pressure flaking question

[iowabow]

I noticed with the new material I have been working that the copper size make a difference. If I work a point with the same large dia copper tool the platform starts to have a small step in the valley of the flake.  The stress must be to great for the small platform. My question is when should I switch to the smaller tools.  What sign am I looking for.

[Tower]

Personally I think it kinda depends on the rock. I use my pressure flaker at an angle to my platforms not straight in. this helps me keep the bulbs to a minimum. But not everyone uses the same technique.

[iowabow]

ok so at an angle the flake produces a smaller bulb.  I noticed that when I push in hard and take a larger part of the platform that the ridges kinda have a dip. If i pressure flake that ridge it will hinge so i take that one at an angle and with light pressure or abrade toward it. It would be great to hear how others do it!

[JackCrafty]

The general rule of thumb is small tool, small flake and big tool, big flake.  But you can get small flakes with a big tool by using less force and big flakes with a small tool by using more force.  Using more force will cause a higher amount of breakage.

I switch to smaller tool when I want smaller flakes.

[JustinNC]

Not to high jack, but thanks to Saw Filer and Sailordad, Ive got to where a can shoot some flakes of decent length...but when I shoot them to a high spot, they get paper thin, and I'm still as proportionately thick as I was before I took the flake, just a little thinner, and a little narrower in width....how to I get UNDER those high spots? Take a deeper bite on my platform, yet still below center?

[JackCrafty]

You don't get under the high spot.  You attack it from different directions and overlap the flakes.  The overlap is what takes off the high spot.

[JustinNC]

That thought hit me about mid afternoon lol. Thanks for the confirmation Patrick

[JustinNC]

Worked lol. Had a nasty hinge on a high spot. Ground it down...shhhhh...and came at it from a couple different angles. Went right down. Now, if I could just keep from snapping them while pressure finishing. Messed up by putting it on the rubber rather than on the soft pad.