3D printed 3-way Unity waveguide home audio speaker

I was asked about what the printer cost and where it came from. I used one of these:
Folger Tech FT-5 Large Scale 3D Printer Kit – Folger Technologies LLC
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You can get it for about $50 cheaper if you usethe coupon code FOLGERTECHFBGROUP. It's a kit and takes quite a while to build (about 12 hours depending on how good you are with tools and how much hardware you lose - be warned, the assembly manual was really bad on this. And the machine has some weak parts that really should be changed). If you don't want to go through all that, then the CR-10 printer is said to take about half an hour to set up and has the same build size. Not as solid a printer, but apparently more trouble free to start out with than the FT-5 according to reports.
Creality 3D(R) CR-10 DIY 3D Printer Kit 300*300*400mm Printing Size 1.75mm 0.4mm Nozzle Sale - Banggood.com
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Coupon code CR1018 gets the price down to $392.

To make a print this big without taking days for each piece, you'll want to use a larger than usual size "hotend" and nozzle, called a V6 Volcano type, and a Titan type extruder to drive it with. Both printers above are designed with a setup for a 0.4mm diameter nozzle so you have to modify them to use a V6 Volcano hotend and Titan. There's quite a bit of info you can find on how to to this by googling (keywords like "CR-10 Volcano"). The "real" V6 hotend, Titan extruders, and nozzles come from the company E3D, who also designed the Titan extruder.. But both designs are open source and if you're pinching pennies there are decent clones available (see Aliexpress or Amazon).
(make sure your read up on the net about the types to get for your particular printer before ordering anything. If you decided to go down this particular rabbit hole, drop me a PM and I might be able to help clear it up)

One of the first things you'll want to print is a "part cooling fan shroud" (keeps the PLA plastic printing nicely), you can download files to do that from. You'll also need to buy a small fan for the shroud, a few bucks from amazon.

Needless to say, you'll have some work and tinkering to do to get a printer up and going for printing a big waveguide. Not terrible, and a nice winter activity if you have time to play, but don't expect to be knocking out a horn in the first days or even weeks after your printer package hits your doorstep!
 
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Bill,

I recall you had some trial and error getting your first prints to come out satisfactorily. Was that related to dialing in the Folger Tech printer or more a matter of the learning curve when designing prints? I'm seriously considering getting a Folger Tech for this project (and I understand the assembly commitment ) but I have little idea how much fortitude I will need to muster beforehand.
 
Somewhat off topic, or perhaps threadjacking (I apologize in advance, if so):

I have a pair of the original Danley Unity horns. I'd done a little testing on reducing the volume (partially filling it) under the 5" mids. It seemed to smooth out the response. Anyone here willing to put their printer to a little commercial use? I can supply a simple drawing with dimensions. I'd need 8 pieces.

Sheldon
 
Bill,

I recall you had some trial and error getting your first prints to come out satisfactorily. Was that related to dialing in the Folger Tech printer or more a matter of the learning curve when designing prints? I'm seriously considering getting a Folger Tech for this project (and I understand the assembly commitment ) but I have little idea how much fortitude I will need to muster beforehand.

I had a number of adventures with the printer, many my own fault for taking too many steps at once. I built the printer with the Titan/Volcano combo from the start, so wasn't able to use the given printer firmware settings (for temperature, flow, layer widths, speeds, etc) to make sure the rest of the machine was ok. With a kit, that's probably not a good way to do it, as you can't easily verify if you have it all right. Turns out, I didn't have it right for a while, the carriage that holds the nozzle wasn't stable enough (combo of not-tight-enough screws with one that was too tight and cracked a melamine piece), caused lots of issues. The learning curve for designing STLS (using Fusion360) wasn't trivial, but if just duplicating my design you wouldn't need to do that -- though it is well worth learning if you want to use the printer for other stuff and there are lots of tutorials on the web for it.

There were definitely weak points in the kit, and I replaced a fair bit of stuff (power supply and a number of parts I printed) and modified others (direct soldered some wires to the control board that used an insufficiently rated screw connector).

But just yesterday I read that Folgertech is starting to take pre-orders for the next revision of the FT-5 (called the R2), and it appears that it addresses all of the weaknesses that I'm aware of in the older version.
Folger Tech FT-5 R2 Large Scale 3D Printer Kit – Folger Technologies LLC
I don't know whether the assembly manual is good yet, though (it was revised from what I used, but I used v11 - !! - but haven't heard any comments whether v12 is lots better or not).

The R2 would've probably save me a lot of time.
There's a very active Facebook group for Folgertech printers, (if you can stand to get onto facebook :eek: Log into Facebook | Facebook)
 
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Somewhat off topic, or perhaps threadjacking (I apologize in advance, if so):

I have a pair of the original Danley Unity horns. I'd done a little testing on reducing the volume (partially filling it) under the 5" mids. It seemed to smooth out the response. Anyone here willing to put their printer to a little commercial use? I can supply a simple drawing with dimensions. I'd need 8 pieces.

Sheldon

Hey Sheldon, I have two printers and a box full of the Misco mids that you use. I'm insanely busy at work lately but I can probably get something printed by Thanksgiving or so.

What I'd need is a photo of the existing mounting plate. I can figure out the rest because I already have mids here at the house.

And, obviously, it's easier to collaborate because you live 15 minutes away from me :)
 
I'd love for someone like Autotech to pick up the design and make them under license as I'm not interested in printing them myself (no resources).

In the meantime I might just make some of your SEOS15 based units. I've enjoyed reading the threads though.
 
Hey Sheldon, I have two printers and a box full of the Misco mids that you use. I'm insanely busy at work lately but I can probably get something printed by Thanksgiving or so.

What I'd need is a photo of the existing mounting plate. I can figure out the rest because I already have mids here at the house.

And, obviously, it's easier to collaborate because you live 15 minutes away from me :)

I'm in no rush John.

The existing mount is like this: first pics of the new speaks



Here's a sketch. My holes are more round than those in the picture, but if a little more plastic was left, then the transitions could be hand shaped with a file:

BTW, great work Bill and others who have really pushed this concept along. Were I to start today, I'd just copy Bill's latest. It seems an ideal compromise for home use.

Sheldon
 

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Thanks Sheldon.
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I was thinking about the measurements yesterday and got to wondering why the "spaced woofer" trick doesn't seem to be helping as much on this speaker as on the SmallSyns. This morning I looked again at some measurements used for designing the crossover and overall directivity plots. The off-axis dips a little more than I'd like at 550 to 700Hz and isn't doing much by 350Hz.
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The raw woofer curves show the response at 45 degrees dropping starting around 500Hz, but good on-axis to near 600Hz so the woofer trick is working a bit too high in frequency. (Edit: these curves are with woofer crossover, but you get the idea....)
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Edit again: Got myself confused here... it looks like the woofer ports should move **outward** a few inches, not inward, and then the mid crossover should be moved down about 25%.... I think. That would put the ports on the edge of the horn. Maybe vertical slits on the cabinet (or in those angled sides) for the woofers?

I probably need to just leave this thing alone!
 

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Have I just been living right?

I was checking and comparing the response of the two speakers at the listening position today (I tweaked the midrange down a few dB on one so they match well). Again, noticing the LF response I'm getting in room with these things (and no subs or EQ).
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It looks like the in-room F3 is in the mid to low 20's. I'd like to say that this is due to good planning and excellent engineering, but its not, it's a surprise to me. It happens in both channels (R more than L). The odd thing is that this is a ported cabinet, there isn't supposed to be much output very far below the cabinet resonance, which is at about 45Hz. T/S simulation says the box f3 should be around 37Hz.
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The cabinets are about 6 inches from the wall (which is designed for), which of course picks the low end up, but this much? One unusual thing is that the woofers close output (just inside the horn mouth) happens through smaller areas than the cross-sectional area of the shelf ports. I did simulations earlier and didn't see any magic happening because of it. And measurement at closer to 1m distance shows the LF about where it was expected.
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So it's the room, I'm just surprised it works out this well. The L channel has a room peak at about 85Hz that I should maybe EQ out and both channels have the usual suckout from floor bounce at about 145Hz (which I'll just leave alone). But almost a free lower octave?
 

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I've been trying, not entirely successfully, to comprehend exactly which parts you need to upgrade to get the print times down.

Am I right in thinking that it's basically;

E3D V6 Clone Hotend PTFE with Volcano Heater Block and Volcano Brass N



– MacEwen3D


which covers all of the bits you need for the hotend, i.e. ; hotend, thermistor/cartridge (though some suggestions you can use stock components for this), heater block, larger nozzles.

plus the extruder - E3D Titan Extruder - The Powerful, Lightweight Extruder | E3D Online

which also needs

a motor - NEMA17 Titan-Slimline Stepper Motor - D shaft | E3D Online
a bowden adapter - 3D Printer Groove Mount Bowden Adaptor - 1.75mm Filament | E3D Online

(links are just to provide examples of exactly which components are required)

it looks like the complete kits from e3d would come in at about £160 (~£190 for the hotend & ~£70 for the extruder), any views on whether the clones are decent quality?
 
You don't need the new motor or Bowden adaptor (in fact, you want the direct not bowden version of extruder for the FT5.... for the CR10 you'd need a bowden).

I use clones for all and they work ok, probably with more confusion during installation than if used E3D though. E3D stuff probably tighter tilerances too. Clones are pretty cheap from Aliexpress, but if you're in UK E3D might be pretty reasonable. I just wasn't sure I'd get anything going and didn't want to sink too much money in what seemed like a whim then.
 
No, I'm retired, so I have all the time in the world. Unfortunately, I've had a small stroke, with residual effects, and my daughter, the know-it-all nurse, has told me that if I try to use power tools and cut my hand off, she'll kill me.

I had hoped that there might be a flat-pack coming from a certain well-known source, but I understand the concerns about that, and I'm giving up. Great project, and would have been perfect for me.