3D Printed ROV Float – Float Pod & Frame
This is the updated float pod and frame design. The float pod size was doubled and a few other minor changes were made.
The new design is now only two main pieces for easier and faster printing. (cut away shown)
It took a bit of doing but I got both piece of the new float pod printed.
Here are both pieces of the float pod being test fit. I added some small windows to the left half of the float to aid in adding the buoyancy filling.
For buoyancy I am using some old micro balloons I had laying around from my R/C Days and a epoxy like polymer coating. I did some initial testing (which can be seen on the forum) if interested.
I did some volume testing this morning… I filled half the float with water to measure how much it would hold. It’s going to take about 26oz. (volume wise) to fill one half of the float up. If my math is right (and by math I mean my conversion app on my phone) the 1 pint of micro balloons I have is about 18.6 Oz and with whatever epoxy I need to use I should have enough to do at least half of the float. I still don’t have an actual ratio to mix at so as usual I’m just going to wing it and see what happens.
On a side note the print isn’t very water proof as I had some small leaks while filling it up. I only printed it at 80% infill, .30 layer height, 3 Outline shells, and 2 Top and Bottom layers (I think the top most layers on the curved section is where the leaks were.) So sooner or later I will increase these values and print a test piece to see if I can accomplish a print that at least stand up to a bit of pressure. Anyway that’s a test for another day…..
I hope this micro balloons buoyancy stuff works at depth, I all ready have some ideas to make molds for tethers floats using this method.
On to the fun part. I have all my stuff ready to mix up some poor mans homemade syntactic foam.
The new Micro Balloons I bought seems much finer than the old stuff I had so I decided just to mix it all together before I started to make sure all the buoyancy would be the same. (even though it probably wouldn’t matter but better safe than sorry later on.) This stuff is not fun to work with it floats in the air everywhere. (wear a respirator if you play with this stuff.)
I then measured off enough Micro Balloons (in volume) to fill the entire half of the float. I know I probably shouldn’t do this all at once but what the hell I just want this done at this point.
I think your suppose to mix half the balloons to part A of the epoxy and the other half to Part B and then mix it together but I don’t know how much epoxy to use so I just dumped half the balloons in the mixing bowl and started adding mixed epoxy and more balloons until I got a consistency I liked.
I ended up using all the epoxy I had and almost all the balloons I measured out. I couldn’t use all the balloons because it was getting too thick to pour.
I was a little sloppy but I got most of it in there.
I used my vibratory case cleaner to vibrate out some air bubbles.
I was a little short on filling it up but that gap I need to fill in will hopefully hold the two piece together better when I fill the other half. My biggest concern right now with doing it all at once is the curing epoxy will heat up to much and melt the outer shell. Now I wait… and see what happens.
Houston we have a problem… I guess it’s a good thing it wouldn’t fit the pressure pot because when I checked on it an hour later I had a little bit of expansion of the front half. (so much for my gap) It seams like the thicker sections are curing faster probably because of the heat build up. The good new is while it was hot from the curing it wasn’t nearly enough to melt anything though.
Thankfully it wasn’t fully cured yet so I was able to salvage everything with a bit of trimming with a razor blade and a hobby saw. A little sanding later and it will be fine, as long as it doesn’t grow any more overnight.
So in theory… I’m covering my windows with packing tape, I’m then going to fill this half with balloons the same way I did on the first half, then superglue the other half on top, and then flip it back over and let the balloons settle to the middle of this half and hopefully join with the other half… This should be fun.
So far everything worked out pretty well. The filling went well and it glue together nicely, I put a bunch of clamps on it just encase things tried to expand it didn’t separate the two halves.
I poured it a little short so hopefully it expands again like last time and it will fill in the rest if not I’ll just top it off later on and then glue the windows shut.
Not Shown- It came out good, I got it topped of and the windows sealed up. This side didn’t blow it’s top so I hope there wasn’t a huge air bubble in the last one.
Next I’m prepping the float for a quick paint job. I gave the float a rough sand, then covered it with spot glazing putty to fill in some of the imperfections of 3D printing and to try and hide the joint, then a bit more sanding. It’s far from perfect but better than nothing I guess.
A few coats of primer and some more sanding and it’s ready for some paint. It looks a lot smoother in the picture than it really is but over all I’m happy with it. I’m going to go with a Florescent green for high visibility.
Here is the finished and painted float pod. It’s hard to get a good picture of the true color and the seam still shows but overall I’m happy with how it came out. I have still yet to test how much buoyancy it will provide (I’m kind of scare to find out at this point) but I’ll get around to it sooner or later.
The frame sides where printed in some cheap Chinese filament which I didn’t properly configure so they came out kind of rough. To get ready for paint I also coated them with spot glazing putty and then sand most of it off to smooth things out. Here you can see one coated and the other sanded they are not perfect but good enough for the prototype.
Here are is the frame assembled and ready for testing. I was able to reuse the cross brace/vertical thruster mount from the first prototype.
Jumping right into testing at this point.
Well it floats….so that’s a good start and I overcame the major issue with the LCUBE design.
(2018) – Here is some video of the first control tests… it’s not very exciting but it looks like it going to work out. It’s not balanced correctly yet I still have to add the camera pod and mini manipulator I designed for it right now it’s pushing the nose up. It actually might be a little to fast for just on/off control though so I might have to add a speed control up top to limit the power to the thruster. I’ll figure that much out when I get to it.
Next it was time to start work on the Camera
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