Top-up valve adapter for boston valve

[GabC]

Hi everyone! I designed an adapter for a top-up valve that screws to the secondary threads on the boston valves. The files for 3D printing are available on Prusaprinters. You just need 3/8″ ID vinyl tubing and you can then top up your raft from paddling position without having to weld a top-up valve to the boat.

The only thing I don’t know is if the boston valves that are supplied with the kits are always from the same source. The threading was not standard. I thought it was 7/8-14 UNF but it was off by a mile and doesn’t seem to match any standard.

Of course, you need a 3D printer, but hey, if anyone wants an adapter, just ask!

• This topic was modified 2 years, 9 months ago by GabC.

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[zachschiada]

I was initially thinking about trying to figure this out, but I was a little DIYed out and just bought one from MRS. Not sure how well it’ll work, but I’ll report back. I’ve found almost all of my leaks and fixed them but I’m still finding I need about 5-10 breaths per hour. If something like this ends up on the store, I bet it’d be pretty popular. Super cool that you designed this.

[mttgilbert]

I printed a couple of these (no scaling) and they fit perfectly. I had to dial in the resolution for the threading, but even the rough prints threaded on (they bled just enough air to make it difficult to overcome the valve).

[pweissma]

I took a boston valve pump adapter and glued a piece of vinyl tubing to the inside. It has a snug fit in the valve and works great for top-off.

On my ultralight I installed a Leakfield c7 valve. For this, the standard c7 screw-in valve adapter can be used but NRS sells a rubber pressure fit adapter that I use for top-off.

[BobDep]

This would be Soo handy !

[Larry]

That was a perfect solution, Dwayne. Thank you.

[Dwayne]

Larry, I had to scale it up to 102% and it fits perfectly.

[Larry]

Mine will only go onto the valve threads 1/2 turn at best.

[GabC]

Sorry for the missed replies, it seems the e-mail notices went straight to my junk folder. It’s fixed now.

If anyone wants a valve or a few, I can be contacted at gabriel.couet@gmail.com (there you go web scrapers, have a field day with my e-mail, lol)

[Lehmann99]

Can you post one adapter to Sweden? Of course I Will pay for the shipment and for the item itself

 

Regards Anders

[Alan]

GabC…I have a group of boys and dad’s going on a trip this summer and would be interested in getting a few of these valves.  Would you be able to make 3 or 4 sets for us?

[GabC]

I used PLA. It’s not the best choice but it’s the easiest to work with for testing and iteration. I have about 3kg of ASA filament sitting in my stash though and when I’m finished making an enclosure for the printer, which is the current project I’m working on, I’ll see how well it prints.

ASA has the main benefit of UV resistance, increased strength, and higher melting temps but I expect PLA should work fine for this part though as it’s not supposed to stay attached all the time on the boat. I remember reading that the boston valve isn’t totally sealed unless the cap is screwed in. A solution to this might be to glue the tip from a top-up valve to the vinyl tube.

As for the threads, they are weird. Definitely 14TPI, so the thread pitch is the same, but almost 2mm wider than standard 7/8.

[Matt (Admin)]

Very cool! If I had a 3D printer I would definitely make one. What kind of plastic did you use?

I tried to figure out what threads are in the valves, but I wasn’t able to find a match. The same threads are in valves from at least two different sources, so it might be a Boston valve thing.

[Author]

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