New Hotness Beats Old Busted Iron

I got the 7 x 14 running, and I’m very impressed.

Let’s see. What can I put here in case someone else Googles the problems I had? “Big Dog 7 x 14 lathe quick change tool post Tormach stud remove.” That ought to cover it.

I have a Tormach quick change tool post in 0XA size, and the lathe comes with a very nice but undesirable turret post. I had to take the turret post off the compound in order to mount the Tormach. The turret post sat on an upright stud threaded into the compound. That stud was too short for the Tormach tool post, so I had to remove it and put the Tormach stud in. As everyone knows, a stud has threads on both ends, so you can’t use a wrench on it.

The turret post lever screws onto the stud from on top, so obviously, it can be threaded onto the stud. The Tormach tool post has a flange nut on top, with the same thread. This gave me the working equivalent of two hex nuts. To remove studs, you use a tool I don’t have. When you don’t have that tool, you use two hex nuts. You thread them on the stud and torque them against each other, and for some reason, that makes them grip the threads. Then you turn one of the nuts with a wrench, and that turns the stud.

So I did that, and out came the stud. Now the tool post is mounted. Little Machine Shop sells a milled-down cross slide for mini-lathes that use a quick change tool post. I believe the idea is that turret posts let you get lower on the work. I don’t know if that has any relevance to Big Dog lathes, since they’re different from most small lathes. It seemed like I had plenty of room with the existing cross slide.

I should add that the turret post looked really nice. The lever cover was plastic, but other than that, it looked very well made. Sharp lines and shiny finishes.

The 3-jaw chuck that came with the lathe looks very good. I have not measured the runout yet, but it appears to be machined as nicely as my Phase II chucks, and if it’s as good as they are, it will work fine. It only holds objects smaller than two inches in diameter, unless you turn the jaws around. That’s something I’ll have to do, as soon as I figure out where the numbers on the jaws are. I don’t want to put them back in the wrong order.

The lathe has what appears to be a for-real tachometer. Inside the gearbox, there’s a flange on the spindle, and the flange has a hole in it. There’s a little reader in there, and the flange rotates through it. I guess it looks to see when the hole is going by. Anyway, if they went to that much trouble, it must be the real thing, instead of some kind of estimate based on current flow or whatever.

I ordered a handheld Chinese tachometer off Ebay before I realized the lathe had one built in, but I need it for the Clausing, too, so it was a good buy. I can also use it for the drill press. It’s not here yet. It was about $14, including shipping. From the little experience I have, I am starting to wonder if it’s even necessary to know your spindle’s speed, since it pretty well tells you when it’s wrong, but I guess I’m not qualified to say.

I got 34 RPM on the low end. The top speed is 2500. At 34, even I should be capable of competent threading. I don’t look forward to changing gears by hand, but it would be such a rare thing, I think I can stand it.

The lathe spins nicely, unless (like me) you turn it on with the jaws out of whack. I assume that means it’s going to be a little lumpy when irregular parts are chucked.

The change gears are nylon. I rented a mini-lathe video by an expert named Jose Rodriguez, and he said the nylon gears on his old min-lathe were nylon, too. He managed to get some metal gears, but he didn’t use them, because the nylon jobs didn’t break or wear noticeably even after years of heavy use. I guess I can live with them, too.

I happen to have an old round-nose tool I ground from 1/4″ tool steel or cobalt (can’t recall). I cleaned it up and stuck it in the tool post and faced an old Home Depot bolt I had lying around. Everything worked very nicely. I tried out the half nuts, and the tool moved smoothly toward the headstock. The facing went well, but the cheese-like Home Depot metal stuck to the tool when I used the half nuts, so the finish was dubious. Doesn’t matter, since I wasn’t doing anything useful.

The compound has a bit of a gritty feel when I move it, and I notice oil oozing out of the joints when I rock it, so I would guess that the underside could stand some cleaning and polishing, and the gibs may have to be tightened.

I have carbide tool holders on the way. They’ll set me free to do what I want.

This lathe is easier to use than the Clausing. I’m not sure why, since it has pretty much the same controls. Maybe it’s because everything is so close and handy, and because I don’t have a heavy 8″ chuck spinning near my head while I’m trying to use it. I usually use a Skinner 4-jaw chuck on the Clausing, and it must weigh 50 pounds. I don’t think I’ll ever get used to having it spinning right in front of me.

I think this is going to be a huge convenience. Big lathes take more effort to use, apparently. Suddenly I have something to think about, in case I get rid of the Clausing and upgrade. Going to 13 by 40 won’t be a big difference, but from there to 14 inches is a big leap. The machine weight goes from around 1600 to 2500 pounds, and I assume the tooling is also heavier and more aggravating to use.

Having played with this thing, I think it would be a great tool for anyone who wanted to learn about machining. If you’re really worried about money, you won’t want to buy a small lathe AND a big lathe, but if you can afford to have both, I think the small lathe is the better starting point. You can tool it up inexpensively, you can do all sorts of things with it, and if you decide you don’t want to use it as your primary lathe any more, you can CNC it.

I really look forward to receiving those cutting tools.