Building a Taller Drillpress

[BF38] bought a mid-range miniature drill-press, and discovered that it was just too short for some of his applications. “No problem,” he thought, “I’ll just measure the column and swap it out for a longer one.” It sounds foolproof on paper.

He discovered, after having bought a new 48.3 mm steel column, that the original was 48 mm exactly in diameter. He’d have to make it fit. But how do you bore out a 48 mm diameter hole, keeping it perfectly round, and only increase the diameter by 0.3 mm? A file is out because you’d never get it round. A lathe is out because [BF38] doesn’t have a lathe.

[BF38] ended up making a DIY honing head, which is a gadget that presses (in this case) two pieces of sandpaper evenly against the sides of the hole to be widened. The head in question is a little bit rough — it was made as a learning project, but it looks like it served the purpose admirably.

23 thoughts on “Building a Taller Drillpress

  1. Looks like what we used to hone pistons in the old days with. Most likely you still can get them, though they have three heads on them, not the two. And have honing stones on them. Maybe they still use them – don’t know. But making one-off tools to solve problems – been there many, many times.

    1. Yup, This “build” was completely unnecessary. Cylinder hones are still widely used, are relatively inexpensive and come in a variety of sizes and types. The two most common types are spring or compression-screw loaded.

      1. If we only did things because they were necessary then that wouldn’t be any fun, would it? Perhaps his necessity was to learn, to feel the accomplishment of doing it himself. There’s a satisfaction from not just building a product, but building a tool to make the product that can’t be replicated. I once built a welder so I could build a recumbent bicycle- it was great fun! I could have bought a welder but I learned so much more doing it myself. Isn’t that what the DIY movement is about?

        1. Agreed. Although sometimes I like to finish the project without having to create 5 more to complete the original. Still, it worked – which is really what counts in the end I suppose, especially if you learn something. Whenever I work with things like this or need to create something original, I learn something about geometry and physics – sometimes it doesn’t work the way you either have learned, think it will, or measured it to be. And doing things that would be easy with a complete shop setup takes on a whole new meaning when having to say do it with a dremel and hacksaw.

      2. While such a tool already exists, the builder said in his log that he didn’t have “a cylinder hone or a lathe,” so he took the opportunity to do some metalworking practice.

    2. 3 legged springy hone would have as much chance of getting the hole to stay geometrically correct as the file. They are spring loaded so they just follow the contour of whatever shaped hole is there, and if they hit a hard spot in the casting, it throws it all off. You tube is full of diy mechanics ruining their engine cylinders with these, theyre designed for glaze busting not honing.

      A two legged rigid hone is more usual, with a means to lock the extension between adjustments, like the op has made. I would personally have made it to take standard delapena stones so I could reuse it in future with off the shelf grit specs and parts but good job on getting the mechanism right and for single use the abrasive ppaper will do the job. Used right it can actually correct geometric errors and make a rough bored cylinder fresh off the boring machine into a true cylinder down to a surprisingly accurate level.
      I use a raybrook rigid hone wet using honing oil in a very old high torque slow speed drill in a machine I built myself, using delapena stones of various grits. It is one of those investments you can pick up secondhand for cheap if your patient, but you will reuse in usual ways during years of use. Theres no such thing as a engine hone or a brake hone, they all just make very round holes, and if your hone adjusts to what you need it can do the job with suitable stone selection.

      1. I know the problem. My phone does the same thing,( But with different words.) but the funny thing is I have the auto correct turned off. And it only does it when Im texting.

        Back to the project. Me I would of done the same as Oxfred. But very cool and I like it alot.
        Its so funny. I think about this web site and how the internet has brought us all so much closer. 10 years ago I onloy done this locally now who knows how far it is getting out. Does the ISS read hack a day?

        Every one have a great day…

      2. @0xfred, that’s not a unanimous “we”. if HaD can implement a method of correcting posts while still allowing anonymous posting, I’m totally on board. But I’m not interested in creating and logging into an account so you can correct your typos.

        1. It’s not rocket science. Logged in, posted, can edit. Anon, not logged in, no edit.

          As far as the post goes, an interesting way to get it done. I’ll add that I would have considered spending a few dollars on turn in the pipe down to be able to replace the old one. But without seeing the wall thickness of the new pipe, can’t make a call from here.

  2. We needed a taller drill press and had a spare base and column, so I cut off 2 feet off the extra and had it welded onto the main column and now it has served more than 30 years. Standing the original on three wooden pop bottle crates was the old way. The head and bit has to be above the height of a grand piano on a process dolly to drill the pin block. It also has a double arm mounted head to glide over a large area for perpendicular drilling with no hand wobble enlarging holes beyond spec. It’s bolted to the floor and the top is extended with a maple post going up to the roof beam.

  3. I had the exact same problem, but solved it using a marginally narrower tube and then filling the gap with very thin stainless steel shim stock. The result is rock steady.

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