Turning large out of balance posts

"Ted" wrote: (clip)have thought of using some kind of weight as a counter balance but I don?t know what kind of weight could be used that would be able to be attached to a post and I am not sure how to find out for sure which side of the post is heavier or how much weight should be used. ^^^^^^^^^^^^^^^^^^^^^^ Start by supporting the unbalanced post by its end caps between two live centers. The heavy side will go to the bottom. Attach weights by trial and error to the end caps, until it doesn't settle to one side. Let's hope that the heavy side is heavy along its entire length--that way you can apply the balancing weights equally at the two ends. If it appears that one end is vibrating more than the other, you will have a more difficult trial and error balancing problem. There are various ways you can hold the weights: lag screws, threaded rods, C clamps, etc. You might go to a tire shop and bum or buy some lead weights. These can be melted into a form that is easy to deal with.

If your lathe bearings are not free enough to let the weight sink to the bottom, try holding some kind of vibrator against it. An engraving tool might do the job.

Keep us posted.

On Tue, 20 Oct 2009 21:07:41 -0500, Ted wrote (in message ):

Please bear with me, this will seem way off the chart. In motorcycle tire balancing, sometimes a product called "slime" is used. It is a rubber or latex compound of some sort, placed inside the tire. As the tire rotates,the "slime" will move around inside the tire in such a way as to help balance the tire. Don't know why or how. It just works.

Your posts are hollow. Make a plastic bladder that can fit inside the post. Put about a cup of this "slime" inside the bladder. Inflate or pressurize the bladder so it conforms to the interior of the post. Mount your end caps as before. tom koehler

"tom koehler" wrote: (clip) Make a plastic bladder that can fit inside the post.

^^^^^^^^^^^^^^^^^^^^^ I like the way your mind works, but I think you have overlooked a serious obstacle. The inside of the posts is square. When it starts to spin, centrifugal force will sling the slime randomly into the corners, probably making the balance worse. Can you think of a way to put a cylindrical bladder into the post?

Depending on the inside diameter, I'd look at using PVC pipe...

On Fri, 23 Oct 2009 16:13:31 -0500, Kevin Miller wrote (in message ):

this could be a possible new tool - the dynamic balancing magafferator - could be wrapped in layers of paper until it is a snug fit inside the item being turned. tom k.

The slime idea is intriguing. But I already have all the post turned and delivered. I got a tip from someone on the Oneway Forum. The suggestion was to attach my large coles jaws on the outboard side of the headstock and use them like a flywheel. I adjusted sets of washers screwed into the jaws at various places using trial and error until I found a point at which the post would balance. It worked on all but one post. That particular post was so far out of square that it wouldn't balance no matter how many washers I attached. Luckily, as it turned out, I didn't need that post anyway.

Thanks for the suggestions, Ted J thelatentlog.com

Hi Ted,

Glad you got your problem solved. Another way to correct for an imbalance of lathe & workpiece is harmonic balancing. We used to discuss this technique here, but it seems not to have caught on. It is an interesting concept.

IIRC, it's nothing more than a 12 to18 in. threaded rod bolted perpendicular (not sure if horizontal or vertical matters) to the headstock and a weight is adjusted along its length to find the best vibration damping frequency. Some of you engineers correct me or explain better. I have never actually made or even seen one, but it makes for conversation. :)

Turn to Safety, Arch Fortiter

"Arch" wrote: (clip) Another way to correct for an

^^^^^^^^^^^^^^^^^^^^^ Yes--it was one of the topics that Lyn Mangiamelli played with. ^^^^^^^^^^^^^^^^^^^^^ (clip)threaded rod bolted

^^^^^^^^^^^^^^^^^^^^^ From a damping standpoint, it doesn't matter, but there is less chance of overstressing the threaded rod if it is vertical.

Arch, do you know whether Lyn ever recovered from his lung problems? Last I heard, he was not doing well at all.

For those too new to the group to remember, Lyn was an outstanding contributor to this group years ago, until he contracted a very serious lung disease from rat droppings in his wood pile.

Leo, I don't know about Lyn, but I sure miss him and so many others. Fred might know.

If anyone here has info about or experience with harmonic lathe balancing I'd sure like to read about it.

Turn to Safety, Arch Fortiter

On Mon, 26 Oct 2009 22:54:04 -0500, tom koehler wrote (in message ):

forget the PTO website! Just type in the patent number in your google search line, and you will come up with Google Patents! who knew? The full patent spec is there and faster and easier than the gummint site. Also got all the drawings there with no fuss. As i suspected, the ring is about half-full of water, and when it spins up, it is clear of the sponge media, and balances the drum at the fast spin-dry speeds. No moving parts, no seals or flexible energy-absorbing material or other parts to fail, as in an engine crankshaft balancer. Just an annular ring with fluid innit. I gotta try to make one of these. G'nite, for sure, this time! tom koehler

Hanta Virus? Does he live in the SW?

I asked Fred awhile ago (a year) and he had heard nothing. Makes me worried that no-one has heard a thing

On Tue, 27 Oct 2009 7:26:40 -0500, Ralph E Lindberg wrote (in message ):

I do a bit of looking for things, on the web. I found this article and it seems to be the balancing device you and others were talking about.

There is also a very good picture of the balancer. It is by Lyn Mangiameli, the man you are concerned about, now. I am a latecomer to this group, and so am unfamiliar with this man's work. Having read this article, I can say that I will bookmark the page where I found this article, and read the rest.

Respectfully, tom koehler

"LDosser" wrote: Hanta Virus? Does he live in the SW? ^^^^^^^^^^^^^^^^^^^^^ Yes, I believe that is it. SF Bay Area.

>

Hantavirus is very bad, but I thought it was only found in the desert south west. Doing a google proves me wrong about the geography and right about the bad.

No, Hata can be found almost anywhere

Get the router bracket for the Vega duplicator and a router with a spiral bit. You can turn at very low rpm, down to 0 ....