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Author Topic: The BT (Balanced Tilter)  (Read 39928 times)

Mac Kerr

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Center of Gravity
« Reply #10 on: October 22, 2008, 12:19:33 pm »

Timothy Allan Jones wrote on Wed, 22 October 2008 11:48

Does the GOG change because of magnet wt.?

The center of gravity doesn't change no matter how you position the speaker. It is the point where the speaker is in balance at any angle. The problem with most tilt adapters it that the COG is not on the bottom of the speaker where the tilt adapter is. To stay balanced the speaker needs to rotate about the COG (which is somewhere in the middle of the speaker) so it always stays directly above the stand. If Nimrod's device works as planned it will make a lot of people happy. I doubt it will make him rich, but he'll have a lot of new friends.

Mac
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Lee Patzius

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Re: The BT (Balanced Tilter)
« Reply #11 on: October 22, 2008, 12:29:49 pm »

Instead of calling it the balanced tilter, why don't you just call it the Nimrod Webber?

OTOH, nice concept.

I'd add more surface area around the hinge points, and add brass sleeves around steel hinges, and possibly PTFE sleeves around the sliding rods.










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Lee Patzius

 

Dan Kok

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Re: The BT (Balanced Tilter)
« Reply #12 on: October 22, 2008, 12:58:22 pm »

Nimrod Webber wrote on Wed, 22 October 2008 01:27

My hands are itching… here is my next project.

[...]

Any insights are welcome…

Smile






Nimrod,

I love your ideas.

I could be completely wrong but given the fixed geometry of your tilting mechanism, doesn't the design work more or less well depending on how tall the speaker cabinet is which dictates how high the CG is?  The further the CG is from your mechanism, the larger the mechanism must be to rotate the cabinet around that CG.

Would a counterweight extending straight down (and offset back to miss the mast of the stand) from the bottom of the mechanism move the CG down?  If so, would allowing that counterweight to be adjusted up and down a shaft allow you to put the CG wherever you wanted allowing the size of the mechanism to be fixed yet allowing its use over a larger range of speaker sizes (because you can move the CG)?  Using something like this it would seem a larger range of speaker sizes could be balanced on your mechanism allowing them to be adjusted to some position where they would stay and be clamped to stay in place rather than the clamping part of the mechanism having to carry weight.

Sorry for the poor wording of that last paragraph, your idea is exciting and I'm struggling to get the thought out in a hurry.

I wish I had your ambition to actually realize my ideas.

--
Dan
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Patrick Tracy

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Re: The BT (Balanced Tilter)
« Reply #13 on: October 22, 2008, 04:40:33 pm »

I think you must be related to Horst Leitner, mechanical engineer and inventor of such things as the Horst Link ( http://en.wikipedia.org/wiki/Bicycle_suspension#Four_Bar_Sus pensions_and_the_Horst_Link) bicycle rear suspension geometry.

SteveKirby

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Re: The BT (Balanced Tilter)
« Reply #14 on: October 22, 2008, 06:35:40 pm »

Lee Patzius wrote on Wed, 22 October 2008 11:29

I'd add more surface area around the hinge points, and add brass sleeves around steel hinges, and possibly PTFE sleeves around the sliding rods.

PTFE cold flows and would develop slop.  Since this is not in constant motion, any reasonable surfacing should be fine.  Steel pins against hard anodized aluminum.

What is your concept for securing the tilt angle?  Some sort of nut on one of the pivots?  Maybe the sliding pivot since it would naturally have the most play?  If you really wanted it secure, you could put some serrations on the side and have a serrated washer that locked into to each step.  Sort of like some drum hardware.

Great idea.  I want a couple too.
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jeffhtg (Jeff Kenney)

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Re: The BT (Balanced Tilter)
« Reply #15 on: October 22, 2008, 08:34:53 pm »

Nimrod Webber wrote on Wed, 22 October 2008 07:27

My hands are itching… here is my next project.

I have started thinking about this while building the Stand Tricks.
See some details here:  http://billfitzmaurice.com/phpBB2/viewtopic.php?t=4378&h ighlight=stand+trick
 
After using them for a while I have come up with some insights and finally completed the design.

This is my take for a tilting adaptor (for a speaker on a stick) that keeps the COG of the cab over the pole's center
at any tilt angle within its tilting range (-12˚… 0˚ … +12˚).

I limited the tilting angle to 12˚ as my experience with the Stand Tricks never encountered a need for more then about 8˚.
The design is true for a cab heaving its COG at about 300mm from the bottom, as this is the average of the cabs I am using.
(and of coarse the cab's top hat being in line with the cab's COG).

The principle and geometry design of the BT is complete.
Only some minor mechanical issues to decide and will start fabricating.

http://i31.photobucket.com/albums/c360/boniton/BT.jpg

Any insights are welcome…

Smile







1. and tilt adjustment must have a secure locking system - none of those drum clamp screw downs.. something that can slip is dangerous. Speaker angle slips.. cabinet tilts foward and falls off stand as the CG moves foward. Someone gets hurt - you get sued.

2. CG's vary from cabinet to cabinet making it difficult to have a safe way of adjusting the tilt to line up the cg to the pole.
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John Cameron

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Re: The BT (Balanced Tilter)
« Reply #16 on: October 23, 2008, 12:37:22 am »

I'm interested depending on the weight rating.
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SteveKirby

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Re: The BT (Balanced Tilter)
« Reply #17 on: October 23, 2008, 01:37:55 am »

jeffhtg (Jeff Kenney) wrote on Wed, 22 October 2008 19:34

1. and tilt adjustment must have a secure locking system - none of those drum clamp screw downs.. something that can slip is dangerous. Speaker angle slips.. cabinet tilts foward and falls off stand as the CG moves foward. Someone gets hurt - you get sued.

2. CG's vary from cabinet to cabinet making it difficult to have a safe way of adjusting the tilt to line up the cg to the pole.

Nimrod's design has a forward limit to the tilt.  Even if the "locking" mechanism came loose, it wouldn't tilt more than 12 degrees.

I was suggesting the kind of toothed arrangement you see of some cymbal stand tilters only laid out linearly along the sliding pin (there are some industrial mechanisms I've seen that do this but I can't think of a common usage offhand).  Maybe instead of a wingnut something over center could be used (like a bicycle skewer) so that it resists coming loose under vibration.  I actually have such a gadget on a hi-hat stand and it never comes loose.  Wish the rest of the hardware was like that.  It could even be easily safetyed so that it couldn't pop open.
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Jason Lavoie

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Re: The BT (Balanced Tilter)
« Reply #18 on: October 23, 2008, 09:49:18 am »

Dan Kok wrote on Wed, 22 October 2008 12:58



Would a counterweight extending straight down (and offset back to miss the mast of the stand) from the bottom of the mechanism move the CG down?  If so, would allowing that counterweight to be adjusted up and down a shaft allow you to put the CG wherever you wanted allowing the size of the mechanism to be fixed yet allowing its use over a larger range of speaker sizes (because you can move the CG)?  Using something like this it would seem a larger range of speaker sizes could be balanced on your mechanism allowing them to be adjusted to some position where they would stay and be clamped to stay in place rather than the clamping part of the mechanism having to carry weight.



a counterweight like you describe would make his device obsolete..
if you added enough weight you could move the center of gravity to the pole socket point, and then tilt at any angle without worry..
(except the added weight on the stand, but at least it would be balanced)

Jason
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Jason Lavoie

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Re: The BT (Balanced Tilter)
« Reply #19 on: October 23, 2008, 09:57:33 am »

jeffhtg (Jeff Kenney) wrote on Wed, 22 October 2008 20:34


1. and tilt adjustment must have a secure locking system - none of those drum clamp screw downs.. something that can slip is dangerous. Speaker angle slips.. cabinet tilts foward and falls off stand as the CG moves foward. Someone gets hurt - you get sued.



I think you're missing the point of the adapter.
even if the setting slips, the center of gravity doesn't move front or back.
it might make an awkward shift, but if the design is right you should be able to move the speaker though its full travel with one hand and without any lateral weight shifts.

Jason
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