[Frank Howarth] is one of the big guns when it comes to woodworking on YouTube, and now he’s doing something completely unlike his other builds. He’s building a gigantic CNC machine. Yes, we’ve seen dozens of CNC router builds, but this one adds a few nifty features we’ve never seen before.
The plans for [Frank]’s CNC machine call for a 4 foot by 8 foot table, over which a router on a gantry gnaws away at wood. This is the standard size for shop-sized CNC router, but [Frank] is adding in his own twist: he’s building a 12 foot long table, by way of a four foot extension. This one small addition allows [Frank] to put tenons in tree trunks, engravings on the side of furniture, or just to make one part of a very large piece flat.
Right now, the build is just about the base, constructed out of 2″ square steel tube. While the welding is by all accounts an amateur job, everything is square, straight, and true. Now, with a metal base scooting around on hockey puck feet, [Frank] is ready to start on the robotic part of the build, something we’re all interested to see.
It’s going to be really big, but still not the biggest.
This is really wild… can’t wait to see how it develops!
It is amazing what you can get away with when you are working with soft materials like wood. It would take about a ton of steel/concrete to get acceptable rigidity/accuracy for a ‘real’ CNC of that size (several tons for a high performance machine), yet the one he built can be lifted by a single person.
Steel doesn’t warp or change dimensions or get moldy due to differing humidity levels or minor temperature changes either though.
“While the welding is by all accounts an amateur job, everything is square, straight, and true”
Anyone to point out the obvious contradiction in that sentence?
that makes perfect sense, square, strait and true is a lot harder to do than most realise.
he might mean his welds needed too much fill or too much grinding.
it’s what we refer to as “pigeon poop welds” that is the problem for structural strength
WIth that thin wall he was welding, every bugger he ground off reduced the strength…. He may be a great woodworker, but damn son get some lessons.
Good: He took his time and in small steps, measured a ton, corrected things as he went, and it looks like thing turned out okay. Slow steps and you’ll get there.
Bad: For some reason he was convinced that he had to weld it inside a woodshop since it “Once I put the legs on, I couldn’t really move it in and out of the door”, yet when turned on its side it was much narrower than that door…and then in order to clear out other equipment he opened a side door that door was enormous – more than wide enough to get a fork lift in and much bigger than would be needed to move the table in and out of.
Did I miss something?
I just used Bosch rail – much easier than welding with a bonus of being able to adjust the size and features as needed in the future.
My question is where is he going to get 12′ leadscrews? Or is he going to run his gantry via rack and pinion?
I think he would have to do Rack and Pinion. I home built a 6′ x 4′ CNC router and I get terrible wobble when my feedrate is > 35 IPM. I’m watching this one… as mine is due for another “upgrade” soon. Looks great so far!
Edit** — I have 6′ lead screws… man we need an edit button.
McMaster Carr sells 12ft lead screws of various widths. Not sure that they would be ideal for this.
The obvious choice would be chain drive like the blackfoot https://www.buildyourcnc.com/blackfoot48v40.aspx
The hockey puck feet are great and a really good takeaway for many here. I have been using these for years myself, and have many of my machines on adjustable hockey puck feet. Yeah, it isn’t as good as bolting the machine directly to the floor, but it you can make a really rigid base out of 2x4s laminated together butcher-block style, bolt your machine to that, and then have the hockey puck feet support that.