Silly Tool Question (absolute beginner!)...

Guys,

OK thaks for all that. I have FINALLY decided to go for a relativel cheap set of HSS tooling which I can ruin at my leisure, and a singl insert tool to play with. The relative cost of the HSS stuff seems no worth argueing about really. And I can hopefully learn a bit about too shaping and shrapening into the bargain.

Norm, at the risk of sounding a bit dim, I don't really understand an of your aviation anecdotes, but I have taken some of your advic nonetheless!

Everyone happy?

Regards,

Garth

-- DR_

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this thread:

To add to the comments about carbide on little lathes:-

This was earlier on this afternoon. I had taken the afternoon of work after a stressful weekend. I was cutting EN24 which is by no means free cutting mild steel. It was about 1" diameter at that point with a 20 thou cut and 400rpm, I had spread cutting oil on the steel before starting the cut.

On the top picture you can see the reflection of the tool in the steel that has been cut. Clicking on the (already large) pictures will show them in their full size. The top picture now shows the chips flying off the tool, already turning blue while in the air. The lower picture shows the pile of blue swarf. This work was being done on a 56 year old ML7 fitted with a 3/4hp motor and inverter in middle belt position. The tool was a Chronos 12mm Glanze RH tool fitted with a J&L CCMT060202LF HC325 Hertel carbide insert.

I think folks will agree that the surface finish is acceptable (pity it wasn't as good when I got the diameter down to 3/8", but the toolpost grinder is going to take off the last 3 thou tomorrow.

HSS is good, especially for grinding form tools, interrupted cuts and threading tools. Carbide is good because you can get repeatable results at relatively low cost and can cut tougher materials without worrying about pushing it too hard.

Even carbon steel is useful when you want to machine a tool to shape rather than grind it, I have done this for making 30 and 40 degree tools for pulleys and 14.5 degree ACME threading tools.

Mark Rand RTFM

Whilst Garth awaits the 'words and music' UK style, I thought that it would be helpful to mention that in Home Shop Machinist and Machinist's Workshop's BBS that a guy is doing 'How'd I do( grinding bits)?' and taking advice from his more expert fellows.

de thing called Aviemoron.

The Forum is different but well worth a visit.

N

Fantastic, you sound like me a year or so ago!!!! Books on order, and being completely bamboozeled by all the options. And you know what, a year or so on, I still know very little!! But I am managing to do what I set out to do, which is cool.

One thing; this is a damn good place for advice. And its always worth just browsing, there is always some thing new to pick up on, or to spark off ideas. Yeah, I have been doing this for a little while, but even this thread advising you as a beginner has been extreemely interesting to me. Its bought some basics back in to focus and some of the stuff about tooling types is invaluable.

Enough of the creepy crawling stuff...........

AC