How are people using the 3-D printed exhaust adapter? I attached mine by loosening the hex bolt near the bottom of the cut out where it sits in the machine’s exhaust port and cinching it down. But no matter how many times I do this, it always comes loose, and my exhaust pipe comes off venting smoke into my workspace. I’ve tried using exhaust tape to tape it in place, but it’s still pops off after some use.
I’m sure there’s been ‘exhaustive’ conversations about this, so feel free to redirect me if there is an existing thread.
I believe that most people here are using an exhaust fan or hood that is not directly attached to the Bullet or an adapter.
You need to be careful about using a fan to draw the smoke outside. The smutz from the smoke from the bullet can build up on the fan blades and make it ineffective.
You will probably need some kind of filter between the Bullet and the exhaust fan.
You can find the Bullet Manual here:
There is a lot of other good informaiton in the manual.
My question is related to the “officially” (?) supported 3D printed exhaust adapters from Aillio:
It helps to be familiar with this adapter. Part A attaches to the Bullet and can be secured by loosening and tightening the screw in the vent port. Part B attaches to a flexible hose and has fresh air flow gaps between the two parts. Part A keeps coming lose no matter how many times I tighten down with the screw.
Am facing the same smoke leak situation but i don’t think tight securing the adapter in place will is the solution, because I manually held it down tightly to see if any smoke would leak and it did!
better just install external fan and buy your piece of mind
Thank you @billc. I’m surprised that the Aillio adpater is not more commonly used. Perhaps because of said issues. It seems like it could use some improvements.
Thanks for filling in the slot. That’s exactly what it needs to make it more secure.
That said, as @gdegde481.i9qy1 pointed out, even when its secured, it still leaks smoke. On my most recent attempt, I taped the base with two rounds of aluminum tape which both created a tighter seal, and created additional material to punch the bolt through. So maybe a combination of your improved design and some heat resistant seal.
Your lazy susan idea sounds excellent. That must make it so much easier to maintain and clean. Great idea. Thanks for sharing the exhaust thread. I see lot’s of other great ideas and alternatives for venting the smoke out. Once I get something in place, I’d also like to explore some filtering on the exhaust to reduce the oder for my neighbors.
I’m also using the 3D printed exhaust adaptor, and was cinching it down in the same way until that bit of the mould broke. I’m using the duct to simply close the gap between the roaster and an open hoof kitchen extractor. My solution is now to bend the exhaust ducting in such a way to balance the weight of the ducting pipe directly down on to the adaptor to keep the join together. It sits precariously balanced like a stack of cards. Not ideal, but fine until I get time to create a more reliable solution.
One of the big problems with this design is that the adapter is in contact with the stainless steel walls of the fan exhaut for the Bullet.
I have never measured the exhaust temp of the Fan on the bullet,But I would guess that it is pretty high, especially on longer darker roasts.
Most 3d filaments are not stable at higher temperatures and warp, shrink (or just melt).
Filaments used for 3d printing have a “glass transition temperature” this is the temperature that the printed part will become unstable and start to distort or melt after the part has been printed and cooled.
ABS has a GTT of 105C or 221F
PETG = 80C or 176F
Nylon = 70C or 158F
PEEK = 145C or 293F but still has warpage issues.
Printing with some of the more specialized filaments (fibre reinforced) requires higher end 3d printers and slower printing parameters.
Since we rarely drop our roasted beans at less than 200C or 400F, I would guess that the Fan exhaust temp is not that much cooler, especially on darker roasts where we are dropping at 226C or 440F.
Also the time that the exhaust is subjected to the higher temperatures goes up dramatically. A 500g batch roasted to 210D or 410F might only take 9 minutes, but a 1000g French Roast at 226C or 440F might take 17 or 18 minutes.
3d metal printing would be very expensive.
Machining an aluminum part would be very expensive.
I wrapped my adapter in metal duct tape which both protects it from heat and makes for a tight seal when simply inserted into the exhaust port. I have a downdraft exhaust hood in my kitchen island right above the basement location for my Bullet. The down draft has a fan on the outside of my house actively pulling airflow, in addition to a fan in the island itself. I just tapped into the downdraft duct and piped a flexible dryer hose from the Bullet into the ducting. Works like a charm. No chance of positive pressure into the Bullet.
I’ve used a nylon 3d printed adapter.
I’ve kit bashed out of 1mm aluminium.
I’ve added padding of aluminium tape…
They always leak smoke.
You’re much better off using the overhead smoke extractor method.
Especially as with particularly oily/chaffu beans, you’re going to get smoke escaping from both ends…
