1/2 - 20 Moderator long and short versions

[naptemp]

I assume it should work on .177 but it would be a little less efficient because of the large baffle holes.

You won't notice unless you are comparing a 30 FPE .177 to a 30 FPE .22:

The stock Marauder baffle bore is 5/16".  This applies to .177; .22 and .25.  The .177 Marauder is not louder than the larger calibers, because they typically operate at power proportional to the pellet weight; as in proportional to the bore area.

If you want a .177 specific version of this TV mod, just ask.  Just make sure not to shoot .22 pellets through it 

If you can make a .177 I would definitely print it.

[subscriber]

If you can make a .177 I would definitely print it.

Done:  https://www.gatewaytoairguns.org/GTA/index.php?topic=218043.msg156592940#msg156592940

[OldCrow]

Welp the darn thing is huge and shooting it a couple of times brought out some "fuzzies" I'll need to trim out but...  no clipping so very good print job.  I love that Bamboo.  I just don't like their attitude towards my data.

I like the wrinkle finish.  It definitely has zero trouble with a 25 fpe .22.  Perhaps I'll get time to test for accuracy tomorrow.  It is quieter than the Wraith 22 I've been running on that rifle for the last few days I'd say a lot quieter.

Here's the pics.

Coyote 22  44 x 195, Three Baffles

[subscriber]

I think I want a Bambu printer, but there are reasons why owning one might  be annoying.  Perhaps the reasons are put out there by jealous competition.

[naptemp]

On the attachment size limit, so posting image of above .177 TV mod here:

Thank you for the Tesla valve moderators.

I have already printed 2 of the thicker/heavier Tesla valve moderator versions in .22.
I will print the light weight .177 tomorrow.

Right now I am printing the Archangel in .22.
It's ridiculously fat and hopefuly very quiet.

[OldCrow]

It's ridiculously fat and hopefuly very quiet.

😋😉 You can call it a big ugly fat feller except I think that nickname is already been taken.

[naptemp]

I printed the Archangel in .22 on an Anycubic Kobra.
It took 15 hours and 132 grams of PETG.

The photo shows the Archangel .22 and Peter's Tesla valve moderator also in .22.

I tried a few shots with both (no pellets) in a 20FPE .22 PCP.

They are both about the same level of noise.
I think the Archangel has more volume.

Maybe (for the  same volume) longer moderators work better than shorter ones.
Or maybe there are internal differences between the two.

All my moderators come out with a rough external surface.
Does anybody have any clues about the rough surface?

[OldCrow]

That looks about right for an fdm printer.  You can reduce It song by decreasing the layer height and slowing the print speed.  That is going to make the printd take more time.  If you feel like it you can send PETG.  It's pretty tough stuff start with about a hundred grit work up to about 400 it'll be all right.  Takes a lot of work

[Robert 5mm]

The 30mm diameter one ( Standard ) I have cut and then glued a 30mm Carbon Fiber tube over it. Looks Very Good.

[subscriber]

John,

Dry firing will be louder than with a pellet because the pellet forces more air to travel radially and be slowed down by the baffles.  So, when you get the opportunity, please evaluate with pellets.

Once a mod has sufficient diameter, increasing the length seems more effective than further increasing the diameter.  There are many good explanations for this, including the ability to sensibly space out more baffles in a longer mod.  And "more dwell time". 

As the air expands in the mod the bulk pressure drops (the reason for the mod).  Lower pressure air has lower force driving radial expansion, but the larger volume of lower pressure air generally is moving faster towards the front opening.  While the mod is designed to slow that down, there is no getting away from the need for a significant leak path for the pellet to travel through.

A mod has at least two overlapping functions:  To expand the higher pressure air from the airgun muzzle to a lower pressure.  And to contain or block the exit of the sound generated by the rapid expansion.   A tesla valve mod not only blocks sound from exiting, it is more effective than conventional cone baffles at blocking the air that generates the sound, from leaving the mod.  In any event, waxing on about how it works only matters, if a given design "works".

The texture on you prints is slightly uneven, but not bad.  Providing you have good layer to layer adhesion, there is nothing wrong with your prints.  I have been applying a fake carbon fiber-like texture to mod ODs for awhile, but removed that from the latest designs because it drove the zipped STL size over GTAs 3200 kB attachment limit.  See images below of a embossed checkerboard 0.2 mm deep, with 3 x 3 mm squares; including pics of such textured mods that Jared printed.   

Mike posted pics of some textured mods that I believe he applied in the slicer - a much easier way to do it.  My point is that some form of shallow texture can hide many print artifacts and make you printed mod look "more valuable" for free, and without additional effort.

[OldCrow]

The 30mm diameter one ( Standard ) I have cut and then glued a 30mm Carbon Fiber tube over it. Looks Very Good.

Once you do that you can polish the ends on emory paper till they look like glass.  Start with 120 grit and then go to 220 wet/dry and finish with 400 wet/dry.  If you really want it shiny take it to 600 or 800.  It doesn't take long.  I used to put the lettering in the ends of my designs when I was building them that way.  Very strong too.

https://www.airgunnation.com/threads/latest-moderator.1302220/

[OldCrow]

John,

Dry firing will be louder than with a pellet because the pellet forces more air to travel radially and be slowed down by the baffles.  So, when you get the opportunity, please evaluate with pellets.

Once a mod has sufficient diameter, increasing the length seems more effective than further increasing the diameter.  There are many good explanations for this, including the ability to sensibly space out more baffles in a longer mod.  And "more dwell time".

Exactly the only thing diameter gives you is volume.  Just a little extra depressurization.  Another problem with adding diameter when you are using conical baffles is it forces you to reduce the angle of your cones.  Reducing them below 45 degrees adds a lot more stress to the structure and you can blow it out if it isn't thick enough.  Reducing them below 60 degrees impacts the efficiency and cutoff time pretty seriously (but when you are adding diameter you get most of the cutoff time back).
 

As the air expands in the mod the bulk pressure drops (the reason for the mod).  Lower pressure air has lower force driving radial expansion, but the larger volume of lower pressure air generally is moving faster towards the front opening.  While the mod is designed to slow that down, there is no getting away from the need for a significant leak path for the pellet to travel through.

Again exactly!

A mod has at least two overlapping functions:  To expand the higher pressure air from the airgun muzzle to a lower pressure.  And to contain or block the exit of the sound generated by the rapid expansion.   A tesla valve mod not only blocks sound from exiting, it is more effective than conventional cone baffles at blocking the air that generates the sound, from leaving the mod.  In any event, waxing on about how it works only matters, if a given design "works".

Performance driven design, yes sir!

The texture on you prints is slightly uneven, but not bad.  Providing you have good layer to layer adhesion, there is nothing wrong with your prints.  I have been applying a fake carbon fiber-like texture to mod ODs for awhile, but removed that from the latest designs because it drove the zipped STL size over GTAs 3200 kB attachment limit.  See images below of a embossed checkerboard 0.2 mm deep, with 3 x 3 mm squares; including pics of such textured mods that Jared printed.

And it looks good.   I have envied you guys working in cad.  While I can write the code that generates those patterns it is more time consuming both to generate the stl files and to write that code.  I have not yet worked out a good way to do that.  For now I will stick with that wrinkle finish but honestly your faux CF pattern is a great pattern.

Mike posted pics of some textured mods that I believe he applied in the slicer - a much easier way to do it.  My point is that some form of shallow texture can hide many print artifacts and make you printed mod look "more valuable" for free, and without additional effort.

Yes, sir.  I did do that in the slicer. I only just realized it could be used to obscure the printing which I can turn off but which would then require a different set of STLs for all the FDM and RESIN files.   I'm just too lazy to do that at this point.  Maybe later I will.  Maybe I should put the lettering back on the end caps or make it bigger so that it prints better on the FDM printers?

Oh yeah that Coyote 22 moderator did evidence some steering today.  It was windy and shooting it that way was a hoot but the moderator was worthless until I took about a mm more in radius out of it.  I could hear a little difference with the hole at about 8mm but really nothing.  Your strategy of adding a little diameter to the bore at each cone isn't costing you anything really because your customer/shooter will have far less trouble getting a good print the first time.  After I reamed that Coyote out a bit with a 7/32 chain saw file the accuracy came back and the fliers weren't nearly as entertaining.  =)  I really should add that feature to my code so that I can push longer designs out to Thingiverse.

You make a fine design, Peter and they are easy on the eye!

Regarding your opinion of Bamboo:  Could not agree more.  I do not like a company almost forcing me to use their cloud to drop my designs back to my printer.  That is just inviting theft.  For me right now it doesn't matter BUT if you ever think you might be worried about intellectual property (and you'd be wise to consider it)  You might look at one of the others.  Sadly it looks to me like the entire industry is leaning that way.  You can still carry a sim card from your computer to your printer when security of intellectual property matters to you.  That's what I do.

[subscriber]

The format for the CF texture I use should be credited to forum member TorqueMaster.  I had been generating a more complex weave pattern using curved sections of "ribbon".  These looked good, but were pain to apply to the model.  TM (Bob) came up with the simple embossed checkerboard and it looks virtually the same as my more complex pattern. 

That said, the larger of the textured mods that Jared printed still takes my PC 20 minutes to generated the texture.   The texture also adds to the STL file, but slicers do not mind, nor is print time affected very much.

I have wondered about generating G-code directly, as the most efficient and versatile way to generate printed mods.  But, as I can use Solidworks efficiently, and am not motivated to learn G-code, no matter how simple it is.  Best to stick to what one knows, if you want to go from an idea to an STL fast. 

I remember learning SW.  The basics are simple, looking back after the fact.  Similar to learning how to drive a stick shift.  The problem is that the software is expensive, and they want you to upgrade every year to the new version, or you can't open files generated using newer versions.  I own a standalone license for the most basic version of 2015.  It cost 4k bucks and would have taken a kilobuck per year to keep current.  I no longer earn enough money to justify that.  I can generate STEP and STL files.  These are universal formats, so any CAD and slicer can open them.    Editing STEP files is more work than opening the part in its original CAD software - if you have that.  Editing STL files is a pain.  I would rather redesign the part from scratch than start with an STL.  Larger STL files crash SW on my PC.  Funny that SW can generate large STL files, but is slow or crashes when the same STL files are opened to use as foundation for a new part file...

[naptemp]

Peter and Mike thank you for the moderators.

The photo shows the old moderators which were replaced by your moderators.

The long ones were replaced by Peter's Tesla Valve moderator in both .177 (printed 4) and .22 (printed 3).
The short ones were replaced by Mike's Wraith .177 (printed 4).

[luge007]

Ugh, Cliffhanger!  I read through the entire thread, wondering if the paint did what was expected to strengthen the print only to end in a big question mark.   Was there a 'spin-off' thread with the continuation of this thread I missed?

Inquiring minds want to know how this turned out...........

[subscriber]

This, Matt?  https://www.gatewaytoairguns.org/GTA/index.php?topic=218338.msg156592117#msg156592117

[luge007]

Danke Schon!

[WhatUPSbox?]

I'm not arguing with Jared's test results from the other thread. The loading is a bit different.
Here are some other results on the topic of coatings increasing strength.

[bduares]

The results of the test seemed to confirm that adding The Rustoleum 2x Primer/paint spray did strengthen the prints. Without the paint the results were destroyed mods even at 100% infill. With the paint the majority of them survived even with less than 100% infill. Watching the paint as I sprayed it on the mods I could see what looked like a thin liquid bubbling, which I can only assume is the result of the paint's solvents combining with the plastic, probably filling any tiny gaps between layers and making the exterior a single solid piece.