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Something a bit different! Model Power Boating. RC Catamaran build thread.

Discussion in 'General Discussion' started by Phate, Nov 7, 2019.

  1. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    There you go :) - glad you liked the video!
     
  2. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    Typically, yes. Although we have ordered a water pump now and plan to pump water through the engine manually, that way we can set the boat up stationary in the water by holding it. This should speed up the setup process massively. Also you can't do this for long without a waterpump due to risking engine overheating and then it going bang. :)

    Boat is recovered with the rescue boat. You see it in the video. Looks like a dark green bath tub with a battery powered outboard on it. We jump in it and go and get it!
     
  3. Feek

    Commissario

    Joined: Oct 16, 2002

    Posts: 228,612

    Location: In the radio shack

    I've got a few friends with boats and the first thing I thought when I saw the engine running with it out of the water was that it was unusual. I was quite surprised because I know how anal some of them are about running (or not running) the engine out of the water. Yes, get that pump fitted so you don't do the overheat thing.
     
  4. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    You're Essex based if I remember correctly or at least in and around Essex? Our lake we go to is at Brentwood if you ever fancy coming along to watch :)

    With regards the engine outside of the water. Each engine is different. In my smaller Sprint Cat I have a MAC engine and it needs the coldest spark plug you can get plus as well if its running out of the water for longer than 8 seconds or so it starts to smoke up. So no messing around with it. This CMB handles it better, although I think the higher caster content helps massively tbh :) - The water pump will help get us a long way thats for sure.
     
  5. Feek

    Commissario

    Joined: Oct 16, 2002

    Posts: 228,612

    Location: In the radio shack

    Thanks for the offer and I'd love to but although I worked in Brentwood for thirteen years, I live at the top end of the county and at the moment, I'm still not driving any long distances.
     
  6. Eurofighter

    Wise Guy

    Joined: Mar 20, 2014

    Posts: 1,645

    Wow. That thing is fast. What happens if it breaks down in the middle of the lake/pond.
     
  7. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    There is a rescue boat with an electric outboard. We go an get it.
     
  8. Feek

    Commissario

    Joined: Oct 16, 2002

    Posts: 228,612

    Location: In the radio shack

    It's March, what's next?
     
  9. Yadda

    Mobster

    Joined: Nov 19, 2009

    Posts: 3,943

    Location: Baa

    Is the rescue boat RC? That would be fun. :)
     
  10. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    Not at this lake, but that idea has come up. Dad and I are brainstorming something like a tug boat with arms sticking out the front to "collect" and push back.
     
  11. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    I am back on Saturday, going to the lake on Sunday.

    When I was there last time I shredded a propshaft as there was a bit of solder in the driveshaft brass tube. oops.

    Drilled that out and ordered a replacement :) - Fuel mixture we believe is well set now but it stopped revving up, so we think its an exhaust length issue. Will be playing with that on Sunday :) - Fuel mixture is the hardest bit to get right and we're there with that :)

    My small outboard model boat was also finished when I was last there so I'll have a go on that as well :)
     
  12. Yadda

    Mobster

    Joined: Nov 19, 2009

    Posts: 3,943

    Location: Baa

    Great stuff. I can see it has its challenges but that's all part of the fun. Just make sure that, until it's fully tested, you have a rescue boat on hand for the rescue boat. :cool:
     
  13. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    Yep :D - it would be ironic.

    Rescue boat would be electric, less reliability issues. Plug in and go.

    Apologies for potato pic, only one I have of the Predators (small hydros) right now - mine is the green, Dads is the blue

    [​IMG]

    Will get them in the water on Sunday. :)
     
  14. Feek

    Commissario

    Joined: Oct 16, 2002

    Posts: 228,612

    Location: In the radio shack

    I was supposed to be doing some aerial work on Sunday but the weather isn't looking great for it. I need to see how I am driving distances..... If you want to drop me a trust saying when and where you'll be, I could be tempted to pop along if the invite is still open?
     
  15. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    Sure :)
     
  16. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    Helloooo

    So after a long "forced" break from the UK (thank you COVID) I am back. So whats happened since last time?

    The last update on this was the boat would not rev up properly and was sort of stuck at around 12,500rpm - which considering its supposed to hit 22-25000rpm, its around half power which isn't good. During my time away, Dad sent the engine and exhaust off to a specialist (who actually supplied the boat and hardware in the first place) to dyno and test the engine & exhaust and confirmed both were fine without any issue, so the problem was to do with the setup within the boat itself.

    This Saturday just gone, a club regular and expert on this brand of engine was there and I spoke to him in advance and asked if he could take a look as it felt like I was banging my head against a brick wall, constantly trying but not getting anywhere...

    So on Saturday he took a look, we ran it, and he kept saying to us to "richen" the fuel mixture. Which means to increase the fuel flow into the engine. So, for those who don't know. With RC models with engines, the general rule of thumb was, if you can see the smoke coming from the exhaust, its running "rich" if you cannot see the smoke, its running lean. In terms of performance, you can increase engine output/performance by leaning out the mixture which means less fuel and more oxygen, but sacrifices reliability.

    We thought the engine was already rich enough due to being able to see the smoke. But we followed his advice, increasing by a it, sending it out, another test, no joy, bring it back, increasing the mixture, rinse and repeat...until after maybe the 3rd or so test...suddenly the engine began to light up as you would expect...

    EUREKA

    Cutting an already long story short...the fuel mixture was way way off, and these engines like to run very rich. So throughout the rest of Saturday and for a few hours today Dad and I were working in adjusting the fuel mixture, exhaust length, propeller height/position and now the boat is really flying! :D

    After a VERY long overdue promise...

    https://photos.app.goo.gl/KDH8VvAj7dCKz9rK9

    https://photos.app.goo.gl/LavXehJ2w9hzfdqQ7

    Couple of videos to show how its going.

    The boat still has more to give. Making more modifications between now and Friday/Saturday. Also I have ordered an exhaust length adapter, which will move the exhaust to make it longer/shorter on the fly. This will allow me to have more torque in the corners to maintain power and pickup speed lost and more RPM in the straights for higher top speed. We've also got a couple of different propellers to try to see what fits this boat & setup best.

    Also on Saturday I will hopefully have a GPS readout to confirm the speed, but we're guessing/hoping 50mph+ also I will put a GoPro on it to give a proper view :D

    Over the moon to say the least :)
     
  17. Yadda

    Mobster

    Joined: Nov 19, 2009

    Posts: 3,943

    Location: Baa

    That's more like it! You're gonna need a bigger lake. :)

    Had me worried at the end of the 2nd vid - I take it you got it stopped?
     
  18. Phate

    Caporegime

    Joined: Nov 1, 2003

    Posts: 35,409

    Location: Lisbon, Portugal

    Ah that's just my dad not sure how to stop the recording :) - no issue with the boat. :)
     
  19. Yadda

    Mobster

    Joined: Nov 19, 2009

    Posts: 3,943

    Location: Baa

    Haha, fair play. :)
     
  20. Feek

    Commissario

    Joined: Oct 16, 2002

    Posts: 228,612

    Location: In the radio shack

    Woohoo, that’s really good news.