# Issues drilling blanks



## Nate029 (Apr 2, 2018)

I have drilled two blanks in a row for my hoot owl calls that the holes are oversized. Im drilling a 3/4” hole on my lathe because I don’t have a press. When I place it on my expanding mandrel it wont tighten up. Any suggestions on what I may be doing wrong?


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## Schroedc (Apr 2, 2018)

What kind of bit are you using? How are you holding the blank for drilling? How fast are you spinning? If you can give us a few more bits of info we can make some suggestions

Reactions: Agree 1


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## Bigdrowdy1 (Apr 2, 2018)

I use a large pen blank drilling chuck I got from Pen State Industries.( this one can hold up to a 2inch sq blank I believe). I drill my holes then turn on centers or use a expandable mandrel from there.
Hope that helps some.


Rodney


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## Nate029 (Apr 2, 2018)

Im using a 4 jaw chuck with an auger bit. I believe it was around 2200 rpm also.


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## Nate029 (Apr 2, 2018)

Bigdrowdy1 said:


> I use a large pen blank drilling chuck I got from Pen State Industries.( this one can hold up to a 2inch sq blank I believe). I drill my holes then turn on centers or use a expandable mandrel from there.
> Hope that helps some.
> 
> 
> Rodney


Im just using the 50mm jaws for now but plan on getting the pen drilling jaws soon. Thanks for the reply!


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## Bigdrowdy1 (Apr 2, 2018)

Since I got the large pen chuck I haven't looked back. Best 100 dollars I invested. Auger bits will give you a rougher cut. I use standard HS drill bits Bradford bits work well on starting holes with small pilot. Drill short cuts and back out. I like outing a little wax on bit to keep heat down and make smoother cuts.

 

Rodney


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## Schroedc (Apr 2, 2018)

Brad point bits or a Forstner bit for a hole like that. Slow it down too.

Reactions: Like 1 | Agree 5


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## rocky1 (Apr 3, 2018)

-- 4 Jaw or Pen Blank Chuck - either should work. 
-- Slow your speed down and don't try to force the feed. Slow and easy, short stabs to clean shavings around the bit that might cause a little wobble, make your bit track crooked. 
-- How tight is your tailstock? Are you picking up wobble with the tailstock extended? 
-- 3/4" Forstner Bit may be your best bet. It'll give you a truer hole, and help prevent wobble to some extent. I also have a standard 3/4" high speed drill bit I use with drilling a pilot hole. 
-- I picked up a set of DeWalt Pilot Point bits at Lowes that help keep things truer on smaller bores and pilot holes. 
-- My wood working bits are strictly that, they never see anything but wood, and the occasional piece of acrylic. 

What are you using for an expanding mandrel Nathan? I bought several in assorted sizes from one of the big tool suppliers, that simply are not forgiving; a couple hundredths over and you're screwed. They will not tighten up tight enough. 

They are a little spendy, but the expanding mandrels from Web Foot Game Calls are fantastic. Pretty forgiving, easy to work with. Set screw in the end, tapered threads. Clean the CA out of the tip occasionally and they keep running strong.

Reactions: Like 2


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## Nate029 (Apr 4, 2018)

My mandrel came from Breakhart tool company. I found them on eBay. 

I have a 3/4 forstner bit, but its a 4” long blank, so it’s just not long enough. I also have to loosen the tail stock and slide it down a couple times before I get through. Im sure that isn’t helping any either.


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## gman2431 (Apr 4, 2018)

Nate029 said:


> My mandrel came from Breakhart tool company. I found them on eBay.
> 
> I have a 3/4 forstner bit, but its a 4” long blank, so it’s just not long enough. I also have to loosen the tail stock and slide it down a couple times before I get through. Im sure that isn’t helping any either.



Buy an extension for your forstner and youll be all set. Ive been using the cheap Enco mandrels for years with good luck and long as you dont have a bunch of runout in the hole.


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## rocky1 (Apr 4, 2018)

Yep... pick up extension for the Forstner. 

Moving tailstock is the norm, as long as there's not a lot of wobble when extended is the biggest thing.


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## Nate029 (Apr 4, 2018)

rocky1 said:


> Yep... pick up extension for the Forstner.
> 
> Moving tailstock is the norm, as long as there's not a lot of wobble when extended is the biggest thing.



I bought an extension and it hangs up on the two set screws that hold the bit in the extension. They won’t fit inside the 3/4” hole.


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## TimR (Apr 4, 2018)

Nate029 said:


> I bought an extension and it hangs up on the two set screws that hold the bit in the extension. They won’t fit inside the 3/4” hole.


Colt maxicut Forstner bits are my choice, and the various lengths of extensions that run very true can’t be beat. Here’s a couple pics showing a bit, the 2mt adapter and an extension that can be inserted between adapter and bit. No setscrews, uses a cam lock that is secure and runs true. Also, the diam of the big part of extension is 9/16”, so 3/4” drill isn’t an issue.

Reactions: Like 1 | Thank You! 1 | Agree 1


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## Lou Currier (Apr 4, 2018)




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