LogicalDIYBuilder
1 mW
Jezza said:Hiorth said:Did it work with O-rings and screws? I will make this on my next version, but I belive the O-ring grooves should be machined in aluminium (not 3d printed) to ensure a good seal. The O-ring should be compressed about 30% to obtain a good seal, see drawing below of tube edge and o-ring groove. Have discussed this matter with a couple of very clever oil engineers, that works with this type of seals daily. If you need to be extra sure you can add in two rings, and bigger is better! In our case 2-3mm O-rings is ideal.
Cheers
I printed some test parts (without screws) and lowered the unit 1.5m under water. Then left it for 1hr 30mins and pulled it out. Didn't take a huge amount of water, but enough to cause trouble. But I agree with the not using seals on 3D printed parts. I will hopefully be cutting the new parts on the lathe this evening and will then test the seals again.
Yes, I did a 48 hour water test through warm water then cold as the motor will heat the air and contract (suck in cold water). Water test was a success but im still waterproofing my motor and bearings this week to protect bearings from moisture. You can youtube how to waterproof your motor bearings and other bearings (just thick marine grease on both sides will save the bearings dramatically.
I would be more concerned with the high torque on the 3D parts glued into tubing as things heat/cool causing expansion and breaking seams which is why I didnt glue mine but threaded into aluminum with o-rimgs