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View Full Version : ESC/radios 101 please



ebfoxbat
04-03-2007, 02:48 PM
So I've got some books on the way. I've read the top hundred Google links. But I've got so many questions.

I have the project in mind, but I'm scared to piece together the parts myself. I'm leaning toward buying a RTR and takeing it apart.

What do I need to know about radio and esc compatibility. I know the esc needs to be rated for the number of cells and the max current the motor will pull. But what about the radio?

Will any 2 channel radio work with an esc? How about reverse and stuff? I can't find anything to address my worries. I'd like to buy some reasonably good equipment. So I've bean reading about FMs and stuff but I can't find a good "idiots guide" article.

I would appreciate advice. Thanks.

saleens7
04-03-2007, 05:07 PM
any 2 channel should work fine, normally the radio system does alloe the trigger to go reverse, but the esc would need to have a reversing feature for this to work...

avengersteve
04-03-2007, 05:24 PM
Also depends on your budget... how much are you looking to spend?

ebfoxbat
04-03-2007, 05:51 PM
$250 or so excluding batteries and the hull. Less is better than more. I need good acceleration and don't care about anything beyond 15-20 mph. I also don't really need range. I was thinking of going brushless because I read it's a bit better power for less battery drain but brushless might be out of my league for a first rig.

SJFE
04-03-2007, 06:09 PM
Ok go for the Hitech Agressor FM 2 channel radio and the Aquacraft Brushless system. That will fit your budget fine. You will be able to order them(if they are in stock) right here with in the next couple days. Keep the hull around 26 inches with that power system. If you want a bigger boat it will cost you another 100$ or so for the next best option in power.

ebfoxbat
04-03-2007, 06:22 PM
I'm going to make a very floaty, self-righting surfer. I had planned to make it longer so I could run in parallel and still be floaty. What's "the next best option in power" ?

SJFE
04-03-2007, 06:29 PM
It would be to much power for your app. Honestly I would go with an RC-Hydros 90amp esc and the 700sc for a motor.

ebfoxbat
04-03-2007, 06:51 PM
Would that be a 9.6v setup or more like 14.4v ?

saleens7
04-03-2007, 08:46 PM
you better get that rc-hydro esc soon...Andy has stopped producing them and he's only got 100 left...although i think its more like 25 or so as that was announced a few days ago.....

Fluid
04-03-2007, 08:58 PM
I strongly recommend that you DO NOT get a cheap AM radio! Sooner or later - probably sooner - you will have problems that will take away from your enjoyment of your boat....issues like glitching, loss of control, etc. If cost is an issue, get a used system off eBay or a swap shop in a car or boat forum. Any good three channel FM system will work, as will a 2.4Ghz radio. I raced a used eBay radio for six years, set a bunch of records with it.

For a first rig either 8 or 12 cells will be fine. I'd recommend not going brushless on your first boat - BL motors and ESCs do not like water and most original projects leak like sieves at lest at first.

.

ebfoxbat
04-04-2007, 05:18 AM
Well that's enough for me. FM it is. I'm leaning toward an 8-cell setup. That way I can run 2 or 3 packs in parallel.

I'm thinking that I'll have two flat packs of 8 cells that are run length-wise down the hull. That'll be at about 45 degree angles (make then perpendicular to each other). They'll be deep in the bottom of the Vee placed appropriately forward for good balance. I'd like to the place a deck ontop of them and the radiobox on top of that deck. The motor and prop shaft should be behind everything, as should the rudder servo.

I'm thinking this very forum might be a good place to chronolog my construction. By the way: it won't be leaking :) I think a brushless setup would be a good upgrade down the road.

I'm still trying to secure a source of foam to shape so the radio and motor are a few weeks away. Though the radio could be sooner rather than later.

ebfoxbat
04-04-2007, 07:50 AM
I didn't realize that RC-hydros ESC doesn't have reverse. That's a problem for me :( I'm going to try to find a 3-channel (though I only need 2) radio that comes with a receiver, esc and servo.

ebfoxbat
04-04-2007, 07:56 AM
How's the radio that comes with the supervee? I'm still thinking about cannibalizing that.

GregS
04-04-2007, 09:48 AM
The radio that comes with the supervee is a cheap AM system with very limited range that is hardly usable. The Profisherman comes with the same radio which is why I'm replacing it. The supervee has been known on many occasions to go full speed into the shore with that radio. With the Profisherman it stalls and glitches constantly and is extremely frustrating.

ebfoxbat
04-04-2007, 10:42 AM
The supervee has been known on many occasions to go full speed into the shore with that radio.

I can see how that may be a problem. I assume an FM swap out of the supervee is pretty straight forward. I may buy the motor and esc from from the supervee from OSE and pair it with that Hitec FM (also on OSE).

Thoughts on that? Does the supervee have reverse?

Rex R
04-04-2007, 12:25 PM
nope. reverse is a no-no for flex shafts(imo one might be able to use a low power reverse if one were very careful about how it was applied).

ebfoxbat
04-04-2007, 12:48 PM
reverse is a no-no for flex shafts

Oh ok... any idea why?... seems like it shouldn't matter.

I mean I could live without reverse but I'm not going to be racing. I'm going to be riding waves. I was even thinking about a jet with a reverse bucket on it. But I can't find a jet that can handle the power of a brushless motor.

avengersteve
04-04-2007, 01:08 PM
i didnt like to stock radio that came on the supervee, mainly because i lost signal due to interferance from another R/C and hit a pier. i now use the Spektrum DX3 and love it, no problems at all

Rex R
04-04-2007, 01:14 PM
Re:reverse
flex shafts have an outer sheath wound around the core, spin it backwards under load and you'll unravel it. you also have an added possibility of loosing the prop.

ebfoxbat
04-04-2007, 02:25 PM
Oh they're sheathed. That makes sense then. Anyone have experience with an electric jet on a boat? I understand they rob some power vs a shaft/prop.