On 04/09/2010 01:01 PM, James wrote:
> I don't actually know the RPM of my drill, I used a nice Maxon
> precision DC motor which is rated 11K RPM under load at 24V, and I
> run it around 32V with very light load, it's nice and smooth and
> turns fast. Whatever the case, it drills a nice hole with carbide
> bits, and the only one I've broken since building this is a 0.020"
> when my finger twitched while I was holding down the PCB.
You know, I am pretty satisfied with:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94606I use those cheap, "regular" bits with a battery black&decker drill.
Granted, I try to do SMD as much as possible, so I do not normally have
many holes to do... but the fact that I can start "slow" with the drill
eases the accuracy of the hole and, as those bits are relatively
"elastic" I've never broke one. So far the bits hold sharpness decently.
bye
as