# automating periaktoi



## amwindle (Apr 27, 2009)

Hi,

I am working for a company this summer that is looking for a way to move six periactoids together. An ideas of how to rig this. They are all lined up next to each other.

thanks


----------



## Van (Apr 27, 2009)

By " way to move six periactoids together", I assume you mean rotate them all at the same time ?


----------



## cdub260 (Apr 27, 2009)

I've moved this thread to the Scenery forum as it is more of a set question than a Special F/X question.


----------



## amwindle (Apr 27, 2009)

yes, we would like them to rotate at the same time


----------



## Footer (Apr 27, 2009)

How Tall? Do you have a false deck? How much do each weigh? Are any of them already built? Whats the budget? Do you want them to be completely automated? Is the top secured to anything?


----------



## amwindle (Apr 27, 2009)

They are 10' tall and 3' wide, there is a false deck, not sure how much they are going to weigh. none of them are built yet, we are in the early planing stages. I do not think that we want them completely automated because are budget is limited. As of right no the top is not secured but it might be if it is necessary.


----------



## derekleffew (Apr 27, 2009)

The term is periaktoi. Adding the suffix "-oid" from the Latin for "similar to" or "in the shape of" is redundant.

amwindle, the most common method is to have a center shaft that projects from the bottom of each unit though the false deck. At the end of the shaft is a sprocket, mounted parallel to the floor. A roller chain then connects all sprockets to a drive motor and tensioner. See Notes on Sprockets and Chains.

Are there any mechanical engineering students in your area? There are lots of factors to be considered: Length of chain, calculating the forces of friction, diameters of sprockets, and if using a motor, torque loads, RPMs, gear ratios, etc. Students love to apply their knowledge to real world uses. And they work cheap. As always when using mechanized/automated scenery, of utmost importance is SAFETY. Be sure to include limit switches, proximity sensors, deadman switches, interlocks, E-Stops, etc., as applicable.


----------



## amwindle (Apr 27, 2009)

what is the average cost of the chain, sprocket and tensioners?


----------



## soundman (Apr 27, 2009)

The cost will change with the system size. I looked at MCMaster-Carr and you can find roller chain for around $3-5 a foot for the cheap stuff. Sprockets around $15. You will need one sprocket per periaktoi and at least an additional one for the control system. The costs will add up quick but these are parts that can be used in other systems or salvaged.


----------



## FatherMurphy (Apr 27, 2009)

Do you need to 'automate' the periaktoi, or merely 'synchronize turns together'? Instead of a motor, limit switches, etc., perhaps a crank and a grunting stagehand located offstage could power them?

Another question to consider is if they all turn together for every cue, or if they ever need to turn independently.


----------



## Van (Apr 28, 2009)

FatherMurphy said:


> Do you need to 'automate' the periaktoi, or merely 'synchronize turns together'? Instead of a motor, limit switches, etc., perhaps a crank and a grunting stagehand located offstage could power them?
> 
> Another question to consider is if they all turn together for every cue, or if they ever need to turn independently.


 
Good call FatherMurphy, I'm always in favor of a low tech solution, they tend to be the most foolproof.


----------



## Didaskalos (Aug 2, 2009)

For the good of the order...when referring to one unit, the singular form is _periaktos_.


----------

