using sand for eliminating vibrations

[tux_linux]

Hey!

I need to annoy you on this. I'm setting up my new wood shop and I'm wondering how to install tubes with sand on the sawstand to eliminate vibrations.

I know some of you already tried this. It worked out quite well. Could you please provide some info?

How much sand did you use?
What size of tubes did you install?
In which direction did you install them?

I'm hopping to get some info and do not need to evaluate all of this completely by myself.

regards
Torsten

[Merlin]

I'm interested in this Technic, so some pictures please, some times it's hard to visalise (sp) tubes of sand.
have never heard of this before.

****Merlin***

[Gabby]

I think he was using inner tube pieces with the ends tied shut. If they are made from motorcycle tubes they would probably be easier to handle. I've made sand bags from pantlegs from jeans, with one end sewn shut then a zip tie on the other. 2 of them weigh about 30# I haven't actually weighed them.
Hope this helps.
Gabby

[Merlin]

Thanks Gabby, that is some what useful.
So if I made a couple and placed them under the saw the vibs wood be a lot less I suppose. hmmmmm.

***Merlin***

[thumbs]

Here in the midwest we get are sand tube at almost anywhere--I bought mine at a grocery store--They are normally used to put in the bed of a two wheel drive pickup truck--they provide weight on the rear wheels for better traction on snow and ice--I put two 60 pound tubes on my stand. I put a shelf under the saw and the put them long ways(front to back) on the shelf. Helps a lot. the tubes are made of the same material as as those blue tarps that are used to cover things outdoor--Does this help anyone??  Richard aka thumbs

[tux_linux]

You're talking about adding weight.

I'm talking about adding sand - a flowing medium in some sort of box/tube.
The sand is not just weight - it should be able to react on the vibrations.

regards
Torsten

[thumbs]

okay then--I'm not familiar with that concept, but after thinking about it, the idea is worth looking at again. Could a person suspend the weight on the saw without it actually touching the floor-would that absorb more vibration?? It's been a while since physics class. If the weight was at the top of the saw and not the bottom maybe that would work--I really don't know--Richard aka thumbs

[mrsn]

I think Dan had this set up, or maybe it was someone else. They built some sort of sandbox to hold a few inches of sand and the saw sat on top of it. I don't remember exactly how it worked.

[dgman]

No not me, but I don't think it should matter much where the sand is, at the top or bottom as it will absorb vibration any where the sand is placed. You are adding mass to the stand. The more mass, the less vibration in the stand.

[mrsn]

I looked and figured out, it was Mark (BoxMaker).
http://stevedgood.com/community/index.php?topic=4459.0

[Merlin]

Thanks MrsN that was helpful, I understand it a bit better know, but if only there was some pictures.
Pictures are worth a thousand words. LOL.

***Merlin***

[tux_linux]

Yes Katie, that was the thread, in which I became aware of that idea.

We should get Mainwood in here, he has mounted some tubes at his stand - I don't know if it's just for the weight or more.

@ Dan
hmm, I think it's more important to place the sand at the top end of the stand. That's where the vibration will be mostly. Also skyscrapers have such systems ( tuned mass damper )too at the top end of the tower to eliminate movement. They are often using water tanks. To my understanding is this a similar or at least related thing.

regards
Torsten

[sbudinger]

I don't know, seems to me if your going to build a box to fill with sand that it would be easier just to sink a couple redheads and bolt your machine to the floor. (Redheads are an anchor bolt used in concreat floors to atatch wall frames)

[Mainewoods]

Torsten, yes, it's just the weight added in the form of tubes of sand.  I used the sand because I figured the fluidity of sand would help to absorb some of the vibration.  I'm not a mechanical engineer, but in my case this seems to be working.  My entry level saw (Porter Cable) has a certain amount of vibration, but the sand tubes have reduced that significantly.  I simply laid the tubes across the cross members of the stand.  I hope this info helps!   

[tux_linux]

ok, seems like I will have to do some development.
I'm already searching for big tubes - the normal rain tubes are just about 4". I want something bigger, around 8" should be nice and will provide half filled enough "surface space" for some fine grained sand.

I'll keep you updated.

regards
Torsten