Antique shop find yesterday :)

[TeePee]

TeePee, the countersink on the billet isnt a problem, yes some have chatter marks but it doesnt affect the operation Using a 12mm drill to CS it as my CS jams immediately on aluminium ! Even the slowest speed on my pillar drill isnt good enough.

Getting good countersinks on AL is a nightmare. I feel your pain!

[matts-uk]

...as my CS jams immediately on aluminium ! Even the slowest speed on my pillar drill isnt good enough.

#confused +1.

I'm wiring more than mech but to stop the bit digging divots, I would have thought you increase the spindle speed and lighten the press. Recommended spindle speeds for ally are two to three times that for mild steel, IIRC.

Nice project btw.

[Jetzki]

Amazing! I wish I knew more about this stuff to be able to spot a bargain.
I once managed to pick up some camera lenses that I knew would sell for 3 times the price.

[g8ina]

#confused +1.

I'm wiring more than mech but to stop the bit digging divots, I would have thought you increase the spindle speed and lighten the press. Recommended spindle speeds for ally are two to three times that for mild steel, IIRC.

Nice project btw.

Yeah, thats what the theory says, but in practise .....

[TeePee]

#confused +1.

I'm wiring more than mech but to stop the bit digging divots, I would have thought you increase the spindle speed and lighten the press. Recommended spindle speeds for ally are two to three times that for mild steel, IIRC.

Nice project btw.

AL is a very soft material, which is why speed is recommended for most processes. But chattering is different. It's caused by a harmonic vibration in the bit. Slowing it down helps, but ultimately the only way to prevent it is to use a single flute. Mostly, it's not a critical thing depending on the finished piece. It's a problem with some alloys, like 2024 where water intrusion and mixed metal fasteners can lead to galvanic corrosion, or when riveting. In this example, it's going to be invisible.

[oldboy47]

Those pictures of the Goldring took me back to the seventies and the Dynatron system we had then. Beautiful work and sounds.