Best way to cut 40mm diameter holes in metal clad boards

NDG Elecs · Apr 28, 2015

Hi folks,

Will be fitting first AMD3 board later this week. Using the Wiska spring tails kit on it. What is best way to drill a 40mm hole through the casing? I have cone drill bits up to 30mm and also have Bosch power change holesaws.

I found the cone drills much better in the past when drilling through Wylex switchfuse casings. I struggled with the holesaws in the past; found the teeth wear away quickly and it is harder to stop the holesaw wandering about a bit and knacking the case.

Opinions please!

Thanks, Neil

Leesparkykent · Apr 28, 2015

Deleted

Leesparkykent · Apr 28, 2015

shanky887614 said:
or use a 6.5mm pilot bit like everyone else

What do you mean? I was following on from darkwoods post (the post above mine) where he mentions "crashing the teeth into the solid surface with either damages them or snags of you have a slight angle then you end up with the pilot bit been wrenched into a nice kink".

shanky887614 · Apr 28, 2015

Leesparkykent said:
What do you mean? I was following on from darkwoods post (the post above mine) where he mentions "crashing the teeth into the solid surface with either damages them or snags of you have a slight angle then you end up with the pilot bit been wrenched into a nice kink".

what i meant is you shouldn't really be drilling the pilot hole with the arbor, its only a grub screw holding it in place

Leesparkykent · Apr 28, 2015

shanky887614 said:
what i meant is you shouldn't really be drilling the pilot hole with the arbor, its only a grub screw holding it in place

Oh, Ive never really had any trouble with using the arbor and pilot bit, with or without the holesaw attached to drill the pilot hole.

telectrix · Apr 28, 2015

problem is that by using the pilot bit all the time, it goes blunt and then more force is needed to get it through the metal. i find using a 5mm tungsten bit first saves the pilot bit from wearing.

NDG Elecs · Apr 28, 2015

Thanks for the input from all. I think I will prob stick with the holesaw and get some lard!

Not really worked with metal much in the past, so it is a bit mysterious to me still!!

Thanks again