I am building an underwater ROV and have 3D printed thruster shrouds and props in yellow Hatchbox PLA. They did not handle the vibrations and power from the motors very well and split along the junction of the mount and shroud that were 3D printed. To put them together I used 2 part epoxy rated especially for water, but 2 of the 4 have already broken along the glue line and some of the props are also shattering too from the stress (Fully 3D printed with no glue used for the props). Maybe using an epoxy is the wrong glue with the PLA, but I thought this would be the strongest I could get since CA is very prone to cracking with the vibrations.
So is there a better glue to use to fuse PLA together than H20 hold epoxy?
I am also thinking maybe I should use a different filament that would especially handle vibrations and have the strength for the 1 to 2 kg of thrust I am producing on the ROV props (This thrust is just an estimate, I have not measured it). I thought maybe yellow PETG would be a great compromise having the strength of ABS and have the ease ability to print of PLA, but I was not sure if anyone had a great suggestion of what yellow filament to print them in. I figured if I changed the props over they would be stronger and hold up much longer. It is also a little scary to test out a prop with the chance part of the blade might come flying off at you.
In short my two questions… (Sorry sometimes I give too much info)
Which glue to use for fusing PLA in high vibration and stress situations?
Which filament would be best to print a prop and shroud in?
I tried the acrylic #3 glue and it worked really well so far. It really does melt the PLA. The joint seems really strong and is so much better than H20 epoxy!
I used the acrylic glue #3 on the ROV thruster and it works great. Looks like it will hold up to the vibrations! Hopefully the PLA will hold up to the extreme weathers… if not I will switch over to ASA… Thanks for all the help and suggestions!
Thanks for the update. I got some gel CA to try out that isn’t “instant” bond. My part isn’t going to be subjected to the stresses of yours! This will be round one of testing glues. I’ll look for the #3 also and have some on hand.
I tried my gel CA glue and it sure gave me plenty of time to align the parts! Taking forever to dry and I still don’t know how good the joint will be.
I looked at the #3 and see how “watery” it is. I have asked them their advice on what glues would be best but no response so far. I would like on that is maybe a bit thicker - maybe not quite a gel but that can fill a little gap.
