Transmitter range...

[Guest]

Hi Guys,

Being rather new to this RC lark i was wondering:

Using my futaba tx and rx on the ripmax boat i can get about 100 feet range! When using the same setup (same tx, indentical rx but different unit) on the new boat (outboarded speed boat with on/off style micro-switch) im lucky to get 20 feet? Same set of cystals.

Could it be that the ariel just inst high enough or that the the other rx is just buggered? Im going to swap them over tonight..

Strange thing is, when it goes out of range, i still have full rudder movement on channel 2 but just no movement at all on channel 1 (power). Im using a seperate set of 4Xaa's for the rx. All bats are brand new energizers (sp).

Im planning to put the Tamiya ESC in there hopefully as i think reverse is kinda useful for a learner....

Any input is good...thanks in advance!

Toby

[Guest]

sound slike apossible receiver fault, but make sure your aerial is as high as possible from the model to help increase range,

there is a chance you are picking up electrical interferance from your motor.

be wary of fitting one of the tamiya ESC`s into your boat, purely because the Tamiya ones are designed for cars, with the delay on reversing , for braking/protecting the gearbox of the model.

This however causes the ESC reverse to be a bit more "harsh" when reverse selected, and less control in revers than a marine ESC.

i can thorughly recomend the range of Mtroniks ESC`s for marine. 100% waterproof!

http://www.mtroniks.net/

and a 15 A is only £20 , with a soft start reverse, which i beleive can be completely switched of for fast electrics.

Adz..

[Guest]

I sail from a quay so the ariel is always much higher than the boat always.

Interferance from motor could be an issue but wouldnt that still happen despite the range.

As for the tam ESC, well im cheap and have lots so they are free. The one im using is programable so you can control how much power goes through on reverse and is waterproved a-la-plastic-bag. I know what you mean about the delay on reverse, that is kinda annoying, however its gotta be better than having no reverse at all! stops me getting stuck in the bushes!

[Guest]

Quite fancy a boat or sub trouble is nowhere to go unless im billy no mates

[Guest]

be carefull of the waterproof "bag" around the ESC as it has heat sinks which require cool air

i meant the aerial on the boat, as high as possible not the TX aerial in relation to the model.

the only way to really find out is to swap receivers and give it a try for your range problem

[Guest]

Make sure the aeriel cable in the boat is completely laid out, away from any other wiring, and prefferably as high in the model as possible.

I have heard that the wire receives better when it is laid horizontally and around the inside of the hull usually works well for mine.

[Guest]

I beleive the receiving aerial , being as parallel to the transmitter aerial is the ideal setting, since radio waves can only travel in straight lines.

which is why the aerial idealy should be made as close as parallel to the transmitter aerial as possible.

with preferably the tip of the receiver lead being at the uppermost section of this assembly.

This can be affected with propogation, humidity and surrounding "noise" to the transmission. and depends on which type of transmission os being made, i.e FM , AM etc .

rasing the aerial parallel with the transmitter takes it away from as many possible interior transmissions as possible causing as little blackspots in the transmission range.

This is the reason you will see aerials at airports, radio aerials , tv aerials etc vertical,

so they are in a parallel plain to the transmitter.

[Guest]

Just goes to show you can't believe everything you hear!!

Thanks for the clarification Adz

[Guest]

Remember a boat will demand far more from a ESC than car even if they are running the same motor and batteries. The Tamiya ESC may not be up to it.

Yes, pointing your aerial on the transmitter towards the boat will reduce the range, you should always be side on. Unless you are using a helical aerial on the transmitter, in which case pointing the aerial at the boat gives greater range.

[Guest]

wow thanks for the replies guys!

Ive just installed the new reciever and routed the airel round the inside of the boat! Would soldering a longer length on help at all?

The tamiya ESC has worked fine for me so far on the ripmax boat? The heat issue is something that never really occured to me, but im sure there must be a safe way to waterproof it! Im an avid believer in DIY!

Mankster, could you possibly detail why the boat demands more than the car? Im so new to this RC lark and trying to absorb as much info as possible!

After lost has finnished im going to put one of these inside it to replace the boring 540 stock thing:



and this is the boat im working on:



off topic- how much would i be looking for to add a clutch to the nitro boat? (kyosho jet stream with OS .15 engine)

[Guest]

wow thanks for the replies guys! Mankster, could you possibly detail why the boat demands more than the car? Im so new to this RC lark and trying to absorb as much info as possible!

Direct drive and the pitch on the prop will mean it will probably draw far more amps. The standard 540 motor in most RC car kits will pull around 8 amps at 7.2v probably less if its in a highly geared truck. Even a highly modified motor in a car will be about 25-30 Amps and they need a serious ESC not the stock Tamiya job.

[Guest]

Squiffy,

All the info I have tells NOT to alter the ariel length as th qhole system is intended to be 'tuned'.

I do scale boats so don't bother with fast electrics but i understand the 'serious' FE types don't use ESC's, they use a switch (all or nothing) , at least that is what I was told by one practiotioner.

If you're going to use a non-stock motor I should consider getting an ESC that can be heatsinked in some way, either a plate mounted in the boat bottom or a wire connection to the prop shaft to let the exposed shaft act as the sink.

J.

[Guest]

off topic- how much would i be looking for to add a clutch to the nitro boat? (kyosho jet stream with OS .15 engine)

can i ask why you would want to fit a clutch ?

you tend to find on nitro boats ( not all , granted) that the water pickup fto cool the engine is delivered from prop wash, or via the boat`s movement over the water.

Hence , if you install a clutch when the boat is sitting static in teh water with the engine running, no coolant is being deliverd to the engine.

outcome ? a very hot and rapidly life shortened engine !

there are traxxas boats that have clutch`s i beleive, but i think they have a electrical system for water cooling, and a electrical motor that is connected into the drive train, in case the Ic engine cuts out. Back To Shore i beleive its called.

[Guest]

Thanks for the quick replies guys :-)

Transmitter range: The boats going to be tested in a couple of hours on the water. Ive range tested in the garden and im getting about about 25feet with the loop and about 50feet when its in the oringal tubing... a little odd i have to say? Could i be getting inference from somewhere? Im on 25mhz would changing to 45mhz help maybe as its not such a common range?

Adzam- clutch because i dont like the idea of continual motion. Never thought about the whole heat issue sounds bad, thanks for the warning! Ive heard of people adding water pumps and stuff but that sounds pretty expensive!

If the engine has a low idle would that make any difference or am i flogging a dead horse?

Electric boat-

The tam ESC is rated to 20A, the bats 9.6v and theres a 22T motor on there. I have however been looking at the mitronics (sp) stuff that you mentioned, it seems they can be had on ebay quite cheaply so i shall get on off there in a few days :-)

Nigel - Your welcome to the old ripmax hull if you want? I used it to learn on and it was a bootfair job to start with, its battered but a nice little boat and im sure with your skills you could make it look nice! I can prolly find an old 540 motor and servo somewhere too for you!

[Guest]

squiff

firstly the radio is on 27mhz, the alternative is 40mhz both are commonly used in land based models ( well models other than RC aircraft ) as for your issue with the radio range the airiel on the boat should ideally be uncoiled, i like my antennas to be uncoiled, i never cross my airiel over, i never wind it up or loop it, i try and always keep my antennas away from any other leads especially those carrying voltage/current, what is the problem with an upright antenna on a sports boat ?- also never cut your antenna lead down in any way, the length is critical...if you want the antenna insode the boat attatch it so that it goes round a hatch opening or similar so its accessible but straight and not crossed over......

as for the nitro boat and water cooling then i would stick with the motor and go clutchless, the gas boats like the jetstream at idle are only moving forward on the water at about walking pace, this is enough to continue flow through the water cooling ring.....but as adzam says open the throttle and cooling is well improved ! -

clutches are fine but with potential of pickup from the bilge of oil and water and there is a potential for clutches to slip if they get wet....i would say more trouble than its worth on a boat....

and a point re the electric boat....... the ESc is rated at 20 amps, but do you have any idea on the motor current draw with your selected prop on load, just make sure its up to the job....-

but after all have fun, a bad day boatings is better than a good day at work !