Flexy Table component rack- why 3 legs???

fajimr · « **on:** 31 May 2006, 05:32 pm »

Hello all,

i ran across the FLEXY TABLE component rack plans and am wondering if anyone has experience building one??

http://www.tnt-audio.com/clinica/flexye.html

Anyone know the design rationale for only three legs??? And do the three legs have to be oriented length wise (i.e. why not have two legs in the front and one in the back). And why not jsut add a fourth leg and make it similar to other racks out there (salamander, for one).

Just wondering what people's thoughts/experiences about it are before I jump in myself....

PhilNYC · « **Reply #1 on:** 31 May 2006, 05:39 pm »

Three legs ensures that all of the legs will make contact with a floor, even if the floor is uneven (with four legs, the height of each leg would need to be adjustable to provide stable contact for all legs).

Regarding two legs on one side and one leg on the other (vs. two legs in front, one in the back), it probably also has something to do with the stability of the shelf...since the width is much wider than the depth of this shelf, there's probably less chance of the shelf tipping...

samplesj · « **Reply #2 on:** 31 May 2006, 05:53 pm »

I thought I read on one of the flexy variation sites that the reason they didn't use 2 up front and 1 in back is that it could cause shorting issues if gear was too close to the rear. Even if it didn't short I could see it wrecking havok with cabling.

toobluvr · « **Reply #3 on:** 31 May 2006, 07:09 pm »

Quote from: samplesj

Even if it didn't short I could see it wrecking havok with cabling.

Correct....
I once had a rack that had vertical posts toward the middle-rear.
They were always interferring with the cabling, and sometimes I couldn't even center the gear on the shelf because of it.

The other comment about 3 legs easier to level is also correct.

But visually, I think the symmetry of 4 vertical posts is much nicer, and would figure out a way to do it......adjustable spikes, appliance levelers, or some similar method.

fajimr · « **Reply #4 on:** 31 May 2006, 07:10 pm »

phil...

makes sense but in principle, since all the legs are threaded you could adjust a 4 legged model so that all 4 legs connected with the floor. Would 4 points of connection be better than three or is there some tripod effect here? Seems to me that there would be more shelf vibration with only 3 legs than with 4.. although it is simply conjecture at this point.

samplesj- yup, I thought about that too.. could be messy

thanks

fajimr · « **Reply #5 on:** 31 May 2006, 07:15 pm »

Quote from: toobluvr

But personally I prefer the symmetry of 4 vertical posts, and would figure out a way to do it......adjustable spikes, appliance levelers, or some similar method.

toobluvr
looks like our posts crossed in cyberspace... I agree about the esthetics of the 4 post but am wondering if there is a good argument for 3 posts

PhilNYC · « **Reply #6 on:** 31 May 2006, 07:33 pm »

Quote from: fajimr

phil...

makes sense but in principle, since all the legs are threaded you could adjust a 4 legged model so that all 4 legs connected with the floor. Would 4 points of connection be better than three or is there some tripod effect here? Seems to me that there would be more shelf vibration with only 3 legs than with 4.. although it is simply conjecture at this point.

samplesj- yup, I thought about that too.. could be messy

thanks

I just looked at the FAQ on that webpage and found this:

"3 or 4 legs?
It's up to you to decide but please consider that three legs are far easier to "level" than four. If you decide for 3 legs then avoid putting 2 in front and one in the rear!
The rear leg would cause some trouble with cables and connections, causing even short-circuits...you've been warned. "

mcgsxr · « **Reply #7 on:** 31 May 2006, 07:35 pm »

I built this one before I ever found that site, honest!

My error was to later add a panel to the back, around 8 inches wide - the idea was that it would hide the cables (there were holes drilled in the panel, designed to organize the cables), but in reality, it simply caused issues.

I would build again with 4 legs (never had any issues with mating with the floor), but advise against any central obstruction, from experience!

gary · « **Reply #8 on:** 31 May 2006, 07:36 pm »

Quote from: fajimr

phil...

makes sense but in principle, since all the legs are threaded you could adjust a 4 legged model so that all 4 legs connected with the floor. Would 4 points of connection be better than three or is there some tripod effect here? Seems to me that there would be more shelf vibration with only 3 legs than with 4.. although it is simply conjecture at this point.

samplesj- yup, I thought about that too.. could be messy

thanks

Three points define a plane, so a stand with three legs will result in each leg touching whatever surface you put it on (even if the surface isn't perfectly flat or level) and each will bear some of the weight. The stand will be inherently stable.

If you have four legs, the odds of each of them being the "perfect" length to reach the surface below are nil... any three will fall on a plane but the fourth will always be a little "off" one way or the other and the stand will wobble as a result. The loading of each leg will also vary dramatically since the stand is statically indeterminate, which is not usually desirable either.

Gary

nathanm · « **Reply #9 on:** 31 May 2006, 09:24 pm »

I suppose you could have 4 posts for the shelves but just put three feet on the bottom for easier leveling purposes. Better yet, I've constructed my flexy rack with only one leg. This leg is approximately 2400 kilometers long and is securely anchored to the earth's mantle. This was a lot of work to implement, but when you're trying to lose yourself in the music the last thing you want is for your equipment rack to tip over onto the floor.

Tweaker · « **Reply #10 on:** 1 Jun 2006, 12:14 am »

I don't know nathanm. Seems to me the rack will be prone to vibration from tectonic activity i.e. subduction, plate tectonics and such. You might want to take extra care to decouple the shelves really well. And if over time the material used to anchor to the mantle is not able to withstand the temperatures brought about by the extreme heat and pressure then you might find you have inadvertantly created a conduit for molten rock into your living room. Nothing will spoil a good listening session more than having your living room suddenly fill with basaltic lava.

lonewolfny42 · « **Reply #11 on:** 1 Jun 2006, 03:39 am »

Quote from: Tweaker

I don't know nathanm. Seems to me the rack will be prone to vibration from tectonic activity i.e. subduction, plate tectonics and such. You might want to take extra care to decouple the shelves really well. And if over time the material used to anchor to the mantle is not able to withstand the temperatures brought about by the extreme heat and pressure then you might find you have inadvertantly created a conduit for molten rock into your living room. Nothing will spoil a good listening session more than having your living room suddenly fill with basaltic lava.

Tweaker's got a good point there nathan....reminds me of the movie....The Core......better safe than sorry !!!

nathanm · « **Reply #12 on:** 1 Jun 2006, 04:59 am »

I had concerns about seismic activity but luckily about 2km into the drilling process I hit a rich vein of pebbles, the same kind used by Machina Dynamica. These immediately sent magical waves of positive influence into the drill bit, making it much less prone to wear. I knew that when I ran the post down the completed hole the magic pebbles would keep any unwanted vibrations away from the rack. But as good as they are they're not flawless. For instance, when the Sumatra-Andaman earthquake occured in 2004 I did suffer a collapse of the soundstage on the Burl Ives track I was listening to. (Probably jitter related) Although this is certainly the least of the problems resulting from that quake, it was indeed a dark day for audiophildom when you realize that your hardcore efforts at isolation are all for naught.

lonewolfny42 · « **Reply #13 on:** 1 Jun 2006, 05:09 am »

Quote from: nathanm

I had concerns about seismic activity but luckily about 2km into the drilling process I hit a rich vein of pebbles, the same kind used by Machina Dynamica. These immediately sent magical waves of positive influence into the drill bit, making it much less prone to wear. I knew that when I ran the post down the completed hole the magic pebbles would keep any unwanted vibrations away from the rack. But as good as they are they're not flawless. For instance, when the Sumatra-Andaman earthquake occured in 20 ...

Ah-ha

....this must of lead to the discovery of the Sonicrock.....your giving away your secrets.........

Tweaker · « **Reply #14 on:** 1 Jun 2006, 05:15 am »

I wonder if Burl Ives ever experienced any soundstage collapses?

Gordy · « **Reply #15 on:** 1 Jun 2006, 05:33 am »

Quote from: Tweaker

I wonder if Burl Ives ever experienced any soundstage collapses?

Only once, with Frosty... it was ugly. Ever wonder why ya don't see Frosty at Christmas anymore????

sas · « **Reply #16 on:** 1 Jun 2006, 05:46 am »

A nice implementation of the flexy is http://www.humblehomemadehifi.com/Flexy.html and here http://www.humblehomemadehifi.com/Flexy_Ref.html

fajimr · « **Reply #17 on:** 1 Jun 2006, 03:12 pm »

Quote from: PhilNYC

I just looked at the FAQ on that webpage and found this:

hmmm, how did I miss that?? sorry I didn't do my DD

but still the information has been helpful.

fajimr · « **Reply #18 on:** 1 Jun 2006, 03:14 pm »

Quote from: mcgsxr

I would build again with 4 legs (never had any issues with mating with the floor), but advise against any central obstruction, from experience!

very nice mark- what material did you use for your shelves??

mcgsxr · « **Reply #19 on:** 1 Jun 2006, 03:31 pm »

I used pine actually - 3 2x6's laminated together, then planed etc, then stained to match those Totem speakers I used to own.

Never tried one with mdf or anything.

Worth the $99 it cost me to build, back in 1994...