Something to replace the Neptune - Short Typhoon?

[Ed Kirk]

I have been looking for a project to replace the Neptune as a fun boat to just play around with. I used Orca slicer to shorten the Typhoon, started printing, can't wait to see how it turns out.

[Ed Kirk]

Getting the short hull printed. Mounting motors in stern with printed bulkhead and mounts.

[Ed Kirk]

Project coming along, I had to make the hull longer to get everything to fit. I used M5 threaded rod to bolt hull sections together, combined sections 2 & 3 and printed as one section - no glue. Glue not required on other sections either. The hull sections are numbered from stern to bow, kind of backwards.

[Ed Kirk]

Threaded rod with nuts, I was going to attach everything with nuts and washers, got to be a hassle so I went with wire ties except the servo tray. Even the bow bolts on, using acorn nuts, plan on using the bow to hold down the upper hull section. Remove the two nuts, slide the bow forward and lift upper hull off.

Photo quality pretty bad, not the print. Reduced quality to take up less space. (edit)

[Ed Kirk]

I am using Du-Bro fuel tank for ballast, very rigid tank should handle depths with no problem. Pump will be in forward compartment, then tank, electronics box then servo tray. Bow plane servo and mechanics will be mounted in bow using threaded rod. Hull section 1 also bolts to section 2 with 2 M3 screws and 4-3MM pins.

Serious kit-bashing;
Hull sections 1 and 2 are 75% length
Hull section 3 is 100% length (printed sections 2 and 3 as one part using Orca Slicer add part tool)
next hull section is section 7B at 150% length
Also had to reinforce strips in lower hull sections so they would stay on during print.

[Ed Kirk]

Plan is to 3D print shells to fit, fill with led shot and resin for ballast. Photo is example I use in my clock pendulums.

[Ed Kirk]

Created bow planes mechanics.

[Ed Kirk]

I'm experimenting with a modular system, was at the local hobby shop and seen the Du-Bro fuel tank and it solved some of my challenges. I am thinking about running the pump on the wet side even though it is brushed. Still undecided but getting there. In the early days of RC cars the break-in method for brushed motors was to run them in (clean) water to seat the brushes and clean them out, was supposed to reduce arcing.

[redboat219]

I'm experimenting with a modular system, was at the local hobby shop and seen the Du-Bro fuel tank and it solved some of my challenges. I am thinking about running the pump on the wet side even though it is brushed. Still undecided but getting there. In the early days of RC cars the break-in method for brushed motors was to run them in (clean) water to seat the brushes and clean them out, was supposed to reduce arcing.

Nate He used one of these brushed motor powered gear pump running in the wet with his 1/96 SWM Blueback.

https://youtu.be/WDhsBM5Itj0?si=hqfZRfPJ987grZvn

[Subculture]

I trialled a couple of those pumps, and I’d advise caution. The design is decent enough but on the ones I got they made the gears from the same plastic as the pump housing, and being very soft the driven gear easily loses its grip on the motor shaft after some use.

There were some metal gears available for a while, but not seen them around for a long time, you could probably adapt some brass gears to fit if you have a lathe.

Perhaps the spec has been altered since I tried them, sadly high quality gear pumps suitable for water are hard to find, most are designed for quick intermittent use or they’re made to pump oils or fuel and will likely corrode in water unless modified.

[JHapprich]

I ordered several of those in 2014 and did not use them because of the weak gears. One pump failed in the boat, one came with broken gear

jörg

[Subculture]

The small orange pumps currently used in the R&R modules were a popular choice years ago. The original units were made in France and used brass gears, at some point production moved to China and the gears were then made from plastic, and the pumps are considerably less robust. Don’t know how well they hold up in Ron’s modules long term, but that system is aspirated which reduces strain on the pump gears.

Kavan pumps are quite popular and have brass gears, but they’re larger than the small orange pumps. If you don’t mind the extra work and expense, I expect a smaller motor could be fitted to the pump head, but not seen anyone do that to date.

The other pumps I’ve seen are units from China intended for either model aeroplane smoke creators and model digger/JCB hydraulics. These look well made from metal, but they’re designed to pump oils rather than water. They tend have an aluminium case, and gears are also listed as metal, so either brass or steel, either way not a good combination of metals when used in water.

[JHapprich]

Yes, i still have one original orange and severeal made in prc.
both work, though the french is 20years older

[TuptubBuilder]

A while back I built a crude rotary vane pump. It seemed to work quite well. A nice feature is that the vanes are the major wear item and are easily and cheaply replaced. I made them from .06" polystyrene sheet. Is there some way to establish specifications as to pump head pressure and flow rates that would satisfy most builds?
vanePump.mp4

[Ed Kirk]

I'm working with this pump, fairly large and heavy, well constructed. Tested on bench pumping water between two large water bottles - nothing scientific but flow rate OK, I didn't get bored waiting for bottle to fill. I'm beginning to think I could use a smaller ballast tank, my system takes up a lot of space and I still have to locate the battery.

I have a Neptune and satisfied with the pump and bladder system, this pump seems to be on par with the time it takes to move water.