SGX 67 Brushless Conversion

[tampa1330]

I am researching a brushless conversion for my Eagle SGX 67. I have no experience with custom brushless setups so I have no clue where to start. I would assume the best place to start would be choosing a motor then the required accessories from there. Any tips on choosing a motor for this application?

 

[TRUCKPULL]

A better place to start would be the Number of cells that you want to run, or the

class that you want to run in, seeing that the classes are set by the number of cells.

You need to know the number of cells or the Voltage before you pick a motor.

Motors are set be KV (RPM per Volt)

Larry

 

[raptor347]

We're going to need some info.

How big is the boat?

Over all length?

Inside tub width?

Boom spacing?

Weight without motor/mount/tank?

Basicly what are the dimensions inside the tub where all the power system needs to go?

Can you post a pic of the tub with a yard stick next to it?

I'll warn you going into this that it's not going to be a cheap power system.

 

[tampa1330]

We're going to need some info.
How big is the boat?

Over all length?

Inside tub width?

Boom spacing?

Weight without motor/mount/tank?

Basicly what are the dimensions inside the tub where all the power system needs to go?

Can you post a pic of the tub with a yard stick next to it?

I'll warn you going into this that it's not going to be a cheap power system.

I'll get some pics posted asap. As far as the cost, I don't want it to be cheap. I want it to be competitive. I'm planning on running 5S or 6S lipo's maybe even 12S with the Castle HV ESC's. I have no clue as to what class I would be racing in since we have no local club here. I would like to build something race legal, run it a few times and maybe pass it along to someone who can race FE riggers.

 

[raptor347]

The drawback to the big cell count boats is there are very few around to race with. Maybe a dozen accross the US and I think that's high. I built mine to race in open hydro at our district races.

 

[pda75]

I have converted a 7,5 cm3 hydro into electric. the hull was 67" long like yours

10S cells,YGE 200 and 2250/12 lehner motor.

Be carefull, it will weight 0,6 - 0,8 kg more than the gas version:

1- you need more sponsom angle (4° instead of 3°)

2- you will have to think carrefully about the center of gravity : watch the weight on the strut and don't increase it, (Keep it around 600 gr, eg 200 oz). increase the weight on the sponsom not on the strut

3 - think about how to close the hull in order to be waterproof (I think it is a complex issue to solve)

4- you will need to move the sponsom tube back in order to place the battery (at the end, I came to the conclusion to place the 2 battery packs one over the other)

It runs well (over 80 mph)

cheers

Pierre

PS : eagle hull are in wood. If they get to heavy you may face some crash issue. Mine is carbon fiber and has already faced some serious flip flap with no damages

 

[pda75]

A link( it's in french)

http://www.offshore-rc.com/forum/index.php...cr%207&st=0

And some pictures

pierre

 

[David Kingston]

Did you get my email with a few pics...

Dave

 

[Randy Naylor]

I have raced the big Gas Cat class (open) with my electrics. I have found that I like to get as much motor and SC as possible. Oval racing is not the same as SAW setup. I like the Neu 2230 1Y, Schultz 40.160 and PollyRC 10S2P 10,00Mah, with a 457 prop. In my cat it was starting to turn on get real fast at that point. I also think I would like a bigger hull too the 41 inch cat was sort of hand full in the rough. Riggers will just run faster with a little bigger prop. I have a 3040 14T Lehener and it does not have the balls to get out of it own way in a extra light CF 1/8 scale. I like the Neu much better. Not cheap though!

You will also need a real good oiling setup with the high RPM on the 1/4 flex shaft. I am going to get rid of the Teflon and have a on board oil tank pressurized for the shaft. And I am still learning every day.

 

[Roger Hooks Jr.]

I have raced the big Gas Cat class (open) with my electrics. I have found that I like to get as much motor and SC as possible. Oval racing is not the same as SAW setup. I like the Neu 2230 1Y, Schultz 40.160 and PollyRC 10S2P 10,00Mah, with a 457 prop. In my cat it was starting to turn on get real fast at that point. I also think I would like a bigger hull too the 41 inch cat was sort of hand full in the rough. Riggers will just run faster with a little bigger prop. I have a 3040 14T Lehener and it does not have the balls to get out of it own way in a extra light CF 1/8 scale. I like the Neu much better. Not cheap though!You will also need a real good oiling setup with the high RPM on the 1/4 flex shaft. I am going to get rid of the Teflon and have a on board oil tank pressurized for the shaft. And I am still learning every day.

Doug Twaits, Jr. set the NAMBA 6 lap heat racing record with a .67 hydro. Just nudging the .67 nitro record. He would probably be a good source to talk to. I am not sure if he is a member here though but you should be able to track him down with the name.

 

[David Kingston]

Dont think doug is a member also.

I have spoken to doug in a few emails, and that setup is just nuts in that 67 electric rigger.

It is to hot for everyday use. Temps were 160deg F. Way over the limit, and the cells wont last long at that temp range.

If you track Doug down he will tell you his setup.

I wont say cause its not my place to.

However somthing that i dont know works in a 6s rigger is a

2215/1y

1670 prop.

Can even go bigger if you want

Dave

 

[sailr]

There is a pretty active FE group in the Tampa Area. You may want to get involved in their new club, the West Florida Model Boat Club. Lots of good knowledge about FE. I'm not familiar with your boat so can't say much here. The club just fired up and doesn't have a website yet. You can PM me (sailr) over at offshore electrics and I'll give you my phone number.