Starrett KA19-N Oops Arbor - Two hole saws on one arbour

[Midwest]

I know someone posted on this subject quite recently, but can't find it, regarding a new arbour which you can fit two hole saws, one to act as a pilot to enlarge an existing hole.

I tend to use the old 'cut at an angle' trick with the larger hole saw, but I've got a 60min ceiling thickness, and it's gonna make a bit of a mess with that trick.

Can't find that thread, googled and found the above Starrett one, but I thought it was something newer?

 

[Wilko]

Hi MW, here's another one ...
Adoxim Arbor - Enlarge Existing Holes - https://www.tlc-direct.co.uk/Products/FXSRDA1.html

 

[rsgaz]

Have you looked closely at your current holesaw arbour?
There may be a little bit of thread poking through the bigger holesaw, which you can just about thread on the smaller size.

Trickier to separate after if the 'anti-jam' pins won't reach the front holesaw, so put some grease where the holesaws contact each other.

 

[mhar]

I just get something like a bit of 5-10mm ply and make the required size hole in it and use it as a template (holding it in place whilst drilling the new hole

 

[Octopus]

My "Old" Arbor will allow you to use 2 hole saws ...

Have you tried the one you have?

 

[Midwest]

Have you looked closely at your current holesaw arbour?
There may be a little bit of thread poking through the bigger holesaw, which you can just about thread on the smaller size.

Trickier to separate after if the 'anti-jam' pins won't reach the front holesaw, so put some grease where the holesaws contact each other.

Thanks, I'll have a look. Both me arbours are ancient, circa 1980 and one is jammed with a hole saw

 

[Jim90]

Drilling 25mm holes and the 20mm knockout comes out of a box and you have to put like a reel of tape around a 20mm wholesaw to fit snuggly in a 25mm wholesaw!
Those were the days. Too poor to buy cone cutters!

 

[123]

CK also do one, I think it's slightly cheaper, here

 

[sam400]

Oops arbors are brilliant ,well worth having in your holesaw set. It's got me out of bother a few times now.

Sam

 

[Midwest]

How do these arbours fit into your existing arbour or do they? Looking at the Starrett web site, they seem to have different shanks for different arbours.

 

[123]

They replace the 6mm pilot bit