If you’ve ever used a drill to turn a round hole into an oval–it’s okay to admit it–then you understand the basic theory behind a mill. As we explained in the last installment of “Making Stuff,” a lathe spins the work while holding the tool steady, while a mill spins the tool while holding the work steady.
Types of Mills
There are many types of mills, and we were searching for one that fit in our garage and was versatile enough for a wide variety of automotive projects. But beyond that, we didn’t really know what we wanted.
Our first instinct was to buy a generic, imported 3-in-1 machine, as we had some experience with one. These cost a few thousand dollars and combine a small mill and a lathe in one machine that’s relatively portable. What’s the third function that gives them their name? They’re technically drill presses, too. Marketing!
Here’s why we decided against the 3-in-1. First, we weren’t satisfied with the size of the work envelope or the rigidity of the machine. Second, we talked at length with friend of GRM and master machinist Steve Eckerich, and he was frank: “Don’t buy a benchtop mill or a 3-in-1 at any price for any reason. You’ll be frustrated and limited, and you’ll end up going out to buy a better machine anyway. Don’t do it twice.”
This advice was from a guy who spends all day every day in a machine shop and has built a zillion fast cars, so we figured it was worth following. “You want a Bridgeport,” Steve said. “Period.”
What’s a Bridgeport?
Steve had a point. Bridgeport is just a brand name, not a type of tool, but just like Kleenex is synonymous with tissues, Bridgeport is synonymous with vertical knee mills.
This size and style of mill is extremely adaptable to different jobs, relatively small and compact, and rigid and accurate enough to do real work. That’s why you’ll find a Bridgeport, or a clone, in almost every machine shop–even modern shops full of expensive CNC machines. As Steve explained, everybody needs a Bridgeport in the corner, as it’s perfect for making a small part or two for your other machines, building fixtures, doing small one-off jobs and more.
Since Bridgeports are so popular, a bunch of other companies copied the design and built their own vertical knee mills. There are lots of different brand names and lots of different levels of quality. These copies range from “pretty much just as good as the real thing” to “expensive paperweight.” And to make things more complicated, the quality of the copies has changed drastically over time as the market shifted. Fun!
Do you save any money by buying a Bridgeport clone? If you’re buying new, absolutely. But if you’re buying used, especially at the bottom end of the market like we were, then not really.
If anything, prices seem to be based mostly on condition and included tooling rather than on the name on the side. For machines in equal condition, we guesstimate a Bridgeport is worth $500 to $1000 more.
With all this in mind, we decided to spend a bit more and buy a real Bridgeport. We figured the guaranteed quality, guaranteed availability of replacement parts, and guaranteed documentation and community support would make it worth the price premium. If we knew more about these machines and could instantly tell if we were looking at a good clone or a bad clone, we probably would have been more interested in an off brand.
Transporting Our Mill
Wait, shouldn’t we talk about buying a mill before we talk about transporting one? Nope: This is a top-heavy, 2000-pound object that has no wheels, which means it’s very hard to transport.
Pickup truck beds don’t have strong enough tie-downs to secure a mill, our aluminum car trailer can’t support that much mass in a 2-foot square, and every solution might require two forklifts, one at each end of the transaction.
For this reason, the asking price is only one piece of the real cost of the mill. Buy at auction, and you can find yourself paying $100 to the forklift driver just to load it on your trailer. Buy privately, and you may need to hire a tow truck or a forklift to place it on your trailer. Or you can pay a rollback to deliver it door to door, but that’s very expensive for anything more than an across-town move.
Many sellers offer to load for you, but you still need a plan to unload it when you get home. There’s also freight shipping, which was too expensive for us to consider.
Machine tools are notoriously challenging to transport, but vertical knee mills in particular are fragile, top-heavy and hard to move without a forklift. We needed to do our homework before we could make a purchase.
The best option, in our opinion, is renting a hydraulic drop-deck trailer, which lowers the deck to the ground for easy loading and unloading. With one of these and a come-along, you can roll the mill on and off using half-inch iron pipe without too much danger. We spent $100 to rent one for the weekend.
What does all this mean when shopping? Simple: Distance matters.
We won’t hesitate to drive three states away to buy a car, but transporting a mill drains money from your wallet every step of the way. We live in Florida, so we simply couldn’t afford to retrieve one from a place like Pennsylvania, where there’s lots of manufacturing and therefore lots of used mills for sale. That means we had fewer options and higher prices than somebody who lives near a more industrial area.
Buying Our Bridgeport
We’d done our homework, figured out transportation, and even sold an old Fox-body Mustang to free up some space and cash for our new mill. It was finally time to go shopping.
We opened the classifieds and searched–and searched and searched. We shopped casually for a year or so, realizing that $1500 to $2000 Bridgeports were few and far between. And when they did appear, they’d sell within hours.
We lost one $1500 mill when we needed 24 hours to rent the trailer. We suspect that during the waiting period, the seller decided the price was too low, as he canceled the sale.
Finally, after noticing prices were increasing, we realized it was now or never. We nearly won a Summit vertical knee mill at a local auction. It broke our clone rule, but it was only 3 miles from our home, had a digital readout and seemed to be nicely kept. We stopped bidding at $2100, an amount that didn’t include any loading fees. Darn.
Then we heard through the grapevine that a friend of a friend–actually, the original owner of the Classic Motorsports Mini Cooper S project car–had an extra Bridgeport he’d be willing to sell. After a few months of cajoling and negotiating, we bought it for $2000. It was at the top of our budget and missing a few handles, but the variable speed head (basically a snowmobile CVT) made it worth the price.
We rented a drop-deck trailer for $100, and it was worth every penny.
We rented the fancy trailer, stuffed an envelope of Fox-body cash in our pocket, and made the 7-hour round trip to drag it home. Shoutout to longtime friend of GRM Rennie Bryant for helping us load the machine.
Once home, we moved the mill into the corner of our garage without a forklift. How? Meet the Burke Bar. It’s a big pry bar that’s perfect for wedging under the machine and picking it up to place iron pipe underneath. We grabbed ours from Lowe’s for $65.
The mill, though, needed some restoration before we could use it–but at least it came with a desirable digital readout. Next, we’ll restore that used mill.
After rolling the machine on the pipe to the back of our garage, we needed to spin it 180 degrees. Here’s another trick: By coating the floor with dish soap, we were able to remove the pipe and spin the mill by hand. Our Bridgeport had reached its new home.
Next, we’ll restore our new find and then put it to use.