Model Boat Mayhem
Technical, Techniques, Hints, and Tips => Radio Equipment => Topic started by: CaptTex on June 29, 2015, 07:32:00 pm
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Hey guys I have a 2.4ghz tx which is 4 channel off a helo i have and im wondering if I can use it for my build I'm getting ready to do, possibly a Dumas Carol Moran or Foss Tug.
Cheers, Tex
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It will be perfectly legal. Most of us are on 2.4 nowadays :-))
cheers
ken
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I'm sorry for my ignorance but what all do I need for radio control? I have a loose idea but im also thinking of just pillaging the Helo for everything maybe......servos, motor and receiver?
Cheers, Tex
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As long as 2.4GHz is legal for boats in Texas and
the Rx is a separate unit with pin connections for
each channel and not hard wired into the helo.
Ned
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Ok I'll definitely need to take a look when I get home, to see whether or not its hard wired.
Cheers, Tex
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Tex
Posible problem with the ESC and the servos from your Helo, they might not be strong enough for boat use, post some pics so we can have a look what you have
Mark
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Ok I cant figure out how to post pics of a smaller size, but the gear is off of a MJX F45 4 channel helicopter, and it also appears they are not hardwired in everything has a plug.
Cheers, Tex
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Ok I cant figure out how to post pics of a smaller size, but the gear is off of a MJX F45 4 channel helicopter, and it also appears they are not hardwired in everything has a plug.
Cheers, Tex
Smaller pictures - most PCs and similar devices have a utility for resizing images. On a Windows PC, a free image handling program called "irfanview" does the job. Just open the image, click "image", "resize", choose your preferred size, then "save as" with a new name and attach the renamed file to your post. Or just right click the image file, "resize" is one of the options.
If everything plugs in, that implies that devices with standard requirements are used, so it can be transplanted and will work. The only considerations then are whether your servos are strong enough for use in your proposed boat, and whether the transmitter has the range - if it is a "park flyer" type, you might be restricted to quite small sailing waters.
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I've flown out probably 150-200ft? maybe more. So I don't think the range will be an issue, the motor is around a 4.8v or so which is what is specified for this model by dumas. the servos are relatively large not super small probably about an inch long each.
Cheers, Tex
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So how do I get around the thing that the throttle goes from 0-100 since its off a helo, I need reverse and forward 0-100? is there a modification that I can do?
Tex
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YouŽll need another ESC.
"Air ESC" donŽt have reverse, so you might look for a "car" or "boat" ESC.
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And this esc will plug into what exactly? Pardon my ignorance....This is a picture of the "brain" from the helo. I bought a new servo which is stout enough to handle the load.
Tex
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Looks like the ESC is "onboard" the big TO220 Mosfet.
If you are lucky the board has an output for the throttle channel.
Should be one of those 3pin connectors.
You can find it out with your servo. Plug it in on the 3 connectors and check if its moving if you move the throttle channel.
Unfortunately I believe there are only servo outputs wired on the connectors, but maybe one of those white connectors?
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The bigger white plug on the right is the one the motor plugged into!
Tex
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The large white connectors look to be 2 pin so yes 1 to motor and possibly other to battery.
Bob
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So I plug an ESC into this port and then the motor into the ESC?
Tex
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The Black and red wires look like main power in, were these connected to the battery?
Bob
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Tex
If I were in your position I'd consider buying a new 2G4 set. They aren't exactly expensive these days and you'd save yourself a world of potential trouble. Marine speed controllers for small brushed motors are available from many UK sites; here's a couple that would do the job very easily http://www.componentshop.co.uk/p81-condor-5-autoset-computer-speed-controller.html (http://www.componentshop.co.uk/p81-condor-5-autoset-computer-speed-controller.html) and http://www.mtroniks.net/prod/Boat-Speed-Controls/Viper-micro-Marine-10.htm (http://www.mtroniks.net/prod/Boat-Speed-Controls/Viper-micro-Marine-10.htm)
Dave M
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It looks like the board pictured is not just the receiver, but the power control for the main lift motor and the steering prop as well, built in.
It does need a different RX so that these functions are available for something different to be used. It might be tricky finding one that will bind with your TX, but the simple, certain answer is one of the current crop of low cost TX/RX combo deals that are on the market, or a TX and the recommended RX to work with it.
That way, you get to plug your ESC or servo or whatever into whichever channel corresponds to the stick you want to control that function.
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So I've opted to go ahead and buy a flysky 6 channel tx and rx, coupled with a ESC off Amazon. http://www.amazon.com/gp/product/B00LXCM3Q8/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER the only question now is what kind of battery to use? I have a 6v that could double as ballast, but I don't know if 12v would be much better.
Tex
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Product Dimensions: 5.3 x 3.6 x 2.2 inches
I hope these measurements are wrong (or give the size of the packaging and not the ESC). That is collosal!
The battery voltage should be chosen to suit the motor. This isn't a big model so you might be better advised to consider NiMH or even LiPo batteries as opposed to lead-acid. It also depends on how much ballast you might need to add, although you won't know for sure until you test the finished model in the bathtub. Are there any suggestions in the instructions? What type of motor and size of prop are you going to use?
Smart move ref the new radio, BTW.
DM
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The actual esc is about 1.5 inches at the longest and doesn't spread or rise very high, the motor is around a 5.4v and the battery is a 7.4v, the prop is a 2 blade plastic job maybe 15-20mm? The prop and motor recommendation came from Dumas.
Tex
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7.4v sounds like a LiPo pack (2S). I don't know about a 5.4v motor - do you mean a 540 maybe?
The sensible thing would be to stick to their recommendations unless anyone else knows better. Having said that, I found a 2-blade 25mm plastic prop with my Lord Nelson tug which was totally unsuitable, I'm afraid - I fitted a 3-blade 50mm Robbe one instead! Just another of Dumas' long list of bloopers with that particular kit. I hope yours goes together better than mine has.
DM
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In the OP, two possible kits were mentioned, a Carol Moran, which is small and needs no more than a 280 to work very well and would probably be overcrowded with any lead acid battery, and a Foss, which isn't small, and would be good with a 545. Reasonable performance on 6 volts, over the top performance on 12. 35mm 3 or four blade prop, if any bigger, a gear reduction would be in order.
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I have gone with the Carol Moran malcolm! so youd recommend a 35mm 3 or 4 blade? I'm assuming more blades produces more thrust.
Tex
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If its the 1:72 Carol Moran, remember that it is only 18" long. Prop size will depend on the space available under the stern, probably max out at 30mm, and, for torque, 3 or 4 blades. The larger size I mentioned was for the larger (30" long) boat.
Similarly, there is a size limit on the motor to actually fit into the hull and allow room for the prop shaft and coupler and leave room for the battery. Typically, the motor diameter should be more than the prop diameter, but gearing can make this up by allowing a small, high revving motor to swing a relatively large prop. It can also make for a more compact installation, especially if the motor is mounted to the prop shaft. A RE280/1 should do the job.
Having decided on your boat, it would be a good idea to google it for any build logs - it always pays to look at one that is known to work.
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Ok so I bought all new radio equipment
Hitec servo
Fly sky 6 channel radio and receiver
Hobbyzone 1060 esc
3000 mh NIMH battery
And a 540 electric motor(I think)
Hooked everything up and was doing a tub test everything went fine and then no response from the engine.......I noticed that when i centered the stick there wouldn't be an immediate response from the engine in all ahead or astern you'd have to wait a minute. Now I'm not getting any response, thoughts?
Tex
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Actually I think the battery might be dead, the blinking light on the esc eventually stopped so I'm assuming the esc and receiver didn't fail simultaneously. Though someone could still confirm so I can keep my sanity........ %%
Tex
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Use your trusty meter to check the battery.
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The new battery will only have had a minimum amount of charge. You should charge it up at 300mA for about twenty hours initially, and thereafter at the same rate for 10-14 hours. NiMH cells don't like being fast-charged for the first few cycles.
DM
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I'll give it a shot!
Tex