AmericanLongRifles Forums

General discussion => Gun Building => Topic started by: Nordnecker on October 11, 2021, 12:53:19 AM

Title: Drill bit advice
Post by: Nordnecker on October 11, 2021, 12:53:19 AM
Gentlemen,  I  would like to solicit the sage advice of this group. I need to bore about 100 really clean holes through some walnut lumber.
The cheap forstner bits that I have clog up before getting through.  I  don't know if Forster bits are the best choice.  Maybe a Brad point with a cutting lip would be better.  I'm drilling 3/8" holes through 3/4 boards. 
I'd like to buy a truly high quality tool. Where can I find it?
Thank you.
Title: Re: Drill bit advice
Post by: Birddog6 on October 11, 2021, 02:33:56 AM
The cleanest way I know to drill a clean hole is to have a board on the top &
the bottom & clamped tight  so you can't tear the wood upon entry or exit.

I have a set of Sears Forstner bits I bought 30 yrs ago & they have done well for me.

But a true cabinet maker could tell you for sure & not be guessing. They drill hundreds
of holes making cabinets & no room for error.

Title: Re: Drill bit advice
Post by: Bob Roller on October 11, 2021, 02:40:54 AM
I would use a 3/8" 2 or 3 flutr end mill running very fast like a router.
Bob Roller
Title: Re: Drill bit advice
Post by: bluenoser on October 11, 2021, 04:38:36 AM
I would use a brad point bit and Freud would be my brand of choice.  The Freud bits have well-defined and sharp spurs. Some lesser brands have ill designed lumps they call spurs.

https://www.freudtools.com/explore/drilling-boring/boring-bits/brad-point-bits

I agree with Keith regarding a firmly attached backing to avoid chipping when the bit plunges through, but see no need to have anything on top.  If you are using a drill press or some other means of positive alignment, back the bit out once or twice to clear the chips.  If not, only back the bit part way out.
Title: Re: Drill bit advice
Post by: Not English on October 11, 2021, 07:55:40 AM
Bob has the right idea. Make sure that they are ground for a plunge cut. If there's a break in the bottom cutting edges, they wont cut when downward pressure is applied.
Title: Re: Drill bit advice
Post by: DaveB on October 11, 2021, 03:43:22 PM
Any of their products are top notch. Both Forstner and Brad Point cut extremely cleanly.
https://www.fisch-tools.com/en/produkte/wave-cutter-forstnerbohrer
Title: Re: Drill bit advice
Post by: Jerry on October 12, 2021, 02:56:20 AM
I have had really good luck with a modified spade drill when drilling patch box cavities. In this application I’m only drilling a certain depth. But the sides of the holes were very clean. I shorten the point to 3/16,” add more clearance to the outside edges, and sharpen the cutting edges to a more shallow angle to keep chatter to a minimum. Hope this helps! Jerry
Title: Re: Drill bit advice
Post by: Nordnecker on October 12, 2021, 02:38:07 PM
Thanks, guys. I found a quality bit and was able to complete the project.
Title: Re: Drill bit advice
Post by: flehto on October 12, 2021, 03:31:12 PM
As a retired tool and diemaker, I never thought drills could be that complicated. I've used HSS  drills of many brands and they all "drilled"......a hole . Now carbon steel drills are usually cheaper but don't perform as well.  The  points of the purchased HSS twist  drills were used as rec'd  unless a flat bottom "point" was used....these we ground by the toolmaker as well as re- sharpening a drill.... both of which which were done freehand....no jig. 

Of course the mat'l being drilled in the toolroom  was usually steel , but have used twist drills while building MLers including stocks w/ regular HSS twist drills usually in a drill press  w/ excellent results......a suitable spindle speed is very important according to the drill dia and many run the drills at too slow a speed. Also, if an exiting  tear  out is to be avoided, easing up when breaking through the opposite side of wood helps, but a fast enough speed is more important.   Some holes require a holeshooter and w/  many of these, the speeds are way too slow.

Thought this scenario was kinda funny......saw my neighbors , both the husband and wife leaning on a hole  shooter  { she was heavier than he } and the attempted 1/2 dia  hole was in a car bumper which is tougher steel. The progress was stalled and the drill became dull. Looked at the drill point and saw that the  heels of the cutting edges weren't relieved. Re-sharpened the drill and told only  him to drill the hole....went through like cutting butter even though the spindle speed was too slow. .....Fred