How to best drill the waterproof plastic box?

Hi,

I received many parts for my efoil project (waterproof box with batteries+esc put on a Gong inflatable wing foil) and now I need to drill it to put the metal cable gland PG16 but I am scared to fail the drilling (hole too big or not clean…)

Here is the box :

Here is the cable gland PG16:

Apparently I need to drill a hole of :22.5mm

How to it the best way (without specific equipment) ?
Should I use:

  • a flat wood drill of 22mm (couldn’t find 22.5mm)
    image

  • a 22mm helicoîdal drill for wood
    image

  • a HSS 22mm helicoidal drill for metal
    image

  • a special flat drill for wood

  • a 22mm hole saw
    image

Any advice ?

Thank you for your help

Unibit the only way,

1 Like

+1 on that!
simple and always clean holes with a stepped drill.

Thank you for the advice. Do you think it is possible to make something clean with a normal drill ?
image

Because I dont have this type of machine

I have used a hand drill with good results.

1 Like

sure, no issues. You can tape and make a small dent with a hole puncher or a spike before drilling, otherwise it might wander a bit before starting the hole.

1 Like