Anti Vibration Goo?

[firemandiver]

Here's one for the collective wisdom of the board: I have an idea.....might be worthwhile.....may be totally silly.

I am making a riser table for my machine. I have cut a piece of 3/8 plate for the base and welded a piece of 4X4 square tubing for the rise. My plan is to get the bottom surfaced by a friend who has a surfacing machine, weld a piece of 1/2" plate to the top, then bolt it to my table and mill the top of the 1/2" plate. That should make it true to my table.

I was thinking about the possibility of filling the cavity of the 4X4 with some type of self curing liquid rubber to help dampen vibrations.

Anyone ever heard of such a thing? Any idea where to get the mystery goo? I'd imagine it'd be some type of 2 part mix?

Thanks, FD

[brian Rupnow]

Do a search for Devcon products.

[tdmidget]

I'm lost . What is a "surfacing machine"? Is this a tiny machine such that a 4 inch square area is pretty much it? What do you do after you put the "goo" in? I would think that you would damp more vibration with shot. . Does this "riser" get a top?

[torchroadster]

I was thinking about the possibility of filling the cavity of the 4X4 with some type of self curing liquid

Concrete???

[firemandiver]

I have a 3 in 1, so it's 15" from my spindle to my crossslide. At full extension of quill I'm still miles away from reaching the table. I am basically moving the table closer so mills will reach. The shorter the "stick out" the steadier the set up.

Base plate is 6.5 X 8 3/8 plate. 4X4 riser is 5" tall, top plate will be 12 X 12 1/2 thick, so that will make a pretty usable surface area.

Hope this clears things up.

FD

[firemandiver]

Already thought of sand, concrete, lead shot, etc. Pretty much anything that creates density will theoretically dampen vibrations. I'm just brainstormimg....nothing chiseled in stone yet. Just wanted to see if it's even practical or just plain silly.

When I raced motocross there was a handle bar company that filled their bars with some type of rubber. It cut down on vibrations quite a bit. Was thinking along those same lines for the sub table. The rubber would take the form of the cavity, fill the void, and never shift,decay, etc.

FD

[Mcostello]

Window glazing putty.

[shipto]

not sure how good it would be but what about spray foam?

[tdmidget]

I have a 3 in 1, so it's 15" from my spindle to my crossslide. At full extension of quill I'm still miles away from reaching the table. I am basically moving the table closer so mills will reach. The shorter the "stick out" the steadier the set up.

Base plate is 6.5 X 8 3/8 plate. 4X4 riser is 5" tall, top plate will be 12 X 12 1/2 thick, so that will make a pretty usable surface area.

Hope this clears things up.

FD

No amount of rubber will make a 4X4 tube adequately support a 12X12 plate. I would make it thicker, too so you can put Tee slots in it. I would think about a 4X4 at each corner.

[macona]

One method to dampen vibration is to suspend a heavy rod in castable rubber.

Either that or use some sorbothane between the plate and the base.

[firemandiver]

Actually the table size will be 8.5 X 10....I just guestimated the 12 X 12. I can buy a tilting mill table with T slots ready made, but it's quite expensive for something I'll use occasionally. I have zero in this so far...made from stuff I have on hand. I plan to drill holes along the table to use studs/nuts to secure the workpiece. It will be more than heavy enough for what I need to do. (mill some slots in a piece of 1/4 plate). In hindsight I probably should call it a fixture rather than a sub table. I'm making this to do a specific job.

I'm not gonna be doing anything big. I'll build it to fit my needs, just wondering if there is any merit at all in trying to fill it with something to help dampen vibrations. Like I said...it may be a silly idea....just wanted to get some input.

Thanks for all the input so far.

FD

[Willy]

A few thoughts.

Steel as you know has a natural tendency to resonate. A plate and mount as you suggest will tend to "ring", especially near the edges. Can you redesign it to incorporate gussets to quell this?

As far as a pour-able fill goes, what about an epoxy granite mix. Although I have not used this personally there has always been much discussion here and elsewhere publicizing it's ability to dampen machine vibration.

Whatever you decide to pour make sure you vibrate it in order to get as much air out as possible and make sure you do this after welding so as not to break the bond due to the heat from welding.

Another thought would be to use cast iron as it's ability to dampen resonance is much better than steel.

Tdmidget's idea of a much heavier plate allowing the addition of T-slots is also a thought worth pursuing. Plus the heavier section would also be less susceptible to resonance.

[firemandiver]

Already planned on adding gussets out to the corners of the table. I had originally envisioned a 1" aluminum plate bolted to the base, but in trying to be frugal I decided to mock it up with what I have in my pile O steel. Right now it's still in the planning stage. I'm still kicking around ideas. As for filling it, if I do....I planned to drill a 3/4 or 1" hole in the bottom prior to welding the top on. Once all welded up I can simply turn it upside down and fill 'er up.
Which is why I was thinking some type of liquid goo that would totally fill the cavity and stay put when it sets up. Unlike lead shot that would not require a plug to keep in held in.

Thanks for the input.

FD

[SteveF]

Lead shot wouldn't really require a plug. Just put in about 90% of it, mix the last 10% with epoxy and stuff it in.

Steve

[elf]

Are you trying to dampen high or low frequency vibrations? Your elastic goo may be good at one but not the other.

Here's an interesting site that includes some experiments in reducing machine vibration: http://www.mech.utah.edu/~bamberg/re...e%20Design.pdf