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All Replies on Forstner Bit WithOUT Pilot or Spur Center

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View AaronSKuehn's profile

Forstner Bit WithOUT Pilot or Spur Center

by AaronSKuehn
posted 07-25-2011 04:03 AM


34 replies so far

View Bertha's profile

Bertha

12951 posts in 1693 days


#1 posted 07-25-2011 04:29 AM

You could chuck a router bit maybe. You could buy a cheap Forstner and grind the point off.

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View bigike's profile

bigike

4036 posts in 2288 days


#2 posted 07-25-2011 04:37 AM

i have to go with bertha

-- Ike, Big Daddies Woodshop, http://www.icombadaniels@yahoo.com

View WayneC's profile

WayneC

12622 posts in 3097 days


#3 posted 07-25-2011 04:39 AM

What size hole? I was thinking plunge router as well.

-- We must guard our enthusiasm as we would our life - James Krenov

View Sawkerf's profile

Sawkerf

1730 posts in 2068 days


#4 posted 07-25-2011 06:08 AM

I don’t think that I would want to use a Forsner bit (or spade bit, hole saw, etc) without a center spur. That’s what keeps the thing from trying to skate all over the place when it’s turning.

Just for giggles, try using a hole saw without the drill bit.

-- Adversity doesn't build character...................it reveals it.

View David Grimes's profile

David Grimes

2078 posts in 1640 days


#5 posted 07-25-2011 06:15 AM

I’m pretty sure there aren’t any forstners made without the center spur.

Start the hole with the “normal” Forstner, then grind the point off to finish it.

-- If you're going to stir the pot, think BIG spoon or SMALL boat paddle. David Grimes, Georgia

View TopamaxSurvivor's profile

TopamaxSurvivor

16214 posts in 2676 days


#6 posted 07-25-2011 08:01 AM

That is what I would do; get it started, then take the point off.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View WayneC's profile

WayneC

12622 posts in 3097 days


#7 posted 07-25-2011 08:05 AM

Set up two bits? I guessing there is more than one hole to drill.

-- We must guard our enthusiasm as we would our life - James Krenov

View Loren's profile

Loren

7967 posts in 2648 days


#8 posted 07-25-2011 08:53 AM

The spur has a function; there for a reason.

-- http://lawoodworking.com

View HorizontalMike's profile

HorizontalMike

6975 posts in 1914 days


#9 posted 07-25-2011 02:26 PM

Use two bits the same size, one WITH the spur, one WITHOUT. Start your hole with the spur-bit to get the outer portion of the bit below the surface and then switch to the de-spurred bit to finish. You did not say how deep your intended hole is so this may or may not work for you.

-- HorizontalMike -- "Woodpeckers understand..."

View TheWoodNerd's profile

TheWoodNerd

288 posts in 2192 days


#10 posted 07-25-2011 02:57 PM

View Bertha's profile

Bertha

12951 posts in 1693 days


#11 posted 07-25-2011 02:59 PM

Thanks Woodnerd, I’d never heard of those!

-- My dad and I built a 65 chev pick up.I killed trannys in that thing for some reason-Hog

View HorizontalMike's profile

HorizontalMike

6975 posts in 1914 days


#12 posted 07-25-2011 03:19 PM

The Nerd dun good! Cool!

Bookmarking the link as I type…

-- HorizontalMike -- "Woodpeckers understand..."

View tyskkvinna's profile

tyskkvinna

1310 posts in 1986 days


#13 posted 07-25-2011 03:39 PM

I’ve a small set of forstner bits that I simply grinded the bit off. You don’t have to pre-drill it—just use a drill press and make sure your work item is clamped or otherwise secured down and it’ll be fine. Go slow for the first couple of rotations to make a groove, then crank it up fast and hold on tight.

those flat-on-purpose bits look really cool!

-- Lis - Michigan - http://www.missmooseart.com - https://www.etsy.com/people/lisbokt

View TopamaxSurvivor's profile

TopamaxSurvivor

16214 posts in 2676 days


#14 posted 07-25-2011 06:08 PM

That looks just like mine so I wondered what the big deal was?? Googling Forstner bits http://www.google.com/search?rlz=1T4ADRA_enUS423US423&q=Forstner+Bits&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&hl=en&tab=wi&biw=1024&bih=515
was a bit of a surprise. I didn’t know they come in such a wide variety.

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View David Grimes's profile

David Grimes

2078 posts in 1640 days


#15 posted 07-25-2011 06:14 PM

I bet the rim-guided are not best sellers at $45 a pop.

How about start ALL the holes, then grind the spur to finish (and still need only one) ?

OP says “a… hole…” so maybe he only needs to do one, anyway.

-- If you're going to stir the pot, think BIG spoon or SMALL boat paddle. David Grimes, Georgia

View ChesapeakeBob's profile

ChesapeakeBob

360 posts in 2483 days


#16 posted 07-25-2011 06:29 PM

Historically, all Forstner Bits were “rim-guided.” They had several advantages including flat-bottom holes, VERY accurate hole diameters, and are capable of drilling “partial” diameter holes since they are guided by the edge of the bit. In the last 20 years or so, machine spur “forstner” bits and other variations of bits got confused with the more traditional design. Techichally, only rim-guided” Forstner bits are truly Forstner Bits. Thank you Woodnerd for including the link to Jamestown Distributors that shows true Forstners.

-- Chesapeake Bob, Southern Maryland

View TopamaxSurvivor's profile

TopamaxSurvivor

16214 posts in 2676 days


#17 posted 07-25-2011 07:28 PM

Thx bentlyj ;-) Good article, how does that feed point retract?

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View TopamaxSurvivor's profile

TopamaxSurvivor

16214 posts in 2676 days


#18 posted 07-25-2011 08:03 PM

What ever it is, it has to be strong!! Those feed screw pints take a lot of torque. years ago I need to drill a 2” hole through about 8” of framing for a conduit. The purchasing agent bought the cheapest forstner bit he could find without a feed screw. By the time I got that hole drilled, it was the most expensive 2” hole in the world!! Gotta love the stupid decisions people who have never done any real work do to save a buck ;-))

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

View ChesapeakeBob's profile

ChesapeakeBob

360 posts in 2483 days


#19 posted 07-26-2011 12:41 AM

Topamax… your’s is good example of a good tool used for the wrong job. The correct bit would have been a bit such as is sold for plumbers or electricians, many times made by Milwaukee. The Forstner bit without the feed screw was not proper bit for this job,as you quickly discovered.

-- Chesapeake Bob, Southern Maryland

View AaronSKuehn's profile

AaronSKuehn

290 posts in 1523 days


#20 posted 07-26-2011 04:16 AM

Thanks everyone for your input!

@TheWoodNerd: that’s EXACTLY what I was picturing in my head. Though about $60 cheaper :) I guess I’m going to take an existing bit and grind off the pilot. I thought of that, but didn’t really want to go that route.

-- Aaron

View marvinlee's profile

marvinlee

3 posts in 1189 days


#21 posted 12-27-2012 02:50 AM

Forstner bits without a center point are available from Carbide Processors Inc. at carbideprocessors.com

The firm makes cutting diameters from 1/4’ to 3”

View AaronSKuehn's profile

AaronSKuehn

290 posts in 1523 days


#22 posted 12-27-2012 03:09 AM

@marvinlee: Thank you! This looks even better than other options I found because it’s carbide. Unfortunately they are out of stock on the 2.25” size I want…and sizes in that range. But I’ll keep checking. Thank you!

-- Aaron

View waho6o9's profile

waho6o9

6214 posts in 1577 days


#23 posted 12-27-2012 03:31 AM

View JNP's profile

JNP

106 posts in 1577 days


#24 posted 12-27-2012 05:03 AM

I have a few sizes that I drilled through 3/4” oak that I keep on hand and use as templates. Then grind the pilots off and clamp the template onto your work piece and use as a guide.

-- Jeff

View gfadvm's profile

gfadvm

13545 posts in 1690 days


#25 posted 12-28-2012 03:03 AM

I went a different way when I needed big holes part way through the stock with no center mark. I cut the size hole I needed in a piece of scrap with a holesaw, taped it to my workpiece, and used a pattern bit in my router. Made a very clean job of it!

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View hhhopks's profile (online now)

hhhopks

604 posts in 1377 days


#26 posted 12-28-2012 03:59 AM

Gadvm, that sound like a winner.

-- I'll be a woodworker when I grow up. HHHOPKS

View daviddoria's profile

daviddoria

66 posts in 938 days


#27 posted 03-22-2015 03:40 PM

waho6o9, it looks like the MaxiCut Forstner still has a center spur so the hole is not flat on the bottom (there is a big divot), right?

View bigblockyeti's profile

bigblockyeti

2361 posts in 721 days


#28 posted 03-22-2015 04:06 PM

I’ve used center cutting end mills on wood before when trying to achieve a flat bottomed hole. The piece being drilled needs to be very well secured before beginning.

View Gene Howe's profile

Gene Howe

6876 posts in 2428 days


#29 posted 03-22-2015 04:29 PM

At 1”+, Andy’s (gfadvm) suggestion is the best. If it’s deep enough, you can use a plunge type pattern bit or a bowl bit, once you get deep enough to engage the bearing on the pattern.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View waho6o9's profile

waho6o9

6214 posts in 1577 days


#30 posted 03-22-2015 04:42 PM

Yes daviddoria there’s a divot in the middle.

View daviddoria's profile

daviddoria

66 posts in 938 days


#31 posted 03-22-2015 05:23 PM

If you grind the pilot off (I’m thinking of doing this with a 2” forstner bit), then how does it cut the center 1/8” or so of the hole? It seems like a “stub” will form (kind of the inverse of the divot formed by the pilot tip/brad point), not allowing the drill press to continue down into the workpiece. Can anyone comment on if this should be a concern?

Thanks,

David

View bigblockyeti's profile

bigblockyeti

2361 posts in 721 days


#32 posted 03-22-2015 08:02 PM

That’s the reason I used a center cutting end mill, the cutters extend all the way to the center of the bit. If you were cutting a soft wood and only had 1/8” or so that wasn’t being cut, it’s likely it would be mashed out of the way. If the center spur was larger and you were cutting a harder wood, like oak or hickory the cylinder of wood not being cut would be much more difficult for the bit to mash out of the way.

View daviddoria's profile

daviddoria

66 posts in 938 days


#33 posted 03-22-2015 09:09 PM

Yea, that makes sense. It seems like we’re looking at over $100 for a 2” end mill though (versus $22 for a Porter Cable or equivalent forstner) :(

View bigblockyeti's profile

bigblockyeti

2361 posts in 721 days


#34 posted 03-23-2015 12:28 PM

No doubt, a center cutting end mill of that size wouldn’t be cheap!

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