Hull\Frame connection question

[Byron Jonson]

Hello! I'm new to this forum and ROVs in general, nice to meet you.
Me and my Dad are making our first ROV and have run into a bump and could use a push to get over it, but first some info on our ROV I guess.

Our current design has a 1/1/2' 1/2" PVC frame and a 2' 4" PVC main hull, both the frame and the hull are watertight with the hull holding the important stuff (camera, control stuff, maybe a battery)
and the frame having the propulsion and lighting on it, plus the skids are attached.

The problem is, We can't figure out a way to connect the frame to the hull! My plan was to file down a couple tees to make saddle fittings,
but after looking at them I don't think there would be enough material make a strong connection. Anyone have any ideas?

(I'll try to get some pictures later)

[Unorthodox]

you might check out FormUFit they sell pvc furniture fittings like this fishmouth fitting. :geek:

[thegadgetguy]

Do you want a solid, mechanical connection, or is it all right if your pressure hull and your frame move a little in relation to one another?

Connecting things to the frame of my first ROV was one of biggest problems. It's funny, because it isn't something you think about at all, yet it can be really annoying.

Good luck on your project.

[Byron Jonson]

Here's some pictures!

The 1/1/2' 1/2" PVC frame, the four larger pieces on top are for stability, the little angles on top are where I'm going to mount lights and the things on the bottom are skids.

Frame 1.jpg (178.32 KiB) Viewed 7069 times

Same as last, different angle.

Frame 2.jpg (100.06 KiB) Viewed 7069 times

Me holding the 4" hull roughly where it will be mounted, the red lines are there to show how I was planning to attach the hull to the side pieces.

Frame&Hull2+Lines.jpg (159.98 KiB) Viewed 7069 times

thegadgetguy, we need the connections to be solid, we are planing on running wires through the frame to the lights and motors.
Unorthodox, I think that those fishmouth fittings would be perfect if they were the right size, I'll keep looking into it though, Thanks!

[derelicte]

that looks pretty nice!

I like your light mounts.

I'm still fighting with trying to mount the flashlight I use.

[thegadgetguy]

Hm, yea I wast just wondering because if it didn't have to be 100% rigid, you could use 4 straps to secure the pressure hull to the frame. I know I've seen it done before somewhere. I'll include an illustration of what I mean.

possiblehullmount.jpg (40.36 KiB) Viewed 7062 times

This design wouldn't be rigid, but it would be simple and easy to adjust and remove.

The frame looks good. Good luck on your project

[Pilikia]

I suggest you use real saddle tees. Look at entry in this thread titled "Attaching Struts to Hulls." It shows how to modify saddle tees so there is no penetration of the hull. It also lists a source for the saddle tees.

[thegadgetguy]

Yea, saddle tees would work well too. Have you glued your frame yet?

[Pilikia]

thegadgetguy, No, not yet. The new design requires redoing the buoyancy calcs. Likely the hulls will get some minor length adjustments. But very soon . . . Ah! It just occurred to me maybe you were asking Byron that question . . . Oh well, you get my answer too!

[Byron Jonson]

I suggest you use real saddle tees. Look at entry in this thread titled "Attaching Struts to Hulls." It shows how to modify saddle tees so there is no penetration of the hull. It also lists a source for the saddle tees.

Wow, after looking at the they seem perfect, they even have the exact size I need! I guess I should check other peoples posts before making my own next time.

Yea, saddle tees would work well too. Have you glued your frame yet?

Not yet, we're waiting until we finalize most of the systems before making anything permanent. Mostly because we don't have a solid plan. In fact, we just completely remade our frame!
I'll make a post in the "Your ROV Projects" section with some pics later today.