Re-claimed Leslie from SS Hammond

[Willabe]

Several years ago my friend gave me an old (proto type) SS Hammond organ. I was hoping my wife's 2 kids would play around with it as they were both in school band and I had bought them each a guitar and a Yamaha electric weighted key piano, + it had many different voices. Yup they never played it once.           It sat around in the garage for several years and a number of the tab/sound/tone levers got broken.

Anyway, I remembered it has a Leslie in it so I took it out along with the crossover choke/coil. (Choke coil says AO-30958-1 and 721 on it.) It has the same 2 motor with Styrofoam (pinkish color) spinning drum and it looks like it's the same unit as found in the Fender/Leslie Vibratone.

Down side is it only has an 8" Jensen (C8-R 220822,  C6996-10,  14-31180) but the drum itself measures 14.5" in diameter. Also the metal bracket that holds the drum/pulley/rubber drive belt is only ~10" end to end. It is mortised into the speaker baffle (3/4" plywood) under the speaker and is held in place with a wood screw on each end that go through the speaker basket 1st.

I think I can enlarge the baffle opening to fit a 12" speaker as the drum is 14.5" and either make a new bracket or maybe extend the old one some how? The Vibrotone's had a 10" speaker in them.

What I need help with is understanding the schematic and what I need and maybe don't need.

It looks like the 2 motors are AC and the PT is only for a relay for fast/slow? I'll have to root around in the organ to see if I can find/figure out where the relay is and how they powered it. Free parts are always good but maybe I really don't need it? I think the relay would have to be able to pull enough current for the 2 motors? That might be a good reason to find the original relay and PT?

Vibrotone schematic posted below.


                Thanks,   Brad    



  

[Willabe]

From the Vibrotone manual on the crossover, they say it's to keep the Leslie effect clean, it might be nice to have a switch to kick the crossover in or out?

And here's a link to the Vibrotone manual that SG posted in his thread on it. (The schematic in it is not complete.)

http://www.nmia.com/~vrbass/vibratone/Vibratone.pdf

                    Brad      

[Willabe]

Here's from the manual on how the 2 motors change the drums speed. When both are on it's the slow setting. Very cleaver I think.


                Brad     

[G._Hoffman]

For the audio side, I'd skip everything but the speaker.  If this had a rotating horn as well as the drum, then yeah, keep the crossover, but if it is just for guitar, then leave the crossover on the sideline. 

I sure wish I had a dual speed motor for mine, though. 

http://www.dairiki.org/HammondWiki/Leslies


Gabriel

[Ritchie200]

Gab,
I agree, it looks like the crossover just cuts the highs - leave that out.  Can't sound like Badfinger with that in there!  I've only seen pics of the styrofoam drum, but it can't be that heavy with a lot of mass, right?  If so, maybe just pick up a little DC motor and drive if you want to trash the existing unit.  It might not be worth messing with the old technology.

Jim

[G._Hoffman]

If so, maybe just pick up a little DC motor and drive if you want to trash the existing unit.  It might not be worth messing with the old technology.

Jim

NO!! Keep the motor stack.  You WANT a slow speed, and it is surprisingly difficult to do with decent DC motors.  The old motor stack works well, and is easy to deal with. 


Gabriel

[Ritchie200]

Oh sorry!  I thought the issue was WITH that drive!  I need to pay more attention....

Jim

[Willabe]

If so, maybe just pick up a little DC motor and drive if you want to trash the existing unit.  It might not be worth messing with the old technology.

NO!! Keep the motor stack.  You WANT a slow speed, and it is surprisingly difficult to do with decent DC motors.  The old motor stack works well, and is easy to deal with.

Oh sorry!  I thought the issue was WITH that drive!  I need to pay more attention....

Thanks you 2 for the responses.           You both have good points.

Jim can't keep up cause he's watching the Cards in the play offs.            

You know Jim I heard the Cards keep a Tele in their locker room. It's by the door that goes to the tunnel out to the dugout. As they leave the locker room they all 1 by 1 rub it for good luck!          

I did find what I need to keep the 2 speed motors that came with it. The relay say's on it 24dcv. No current number but it's the relay that came with it from the factory.ALL the can caps and internal filter caps say 25v on them. I even pulled the old PT from the unit, I bet it will work fine. Even has 2 steel bell ends and a copper flux band.

Although I would like to do some research on using a DC motor for variable speed. The drum is light as a feather and maybe hook up the speed adjust to an old wa/volume pedal? Could be very cool. I've seen these drums on ebay for very little $. Maybe I'll get 1 to play around with a DC motor?

I'm going to talk with a good friend of mine who has a cabinet shop and see if I can get him to make a new speaker baffle (for a 12" and the rotor drum/motors) and cab for the whole enchilada.


                  Brad        

[Willabe]

I found a schematic for the model I have.

Their using -25dcv on the relay coil.

I wonder if it's for a little better isolation from the main B+? I guess the relay doesn't care if it see +25 with respect to ground or -25 with respect to ground?

Relay is marked; Sigma 59F1D-24DC    021166


                    Brad      

[G._Hoffman]

The problem with variable speed DC motors is you need to do a lot more to control them than you think.  Some of them can be controlled with just a resistor, but those are pretty loud, and most DC motors just loose torque that way.  The best way to do it is with PWM (Pulse Wave Modulation).  You can do a fairly simple version of PWM with a 555 timer (well, two, or a 556), but if you want things to be repeatable you are probably going to end up wanting to go with a microcontroller - which is a whole other kettle of fish that will ruin your life.  Or not.  It is sure distracting, though!!!

You can also do variable speed with AC motors, but there you need to use a VFD (Variable Frequency Drive).  Again, you can do this with various timer circuits, but for repeatability you want to use a microcontroller.  

And of course, once you start thinking about microcontrollers, you start thinking you want feedback in the system, and start trying to come up with an encoder wheel that allows you to have a tap tempo Leslie.

And then, half a decade later, you realize you only ever really need the fast and slow speeds.

At least, that's been my experience.


Gabriel

[Ritchie200]

"And then, half a decade later, you realize you only every really need the fast and slow speeds."

 
Jim

[G._Hoffman]

"And then, half a decade later, you realize you only every really need the fast and slow speeds."

 
Jim

Yeah, I can laugh about it now.


Gabriel

[Ritchie200]

I'm laughing WITH you, not at you!  It sounded like so many of MY projects!

Jim

[G._Hoffman]

I'm laughing WITH you, not at you!  It sounded like so many of MY projects!

Jim

I think it probably sounds like a lot of people's projects.  There is a reason this icon - - exists!   


Gabriel

[super&plexi]

Ive had a few of 'em, and kick myself for selling  them. that ramp up/down, when you're going into, or out of chorus-verse.....or verse visa!, MAN!... that's sweet. you can get away with mounting 12'' right in, (over) 10'' hole. Iv'e done it, no probs.

 the spkr cab is not built for ultimate fidelity. and it's a good home for higher power EV, or JBL type spkrs, that have fallen from vogue. they loose shrill top end trying to get out of there!. I think the styro spinner is taken from a tortilla warmer, and the motor from a sewing machine. ok, not so sure about tortilla warmer.

 I've seen leather pulleys, and think they're stock. when motor speeds are adjusted, seems there is a setting where wheel skips every now and then, and gives more #3 dimensional (think echoplex w/tape flutter) sound. I've seen em where wheel bounces, and sounds cool as heck.  I have 2 button foot switch, but if using only guitar, might think about bypassing 5pin, and put 1/4'' jack on aluminum ''L'' angle, then wire directly to 5 pin..(best of both worlds if you ever want to use w/organ), and people thought it was stock it looked nice  tucked into square hole along side cord/on off.