Holesaw hole widening attachment - GIF

**ToolTalkBot** · Apr 4, 2025, 08:14 AM

Holesaw hole widening attachment.

Previously:

25-inch holesaw - photo
Drywall holesaw - photo
Holesaw plug removal techniques - GIF
Large holesaw stabilizing trick - GIF

**nova_robotics** · Apr 5, 2025, 07:28 AM

Oh that's smart. I need that.

**Frank S** · Apr 5, 2025, 07:59 AM

Pretty good idea.

**dain176116** · Apr 5, 2025, 01:10 PM

is this a for sale item? who made it?

**ductape** · Apr 5, 2025, 02:15 PM

If interested in purchasing, search for "HCD Hole Saw Centring Device".

**IntheGroove** · Apr 5, 2025, 06:15 PM

If interested in making them get some plywood and various holesaws. A spring and a bolt. Homemade Tool...

**BuffaloJohn** · Apr 6, 2025, 04:34 PM

This would be a very easy 3d print - and you could make one for different hole saw sizes. It took me all of 10 minutes to model one that was 3.25" in diameter, 1" tall with 1/4" hole, looks like you can print it for about:

$0.68

I guessed on the bolt size, but wow, that is a great idea!

Holesaw hole widening attachment - GIF-holesawdevice.jpg

It have taken longer to make this post than to design the part...

**tleathem55** · Apr 9, 2025, 11:32 PM

would I or anyone interested be able to get a copy of that cad drawing

Cheers and thank you in advance

Tony..

**BuffaloJohn** · Apr 10, 2025, 12:42 PM

Originally Posted by tleathem55

would I or anyone interested be able to get a copy of that cad drawing

Cheers and thank you in advance

Tony..

I did it as a 3D model in FreeCAD. It's pretty simple:

The diameter of the wide bottom of the cone is 1/4" (~6mm) less than the inside diameter of the hole saw. The base is 1/8" (~3mm) tall. The top of the cone is 1" (~25mm) diameter and is 1" (~25mm) from the bottom of the base. I then put a through hole which should match the hole saw pilot. In my case, I guessed it was a 1/4" drill. That drill is replaced with a bolt that goes through the hole of this adapter into the hole saw arbor and is held in the arbor by a set screw.

As for the bolt, in the video, it is a wide head, not a standard head profile. I would just use a hex bolt and a large washer so the adapter will slip on the bolt when the drill turns.

As for the adapter, you could make it on a 3D printer or turn it on a lathe.

If you want my FreeCAD file, send me a private message (click on my name and the option for a private message shows) and I will email it to you...

If you want a specific diameter of the base, hole diameter, or height of adapeter, tell me what you want and it takes just seconds to modify. If you want changes and only want as STL or STEP, I can send you that as well...