[3DP] DC Pump

Discussion in 'Construction' started by Tugboat, Nov 17, 2013.

  1. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    What do you think one of these would cost without the motor, and does the $20 include shipping?

    Beaver
     
  2. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    It does not include $5 for priority mail flat rate box. I kind of thought that setting my price $12 cheaper than the other guys and using all stainless hardware (even the setscrew) was enough of a bargain.
     
  3. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Update on pumps:
    1) The motors that were ordered did NOT have the same speed characteristics as the previous ones, and thus output is far too low. Until I can get a better solution, I am going to have to sell the pumps sans motors. Some people wanted them that way anyhow, and it'll make the pumps $5 cheaper.

    2) Ran out of grey plastic, and white as well. This is problematic because the pretty green color that I do have does NOT form a nice slurry for chemical welding purposes. Mercifully, I had just enough white to print off 6 more impeller, which is the part that needs the metal insert welded into it.

    So, the end result is that no pumps (only 2 were ordered) got shipped this weekend but that there is an oncoming train providing light at the end of the tunnel. More importantly, I didn't ship you a pump with a motor that would probably have given 1/2 gal per minute, or with an impeller that wouldn't stay bonded to the metal insert. Sorry for the delay, but at least it's for a good reason. For the guys who ordered one, it's coming soon, the good impellers are curing right now, and you will be refunded $5 for the lack of motor.
     
  4. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    How are the pumps coming along?

    Beaver
     
  5. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    The pumps are good, I finally found a source for good 550 brushed motors that are 1) 6V not 12V, and 2) not $15 or more.
     
  6. SteveT44

    SteveT44 Well-Known Member

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    I'm building a new pump from from scratch and was wondering whats a good no-load rpm range to look for in a pump motor?

    Thanks
     
  7. SnipeHunter

    SnipeHunter Well-Known Member

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    For starters I'd aim for 20k RPM, 15k at the absolute low end. I also wouldn't go with a brushed motor, there isn't much reason to if you're designing from scratch.
     
  8. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Darth Kessler, do you want one without the motor? I'm not putting titans on them, but they fit; Brian K already put one on his. My 'stock' motors do about 9k rpm on 6V, but are rated to 12V doing around 19k rpm.

    As far as brushless goes on my pumps, the 550 ones fit, but care must be exercised to get one with a shaft long enough to get into the rotor (10-15mm is good), and I'd have to print an impeller that accepts the larger 4&5mm collars. I have some motor mount plates for the standard pump that accept the 19mm bolt pattern of the 380-size brushless motors if you want to go that route; a lot of those have a 1/8" shaft that doesn't require any new impellers be made.
     
  9. SteveT44

    SteveT44 Well-Known Member

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    20K it is. I should have said I'm designing a pump casing from scratch to go around a really nice impeller I've found. As far as brushed or brushless, that's just a matter of mounting holes on the top plate. I've got some RS775's laying around that will be good to start off with.
     
  10. SnipeHunter

    SnipeHunter Well-Known Member

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    I'd love to have the "stock" motor! Of course I was planning on testing it with a range of motors/voltages, would you expect any less of me?

    If brushless motors I have fit or can be fitted with a simple adapter plate then I might do that as well but if not it isnt a big deal.

    EDIT:
    Also Steve I should have been more clear, those RPM are for "typical" impellers. Stuff around the 1" diameter range. Significantly change the impeller size and the RPM reccomendation will change as well.
     
  11. SteveT44

    SteveT44 Well-Known Member

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    Good point. I'm thinking a gear reduction on the pump so I can play around with optimum rpm ranges and amp draws.
    So what's the current GPM record for a 1 unit pump?
     
  12. SnipeHunter

    SnipeHunter Well-Known Member

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    Probably higher than you would ever actually want to use in a boat if you're counting points. (Hard to tell the rumors and chest pounding from legit data, same goes for gun velocity.)

    Taking LOTS of damage isn't really a good thing, better to avoid taking damage in the first place if possible. When boats get shredded (and would "need" a super powerful pump) they tend to help out the other team a lot more than their own.

    Plus it isn't nearly as much fun without sinks.
     
  13. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    Kess, I'll send you the mount plate for the 28mm motor with the pump so that you can test the stock motor (and stingers and Titans), plus any of the brushless that fit a 19mm bolt pattern (almost all the 28mm size, plus some of the larger size). Limiting factor is that the impeller collar fits 1/8" shafts.

    @Steve - I agree with Kess. It's cool to have a boat that can take 5 times its' sink value in damage, and remain afloat... until you 1) tally the points it cost and 2) have to resheet every night at a battle. #2 bugs me far more than #1. I am definitely NOT in the 'turn off your pump to save the points' camp, but 3gpm is a LOT of BB holes.
     
  14. SteveT44

    SteveT44 Well-Known Member

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    It's my understanding that some events count sinks only and a god-pump would be a benifit here. Where holes are being counted, the pump could be dailed back to mortal status. Once declared sunk with decks awash, pump to full and get her back to shore! :cool:
     
  15. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    True, but there are 2 campaign battles (in which only sinks count). That's 2 days you'd be resheeting on at Nats, guaranteed :)
     
  16. SnipeHunter

    SnipeHunter Well-Known Member

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    Thanks Tug! When I get them and get a chance to test them I'll add that data in for you. I probably wont get much more testing done until next week anyway since I've got other stuff going on this weekend and chances to get to the basement will be limited.
     
  17. Beaver

    Beaver 2020 Rookie of the Year Admiral (Supporter)

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    How soon till you start filling out orders, Tug? :)

    Beaver
     
  18. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    The motors are ordered and as soon as they get here, it takes all of 3 minutes or so to put them on the mounting plate and assemble the pump. I was kind of hoping that they'd get here today...
     
  19. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    I got the shipping confirmation yesterday, pump motors are on their way to me, and so I hope to mail the lot of them (pumps with motors, gearboxes for those who ordered them, too) this weekend!
     
  20. Tugboat

    Tugboat Facilitator RCWC Staff Admiral (Supporter)

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    For those waiting on pumps.... the motors got here today!