Rubber band chatter reduction

[john lucas]

I was turning more cupcakes today. when I turn standard boxes that are thin sometimes you get chatter out toward the edge when hollowing. On regular boxes I just dampen it with my fingers on the outside. Can't do that with the cupcakes because of the fluting on the outside. I put several rubber bands around the outside and it completely eliminated the chatter so I could get a clean cut on the inside.

 

[hockenbery]

I was turning more cupcakes today. when I turn standard boxes that are thin sometimes you get chatter out toward the edge when hollowing. On regular boxes I just dampen it with my fingers on the outside. Can't do that with the cupcakes because of the fluting on the outside. I put several rubber bands around the outside and it completely eliminated the chatter so I could get a clean cut on the inside.

Cool idea what made you think of it?

When I hollow things like a goblet I do the hollowing first and then turn the wall thin from the outside.
Can even use a light on light woods to show the thickness.

Have you tried hollowing the inside first with the cupcakes?
Fluting the last might be a problem with a thin wall even supported from the tailstock with a ball inside.

Your cup cakes a really nice by the way!
Al

 

[john lucas]

If I hollow the inside first I run into the risk of the flutes cutting into the inside. It's hard to get the depth of the V's really precise. someday I hope to add an X/Y axis to the router table to help control the depth. The whole piece also vibrates less when cutting with the router if the piece is solid.
As far as the rubber bands go I think I heard that one time when discussing turning thin bowls. Don't know where it came from. Just thought I might try it on these boxes and it worked perfectly.

 

[Bill Weaver]

John,
Your thought and the principal is correct. A brake drum/rotor lathe used in auto parts machine shops uses a leather or rubber lined strap for the very same reason to eliminate vibration when turning a drum inside or end cuts on a rotor.

Just thought I would throw that in there for comfort.

 

[Hu Lowery]

surgical tubing

Keeping surgical tubing on hand is convenient for bigger stuff. You can also cut an inner tube in a long continuous spiral and get a long rubber strap. It doesn't take much to dampen vibration when it is first getting started, can be impossible to control once it gets bad.

Hu

 

[Tom Coghill]

John,

Great idea - Thanks for sharing!

 

[Ian Thorn]

That's a great idea thanks for sharing John

Ian

 

[odie]

There are times when I am unable to use either of my bowl steadys because of flaws, voids, or other irregularities. I'll keep the rubber band idea in mind, and use it when it applies to my particular needs.

Thanks for adding your ideas, John........:cool2:

Out of curiosity......I assume your cupcakes are end grain hollowed. What size, rpm, and tool are you using? (Gouge, or scraper) Are you using a variety of wood species, and do you find different species may effect the performance of your methods and tools?

Most of my work is cross-grain bowls, but I do have occasion to hollow out some small bowls of similar size to your cupcakes. With most work where obtaining a finely produced "tool finish" is necessary before sanding, and eliminating chatter, or vibrations is problematic, I find it beneficial to bring the finished interior wall surface level down gradually in depth, prior to lowering the depth of the rest of the interior. This way, the stabilizing effect of the bulk interior waste wood is used for as long as possible before eliminating it. Any chatter at all destroys an otherwise finely created "tool finish", so your rubber band idea could be used in conjunction with my methods of eliminating as much wood vibrations as possible, through the use of tools and technique. First preference would be to use a bowl steady, but as said previously, sometimes that option isn't available to me. My goal is to eliminate as much sanding as possible, and I will use whatever method or technique I can to get there.

I can foresee myself using this rubber band idea from time to time.

(Disclaimer: Because of past input on this forum, I must point out that what works best for me, may not be what works best for everyone else......or, anyone else, for that matter. First class results are the ONLY thing that count, and there is often more than one path to that final destination.)

ooc

 

[john lucas]

I hollow with either a bowl gouge or detail gouge. On larger pieces i thin a little at a time but on small boxes I usually hollow as I go and then make a clean up pass with a Hunter #4 or #5 so I don't have to sand with any course grits Its that last pass when the chatter developed. The hunter cuts as a be el rubbing tool on the bottom and shear scrape up the sides It's the difference between the super clean bottom and less clean sides that I have to sand at all. I usually just hit it with 600 grit to even out the sheen