A workholding dilemma

...

Set so any load on the nut causes it to get tighter?

Not sure if this will help, but I sort of picture starting with a disk sander before the lathe part...

Maybe with a jig with a mandrel or something in the middle, like a circle cutter on a band saw, and turning them into the disk a bit at a time until they're ready for the lathe?

mac

Please remove splinters before emailing

"Prometheus" Would switching the end that the nut is on make a difference? ^^^^^^^^^^^^^^ Put a set screw in the nut, and then you won't have to worry about which end you put it on.

OTOH, if you use it without a set screw, there is a possibility that the torque from the cymbal will cause it to loosen, regardless of whether it is bearing on the bolt head or the nut. What will happen then? The cymbal will stop turning. Use a Nylock nut, so the loose cymbal can't apply enough torque to unscrew it.

Rob

Hi Prometheus Stick your bold all the way through the headstock shaft and chuck, hold the bold with your chuck, then a crown nut would tighten against the chuck jaws and a splitpin through a hole drilled through the bold would keep it secure. Have fun and take care Leo Van Der Loo

That's what I'm looking for, yes. It's just been a long week, and I can't get my tired brain around how it needs to be threaded for that to happen.

That's an idea, but I think that would be a pretty inefficient method compared to what I've got going now. To sand all that off would take quite a while, and generate a tremendous amount of heat. Cutting it off with a tool bit in a holder is pretty easy, I just want a good one-size-fits-all way to mount them.

To tell the truth, I've never checked to see if my lathe has a morse taper on the outboard side. If it does, I bet I could use the jacob's chuck and mandrel if I make a tool rest that can act as a stop to prevent the taper from sliding out. That would sure be easy...

I could certainly do that- but my only concern would be that the set screw would eat up the treads on the bolt pretty quickly. I don't know how precisely these things are controlled when it comes to thicknesses, but it would be a PITA to have to buy a new bolt every week or two because a set screw ate up the threads, and I could no longer tighten or loosen it properly.

I think we have a winner there. Thanks Leo- that's a great idea!

Put a small fiber disk under the setscrew.

MMMM ... lets think about it...

Outbourd mounted Rotating in a clockwise direction Bolt passing throught head with r/h nut.

The nut will only tend to tighten more as you are working. In normal operations nut cannot come loose. The only way that the bolt/nut can come loose is if you suddenlt apply a brake to the spindle and centrifugal force keeps the symbol spinning. Let the lathe run down naturally and this will never happen.

Lets look at another similar situation which I am sure most of you would use regularly, spinning a disk which is probably heavier than a symbol and at much higher revs than you would be working at ..... A circular saw ..... No double nuts, nyloc nuts, split pins or grub screws used here and for some reason they never come loose .... must be magic :). Just work on the principle of nut tightening in opposite direction to rotation. .... simple,no extra expense or time required, prooven over hundreds of years...

"Paul D" wrote:.(clip) The nut will only tend to tighten more as you are working. In normal operations nut cannot come loose. (clip) ^^^^^^^^^^^^^^^^^^ Paul, the torque on the workload is always counter to the rotation--it acts like a brake. Any slippage will tend to loosen the nut. That is why lathes always have a left-hand thread on the outboard end. We don't have to look at table saws for guidance--it's right there on the lathe.

BTW, rotational momentum is NOT centrifugal force.

Tablesaws also have left-hand threads on the arbor. Go figure.

Right hand rule on torque, isn't it?

Forgot to mtake into account effect of torque on lhs ..... I was thinking from the wrong end.. Didn't allow for the fact that the bolt could spin .... was thinking along the lines of fixed shaft. Unless there is some way of locking the bolt through headstock it will need some locking method on nut

"Paul D" wrote: (clip) Unless there is some way of locking the bolt through headstock it will need some locking method on nut. ^^^^^^^^^^^^^^^^^ There is a way. Very clever idea provided by the other Leo (Van Der Loo): Slip the bolt through the jaws of a chuck and lock it.

I am a turner who also plays bass in a band, my drummer has a couple of cymbals that has had splits in them for several years now. The way we "musicians" solve this problem is to drill a small hole at the inner end of each split therefore stopping it from splitting any further . The cymbal should then still be as large as it was and usually retain the same ring it had as well. Unlike a cymbal that has been turned down to a smaller size, this will definitely change its sound characteristics.

Another thing you can do if the cymbal is not ringing out as it should is to change its characteristics altogether by drilling holes and putting long pop rivets through the holes so they protrude quite a bit and hand loosely, so that when the cymbal is hit the rivets vibrate and cause a kind of crashing sizzle sound.

I know this doesn't help with your problem but it could save your friend a lot of money buying replacements. Hotfoot

What happens if you silver-solder the cracks? I would be tempted to try it, with the turning/trimming operation as a fallback if it doesn't work.

You want a LH thread. I have purchased LH all-thread, but forget where. You could find a short LH machine screw and have someone weld on an extension to pass through the spindle.

Cymbals are made by spinning on a lathe and trimmed to size with a metal spinner's handheld cutoff tool. Very long handle as you can imagine.

Your trimmed cymbals will make noise, but they will be off pitch and may have poor harmonics.

Dan

Nah, I think he really beats on these things- they have flopping pieces of brass hanging off the edges. While I see what you're saying, drilling a hole in the ones he gave me to fix up wouldn't come anywhere near close to repairing them.

I'll pass that along to him, but he does seem happy enough with the turned down cymbals the way I'm doing it. He expects them to sound different, and he's fine with that. I suspect he's just happy that he can use them at all, and doesn't have to just toss them out entirely. They still sound like cymbals to me, but I'm no expert.

So will turning them down- though I will pass along your suggestions to him for his consideration. For all I know, half of the ones he