Benchmaster, Master of Benches: a Robot Trap Shop Tale

You know, I told myself I’d take 2020 as a year to learn to relax, reflect, and stop building everything all the time because we’re all going to die soon anyway. And then I had to try and remember everything I did just since late September to write the last post. But there’s more, as in that post, I neglected all of the shop-building I’ve still been on a quest to do.

For one, I’ve been seeking a milling machine to accompany tinylathe (which does need its own writeup), but not needing one for business purposes, I wasn’t keen on buying a tinymill new. I kept an eye on Craigslist and Zuckerburg’s Emporium for good deals on small to medium sized mills – while I could have easily bought Bridgeport sized machines for days, that violated my rule for the time being of No Multi-Thousand Pound Objects That Can’t Drive Themselves.

My other constraint was no round-column mill-drills. I know they’d get the job “done”, but I can’t stand those things because of their propensity to rotate on the column and lose all your zeroes for you. So really I was just sitting on my ass waiting for “The One”, and was close to being able to get a few Grizzly mid-sized mills with square columns (and similar)… but damn, it turns out other people also want them, and they went quickly.

Luckily, fellow robot builder and machinery enthusiast Alex Horne made me an offer that I found very hard to refuse – on my way to Boston last November to obtain Overhaul 1 Among Other Things, I picked up this little guy from him.

Huh. Well that’s cute. It’s like a larval version of the classic American heavy manual mill pattern, like the first instar stage of a Cincinnati or Kearny-Trecker. I loved it.

The travel is about 12″ x 6″, which is pretty impressive. It’s in a similar size class as the Seig X2 type “tinymill” that’s sold everywhere, but built like a battleship. This was a difficult two-person lift, where as I alone can chuck a tinymill-sized machine onto the workbench back at MIT.

So I’m barely 2/3rds of the way to Boston and already have picked up several hundred pounds of junk. Well this trip is certainly going well! The mill came with this very heavy work table which itself was another hundred pounds or more of very dense and nicely finished Old Wood topping a frame made of 1/4″ thick steel angles.

We stopped by a local machinery dealer which I keep calling Hank Hill Machinery or Hillbilly Machinery to inspect their wares, and ended up finding a small treasure trove of full drill/mill/tap organizers. I spent even more money I didn’t intend to in order to swipe these – we made a “What if I took all of them” offer and split the goods afterwards.

So after I got back home and unloaded…. what on earth did I just buy. This is how I operate, as you know. Obtain first, figure out what it is you got after the fact. I’m literally the most advertisement-agnostic person on the planet. You can’t egg me on to buy something through viral targeted marketing, but you can set your product out so I trip over it and bring it home, then I’ll do research on how to buy more and subscribe to your services.

This adorable neotenic critter is a Benchmaster, made by a company called Duro that eventually just became “Benchmaster”. The product? Benchmaster. What does it do? Be the master of benches.

Picture shamelessly stolen from, so go visit them.

It was, as it seems, targeted at the hobbyist or a ‘second machine’ type situation. Sounds like a limited market, but they aren’t as rare as I thought they were, and an enthusiastic community exists around them where people have done comical swaps such as putting a Bridgeport M-Head on the damn thing.

If I haven’t beat this drum enough, I’d like to reiterate a point I made when I posted about crabmower: I bought an old, obscure device without knowing what it was, and someone had made an entire page on how they fixed up and modified it. Folks, this is why we’re here.

Alright, I now had to find a home for the Benchmaster so it can be the master of a bench. Ever since I built the benches, I’d already earmarked half of one of them next to tinylathe for the installtion of a mill. It had recently become occupied by random sanding/grinding tools and Overhaul parts, so there was a lot of cleanup and displacement to do.

Namely, all of my tooling (the stuff you need to USE a mill and lathe) had to be displaced. I therefore was forced on a hunt for new tool organization, which will come later. For now, it’ll just live in a pile on the floor like my soul.

I decided to disassemble the original heavy wooden bench to form a foundation for the mill. The 1″ of OSB my benchtops were made of felt just a bit too flexible for it to be a good anchor, so the plan was to secure the big wooden block to the bench, then bolt the mill through all of it.

The interesting thing about the Benchmaster is that the knee leadscrew pokes down from the mill by a fair amount. That’s why they always have to be on stands. I decided to drill a 3/4″ hole through everything as the leadscrew sphincter

#OSHACrane was used to line everything up and set the machine into position…

…upon which I lined it up with the marker lines I had drawn, then drilled through and bolted in-place.

And here it is, the menagerie of miniature machinery.

Alex threw in the 4″ milling vise, which we both agreed was way too large for this machine. It used up a significant amount of the Z travel just for itself, and this mill doesn’t have a quill (A bit annoying, and a good excuse to do a head swap later on), so its usefulness is severel curtailed. With the thing finally installed in place, I gave everything the ol’ lube n tune, taking the axes apart to adjust the slides and leadscrew nut tightness.

But damn is this thing rigid. Being made back when America was Great, Men were Men, and Steel was Free meant it’s exceptionally smooth (once I tuned the gibs in and cleaned & oiled everything) and I dragged this 1/2″ endmill at 1/2″ DOC through my sacrificial aluminum test piece at the highest spindle belt speed, and it barely flinched. This is a suicidal cut on a Seig X2 class mini-mill, and even if you did manage to do so by feeding slowly, the finish would have been chattery.

For now, until I want to get a 3 inch milling vise, I bestowed upon it my old toolmaker style vise that usually held motors under testing.

The other downside is at the moment it doesn’t have digital scales, so I’m back to using a lot of my “vernacular machining” skills learned years and years ago. My “edge finder” is really just putting a 1/2″ drill rod (itself really a cut-down, destroyed 1/2″ drill bit) into the collet and bumping off.

It fulfills my current “mill” needs quite well either way: Flat this shaft, key this, shave that down, bore this out. Anything substantially complex right now I have enough contacts and favors to call in so I can have a part made. I’ll be planning to add digital scales soon, and I’d like to eventually see if I can get it a quill via head swap or severe head modification.