Fun with Bilge Pumps

Discussion in 'Electrical & Radio' started by Litch42f, Apr 3, 2019.

  1. ZARUBA1987

    ZARUBA1987 Well-Known Member

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    Good to know. I looked At my pump last night. It has the same issue
     
    Last edited: Jan 28, 2020
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  2. ZARUBA1987

    ZARUBA1987 Well-Known Member

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    Just wanted to follow up I moved my pump discharge. It is now located at the top of the pump casing. I did a few test and the pump was a BEAST. No priming issues at all! To bad that the new BC pump can not be modified like the old school one. I’m on the look out for old school BC pumps if there are any available for purchase
     
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  3. NickMyers

    NickMyers Admin RCWC Staff

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    upload_2019-4-30_11-9-46.png

    When you have a 3d printer, lots of things are suddenly options... like building an entirely new body&volute around the BC impeller...

    I really need to revisit this project. Right now it needs a bit too much hand-work after printing for my likes, and I want to move the priming hole (I basically kept the BC location, but i'm not a big fan of it there)
     
    Last edited: Feb 10, 2020
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  4. Kotori87

    Kotori87 Well-Known Member

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    The picture isn't working for me...
     
  5. bsgkid117

    bsgkid117 Vendor

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    Did you get .step files for the BC pump, or did you just design based off the small engineering drawing on the BC site? I like your vertical output, wish BC would offer that as an option.
     
  6. NickMyers

    NickMyers Admin RCWC Staff

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    neither.
    bought a pump. didn't like the body and wanted to mount up a brushless motor. Was originally going to just remodel the top-plate for the brushless mount but since I didn't like the rest of the body I just took a few measurements off things and set about making something around the impeller. I've never really liked printing impellers.
     
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  7. bsgkid117

    bsgkid117 Vendor

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    D'oh. That makes too much sense haha. Who would've thought, taking physical measurements! :bang::bang::bang::laugh::laugh::laugh:
     
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  8. Vintabilly-J.Turner

    Vintabilly-J.Turner New Member

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    With all due respect to the bc style pumps. They will be prone to priming issues until a volute is added to the water path. What you're missing is time and space for the energy to be converted from kinetic to pressure. My experience is with hydraulics and turbos but fluid dynamics are more or less the same. :p

    A spiral. The tighter you make it the worse the effect will become.

    PS EDIT- looks like the volute is being incorporated in the latest 3d-print designs. Well done fellows.
     
    Last edited: Apr 16, 2020
  9. GregMcFadden

    GregMcFadden Facilitator RCWC Staff

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    Indeed there is a lot that can go right or wrong in the volute.... A lot of efficiency loss can occur there. you can also split the volute if you wish to reduce the radial side load from pressure on the impeller and it's bearings. I have had good success with split volutes.
     
  10. Vintabilly-J.Turner

    Vintabilly-J.Turner New Member

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    Yes. In each instance except for the newest 3d-print above the impellers have been mounted central in the pump housing. This "stalls" the blades and causes more flow turbulence the tighter is becomes. The flow needs time and a direction to accelerate.

    Lots can go wrong but less if the fundamentals are adhered to. A volute is defined as an ever increasing spiral. It's the part that makes it a pump.

    This video is pretty good for design inspiration.
     
    Last edited: Apr 16, 2020
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  11. Litch42f

    Litch42f Well-Known Member

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    Wow, over a year since the last post in this thread, where does the time go? I wanted to try and keep bilge pump content in one thread so I’m semi-reviving this one. So I’ve been messing around with brushless pump motors recently and have been using the hobbyking prop drive series out runner motors. They seem to work reasonably well. That being said I’ve had two of them fail after only a few battles. In one case the motor would rotate slowly and erratically and heat up the ESC and associated wires significantly. The other time the motor seemed to just stop responding completely and fried my ESC. Both instances involved a sink so I’m wondering what everyone does as far as post battle maintenance on their brushless motors?
     
  12. Kevin P.

    Kevin P. Well-Known Member

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    I only have about 1 full season of pond time with them (4x weekend events and 1x nationals), here's what I do each evening after a day of battle. So far no failures, I had one bearing going bad but preemptively replaced prior to mid-battle failure
    1. Remove pump from boat
    2. Dunk the pump in alcohol, rotate the motor (ideally submerge motor). I do this so the alcohol will cause water to evaporate away
    3. Lubricate upper and lower motor bearings (I use Fluid Film) - rotate the motor to distribute
      1. For lower bearing, I drill hole through motor plate so I can shoot the fluid film into the cavity between the lower motor bearing and impeller
    4. place pump in front of fan to help dry out
    For your situation I would try to further diagnose the failure mechanism (i.e. is it bearings, magnet delaminate, poor ESC or waterproofing, etc). I also don't run my pump when submerged although I don't have data if that leads to failures or not

    Here's my video of pumps which I think discusses some of the above

    View: https://www.youtube.com/watch?v=570BiWwm-EY
     
    Last edited: Apr 26, 2021
  13. Kotori87

    Kotori87 Well-Known Member

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    I don't have a brushless pump, but I do use brushless drive. slow and erratic motion sounds like a single-phase failure, although whether that's a failure of the ESC or motor I cannot say. The other one sounds like possibly debris or seized bearings? I have learned to be very protective of my brushless motors, I carefully run each motor for several minutes and oil every bearing as soon as the battle day is over. Maintenance takes around 45 minutes to an hour at the hotel, but a fair amount of that is spent pulling apart my tetris-stack predreadnought (it's a very tight fit, only goes together one way) and disassembling the pump so I can access the lower bearing. I like Kevin's idea to drill an access hole for the lower bearing, that sounds like a great way to save time on disassembly.
     
  14. GregMcFadden

    GregMcFadden Facilitator RCWC Staff

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    I spray down mine with a dry film lube before they ever get wet and then hose them off periodically with oil or dry film lube. that seems to do a pretty good job of getting the water out. After battle is over I blow them out with compressed air and put a fan on them to dry. All bearings are accessible from the outside with oil in pumps I use.