Water pickup drag testing

[kfxguy]

kfxguy: https://www.google.com/search?q=Micr...Micro+Air+Pump

http://www.bgmicro.com/search.aspx?find=pump

http://www.skycraftsurplus.com/3a120insnf20vc2airpump.aspx

http://www.ebay.com/itm/Mini-Air-Pum...sAAOSwBahVVzg2

Thats what was mentioned in his rcgroup thread.

I bought the one from the eBay link. If it allows flow through with it off that will be perfect.

I think I can turn off the limiter but I'd rather keep it on so I don't smoke it. I may put a sf300 in it to put more power down.

[dmitry100]

kfxguy: https://www.google.com/search?q=Micr...Micro+Air+Pump

http://www.bgmicro.com/search.aspx?find=pump

http://www.skycraftsurplus.com/3a120insnf20vc2airpump.aspx

http://www.ebay.com/itm/Mini-Air-Pum...sAAOSwBahVVzg2

Thats what was mentioned in his rcgroup thread.

[dmitry100]

Any way of actually removing that limiting feature? Do they have that option in their firmware at all? There is an option to increase the temp cut off though right... maybe that could be cutting it off as well?

[kfxguy]

[ATTACH=CONFIG]143724[/ATTACH]

Pump Specifications:
Free Flow Range: 850 - 2660 cc/min
Vacuum Range: 0 - 12.6 "Hg
Pressure Range: 0 - 7.7 psig
Standard Motor Voltage Options: 4.5, 6, 9, or 12 VDC
Motor Construction Options:
Ironless Core - Sleeve Bearing (single bearing also available)
Iron Core - Sleeve Bearing
Brushless - Ball Bearing
Diaphragm Material Options: Neoprene (EPDM & Viton also available)
Operating Temperature Range: 32??-122??F (0??-50??C)
Weight: 1.2 oz (35 grams)
Size: 1.4 cubic inches
There are receivers, and servos that can handle up to 9 volts, so a small 2s receiver pack should be able to move about 30+oz. a minute. (enough?)
One time I brought a boat back in, and it was so scary hot, I gave it mouth to mouth blowing threw the inlet tube from a bottle of ice cold water, LOL.

Where do I find one of these pumps?


Sorry guys that this test was delayed. I was supposed to rain all day so I took the zelos apart yesterday to paint it. Well it rained just a little bit and I was actually able to get to the lake and run my Rivercat for two different sessions but getting them on video. My temps were actually low except when I tried to run a prop with more pitch....the motor and esc didn't like it. The esc what actually cutting out. Swapped my original prop back on and no cutting out. I guess that castle mamba xl2 has a current limiting feature that actually works. I think it's set at 260a. So for getting off subject here. I'm probably still going to either put a pump in it or do a knife blade with the inlet and outlet in the bottom of the hull.

[runzwithsizorz]

pump.jpg

Pump Specifications:
Free Flow Range: 850 - 2660 cc/min
Vacuum Range: 0 - 12.6 "Hg
Pressure Range: 0 - 7.7 psig
Standard Motor Voltage Options: 4.5, 6, 9, or 12 VDC
Motor Construction Options:
Ironless Core - Sleeve Bearing (single bearing also available)
Iron Core - Sleeve Bearing
Brushless - Ball Bearing
Diaphragm Material Options: Neoprene (EPDM & Viton also available)
Operating Temperature Range: 32??-122??F (0??-50??C)
Weight: 1.2 oz (35 grams)
Size: 1.4 cubic inches
There are receivers, and servos that can handle up to 9 volts, so a small 2s receiver pack should be able to move about 30+oz. a minute. (enough?)
One time I brought a boat back in, and it was so scary hot, I gave it mouth to mouth blowing threw the inlet tube from a bottle of ice cold water, LOL.

[runzwithsizorz]

A very old thread I had bookmarked about the subject of pumps. http://www.rcgroups.com/forums/showt...=590807&page=4

[Nikolas Andriop]

I think that isn't worth it....
It has toooo little flow rate

[kfxguy]

Check this out. If money wasn't a factor......


http://www.ebay.com/itm/231587767607?redirect=mobile

[Nikolas Andriop]

Anyway you provided me a link to this pump?

Here you are.....http://www.ebay.com/itm/Mini-6V-12V-...YAAOSwxCxT8cTB

Here is mine...IMG_6109.JPG

[dmitry100]

Ts Davis, perhaps look around ebay to see if they have a diaphragm pump in a smaller size... I think I might of came across a few.

[kfxguy]

Actually the spec boats are the most susceptible to heat creep at the end of a 1 mile heat than my big boats. I suppose heat is the enemy in all our boats though. The motor quality is such that I worry less about it in open boats.

Ball had mentioned in some other thread a few weeks ago that his temps climbed substantially on the way back to the bench from the pond. My thinking is that I can allow the boat to cool right there in the pond like Marty Mcfly in Back to the Future.

An extra 100 grams is a bunch. Might have to go back to a geared pump with the check. Cheap pumps and relatively small.

That little pump I posted only weighs 55g. I think I'm gonna try one of those in the Rivercat.

[T.S.Davis]

Actually the spec boats are the most susceptible to heat creep at the end of a 1 mile heat than my big boats. I suppose heat is the enemy in all our boats though. The motor quality is such that I worry less about it in open boats.

Ball had mentioned in some other thread a few weeks ago that his temps climbed substantially on the way back to the bench from the pond. My thinking is that I can allow the boat to cool right there in the pond like Marty Mcfly in Back to the Future.

An extra 100 grams is a bunch. Might have to go back to a geared pump with the check. Cheap pumps and relatively small.

[dmitry100]

TS Davis, how big of a boat are you planning to use that diaphragm pump on? It weighs about 100 grams.
If you want dimensions ... let me know.

[kfxguy]

I actually have been thinking about this for a while but not for the friction issue. Just as a means to cool everything right after the run when I'm not really moving.

I don't think that these pumps are turning enough rpm to burn themselves up in the time it takes us to get from the bench to the pond. Experimenting at these costs wouldn't be bad. plug er and wait fer the burn out I suppose. I know our fire pumps will run for quite sometimes without a fresh supply over water. It;s pretty horrible when they fail but it isn't immediate. I'm not suggesting these are any where near the quality of a $75k pump but the theory is similar.

If the pump is self priming I don't think it matters how the water pickup is pointed. The only thing would be, can it suck water if your at speed? It may skip past the opening due to velocity.

I was thinking about using a pump and a bypass. You put a mini check valve (think aquarium check) in the bypass loop. This way high pressure water from the pickup takes the shortest route (through the system and not the pump in theory) and the pump doesn't just push water out the pickup when your at rest. This way you can get full flow from a pickup and still the benefit of a pump.

Sorta like this.....

[ATTACH=CONFIG]143650[/ATTACH]

I think this pump idea is great. For saw use. More of a novelty I've always thought for anything else but seeing how a two pass saw run is made where you made a pass and then left the boat sit and let the wake subside......while its sitting the temp creeps up unless you have water flow. So I thing it's going to be awesome to have on a very hot setup.

I've notice in my data logs that after I make my pass the temp creeps up. Sometimes higher than I like and if that's the case and I make pass again I could toast something. So I think it's worth doing.

[T.S.Davis]

I was worried that if a geared pump were allowed to free spin with the incoming water that it may actually generate electricity. If we're running it off the RX..............maybe it's not an issue. I just don't have a feel for how much water is actually coming through our systems normally. It may be no more than the pump is capable of to begin with.

The diaphragm negates the problem entirely.