Dosing peristaltic pump for swimming pool

cults3d

Peristaltic pump for swimming pool or any other application, based on Nema 17 motor (5mm axis). This pump allows an injection of about 2.4l/h at 30 RPM or about 4cl/m, which is more than enough for most pools. List of components: Santoprene tube 5x7 with fittings for PTFE tube 4x6 : link 2x metric domed head screw 3x20: link 2x metric pan head screw 3x14 : link 4x metric domed head screw 2x20 : link 1x flat headless screw 3x6: link 4x screw for thermoplastic 3x10: link 4x metric screw 3x6: link 1x M3 nut: link 4x M2 nuts: link 1x d8 stainless steel round or anything else that can be used as a smooth rod for needle bearings. Pieces of d8x16 iron also work: link 2x needle bearings HK0812 : link 1x Nema 17 42x42x48 : lien Total cost of the pump about 40€ if you manage well, and even less if you already have most of the materials PREPARATION The tricky part is getting smooth 8x16mm pins that will allow the needle bearings to turn properly. I've been experimenting with a metal fret that I cut the base into 2 pieces of 8x16 and it works great. It is also possible to find ready made ones in the shops. I was afraid it would rust so I did the same thing again but with a d8 stainless steel round. The rest is a basic assembly, there is no particular difficulty. OPTIMIZATION For better reliability, do not forget to grease the tube and the inside of the pump head. Remember to also put some threadlocker on the screw/nut assemblies. The Nema generates a lot of vibration. CONTROLE The control of this type of motor is usually done with a Raspberry or an Arduino, there are many tutorials on the internet to control a Nema 17 this way. LIEN Pump in action: link