Unusual Combination

I have to catch up on a few things.

Og’s friend Ken has cancer. It has invaded his femur. He stumbled the other day, and the femur broke. Send up some prayers.

A guy who refers to himself as “Gorak” just popped up on the Chaski forum. He says:

I live in a suburb of Vancouver, British Columbia. Professionally, I work for a large consumer electronics company at an R&D facility managing all of the test laboratories. Outside of work, I am an avid sea kayaker, woodworker and wood turner and am in the planning stages of building an 18′ cedar strip sea kayak. My current hobby time however is severely limited as I also act as primary caregiver for my wife who is fighting an advanced terminal cancer.

Couldn’t hurt to pray.

Longtime reader Ruth has started a blog. You must begin reading it immediately.

Back to business. Sort of. Sondra has blogged my blogging of her excursion to church. So if you want, you can go over and leave a comment. I don’t know if she realized how many of her readers were Christians, but she definitely knows now.

I feel like I am partly responsible for helping Sondra decide to go to church. But who helped me? I have tended to think my own prayers made the difference in my life, but I now understand that that’s wrong. I was not the only one praying. Looking at Sondra’s blog comments, I have to wonder how many of my readers prayed for me all these years, trying to straighten me out. Keep it up. It obviously works. And thanks.

I think I’ve found the solution to my metric threading problem. I considered buying dies, but that would be a limited answer. I would have to buy a die for each thread I planned to cut, and I would have no choice about the diameters of the stock I threaded. I don’t know if there is any point in putting a thread on a rod of unusual diameter, but why give up the option? I also considered getting a 7 x 14 lathe and setting it up for metric threading. This would be great, but it’s one more machine. Someone on the Chaski forum suggested I look into a new idea: the electronic lead screw (ELS). I checked it out, and I think it’s the way to go.

Here’s how it works. You buy a stepper motor and a little digital controller, and you connect the motor to your lead screw. You also put a sensor on your spindle to tell the control box how fast the lathe is turning. Now you can move the carriage back and forth at any ratio you want. I assume there is some error, but it would be insignificant. This works so well, people who use ELS boxes commonly thread at 500 RPM. I have no idea why they would want to do this, but they do.

You can also wire it up to your cross slide to get a cheap version of CNC. This means you can cut tapers without a taper attachment. That’s a great thing. A used Clausing taper attachment would cost a grand. I can make one, but it would be a pain in the butt to store when not in use, and I’d have to put it on and take it off.

There are lots of other ways to get metric on my lathe. You can buy a 30-piece metric attachment, if you’re lucky enough to find one. They pop up about once a year. This lathe requires a metric quadrant and a bunch of other stuff, so you can’t just stick a gear in there and hope for the best. Getting a metric attachment is totally unrealistic. The ELS, on the other hand, goes on with a few bolts. And when you don’t need it, it disconnects. It won’t ruin the lathe, either. If I hate it, I can take it off and throw it in the trash.

It sounds very sweet, not to mention relatively cheap. I would have to find a way to couple the motor to the screw; that’s the only challenge. The screw on my lathe is completely covered at the right end, except for the end surface. I would have to machine into that surface to make a way to put a pulley on the screw. I guess it can be done. It’s supposed to be pretty hard to machine a square hole into a flat surface, so that probably won’t work. A tapped hole won’t work, because the screw needs to reverse, and that will make the threads come undone. Maybe I could bore a hole and put a set screw in from the side, with the screw sunk into the side of the screw, so it wouldn’t interfere with the thing the end of the screw spins in. Then I could make a shaft with a flat on one side and stick it in there. I have to make sure the screw hole would not have any ill effects on the lubrication. I suppose if it did, I could fill it with epoxy or something.

Funny, I had no idea how to do this, and then this idea came to me while I blogged it.

How do I bore a hole in the end of a lead screw with no lead screw in the lathe? Angle attachment on the mill? Arrghh.

Wait, I don’t need a lead screw. I use the ram on the tailstock.

I feel better now. That was a close one. I’ll bet the steel in that screw will eat drill bits like candy. But I have a carbide end mill I can use.

The milling machine should be at the rigger’s RIGHT NOW. Can you believe it? I feel faint. I am dying to crank that thing up.

Go visit Sondra. I mean it.