[simpits-tech] ShopBot video...

[Gene Buckle]

> Sweet as !  whats a shop bot worth in US dollars.
>
As configured it was somewhere north of $17k.  Suffice to say that I got 
really lucky when we sold our old house. :)

> and do you have to programme in any pauses to limit cutter temps ?
>
No.  Like with any kind of CNC (or even manual) cutting tool, you've got 
to make sure that the RPM of the cutter and the rate in which you run the 
cutter through the material will create the optimal "chip load".  This is 
a fancy term that describes the size of the chip created by one full 
revolution of the cutter.  Each cutter type has a range of chip load 
numbers that as long as you stay between, you'll be ok.  Correctly sized 
chips carry away much of the heat generated by the cutting process.

When you're cutting metal or plastic however, it's a totally different 
ball game. In those instances you can generate far too much heat for the 
cut chips to remove by themselves so you need to use some kind of coolant.

When cutting steel you'll typically see the machine using what is known as 
flood coolant.  This type of setup continually "floods" the bit and work 
area with a steady stream of coolant.

The setup I'll be using when cutting aluminum will be high-velocity air 
directed at the tool.  I've seen pictures of people using a similar setup 
that adds a 50/50 mix of water an alcohol(sp) that resulted in frost 
forming on the tool. :)

> I must admit when the word " oops " was used I would have used something
> else !  8-)

Hehe.  That actually wasn't a problem.  Turned out it did just what it was 
supposed to do. :)  The original problem I had cutting the project was due 
to the documentation not mentioning that you needed to manually start the 
spindle.  When the program started, it promptly tried dragging the idle 
cutter though the wood.  Fortunately I stopped it before it did much 
damage.  I also made a mistake on 2nd run in how I set the zero point for 
the Z (depth of cut) axis, resulting in two gouges in the wood.

I've got it all put together and I'll be posting pictures soon.

g.


-- 
Proud owner of F-15C 80-0007
http://www.f15sim.com - The only one of its kind.