3D printed exhaust port


#1

I had an exhaust port printed using MJF nylon and it softens because of the exhaust heat, it cost around $33, reasonable price but it doesn’t withstand the heat generated while roasting.
Using a material called ULTEM 1010 for the printing will withstand temps to 450F, but the cost is $275, not a reasonable price,
Can anyone recommend a company that has had success printing an exhaust port that can stand up to the temps created while roasting?


#2

I had mine printed by 3dhubs.com from ABS. Annealed at ~105°C. No issues with deformation.


#3

Thanks, I will check the company out.


#4

I just printed off a bunch made out of ASA. Running through my seasoning batches I can say that the piece that is in the roaster does soften but that was only at the end of 2nd crack (extremely hot) and it never lost form or shape. The rest is solid the whole time. I have been charging $25 for them. Shoot me an email. lotus@ix.netcom.com

Thanks, Rich


#5

Thanks for the offer, but at this time I am going to hold out and try to get one printed that will not soften.


#6

Anytime! Part of the issue could how it was printed. Nylon is inherently heat resistant and I have seen people happy with Nylon printed adapters, but I am unsure of the powder (MJF process) and how that translates. So far the ASA I printed with has been great. Like I said, if you take it out 1 second after you hit cool on a full on after second crack roast, there is some give to it but it cools quick and retains form. I have Nylon 910 and some Ultem (not sure I have enough though for an adapter, was a sample). Might have to print a few more and test them out.

Whatever you choose, keep us posted so we know!


#7

I ordered an exhaust adapter from 3D Hubs using heat resistant resin with a 238C heat tolerance.
It was a bit pricey at $168.
I realize I probably will not be roasting at this high temperature very often, but now I will be able to if need be.
The problem with the nylon one I currently have is it starts to soften around 300F and continues to deform and smoke escapes. After cooling it reshapes itself, but constant usage will probably destroy it.


#8

I looked at 3DHubs when I bought my Bullet, but wasn’t sure about the correct specs to use.

I then found a black nylon adapter from a company called Shapeways.com . I have 73 roasts on it and it is still performing great. I did a tiny bit of filing on it in one spot to make it fit the Bullet better.

I just looked on their website and they have raised the price to $65 plus shipping. They have a couple of cheaper ones, but I believe are made of a different plastic.

Please let us know how the 3DHubs adapter works. Good luck and happy roasting!

NOTE: I just looked again when testing the link I posted and see that the cheaper one is the same nylon plastic, just a smaller size, and is the size I actually bought (3"), so that means it has come down in price, to $48.


#9

Annealed PLA here, works great after the annealing process. Wasn’t as hard or complicated as it sounds, and now its very heat resistant :slight_smile:


#10

It is funny how roasting coffee got me back into 3D printing. Anyway, got 10 roasts, almost 11 pounds of coffee through my adapter and although it is a little dirty, it has help up nicely. If anyone needs, always here to print for you guys and save a couple bucks!


#11

What we sometimes do is to line the inside with aluminum foil. This makes for an extra layer of protection and you can rip out the foil and replace it when it gets too dirty.


#12

The reason I didn’t want to use ASA and actually any other plastic is the low heat tolerance.
ASA technical data recommends a maximum service temp of only 95C (203F) and we all know the Bullet reaches much higher temps than this.

What irks me about this adapter part is the No Support from Aillio in getting this part printed.
The last email I received from them they actually stated they have never printed it! Go figure!
You would think that they would be on top of this, being the manufacturer and all. I have spent hours researching this part and material to use for the actual printing. The last chemical engineer I spoke with said you will be pushing the limits of any plastic at Bullet temps. I will find out how Heat Resistant Resin works, stay tuned!

Good for you that you are able to make ASA material work for your roasting, I can’t chance smoke escaping from the exhaust in my roasting situation.


#13

No doubt, no plastic will be able to hold up forever under those conditions. From everything I read ASA was able to hold form just past ABS at ~105C. Regardless, so far so good. With the model in hand, I can print one when needed. next one may be Nylon or PC. Have to see what I have in my filament bins. Still unsure why a $3k roaster doesn’t come with a $10 part, but whatevs. Best thing to do is to print a part and make a mold and cast it. Honestly, I may just do that for the next one.

keep us posted on your findings as well!


#14

There is plenty of plastics in the Bullet, also where it is in contact with the exhaust air. I agree that ABS is not the best material but it is widely available for 3D printers and relatively easy to print. If you want to try others such as nylon go ahead. SLA printers now also offer high temperature materials…
As I mentioned above you can line the inside with aluminum foil for added protection.

I don’t know who you wrote with but Aillio has printed plenty of 3D adapters so we know it works - but I don’t think we have ever printed one in metal.


#15

Many plastics can easily withstand these high temperatures. Modern cars makes extensive use of high temperature plastics on the engine etc.

The reason the bullet does not ship with the adapter is that each mold for a different size of adapter would cost in excess of 10000 USD, and we would need to invest in 3 just to satisfy a few different sizes of exhaust pipes.
Also, we think it is better to not have a direct connection to the exhaust pipe, and prefer a hood type just above the exhaust as this will not influence the airflow as much as a directly mounted exhaust pipe.


#16

On my next roast I will try to remember to take the temp of the exhaust port area. I’m sure it is very hot, but has no affect on the adapter I referenced earlier from Shapeways.

I chose them, because they stated their material was nylon, and I did not have to send them any specs or files. They already had them…and the price was right. I’ve seen no change in the looks or performance of their adapter after 78 roasts (except some bean dust). I use a 3 foot flexible pipe extended up under the hood of the kitchen exhaust fan and have had no smoke issues.


#17

Knowing the exact exhaust port temps during roasting would be good to know. I assume it would be similar to the drum temp and during my initial drum seasoning roasts the temps exceeded 450F according to the digital read out. The exhaust port must definitely hold up at these temps as a lot of smoke is generated at these temps and my nylon one did not filling my shop full of smoke. I would rather not go through that again and hopefully the heat resistant resin adapter I’m having printed will eliminate the problem.


#18

The technical data of the heat resistance of materials used in 3D printing does not support the temps created by the Bullet. Molded plastic parts are different.
My apologies, it was not your company that had never printed an exhaust adapter, it was one of your major distributors.


#19


Blue line is exhaust air temp measured near the bean chute lid, so nowhere near the drum temperature. This is during roasting and might be different during pre-heating and cooling.


#20

I printed a Stainless\Bronze exhaust adaptor for $183 USD through Scupteo. Received a fairly high number of recommendations and quotes from a variety of vendors, this was by far the most reasonable. There was a little shrinkage in the part when printed due to the Bronze sintering process. Might suggest a edited version of the adapter for better fit, starting with 1 mm increase in size. I Have some tape designed to masking and use in oven related temperatures I will be using to obtain a airtight fit on the model I had printed.