Looking for Forstner Bit Extension

[Flute Maker]

I am looking for a Forstner Bit Extension about 16” long at least. My Forstner bit is 3/8” in diameter….round not hex shape.... I just need to go inside of one of my flutes and sort of clean up the end of a plug in there. It would take a light touch just to remove
a small amount….It’s more of a cosmetic thing for me…not needed to make the flute play….I just know it’s not like I want it to be! Lol…..Thanks in advance!!!!

*** I have a Porter Cable set from 1/4” to 1 3/8”…. All are 3/8” on the chuck end.
I want to use the extension with this set of bits…( I may have use for the other sizes in the future)Sorry for not being clear but I didn’t say I was drilling a 3/8” hole….I’m just using Forstner bits with 3/8” shaft on drill end …. My fault!!!!

 

[Mike Davis]

I think most of them will be 1/2“ at the chuck end.

 

[Bill Clemmons]

Would something like this work?

 

[Mike Davis]

If your Forstner has a 1/4 inch shaft and the extension has 1/8” wall thickness the total diameter is going to be 1/2” which is bigger than the 3/8“ bit.

 

[Henry W]

I expect you may need to purchase a long twist bit - as I agree with Mike that the math does not work for a 3/8" bit/hole. If you need a Forstner bit (i.e. flat bottom hole), there may be one out there that long, but I have never seen one. Seems like you are into a custom bit here? Could a long 'custom' flat scraper (lathe tool) work? (rotated slowly in the hole).
Or if you need a flat bottom, get a long twist bit and grind the end flat.

Hope that helps.

 

[tghsmith]

I would order up some ground drill rod and grind and hone a D bit end..

 

[Flute Maker]

Would something like this work?

It probably would ….. I can’t see end of it though…I have one similar but it is hex shape and the 3/8” wont fit

 

[Keye]

I know nothing about a 3D printer but could one make what you need?

 

[Flute Maker]

I expect you may need to purchase a long twist bit - as I agree with Mike that the math does not work for a 3/8" bit/hole. If you need a Forstner bit (i.e. flat bottom hole), there may be one out there that long, but I have never seen one. Seems like you are into a custom bit here? Could a long 'custom' flat scraper (lathe tool) work? (rotated slowly in the hole).
Or if you need a flat bottom, get a long twist bit and grind the end flat.

Hope that helps.

I

It probably would ….. I can’t see end of it though…I have one similar but it is hex shape and the 3/8” wont fit

Dont want to use a lathe tool

 

[Flute Maker]

I expect you may need to purchase a long twist bit - as I agree with Mike that the math does not work for a 3/8" bit/hole. If you need a Forstner bit (i.e. flat bottom hole), there may be one out there that long, but I have never seen one. Seems like you are into a custom bit here? Could a long 'custom' flat scraper (lathe tool) work? (rotated slowly in the hole).
Or if you need a flat bottom, get a long twist bit and grind the end flat.

Hope that helps.

I’m wanting an extension to put a Forstner bit into to make it longer…Not a Forstner bit that long….I’m sure or I would think there would be an extension for them…hmmmm maybe not…

Thanks again!

 

[Flute Maker]

I know nothing about a 3D printer but could one make what you need?

I don’t know about 3D printer….I was just trying to find an easy way to do this.

 

[mdbuntyn]

Klingspor's sells a 5" long extension:

Forstner Bit Extender 5" / 3/8" shank

Klingspor's Woodworking Shop is full line distributor of woodworking tools and supplies from respected companies like Klingspor Abrasives.

www.woodworkingshop.com

 

[cliff56]

Have seen twist bits that size in the elec depth at lowes, they do have bit extensions don't remember shat size.

 

[bowman]

Find an 'installers bit'. These are usually between 12-48", then see if you can regrind the point off of the blade tip. As mentioned before, the extension connection will be larger than the 3/8" bit you are drilling.

 

[Canuck]

Maybe.....

Amazon.com

 

[Flute Maker]

Klingspor's sells a 5" long extension:

Forstner Bit Extender 5" / 3/8" shank

Klingspor's Woodworking Shop is full line distributor of woodworking tools and supplies from respected companies like Klingspor Abrasives.

www.woodworkingshop.com

Yes that would work if I could find a longer one

 

[Mike Davis]

I think you will have to get an extension brazed to a bit.

 

[Flute Maker]

Find an 'installers bit'. These are usually between 12-48", then see if you can regrind the point off of the blade tip. As mentioned before, the extension connection will be larger than the 3/8" bit you are drilling.

The Forstner bit set all have a 3/8” shaft…. 1/4” to 1 3/8”….. The connection where the Forstner bit goes into the extension won’t go into the flute if I can get an extension long enough plus the bit size I’ll probably use will be 7/8” which will not be hogging out any depth at all…….just cleaning up a 1/16” on a plug in a cylinder or flute . It’s just 15” up in the flute…

 

[bob vaughan]

Anyone moderately familiar with a metal lathe could make what you want out of a 14" piece of 5/8" diameter CR steel. One end gets bored, reamed 3/8" and then cross drilled and tapped for a setscrew and the other end gets turned down to 3/8" (or whatever).

 

[bob vaughan]

Yes that would work if I could find a longer one

So put three of those extensions together.