Leslie cabinet project

Thanks brother, but it ain't done yet!

I recommend you pass judgment on it when it's done, because there's still plenty of time for things to go all pear-shaped on this project 

Hey Peegoo - On another thread a couple days ago you said

"I have a really small one that came as a kit from Mahaffey Amps"

Thanks. I remember reading about the LL years ago, and thinking it looked pretty cool.

Looking good Peegs!

I really should stop poking my nose in threads like this. It’s expensive.

🐟

Finally had a no-rain day so I could shoot paint outside.

This is Rustoleum pickup truck spray-on bedliner. It's got a pebbly texture to it, and when it's completely dry it has a satin surface finish and from a foot or two away it looks like Tolex. And it's a lot easier to apply.  It's pretty shiny in this pic because I just shot the 2nd coat on and it's still a bit wet. 

Lissin UP, bugs!  Don't land on this thing for at least 30 minutes or you'll experience the La Brea Tar Pits of the East Coast.



Next step (after two days of dry time) will be applying the grill cloth to the four windows, and then install the Leslie board with speaker and rotating drum.

Cheers, Cal. I knocked this out today because the paint was nice and hard. First task was to install grill cloth in all four windows.

I used repro early-70's Fender silver stripe, mounted vertically, and I used a trick I came up with years ago to keep the stiff plastic fibers from unraveling from the edge of the cloth. The technique involves marking the cloth sections with cut lines, but before cutting it, run a very thin bead of caulk right along the inside of the cut lines. What this does is bond all the fibers together. When you cut the panels, the cailk line is right up against the outer edges of the cut-out section. It holds it all together very nicely. The little bead of caulk also allows using the nose of the stapler to push against it to gently stretch the fabric before you shoot the staple to anchor it.

I learned something very interesting while working on a speed control for this: these little single phase shaded-pole AC motors can be controlled by chopping up the AC sine wave using a MOSFET and a couple transistors and resistors...but only when there's a load (resistance) on the motor. Since this motor is not loaded at all, the MOSFET controller was a no-go, even dialed back to 25% of the sine wave showing on the scope. It still ran full speed.

I needed to find a way to dial back the voltage, so I tried a series of 10-watt wire wound ceramic resistors and that did the trick. But rather than making a multi-position switch with multiple fixed speeds, I went the path of least resistance [electric joke!] and found a little rheostat designed for fireplace fan speed control and dimming incandescent lights. It works perfectly and spins the drum from barely moving to about 400 RPM...perfect. It also has a zero-position on/off switch, which really simplified the wiring for this project.

This:

www.amazon.com/gp/product/B07P9DR7SN/ref=ppx_yo_dt_b_asin_title_o02_s00

The listing states "d-shaped stem" but it's not. It's a split knurled aluminum shaft identical to a guitar's volume/tone pots.

The way you wire it up is everything in series using a two-conductor AC cable.  The live wire from the AC cable goes to one of the rheostat leads.  The other rheostat lead goes to one of the motor leads; the other motor lead goes to the neutral wire on the AC cable. Could not be more simple, and nothing is polarity-sensitive.

Here's a shot of the completed Leslie. It runs great and sounds *fantastic*. It gets that slow Trower swirl and it gets the fast Jimmy Vaughan warble, and everything in between. I'm running it with a Traynor Quarterhorse (25-watt amp built into a little pedal with reverb, delay, tremolo, and clean/dirty channels).

Cal, as you can see from my first post, I had all the hardware for the top and bottom bearings of the rotor. The bearings are very simple: little Nylon cups pressed into rubber cups that fit into holes in the steel hardware.

The rotor's shaft is polished steel...I added a little dot of silicone plumbing grease to each bearing cup before I assembled it.

The speaker panel is composition board with an 8" hole cut in it. The speaker mounts on the bottom (using T-nuts on the opposite side) firing upward into the throat of the foam rotor.