Leslie Rotating Speaker from scratch

An introduction here. I'm a newby from the US interested in Leslie Rotating Speaker technology. Anyone else in here with an interest?
Y

Dig it, brother.
My day job often gets me involved with industrial servo motor control. If you are interested in adding a modern twist to the rotating mechanism like: a whisper quiet drive, electromagnetic interference isolation, manual / programmable speed control & modulation with save-able settings, LCD / touchscreen display / controls; then I could hook you up!

Yikes!
It sounds like you're a light year ahead of me.
I have the top treble horn and compression driver but was ripped off on ebay when trying to buy the lower bass rotor drum. I can build one, but the auction item included bearings, straps, pulley, axle and drum. Plus there was something warm and cuddly about having an original Leslie component.
I have never been burned on ebay until now. The auction noted:Since this is an international shipping item, please allow additional time for it to arrive [from Buckinghamshire, Great Britain] I waited too long 47 days so ebay would not take action nor would PayPal. Don't you hate it when someone bullies you and there isn't a damn thing you can do about it besides having your bank go after a thug. . .anyway. . .

The two speed motors are a mystery to me to I have opted to use continuous duty AC sewing machine motors with a speed control so I can dial in to 55 RPM to 255 RPM and still have the same ramp up and down differential of a Leslie. I also planned on using separate amps for the bass and treble so I could dial in the sound I was looking for since my Yamaha MO8 is wonderful but takes additional time whereas dual amp settings are in my head with a backup list in case I space out and forget.
I had planned on using round 24 inch Sonotubes [concrete forms] with reinforced ribbing and vaneering the outside but was gifted 2 vintage RCA speakers [before RCA turned into fecal matter] They house 15 inch speakers and are slightly rectangular allowing for the drive mechanisms. I am ready to start and am still checking my front porch three times a day hoping the Brit wasn't just pulling my twanger but I think he won this round.

I can't tell you how happy I was to get your note and would love to stay in touch if the feeling is mutual with you. I am a constant 'fiddler' and would love to hear your opinion on my approach to this project. I have wanted a Leslie since I started a band in 1965 playing a Doric Combo Organ. Not a Hammond B3 or even a Farfisa or Vox Continental but I payed $600 for it washing dishes for $.90 an hour. The amp I used was a Fender Bassman with an expanded cab making the original height become the width and added two more Lifetime Guarantee Jensen speakers. It could blow your socks off but my rig never had a Leslie and I wouldn't be happy until it did.
Now, almost 50 years later I'm finally getting close.
Hope to hear from you soon,
Tom

I will soon have some BT7 servodrive parts available if anyone wants them.....

Sorry about your Amazon woes. That sux.
The sewing machine motors are an interesting approach. I'm fixing my girlfriend's sewing machine right now and was pleasantly surprised that modern speed controls are somewhat sophisticated. The principle is still the same; they control speed via voltage & torque slip. My only concern is that since your rotating mechanism will not drag like a sewing machine, torque slip speed control may be a bit of a challenge as far as repeatability of a certain speed. If it works for you, then great; a simple elegant solution.
However, if you haven't committed to the sewing machine motors; check your local electronics surplus distributors for DC servo motors. Try to get lower voltage motors like 24VDC or 12VDC if you can. What the DC servos allow is pulse-width-modulation (PWM) speed control. If you use a rotary encoder for speed and position feedback, a programmable logic controller like I mentioned can make your motors do really smart things like adjustable and repeatable speed ramps (up & down), repeatable and preset speeds, speed modulation effects, coast & stop when the horn faces forward, etc.
I'm stoked for you, man; it is good to hear that a 50 year dream may soon come true! Best of luck to you.
Leslie speakers are one my favorite effects; they are something that has a psychoactive effect that can not be improved upon by modern digital signal processors / modulators.

It was actually ebay that helped the Brit do me, but anyway. . .This is the only site I know of with DC servo motors. www.sciplus.com/category.cfm/subsection/18/category/173
I don't expect you to teach me all you know but any sites to pick up parts or if you have items to sell I would appreciate any help you could offer. Should you need any graphic design help in the future I would be there for you.
Thank you so much for responding and getting excited about my dream that until now was just a Pipe Dream
T.

Howdy, YoCat.
I have recently checked out YouTube vids of some home-built rotating speakers. Fun stuff! What was really impressive was a dude playing a guitar though one; amazing tremolo effect! I can only imagine how it sounds live with the spatial separation and all...
You have got me really interested in your project, so I have been doing some preliminary tinkering: I've worked out a PWM motor drive controller program on my PLC simulator. It works very well. It trucks right up at a user adjustable rate to the programmed speed set-point and holds beautifully. With some more programming and some moderate circuit building, I could make it automatically start rotating once the note is played; also could ramp to stop where the horn faces forward when the note is done or if the user commands.
I have most of the parts to build a system in stock at my shop at work. The trouble is, the replacement cost of the components. A system with all the candy would be near $1500! Knowing that this would never fly, I parsed some features and components down to <$1000; still pretty steep unless you are in a touring band!
On the other hand, it would control up to 4 rotor motors individually or synchronously. In a pay it forward sense, it becomes more attractive at about $250 per motor driver.
The system would be fully expandable in both hardware and software: say if you wanted to expand and run eight, your per motor driver costs would get down to about $150. You mentioned that you are a tinkerer; I would include the core software with the system which would allow you to innovate features and expand it on your own for lights, effects, or whatever you dream up. These programmable logic controllers (PLCs) are a lot of fun. Using a PLC as it's 'brain', I've recently made a drumming robot; kind of like a drum-machine, except real drums!
If you aren't sticker shocked by the core system estimate; I would be happy to private message you a formal quote.