Acoustic Horn Design – The Easy Way (Ath4)

[TNT]

The guides to connect petals seem like s good idea. Why did you remove them? If the last one had a bit of a snap when fitted, maybe cyanoacrylate glue could be added from the back and perhaps succeed in by capillary forces to make a good joint.

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[mabat]

Do you think you might release this version with step built in? I would like to give that a try to see how it joins together.

Now I work on CE360, but the ST260 have STEP file available - you can modify it at will. I may do it later.

 

[mabat]

The guides to connect petals seem like s good idea. Why did you remove them?

It complicates the printing at the moment. The petal thickness is currently 5 mm, which should not be a probem to connect and glue together without the ribs.

 

[fluid]

Now I work on CE360, but the ST260 have STEP file available - you can modify it at will. I may do it later.

Thanks, have you built in any tolerances between the parts for glue etc. in the model you are working on?

 

[mabat]

Not yet, that's still to be found out.

 

[TNT]

If you can find a reproducible method to make solid WGs I think this could trip me over to buy a printer and also buy something from you

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[mabat]

I'm not sure if buying a printer just for that pays off. You will face a lot of struggle, unless you buy a printer for 3000 EUR. I have now a quotation for a CE360 kit, printed on a professional FDM printer (Raise3D), including the dissoluble supports I mentioned (PETG + PVA), it's around 500 EUR for a two-piece set. You won't get a 3D printer capable of prints in that quality for that money, IMO.

 

[TNT]

OK. But it could be an excuse as I might have other uses for one W'll see... I'm only interested in 360 or larger...

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[mabat]

Sure, there would be nothing easier for me than to sell STL files

But I had to warn you.

 

[jzagaja]

You won't get a 3D printer capable of prints in that quality for that money, IMO.

Even on cheapest Anet A8 you can print very nice. It depends on speed and filament.

 

[mabat]

I will believe it when I see PETG petals assembled without any warping and flawless surface

 

[mabat]

I've just realized it's plain possible to print the petal completely hollow this way and then fill it with just about anything through a drilled hole (0% infill; there's in fact no top layer, only perimeters). It can also be made a lot thicker (not shown).
Not to mention the substantial speeding up of the print and improvement on the surface quality. Well, sometimes it takes a day or two to have a bright idea..

 

[TNT]

Maybe there should be some support structures between the sides inside the petal to secure that the shape is maintained when something that is going to harden (almost always some shrinkage or expansion!) is poured into to it..?

But I like the idea!!! Perfect!

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[jzagaja]

Adaptive cube infill (Prusa Slicer) or gyroid is perfect for filling with resin or concrete.

 

[mabat]

The walls can be made strong enough (it's not a "vase mode" which is limited to one perimeter only). It prints as we speak, looks very good so far.

 

[-CGL-]

Keep us updated

To fit it on the print bed is one thing, the other is to reach the desired quality. The bigger piece it is, the harder it gets, as it tends to warp and so it may be dificult to assemble. At least this is typical for the hobby printers, without heated chambers, etc. I don't know how good is your printer.

Update:

Throat and two 180deg petals printed....

Not too happy with the petals....

Tomorrow some epoxy and then Dremeling.

 

[mabat]

Here it goes -

 

[pelanj]

I wonder if the petals would print better with a flat back - and low or no infill.

 

[TNT]

2,5-way sealed...

800Hz, MB15N301, CamillaDSP.

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[mabat]

That's quite nice. I would round the front vertical edges though.