Bit retailers

[cnc_fabricator11]

Hello,

I will be cutting through 1/8" aluminum composite with my PRSalpha and I was trying to find a bit strong enough to cut the material but also small in diameter. I will be cutting out rectangular openings in the material and I need to get the corners as sharp as possible, and seeing as how its not possible to cut a perfect 90 degree corner, I need to use the smallest diameter available. I've talked to Onsrud about their line of 63-600 bits but the smallest is an 1/8". Would anyone have suggestions for other retailers?


Thanks,

-Patrick

[Brady Watson]

Harvey Tool (http://www.harveytool.com) has 1/16" spiral-O bits. My advice would be to try a 1/16" 2-flute high helix HSS end mill. At that size, burrs are minimal and you'll save a TON of cash on tooling.

When you say AL Composite - what do you mean exactly? Honeycomb?

-B

[SomeSailor]

I cut a lot of aluminum and when I need square corners, its usually very quick and easy to hit them with the edge of bastard file. Just takes a sec and it'll square up the corners nicely.

[cnc_fabricator11]

Thanks for the feedback. Something similar to this:

http://www.diytrade.com/china/4/products/5083250/Aluminum_Composite_Panel.html

Not trying to spam just showing an example. SomeSailor, what to do you mean? Could you elaborate on this?


Thanks,

-Patrick

[fozzyber]

You are cutting dibond,
Onsrud does make a 1/16 bit 63-700
I used it tonight to cut dibond.
.6 ips, .05 stepdown, 20k rpm
But for straight corners use a file and a 1/8. The 1/16 bits break real easy.....ask me how I know...
I cut over 10 feet at 1ips before snap......


You could use a 2 tool path setup, use 1/16 only for corners....

[Brady Watson]

Dibond et al, isn't really "cutting aluminum". O-flute would be best, but you can get away with using a 2-flute end mill or straight. The AL is really thin, especially on non-Dibond brand name discount panels. Some are almost like foil, sandwiching polypropylene.

As long as you ramp into your cuts, you can use just about any bit. My advise would be to get a 2-flute straight, a 2-flute spiral and a 1-flute spiral-O and do some testing. You'll learn more about what works and what doesn't than just asking for advice.

If you are snapping bits - you have some setting wrong. You are either overloading the tool - MS too fast, or RPM too low OR you are grossly underloading the tool with MS too slow and/or RPM too high, which can overheat the tool and cause it to snap. This is why chipload is important.

-B

[fozzyber]

bradly i agree with you, but standard formulas are out the window for this small of bit. (1/16) I like o flute for more bit strength at this size,
Well I like o flute for most every thing except acrylic.

I cut a lot of signabond lite (dibond) my advice is dont cut to fast (rpm)
and buy a deburing tool to finish
jerry

[sailfl]

Jerry

What bit are you using to cut acrylic? Thanks

[Brady Watson]

...standard formulas are out the window for this small of bit. (1/16) I like o flute for more bit strength at this size

Remember, the smaller the bit, the more RPM you need to get into the right chipload range. The chipload formula is still valid using a 1/16" bit. The question is, does your spindle have enough RPM to match your desired move speed? This is why I am not a big fan of HSD 300Hz spindles...they max out @ 18,000.

-B