On Wed, 24 Feb 2021 13:30:06 +0000
S wrote:

On 24/02/2021 12:20, jon wrote:
On Wed, 24 Feb 2021 11:37:22 +0000, Dave Plowman (News) wrote:

Just as an update I've made up the dimmer. Used a Knightsbridge polished
chrome 2 gang plate from TLC. Which I've used before to make 'specials'
like say for AV.

I think the last one I used was chrome on brass. So not that difficult
to drill/work. This one - not in the usual Knightsbridge cardboard box
seems to be polished stainless steel. Looks just fine, but a nightmare
to drill.
Blunted a couple of new 2mm HSS drills while attempting the first pilot
hole. Eventually used a tungsten one. And broke it on the forth.
Enlarged it 0.5mm at a time - it did get easier with the larger sizes.


I bought a baby bench grinder to sharpen drills.


with stainless steel, you need to use cobalt drill bits.

drill slowly and dont let the drill tip get too hot. (the heat will
blunt the drill tip quickly

https://www.screwfix.com/p/dewalt-he...-x-133mm/7459v

My Dad was a light engineer. He kept a small bottle cap on his bench with some wadding in it that he soaked with oil. Wgile drilling, he would periodically dip the drill tip into the cap to keep his drill bits cool. well cooler.

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