32mm Holesaw in Metal Consumer Unit knock out - balls up!

[Redvanman]

Doesn't help your situation but in future get the Hagar boards that have no knock outs if you are going to drill it out.
They do make both

 

[PEG]

I have had this occur,when knock-outs displace,or errors,retro-fit etc,necessitates a change of position or aperture size.

Usually,it is best to fit as large a piece of material as is possible,which matches the original cabinet. This can make any "special" shapes or slots,easier to machine,as it can be vice-work.

A few years back,i had cause to strip out several phone mast control cabins,which possessed a myriad of enclosures,cabinets and racking.

The stores area had a large pile of packaged,stainless blanks,epoxy coated on one side,and in varying size,from 50mm square,to 100 mm x 500 mm.

These have proved invaluable for such tasks,fixed suitably to maintain continuity.

When drilling around such knock-outs,you have to be ready for when they fall out...with only a "knock" :stooge_moe:

 

[overskilled]

For me make a new plate and pre drill this so fits nicely over balls up and your glans holds it all together !

don't think he or the customer will be very happy with the end of his penis holding a CU together!!

 

[Geordie Spark]

Not any help now, but you could possibly drill a smaller hole and then open it up with one of those cone cutter things, designed to open metal holes up.

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

 

[davesparks]

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

Apart from being made by silverline and sold by CEF it looks lovely

 

[Geordie Spark]

Apart from being made by silverline and sold by CEF it looks lovely

Yes I know! BUT it shows that they are available up to & beyond 32mm ....... I thought the biggest was 22mm.

That said, it's not something that you use all day everyday so for the occasional use it could ok PROVIDED you keep the speed (RPMs) down & use plenty of lubricant.


And there's always this:

 

[malcolmsanford]

Yes I know! BUT it shows that they are available up to & beyond 32mm ....... I thought the biggest was 22mm.

That said, it's not something that you use all day everyday so for the occasional use it could ok PROVIDED you keep the speed (RPMs) down & use plenty of lubricant.


And there's always this:

Ohhhhhhh now we are talking. Great for making holes in stainless

 

[Marvo]

I don't think you should be drilling the knock-out smaller than its intended diameter in the first place, you should either remove it entirely or not use it at all. Problem is if you drill it and fit an SWA gland there's a good chance it's going to break free anyway at some time in the future. The CU manufacturers should stop catering to DIY'ers and fit a proper gland plate that doesn't have pre-perforated knock-outs or leave the side and back walls without knock-outs assuming they're strong enough to take SWA glands without distorting.

 

[Octopus]

I don't think you should be drilling the knock-out smaller than its intended diameter in the first place, you should either remove it entirely or not use it at all. Problem is if you drill it and fit an SWA gland there's a good chance it's going to break free anyway at some time in the future. The CU manufacturers should stop catering to DIY'ers and fit a proper gland plate that doesn't have pre-perforated knock-outs or leave the side and back walls without knock-outs assuming they're strong enough to take SWA glands without distorting.

Problem is Marvo that there are countless existing installations where changing the CU is made difficult by all the DIY changes and hence why, I suspect, they have these large knock outs - quite how they expect the installer to maintain the IP rating and the "non combustibility" is questionable.

 

[Geordie Spark]

Ohhhhhhh now we are talking. Great for making holes in stainless

And the beauty of it is it's operated by hand so there's no fear of a numpty spark who has no comprehension of Speeds & Feeds (basic engineering stuff) ever burning it out!!! :laugh:

 

[uksparks]

I have not yet fitted a metal domestic board yet, and have to say I am not looking forward to it, I can see them just being awkward and problematic.

 

[uksparks]

Doesn't help your situation but in future get the Hagar boards that have no knock outs if you are going to drill it out.
They do make both

yes thats correct, the ones with knockouts have a "K" at the end of the part number.

 

[uksparks]

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

i only ever use a cone / step drill when drilling a hole in metal as I know I can control it quite well, I would recommend using one certainly, may not be the quickest method, but they don't skid about and you feel a bit safer / more confident about know its not too big, you can check the size as you go. Plus it gives you time to think about what size you are going to whilst its drilling.

 

[Englishman]

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

Similar sort of thing that I've got in my drill box, comes in useful it does, and is bloody amazing at its job! Goes up to 30mm I think.

 

[Englishman]

I have not yet fitted a metal domestic board yet, and have to say I am not looking forward to it, I can see them just being awkward and problematic.

Thought that before I started fitting them but they're actually a lot nicer to fit than the old insulated ones. Take a bit longer getting it on the wall and fireproof etc but it looks better and is so much nicer to work with.

 

[happysteve]

This could be useful:https://www.cef.co.uk/catalogue/products/1039967-20-36mm-titanium-coated-step-drill

Not at the price the "CEF random number generator" has popped up!

And there's always this:

Yep, used them plenty in my "making XLR patch panels" days... I'd actually forgotten they existed... so cheers!

 

[shanky887614]

plate it.

ive just installed a tpn mem4 board and it was perfect with no knockouts in the top and an easily removed gland plate ^^

 

[shanky887614]

Yes I know! BUT it shows that they are available up to & beyond 32mm ....... I thought the biggest was 22mm.

That said, it's not something that you use all day everyday so for the occasional use it could ok PROVIDED you keep the speed (RPMs) down & use plenty of lubricant.


And there's always this:

you can get 51mm step cutters now.

i only had to drill two holes but the ****e stocked by cef struggled.

dart holesaws are awful, ive got one of there arbors that is only any use without a pilot bit XD

 

[richy3333]

Not a bad idea at all. I wander whether the knock out would still hold firm though. Malcolm's idea should allow for the hole to be drilled neatly. Silly design by the manufacturers, they should have a couple of different options for the actual enclosure. Maybe they should do a bit of market research, asking sparks their views..

I emailed Hager about this exact problem over 6 months ago. Never heard anything back. I too had to drill out the board and there's little tolerance/ room for error. The old metal hager boards with the plastic fronts had 20 and 25mm round knockouts. Personally if I need to secure SWA now I'll choose another make of board instead.

 

[Octopus]

I emailed Hager about this exact problem over 6 months ago. Never heard anything back. I too had to drill out the board and there's little tolerance/ room for error. The old metal hager boards with the plastic fronts had 20 and 25mm round knockouts. Personally if I need to secure SWA now I'll choose another make of board instead.

I was doing a 5 way "garage" type install last week - so went into a wholesaler and asked to see the metal box and looked at the knock outs before I parted with my money! I used the Wylex unit - 3 x 20mm knockouts and I needed 3!