Has anyone ever built themselves a rotating speaker?

stickyfiddle

gretschthumper said:

MikeP said:

I think any successful design surely needs to involve a bicycle?

Yes! Pedal powered, now we're talkin' ... you could even use the derailler gears for speeds!

I presume this also requires a hamster in a little cab to drive the thing. 

I'm picturing @sporky and his monkeys again... 

MikeP

See, now this thread is producing some worthwhile thinking

stickyfiddle

Without doing proper research. I figure you want a well-regulated motor that gives you consistent speed for a given input voltage, then appropriate gearing and some form of belt-drive system like a vinyl turntable. 

And possibly another one on the top for a horn, though I wonder if that's strictly necessary as obviously not all designs have it. 

I like the idea of modern control on the speed, so potentially something via Arduino or whatever to control rotation. You could certainly have pre-set fast & slow, or even give it tap tempo if you wanted if you get a computer involved on the speed control side. 

normula1

Actually you don't want constant speed. The magic in Leslie's is in the ramping up and down, so I imagine a small variance in speed would be beneficial.

robinbowes

I built* a Vibrotone clone a few years ago using a Leslie mechanism from a Farfisa organ:



I designed a control module to do the switching with relays so it could be controlled from a regular footswitch:



Here's a terrible video, recorded on a phone, of a few sounds from the finished cab (off, slow, fast):



It's the box under the amp.

The in-room sound is like nothing you've ever heard. It's awesome!

R.

*Full disclosure - I did the electrics, someone else made the cabinet.

stickyfiddle

robinbowes said:

I built* a Vibrotone clone a few years ago using a Leslie mechanism from a Farfisa organ:



I designed a control module to do the switching with relays so it could be controlled from a regular footswitch:



Here's a terrible video, recorded on a phone, of a few sounds from the finished cab (off, slow, fast):



It's the box under the amp.

The in-room sound is like nothing you've ever heard. It's awesome!

R.

*Full disclosure - I did the electrics, someone else made the cabinet.

That sounds brilliant. How does the speed control work? Just 2 diff voltages to the motor and inertia means it naturally ramps? 

robinbowes

stickyfiddle said:

robinbowes said:

I built* a Vibrotone clone a few years ago using a Leslie mechanism fro

That sounds brilliant. How does the speed control work? Just 2 diff voltages to the motor and inertia means it naturally ramps? 

There are two switches: on/off and fast/slow

The on/off simply turns the power on & off.

The fast/slow functionality is built into the Leslie unit - I’m not sure if it’s a voltage switch or a mechanical gear change.

 The control board is nothing clever, just a low voltage PSU to power the relays, the relays themselves, plus some suppression caps and blocker diodes.

I have spare boards somewhere (gawd knows where!).

R.