Starrett Adapters

[Onoff]

Say you have a 16mm hole but you wanted really to put a 20mm hole in or you drilled a 20mm hole and wanted a 25mm. Yes, I know cone cutters / step drills etc but they go blunt. Starrett have the "OOPS" allowing holesaws of two DIFFERENT arbor sizes to be used but no good for the smaller sizes:

 

 

But for using two of the smaller sized arbor cutters together........I think I'll call mine the "FOOKIT". First, get yourself a 1/2" UNF 20tpi x 2 1/2" long bolt and cut the head off, file neatly and de-burr:

 

 

Then screw on a couple of Starretts:

 

 

Job done. The one in the picture needed a 13mm chuck you could turn it down to 10mm.

 

I did the above one in 2014. I keep one in my tool bag for electrical work. I call it the "FOOKIT".

 

Then today, needs must and all that, the FOOKIT+:

 

Take one 5/8"-18 UNF bolt. Black would have been better but they gave me BZP and plain nuts:

 

 

Stick 3 nuts on and bung it in the lathe. Roughly turn down the head end to 10mm dia x 25mm long. Drill and pin the nut onto the shaft (you could of course weld it on):

 

 

Screw on a big "Starrett":

 

 

Screw on the small Starrett:

 

 

Pack between the two with M16 washers if you want the smaller one to project more:

 

 

Best go and use it for the job I need it for now!

[Onoff]

Well it worked a treat:

 

 

In fact it's been a day of invention. The reason for the latest Starrett adapter was to get a 65mm core cutter in to try and open up a 32mm hole down through the footings. This so I can get an insulated sleeve through. Had to split the core cutter and put a home made extension in. Then drilled and tapped a piece of 32mm bar to go on the end and stick down the existing 32mm hole:

 

 

 

 

About 400mm down so far.....gave up for tonight.

Edited September 17, 2016 by Onoff

[Onoff]

Prompted by a request elsewhere but a little sketch ref Starrett holesaw adapters:

 

 

 

[Steptoe]

You can also get F-M adapters that go from small size internal dia to larger size ext dia, 

so you could go from a 20mm hole to a 50mm hole.

 

[Onoff]

1 hour ago, Steptoe said:

You can also get F-M adapters that go from small size internal dia to larger size ext dia, 

so you could go from a 20mm hole to a 50mm hole.

 

 

That's what I use the "genuine" Oops for.....

[Nickfromwales]

Bosch Quick change for me chaps. ?

If I get a FOOKIT moment I just make a template out of ply and use that to centralise the bit. 

Oh, and I don't have a lathe ?.....( yet ) ?

[Onoff]

1 hour ago, Nickfromwales said:

Bosch Quick change for me chaps. ?

If I get a FOOKIT moment I just make a template out of ply and use that to centralise the bit. 

Oh, and I don't have a lathe ?.....( yet ) ?

I actually unscrewed the 40mm hole saw off of a Progressor bit the other day and put it on my Fookit +.....was enlarging from 32mm.