So I haven't been fair to this forum, I've been hanging out on our cousin-forum, the Facebook Gretsch group. If you're there, you know about the Leslie I built! It's all done, except for tolexing. Here is a condensed thought process and photo album for your viewing pleasure! My roommate and I decided after seeing Peter Frampton live last August that we needed to get our hands on the real rotary sound. So I did research for three or four months on how to get as close to the real thing for less than $500, and came up with a single axle design, that could be powered by an existing amplifier/combo amplifier in a musician's rig, focusing on the points of cost (as stated), weight, and ease of use. For size and weight, it had to be compact. Just big enough to accomplish the motion process of a rotary speaker. A dual motor system would have probably allowed me to design speaker layout differently and make a shorter model, but we've already established cost, and I'm working with plywood. 32" tall by 20" wide by 16" seemed decent enough. I had my friend with a table saw cut dado joints for me since my dovetail jig was too small for any of those dimensions, and soon it would be off to the races. For cost, two motors was out immediately. I could have used two stage ceiling fan motors, but then I would have to build a custom control pedal or switch. Having to buy all of the extra parts made no sense when I could use a sewing machine motor with a speed foot control, at 110V, 60 hz, .9A, and 100 Watts (which turned out to be too many, 6000 rpm top speed!!). This is an effective motor, but for full sweep of the pedal it requires a governor in the form of a kitchen light dimmer (triac, 120V, 600W). For ease of use as a guitar player, the sewing machine idea operating like a wah or volume pedal made the most sense. How then would I go about doing the rotors? I didn't want to buy the real things for hundreds of dollars. My sister is a baker. I thought, oh, cake dummies! Perfect. What would I do for a horn? ...lightbulb, oil funnel! So after settling on a single motor design, I had to design a single axle process. I know about basic mechanics from high school physics, so I'll need an axle, at least two bearings, and a pulley system. First I tried to use half inch parts, with the idea of using half inch pipe floor flanges to attach the rotors. The outer diameter of 1/2" pipe though, is not 1/2", and so the pipe did not fit my pulley. Back to the internet we go, to use metric! I came across pulleys used in 3D printer parts, never even considered anything like that existing, but onto amazon and hit buy I went, standardizing my parts at 12mm, close to 1/2" since I already had some holes for my parts drilled. I considered using drywall anchors to attach the styrofoam to wooden platforms, but the glue did not hold the anchors when I tried to drive the respective screws in. Back to the drawing board. The 12mm flanges arrived, and holy CRAP were they way smaller than the 1/2" flanges... so the wood platforms shrunk to the width of the flanges, and I realized, glue and dowels! KISS! Once the rotors and axle were ready for assembly, I drilled four shelves with pilot holes to line up the axle and speakers. I made a couple of measurement errors along the way that weren't fatal, but definitely made the motor housing chamber more compact than I had wanted, along with the tweeter chamber. This was where I made my first real mistake. The plywood is warped a bit. To get the shelves in right, I installed the front panel to open up the sides. I installed the shelves, made their marks for screws, and drilled pilot holes into them and the support beams. For some terrible reason, I decided to fix the front panel in. The one side was warped out pretty badly, by a 1/4 inch. So I screwed the front in, and then I clamped and glued the sides to the front panel. I did this before locking down the shelves because I needed to make sure they would go in at the right depth, up against the front panel, I needed to cut and route proper sound holes, and I had the middle two shelves and axle pre assembled. Because of this, only half the shelves are bolted down on all four corners. Installing the drive assembly, speakers, and crossover was really easy after I drew up some good schematics. Truthfully the most difficult part of the whole thing, tolex excepted, was cutting the stupid little interface panel on the back. Hole saws for the aux power outlet and speakon jack, jigsaw for the breaker and IEC plug. I hate metal working. Front to back from first actual cuts in the wood to theorizing, troubleshooting, and first test with band practice tonight, this took 7 weekend days to do (Monday and Tuesday). If I were to build another one or make a hobby of building this cousin to a Leslie, I have three takeaways: 1. Do not affix the front panel with glue until the end of the build - secure all shelves at all corners first 2. Cut a channel down to the axle hole of the middle shelves, the motor chamber shelves, for removing the drive train with ease - shelving installation, then soundhole cutting, then parts installation. 3. This project was absolutely worth doing.