There is.a Koi pond in my backyard, and it needs a new filter. The best filters are called “Rotating Drum Filters”, which are large boxes usually made from polypropylene sheet or HDPE sheet, with a lot of complex cuts, welded together, with electromechanical parts. I was going to buy one, but they cost about $4000. Figured I could make one, if only I had a CNC. Also my 8-year old inner self took over and I spent the money on an mini excavator instead, for the said Koi pond renovation.
I have a Bambu A1 mini with 180mm^3 build volume, which is a bit small but will work. Plan is to print the parts with the A1, build the LR4 with the V1 Engineering h/w kit, then use the LR4 to cut the parts for the RDF and then justify why I bought the excavator by installing the filter in the Koi pond.
Hopefully will complete all of this without spinning up another hobby.
This is the Bambu Studio “Prepare” screen. Everything fits on the 180mm x 180mm plate except for the YZ plates, which I split and printed the overhanging part separately. Will glue the parts back together after printing. Everything is printed with Gyroid infill, with 3 walls, and at the recommended density.
I have a spreadsheet to keep track of the parts. Build time for the Core is 20h 35min. Total filament used is 1882g. The A1 Mini allows for remote operation, so most days I started the print job during a short break at work, and it was finished by late evening or next morning. Then remove parts from the plate, and head to work. Repeat each day until done. There were no major failures during printing. Worst I got was minor stringing on one part due to bed adhesion. The A1 Mini is a great printer if you have too many hobbies and don’t want printer tuning to be one of them.
Finally, everything is ready. Total build time was 73h:52m, with no failures. But I really didn’t notice because the printer just works. I probably spent 30 minutes of prep time, including setting up the build plate layout, changing filament twice, and moving prints off the plate once a day.
The big ones for me are a pre main sieve filter (with sensor?) to collect big bits of blanket weed as dealing with thing in my drum is still requiring loads of maintenance. It would also be great if the drum sieves were modular like the Oase proficlear, or even use their filters. Having the whole filter as one long strip is a real nightmare to replace/change.
Anyways, if you want help with the design part of it, even some of the modelling (if you’re using Fusion 360) let me know. I’d be really keen to help out with a project like this.
This is sage advice. Super glue on these structural parts is suspect. A structural adhesive is better, printing the part as-designed is the correct way to do this.
It might take a while! The pond is under heavy renovation. I’ve removed the old filter from the hole. Next step is to trench and extend the drains to the fence line, dig a new filter pit, and then work on the RDF once the LR4 is up and running. It started the rainy season as soon as I pulled the filter out, so if we get another drought I will know how to end it next time.
I will be building the drum as well. The advice on blanket weed is helpful. The main motivation to move to RDF is the old filter couldn’t handle any weed or debris from the pond, and to lower maintainance!
