M2 Synergy Horn

[bwaslo]

well... damn.

Now I have to go get a 3D printer (last time I checked they didn't seem worth using and had a failure rate of complex printed parts of about 90%).

[Patrick Bateman]

TBH, I've never had issues with complex parts, on either printer.

Oddly enough, the most difficult thing to print (on my old printer at least) is anything flat.

IE, I could print something like this easily:



But printing a 6"x6"x 1/2" piece of plastic would fail.

This is because the plastic tends to 'curl up' on the edges. If you're printing something that's 2"x2"x1/2", the 'curl' might just be a fraction of an inch. But if you're printing something that's 6"x6"x1/2", the 'curl' will be magnified by the size, and the 'curl' could be 1/4"-1/2" at the edges.


This pic shows what I mean

But the Monoprice printer seems to have solved that. I believe it's due to three things:

1) a heated bed, to fight the cooling that causes the curling
2) a beefy print head, to keep the plastic hot, all the way through the printing process
3) multiple fans, to cool the newly printed layer

Seems to be an art and a science, but this one is way better than my old one


One 'neat' thing that people may not realized about 3D printers, there's no real penalty for complexity. IE, you could print something uber complex, like a phase plug, and the print time is simply based on volume. A cube of the same size would take just as long, for the most part.

[bwaslo]

John, what midranges is that molded for?
Seems like a lot of front volume on them.

How much others stuff has to be bought with that 3D printer to make is useful?

[bwaslo]

The complexity I was referring to involved the bottom level being narrower or smaller than higher levels, and the design necessities to keep it standing while printing the upper sections -- the printers I saw running regularly screwed up when doing something like a toy car shape (maybe the guys at the hobby club just didn't know what they were doing?)

[Patrick Bateman]

Originally Posted by bwaslo

John, what midranges is that molded for?
Seems like a lot of front volume on them.

How much others stuff has to be bought with that 3D printer to make is useful?

It's for an AuraSound whisper. And I agree, now that it's printed, the front chambers are definitely deeper than they need to be.

To make speakers in 3D, you need the following:

1) a 3D printer that can build a reasonably large volume. Mine is $399, builds 8"x8"x7"
2) Something that can make the model. I use 123D, costs $0
3) Once you make the model, you have to 'slice' it into "G Code" that the printer understands. Cura is the most popular, cost is $0
4) Filament is remarkably inexpensive. The filament for this print cost me about five bucks.
5) Time is very expensive. It's not unheard for me to spend 10-20 hours on a single design. Synergy Horns are painfully time consuming, because you have to check and double check that EVERYTHING is correct. 'Drilling' sixteen screw holes in 3D is surprisingly time consuming. (You have to make the hole, flatten out a spot for the head of the bolt, flare the entrance to the hole, etc etc etc) Obviously, this pales in comparison to doing it by hand, and it's way more fun to sit in front of the computer for twenty hours than work in the garage for 20 hours.
6) My old printer was tethered to a PC. This meant that I had to keep a PC attached, which is kind of a waste of space and power. My new printer simply prints off an SD card, which is way more elegant IMHO. You just save the file onto an SD card and plug it into the printer.

[wesayso]

There are quite a few printer models out today using 2 extruders. One for printing your actual model and the other is used for support, and easily solvable. That way your modeling has even more freedom.

[bwaslo]

John,

Any comments (have you heard/read anything in comparison) about the fancier $600 model? It has 5x the resolution (which I assume probably takes 125x as long to print if you use the highest). And capability of putting plexiglas windows (to keep cats out of it... I'm sure our white cat will go nuts when he sees the little gizmos scooting around on the printer).

I think the trick to using a dome tweeter (low magnetic force) is to not compression load it -- just put the whole dome into the throat. No efficiency benefit then, but most of us don't use waveguides to maximize efficiency (power is CHEAP) but for radiation pattern control.

[Patrick Bateman]

Originally Posted by bwaslo

John,

Any comments (have you heard/read anything in comparison) about the fancier $600 model? It has 5x the resolution (which I assume probably takes 125x as long to print if you use the highest). And capability of putting plexiglas windows (to keep cats out of it... I'm sure our white cat will go nuts when he sees the little gizmos scooting around on the printer).

I think the trick to using a dome tweeter (low magnetic force) is to not compression load it -- just put the whole dome into the throat. No efficiency benefit then, but most of us don't use waveguides to maximize efficiency (power is CHEAP) but for radiation pattern control.

The waveguide pictured in this thread was printed with a layer height of 0.28mm and it took thirty two hours to print

If you went down to 0.1mm you'd be looking at a four day print

The $399 machine can go down to 0.1mm iirc

If I wanted a super smooth finish I'd probably print in PVC instead of PLA and simply rub the waveguide with acetone to make the surface smooth

Note that this won't make an audible difference of course; even at 20khz the wavefronts won't "see" a 1mm ridge

And note that there's a relationship between cost and strength:

For instance, imagine that you have two models:
Model one uses a 4mm nozzle and a print height of 0.28mm and takes 32 hours to print
Model two uses a 2mm nozzle and a print height of 0.14mm and takes 64 hours to print
Model one will be STRONGER than model two because the extruded plastic has four times the diameter. This was something I noticed when I used a 7mm nozzle; my models were ridiculously strong and they printed super-fast. On the downside, they didn't look as good and they used up a lot of PLA. (Which is admittedly quite cheap, but it's still annoying to blow ten bucks of PLA especially when prints fail all the time.)

I actually had the $600 model in my cart and went back and opted for the $400 model

If I'm not mistaken, the Monoprice is a clone of some printer out of the Czech Republic, so there's ten or twenty variations on this exact same printer out there. Most of the clones are for sale on Aliexpress.

I learned a lot about what to buy over at the Reddit 3D printing forum.

[bwaslo]

Thanks John.

A lot to consider. Is the direct drive power system of the $600 printer of any consequence? Do you know which is the later model (did the one you have come out before or after the $600 one)?

Bill

[pcgab]

There are a few mods you can do to that printer to make it even better, and inexpensively.

Ill post some links in the morning when I'm on my workstation.

I know quite a few people with that printer, they all love it.