 stuff, I doubt that the commercial sizes of boring bar will suffice.

Frankly, I would go 'George Thomas' as suggested and make my own tiny boring tools. He talked about doing 1/4 inch stuff with his tools.

In his MEWM, he gives advice on honing which I think really what you were after.

Norman

[ianmac]

Thank you everyone

Tis sorted. ended up drilling s 13mm hole and boring out to 15mm.