How To Drill A Curved Hole

Next time you’re renovating and need to run some cables around corners in you walls, save yourself some frustration by building [izzy swan]’s corner drilling rig. It’s something akin to a custom tunnel boring machine but on a small scale.

drill-a-curved-holeStarting with a piece of steel, [izzy] traced and cut out a 90 degree curve with an attached arm that will allow it to rotate from a central block. He then grabs a random drill bit and attaches it to a flex shaft which is secured to the leading point of the steel curve. To complete the handy setup the entire rig is bolted to a block that will clamp over the corner stock.

As it stands, it takes some elbow grease to get the drill through, but it’s not a purpose built setup. On a second demonstration, the flex shaft breaks, but the idea is there. Now, [izzy] advises that this is most easily accomplished when re-framing walls with no drywall obstructing your drill, but the concept for this rig could nonetheless prove handy for welding, grinding, and so forth along any angled curve.

If instead you want to push your carpentry skills to their limits, build a wooden Vespa.

[Thanks for the tip, Itay Ramot!]

34 thoughts on “How To Drill A Curved Hole

  1. I run cat6 and coax in residential buildings for a living and I can say there are tons of products out there for doing just this, from special bits to setups similar to this. I’ve used quite a few, and found that for most things cutting a shallow trench into the face of the studs that make up the corner, laying the wire in the “trench”, and then covering the area where the wires pass with nail plates to prevent someone from stabbing them with a drywall saw. Like izzy points out, most of these products dont work as well if there is still drywall around where you are working and some take more time to setup than they are saving. It does look a bit nicer and I guess the wire is technically safer going through the stud as opposed to being just below the drywall surface, but when its all getting covered in drywall I dont think the reward is worth the effort. I was impressed with how clean his hole came out, most of the products i’ve seen make a bit of a mess out of it. Just my 2 cents.

    1. cables go in center holes, leave notching out to the plumbers.
      saying that if its elv like comms i guess it doesn’t matter.
      this project is lost on me for installing cables. never had to drill around a corner like this i can’t think of any situation where you would want to unless i guess your a tv cable installer or something and its not your house and you just want to mash the cable into the shortest and quickest route instead of taking the time to do it properly.

        1. Don’t laugh. Been involved in jobs where the inspector failed wiring for the bends (clean, neat radius, and not sharp; some of the nicest work I’ve ever seen) being too tight. One actually said will obstruct flow of electricity. The electrician made the job ugly to meet inspection, in the interest of getting signed off so he could get paid. That inspector was hammered less than a year later. Don’t know why. He resigned rather that fight charges.

        2. Well, that’s actually true.Sort of. In high speed ethernet sharp bends are out of spec – apparently because they create timing problems and increase collisions. CAT5 and above can be amazingly sensitive to over tight cable ties, inductive interference from nearby hi voltage lines running in parallel, stretched cable, bad termination, etc. Of course, since it’s also true that most manufacturers don’t actually test their cable to spec and even fewer installers have the test equipment to field test hi-speed cabling end to end (patch cables, I’ve read, are often out of spec) it’s probably all moot.

      1. Based on what’s being shown in the example picture, drilling a radius like that with such a wide bore will compromise the structural integrity of the drilled members. There are very specific structural engineering guidelines for drilling through studs/plates/joists/etc… that take into account the penetration diameter, ratio, spacing, etc…

        Disclaimer: As always, this and other similar dire messages of doom will only apply in certain scenarios. Murphy’s Law will ensure that those who care about such things will never be benefitted by actually following them, and that those who couldn’t give a crap about such things will always suffer the consequences of ignoring them. That’s just how it is. We’re all doomed.

      2. I agree in new open construction, while it may take a slight amount more of cable to do so running cable around a corner in this manner can be avoided, by an electrician worthy of the title. Hell when the construction is completed this technique looks to be unusable. The same is true when it comes to plumbing as well.

        1. I didn’t mean to tar you all with the same brush, it must just be the ones i have met were all either lazy or i did something to offend them before they started work. The last time i ran all the cables under the floor in preparation and the guy was over the moon, he told me there was no way he would have gone to the trouble of hiding cable like that and just clipped it along the skirting.

    1. Funny part about that is that in earthquake country in the USA, wood is preferred. The flexing it allows makes the building safer (up to a certain size) than bricks or cement because of their rigidity making them more brittle. It’s also more environmentally friendly as it takes carbon out of the air with man-made forests for wood.

        1. It’s only putting back what was there originally.

          Maybe be a big brown eyeball would be more appropriate.

          But that aside I can think of a few projects I’ve done not necessarily building renovation where a curved hole through a block of timber would have been usefull

          1. Right, but the originally we are talking about is way way before the land was inhabitable, when large proportion of atmosphere was CO2, before free O2 existed, and it took billions of years for ocean life to suck it out and deposit it as sedimentary rocks. There are some posited doomsday scenarios where a very small number of nuclear weapons could wipe out 99.9% of current life, not merely bombing us back to stone age, but the primordial slime itself, (Figure another 3 billion years before something crawls onto land again) just by their heat releasing gigatons of CO2 from calciferous rocks, coral reefs etc.

            Anyway, industrial production of lime for mortar and concrete CO2 release, is outpacing the sequestration by forestry. Then if you claim said forestry is neutral and also use that, we’re really not getting anywhere.

          2. ??? Burning “fossilized carbon” can’t and doesn’t return it the environment where it was first created. Wood construction could become sustainable, where wood construction is best for the tack perhaps, but I’m unaware of any coordinated efforts that could meet future remand. AFAIK all concrete and masonry construction use finite resources

        1. It was bored and rifled as normal then bent. Rounds through the shallow bend (60 degree?) barrel would tumble and keyhole. Rounds through the 90 degree bend would tumble and fragment, barrel life was (for practical reasons) unimportant.

  2. For simply doing it, rather than caring much about whether it is practical, I give it my vote. There’s nothing as heart-warming as seeing someone actually tackling a problem like this for themselves. It’s the opposite of boring (groan…).

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