Hms holland 1 build

[redboat219]

Maybe Bob has these in stock.

[redboat219]

https://www.amazon.com/Water-Self-priming-Aquarium-Pumping-RS-360SH/dp/B077VX9DNP

[RCSubGuy]

And, I bet he could get away with not using a pinch valve. Any leakage through the pump would be negligible. This is a low pressure pump system, not high pressure like an OTW unit might be. Pump and you're done!

Whadda ya say, Rob!? Can discuss at DIveTribe today!

Bob

[He Who Shall Not Be Named]

Don't give up on the ballast! Just find a little gear pump and your problem will be solved! I have a few here that I've collected over the years. I'm sure I could find you one to use.

Bob

Take him up on that offer, Rob! A gear-pump, a solenoid driven pinch-valve and you're done. You've already built the ballast sub-system infrastructure... USE IT!

Hell, Bob... don't wait on Rob's reply, send him a gear-pump, pronto, before our man has a chance to think about it!

David

[RCSubGuy]

Don't give up on the ballast! Just find a little gear pump and your problem will be solved! I have a few here that I've collected over the years. I'm sure I could find you one to use.

Bob

[redboat219]

Unattainable with current pump. As I stated before diaphragm pumps are unidirectional. You can pump water in but not out ( reverse also holds true, water out but not in).

You could however use two of those pumps. One dedicated to pump water in the other one to pump water out.

As you'll only be using one pump at a time current draw would be similar to using a single pump. Problem is finding space inside the WTC for the second pump.

[redboat219]

I have a question about the low pressure ballast system?



This photo shows a flood valve! is that similar to a check valve?



With that in mind, would the pump that I am using (above photo) require a flood valve/check valve?

Rob
"Firemen can stand the heat"

That particular pump is a diaphragm type pump designed to pump fluid ( air or water) in one direction only, it has a set of rubber flap check valves inside. For pumps that work in either directions (reversible) you need a gear or peristaltic pump.

[trout]

Rob, it can be a pinch valve or something like that. When that is opened it will flood your ballast. Then you close the valve and use the pump to pull the water out (and air in).
I do not think a check valve would work.

[SubDude]

Thanks Steve!

It may not work very well, or at all! I like trying new ideas that are not always by the book and you never know what you might come up with! I think you are the same way!! Your builds are certainly pushing the limits! and that is a good thing! Keep it up! :-))

As for the colors, orange and green is all I have left of the Dremel PLA so I thought I would just use it up! Dremel white PLA is now going for $68.00 a roll on Amazon, if they have it!

Rob
"Firemen can stand the heat"

That's expensive stuff. I just got 5 spools of ABS for less than $100.

[Sam Victory]

Cool components with colorful 3D printed items! Did you design and print all of these colorful parts yourself with 3D modeling? Respect! Reminds me of the famous saying: It's never too late to learn.

V

[SubDude]

Good ingenuity Rob! And very colorful :o)

[RCSubGuy]

Ignore the leads coming out the antenna side. They're for programming. Nothing to concern yourself with.

If you look at the markings on the top of the receiver, the pins literally pop through the markings showing their job. In this case, the "top" pins (according to how you are holding it) are negative, center is positive and bottom is signal (black, red and white respectively).

Also.. the manufacturer ships these with stubby antennas. To get full reception, you need a complete 1/4 wavelength antenna. A 75mhz wavelength is 3.997m. 1/4 of that is .999m, or 39.33inches. You can snip the stock antenna about an inch from the unit and then splice on a length of 22ga wire that is 38.33 inches long to get your full antenna.


Bob

[SubDude]

I have to admit that as I follow this thread and learn more about the Holland it has me wanting to build one.

[RCSubGuy]

I am also going to use linear servo set ups. (Special shout out to "SUB ED" for his great design! He designed the special mount that just fits on the standard size servos. Fits perfect on the Hitec servo!

Rob
"Firemen can stand the heat"

Those linear adapters look like the ones that I offer...

https://www.rc-submarine.com/product-page/linear-adapter-for-futaba-s3004-servos

Bob

[Subculture]

Looking at the design on the cults 3d website, it appears that the boat is not incorporating a scale prop, hence the spec of motor. I'm assuming they're using a smaller prop inside a hollowed section at the stern which acts like a duct

If a scale prop was used it would be around 3" diameter, so you would want low rpm, somewhere between 1000-2000RPM.