Band of Dans
Well-known member
THIS. Pilot holes take extra time, but are 1,000% worth it. The bigger the bit, the more it will want to wander.
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Cepheid Chorus
- Thread starter jcpst
- Start date
owlexifry
Well-known member
agreed. pilot hole is kinda mandatory. defeats the purpose of the centre punch if you don’t.
i usually use a 2 or 2.5mm
And at that I STRONGLY recommend a set of center drills vs just using a smaller twist drill bit. Twist drills can flex and runout, center drills are much larger diameter up until the point which is of size, and leaves a slightly countersunk hole.
I've been suffering from drill-anxiety for the last few months myself. But can share a few tips.
Recommend finding a 3-12mm bit. Only finding out of stock ones currently but I'm sure there's some on Ali. Buy a couple at this price.
Grab a auto punch for a couple bucks too. I don't like using a hammer and centerpuch as you can over do it and warp the enclosure.
Then, mark you common hole sizes with sharpie. For the black ones, I used a silver sharpie. It's a lot easier than counting the steps. Pots are first line, jacks second, DC is 3rd, footswitch is all the way.
The AliExpress stepped bits aren't great for hard metals, but work fine in aluminum. For powder coated or already painted enclosures I sometimes use an awl. For bare aluminum I'll tap the marked hole with a sharpie to usually add a black dot my mark. Helps with my aging eyes.
Before drilling, remove the drill template and check your marks with a speed square. Can check spacing with a caliper as well if desired. Or,not the pcb isn't populated, lay it over the enclosure and use the center leg hole for pots to check spacing. Also advisable to do after pilot holes as it only takes a second. If a pilot hole is off by just a little, drill to one size smaller on the step bit and correct with a round file. A couple of chainsaw files are good for this. Grab a 4mm and a 5.5mm and work the hole in a semicircular pattern.
In regards to pre drilled enclosures, they're great but they aren't 100%. Namely, the 6 hole variety. I can recall what but I did have a 6 hole build that didn't align to the pre drilled 6 hole box.
Hope this gibberish helps someone out.
Recommend finding a 3-12mm bit. Only finding out of stock ones currently but I'm sure there's some on Ali. Buy a couple at this price.
Grab a auto punch for a couple bucks too. I don't like using a hammer and centerpuch as you can over do it and warp the enclosure.
Then, mark you common hole sizes with sharpie. For the black ones, I used a silver sharpie. It's a lot easier than counting the steps. Pots are first line, jacks second, DC is 3rd, footswitch is all the way.
The AliExpress stepped bits aren't great for hard metals, but work fine in aluminum. For powder coated or already painted enclosures I sometimes use an awl. For bare aluminum I'll tap the marked hole with a sharpie to usually add a black dot my mark. Helps with my aging eyes.
Before drilling, remove the drill template and check your marks with a speed square. Can check spacing with a caliper as well if desired. Or,not the pcb isn't populated, lay it over the enclosure and use the center leg hole for pots to check spacing. Also advisable to do after pilot holes as it only takes a second. If a pilot hole is off by just a little, drill to one size smaller on the step bit and correct with a round file. A couple of chainsaw files are good for this. Grab a 4mm and a 5.5mm and work the hole in a semicircular pattern.
In regards to pre drilled enclosures, they're great but they aren't 100%. Namely, the 6 hole variety. I can recall what but I did have a 6 hole build that didn't align to the pre drilled 6 hole box.
Hope this gibberish helps someone out.
giovanni
Well-known member
I never tried a center drill bit, that’s good to know. I can totally see your point about making the job more accurate.
