Re: [ATM] Another machining question, please

["Norm Prince" <norman.prince@verizon.net>]

Ken and James are 100% correct on this one...the forstner bit will be none 
the worse for wear if you take it slow...if you drill a small (1/16"-1/8") 
pilot for the forstner bit first (many of them have a little pointy 
center)...and drill out the "ledge" hole to depth...then flip the work over 
and drill out the "thru" hole from the other side..(the pilot hole will help 
keep this bore on course...if the thru hole is large...step up the pilot 
with a bigger bit first)...I always find i get a cleaner hole with 
forstners, spayed bits, and hole-saws if i go most of the way and then 
finish the hole thru the other side of the work...People may disagree with 
me a bunch on the last notion for many imaginable reasons, but thats my 
experience with drilling holes in metal...not making telescopes.

-norm-
Georgia, USA (land of bad seeing...and such)



----- Original Message ----- 
From: "Thomas A Simmons" <tasimmons@raytheon.com>
To: <atm@atmlist.net>
Sent: Thursday, February 15, 2007 11:01 AM
Subject: [ATM] Another machining question, please


>  I want to have 3 flat bottom holes ~ 3/4 to 7/8 inch in 6061 Aluminum. I
> don't have access to a lathe
>
>
> or mill, but do have a benchtop drill press.Could I drill the holes to
> depth with common metal drill bits
>
>
> and then run a Forstner bit down after it? All I really need flat is a 
> 3/16
> inch lip for a nut to rest on. I would
>
>
> assume this would ruin the Forstner bit...
>
>
>
>
>
>  Since I'm effectively "homebound now" due to medical issues, taking it
> locally to a machine shop or
>
>
> shipping it anywhere isn't going to work.
>
>
>
>
>
> Tom
>
>
> Too stubborn to quit being an ATMer
>
> _______________________________________________
> ATM mailing list http://www.atmlist.net/
> 


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