• Disclaimer: This Vendor's Forum is a paid-for commercial area. Unlike the rest of diyAudio, the Vendor has complete control of what may or may not be posted in this forum. If you wish to discuss technical matters outside the bounds of what is permitted by the Vendor, please use the non-commercial areas of diyAudio to do so.

Hole for Motor Run Cap

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
What have other members used to drill a 2" hole to install one of these big motor run caps upright on their case. I have a 2" height case and because of a larger lip on the cap it will not go underneath and I would rather have it upright taking up less space. Another question is how to mount this cap after getting the hole.
I depends on what material you are using but if it is steel or aluminium I would say that the best is a step drill.
Second choice for me would be a hole saw and third choice would be to drill a series of small hole then cut and file.
Other materials, I would use a router.
What did you use for the tube socket holes?
For securing it underneath, there are special brackets available which go around the cap and fix it to the underside.
A jubilee clip could be adapted to do the same thing.
I used a step drill for all the other holes, I have 2 sizes but neither is large enough for a 2" hole. The material is Aluminum. Drilling small holes and filing is the way I do the IEC socket but I am afraid when I finish doing this in the top plate is will not be pretty. I am sure I can find a 2" metal bit but then I know from experience it is going to be pricey.
Hole saw. Usually cheaper than 2" step drill bit.

For mounting, I used capacitor mounting clamp under the surface, like the one shown below.

Last edited:
Another idea is a fly cutter. Harbor Freight has them. Grizzly, too. The can be adjusted to any diameter in it's range. I've used the single cutter and it takes a steady hand on the drill to keep it from binding. They make a two cutter model but I haven't tried them yet. Another idea might be to flatten the rim on opposite sides, to make it fit, so long as you don't cause a leak:(
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.