3D Printed Waste Pipe Silencer

[Nias]

I made a silencer for my airgun a few years back base on a design on Thingiverse.
The end caps and baffles are 3D printed and the tube is 40mm ABS waste pipe.

The silencer fits on a standard threaded barrel or can fit over and existing silencer eg on an Airacobra.

I have just got round to measuring the performance and it compares very well to ready made silencers.

Full build details and links here Silencer Site

 

[GaryM]

I have done a similar thing but those k baffles I made a little smaller and wrapped everything in felt , this made a massive difference and quietened even more.

 

[Nias]

Thanks for that, when I get some time I'll play around and tryout your idea. Will post the results here.
When I took my factory fitted silencer off my Airacobra I found it is just a hollow tube. It takes less than 1dB off the sound.
To my ears it took some of the sharpness off the sound.

 

[insertusernamehere]

Very nice

I found the most effective (to my ears) to be be
1st chamber hollow (3d printed it this way)
Then a baffle, then a hair curler wrapped in felt and repeat this x times.
The final thing I found quite good is to make the end cap conical into the silencer which helps direct some of the residual air back.

Also I found that the bore can be too tight, I had dreams of a tiny exit hole but actually a bit bigger worked better, something to do with the exit flow impacting accuracy or something!

 

[Brooksy]

Try making baffle plates in 3 mm thickness, with a bore as close to the pellet width as you dare to go, eg. 5.3 mm for .177. Then, make three chambers, long, short, long to fill the total length available. Use plastic hair curlers for the chambers, but, wrap them, not too tightly, in microfibre cloth, the fluffy type used for drying. Very effective.

 

[Nias]

Wow loads of ideas to tryout! I think this will be my next project after my DIY chrono.
The results I am getting already puts it near the top performing silencers - the challenge now is to make it the best....................................
I noticed on AAR silencer review the larger volume the better the result and I think my one has the 2nd largest volume compared to his review samples.

I wonder if the ABS tube helps by flexing outwards to absorb the blast? Alluminium is not ductile so probably does not expand with each shot blast.

I did try making the bore down to 5.5mm that's just 0.5mm each side of the pellet but found it affected accuracy. I settled at 7mm I think is the .22 cal setting.

 

[Brooksy]

The best one I made, with the baffles described above consisted of five chambers, separated by delrin baffle plates. The chambers got gradually longer from barrel to muzzle.
1st 18 mm (including 10 mm bore in the screw cap).
2nd 26 mm.
3rd 38 mm.
4th 50 mm.
5th 70 mm (including 10 mm bore in the end cap).
The silencer was quite long when I included the end caps, but it was virtually silent.
Plastic pipe will absorb the sound of the bang, aluminium makes a brief ringing, or ping.

 

[crissdee]

The mod on a Stealth is just an empty tube. I played around with mine for a while and ended up filling it with discs of scouring pad, the type without the foam., then I just shot through it to make as much of a hole as it needed. I only shoot at 6 yds, so any "inaccuracy" is marginal anyway. If I ever get round to it, I might try punching the holes out to 6mm or something to see if it makes any difference, but as it stands it is at least as good as any of the shop bought ones I have.