Something big and heavy is headed this way. Yeah, a mill is half way across the country, hopefully one that I won’t think about upgrading for a very long time.
Some background: I’ve gone back and forth on getting a mill for decades, weighing the small (which fit well into a crowded garage) and low-priced import bench mill/drills, against knee mills, and those against enormous, stout, and very used Bridgeport-sized machines. Long story short, I wanted the impossible: a small, high quality, inexpensive, and reliable machine—it doesn’t exist. Proponents of Big American Iron, who always seen to know of deals nowhere near me or deals I missed, insist that anything short of US-made machinery is junk. As is written in the book, if this machine was in a factory where time is money, I might agree with them, but that’s not me.
Buying an old, well-used large machine is not an guarantee of success, and I don’t know what I’m looking at. I get the point about them being more rigid, but that doesn’t guarantee accuracy or repeatability if the ways and/or bearings are shot. The big picture purchase price includes fixing the worn parts (who’s going to make the repairs and what does that cost?). Buying something used means looking at it in person, and most are far away. Then there’s tax and the expense of moving a 3000 lb machine to where I want. Since I don’t have the space for a full-size machine anyway, that doesn’t matter, narrowing the choices to smaller (non-domestic) units.
So many times I nearly bought a bench-top Chinese mill, figuring something was better than nothing, but I just couldn’t. There are so many negative posts about them that I figured there has to be something to that and they should be avoided.
There’s another aspect of this as well, at least as important as the machine itself. Due to the expense, this needs to be a one-time purchase. I don’t want to risk spending $$$$ on a beat-up or low quality machine only to find out it’s terrible, then have to explain to the wife why I have to dump more money into it, or worse, get rid of it for half what I paid, and then spend double that to get a good one. I ended up compromising between American and Chinese and went Taiwanese. The mill is available in several versions: switchable belts, variable speed, and single or 3-phase. The variable speed version is mechanical, meaning that the speed is set by an adjustable-radius pulley. I’d have gone for that one but it’s $800 more and has a lot of moving parts. Because 3-phase is also available, however, a variable-frequency drive (VFD) can be added, resulting in a much wider speed range, more torque, and it’s also much cheaper, but does require substantial setup. The manual for the VFD alone is 98 pages of dense settings, so there’ll be time spent getting that going, and making a small box containing the controls (speed, fwd/reverse, start/stop, and bump).
The unit is basically a baby Bridgeport and weighs 1500 lbs. so I don’t want to move it any more than necessary. Also, being a baby Bridgeport means that at normal working height, the table is (said to be) fairly low for anyone taller than maybe 5′-8″. For those reasons, a wheeled stand will be made to adds roughly 7″ of height. While it’s tempting to go higher, the thought of having that much weight that high up makes me nervous. The large iron-wheel casters will give it mobility, and it’ll have three (yes, three) leveling pads. The thinking is that four pads won’t spread the weight evenly; there’s always going to be one that has more, less, or even no(!) weight on it, distorting the machine base to some degree. Yes, having three is less stable, but the idea is to crank the pads down so that they just remove weight off the castors. That way, if there’s ever any tendency to tip, the wheels are there to stop things. The plan is to use the engine hoist and lift it off its pallet, straight onto its stand, where it’ll live from then on.
Before it arrives, there’ll be a massive garage cleanup, pulling out everything and probably tossing out or giving away a bunch of stuff. The final layout will probably be slightly different than the drawings from the last blog entry. I’m also going to try something which may or may not go well, as the new layout requires a slightly smaller storage shelf. The one I have is huge, 8′ high, 8′ wide, and 2′ deep, and heavy duty. I just hate to throw it out and then spend more on a smaller unit that probably won’t be as good. The plan is to disassemble this one, cut the frame down 24″, and reassemble it. Either I’ll congratulate myself, or get pissed if it all goes wrong or takes too long. We’ll see.
Lastly, I ordered a manual mill because I can’t justify the expense of CNC. Plus, some of them don’t even have handles! About the only thing I think I’ll miss is the ability to mill curves or circles, but again, the number of times that’ll come up will be few, and virtually everything I make is a one-off, nothing requiring “production”. Because, if I just have to do something requiring a CNC, I know a buddy with a $25K machine 🙂