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4" Waste Pipe Trommel

by Seafax Feb 24, 2019
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Love the design. It's exactly what I'm looking for as a basis for a hazelnut sorting machine. Would it be possible to hire you to modify the design a little bit, so that the pipe can be fitted with modules containing holes for the following size nuts:

12 mm
14 mm
18 mm
20 mm
22 mm
24 mm
26 mm
30 mm

And also a funnel under each of the modules so that I can collect the nuts of these sizes in different bags or compartments of some sorts?

I do also have a challenge, as I have a Snapmaker printer, which allows for appx 110x110x110mm prints.

Do you think this would be possible? If so, how much would you charge?


Hi Thor and thanks for the request.

If I understand you correctly it shouldn't be so hard to do.
Could you email a copy of your txt and a sketch of the funnels with sizes showing exactly what you want so we can talk about it in private please.



I'm actually printing your model here now as it is, with a slight engine modification, and then using a regular waste pipe with drilled holes for the nuts. Then I'll collect the nuts in bags below hanging under. Not as refined, but it should work :)

Btw, great design!


Thanks. Good luck.

Hey may I ask you about your opinion. Will it still work if I scale up all the parts with the same percentage?
That thing is exactly what i'm looking for since ages, just a bit too small.

If you could scale everything up by exactly the same percentage it would work fine. I can see two potential problems though... the first being finding a length of pipe the diameter you want and calculating how much to scale all the printed parts by... the second problem being that when scaled up by that amount the parts that require metal bearing or shafts would all need different sizes bearings and shafts. If you can overcome that you'd be good to go - but if not there's be nothing to stop you loading the effected parts into (say) tinkercad and modifying them to take different bearings etc.

Great design I'm starting to piece one together for my kids, have a few questions:

  1. The tyres for the rollers - do we need a bearing here? are the a 608 or similar?
  2. How do we attach the motor mount to the hopper? There is also a second part in the file for the hopper, what is that?
  3. The transfer from the hopper to the trommel - you appear to have some foil (or something) to guide the dirt into the trommel, could the same be achieved by slightly reducing the size of the hopper output so it can sit inside the start of the trommel? (If you are happy to share your design files I can look into this).
  4. I have some motors with threaded shafts (old drill motors) - Id like to adapt the auger and drive gear to suit, would you mind sharing your design files? (Ignore this, I just ordered a couple of the recommended motors).

Any brand of skateboard bearing should fit in the rollers. The second part in the powered hopper file is the mount for the motor I recommended. It was left seperate (superglue it on if you want it) to allow other motors to be used instead. The original files are here if you care to re-work anything... https://www.tinkercad.com/things/6gA9C4d1YUg-waste-pipe-trommel :-)

I got it figured out thank you I ended up checking a box that wasnt needed

Are you using the Cura slicer? I can ssure you the instructions do work, but if you're not using Cura I have no idea how to help except to suggest that you re-visit the thing files (https://www.thingiverse.com/thing:3448816/files) and download the new Simple_Auger.stl file and try that instead.

4" Waste Pipe Trommel
by Seafax

did everything that was posted on printing the auger an its just printing the shaft without the auger blades is that right little confused

You can already see bits of my conveyor in the video but it's not quite finished yet but I'll release the plans when it is.

Ive got 100mm wide neoprene rubber 1.5 mm thick. Something a little less stretchy might work better but it's holding up better than I initially thought it might.

thanks Seafax, im gonna wait ,or maybe draw one :P what kind of belt do you use ?

Great deseign! have you make the plans for the belt convoyor ? what kind of material do you use to make the belt ?

Absolutely marvellous! I have spent months trying to figure this out and I never thought of drillingrigs. hehe.
Can you put out a link to the motors you recommend? :)

You're also missing the sprockets for the trommel and the motor below it seems like.

What a glaring ommission. Gimmie a sec then check the files again and you should be able to get the ring gear. I'll also put a link to the motor I used but it'll be from a uk source since that's where I live.

great build very kool! gives me a great idea i am going to try to build something very similar atleast thank you for the inspiration i really like this little machine and how the auger system works! i would like mine to be a bit more powerful possibly for the conveyor and have maybe a bit larger area for the auger to be longer and hold a larger amount of dirt or sand. really great job!

Thanks for the comments Tommy. I should probably have added in the text that the motors shown in the video are NOT the ones I recommend... I just happened to have some slower/lower powered ones laying around and was too impatiend to see what it was like to wait for the better suited ones to arrive.