ReddyWatts
Oct 13, 2006, 02:23 PM
I have written down some ideas for building a reliable, brushless boat from what I have learned from another forum and experiences. Keep in mind; this has nothing to do with racing. It is for the novice that wants his new hobby project to be dependable. I would like to know what experienced racers think about this guideline? You are welcome to criticize or add to it. Be kind. ha!
1.Use no more than 8 inches of total wire between the batteries and the controller.
2. Use a .150 flex cable or larger on 12 cells or more. Use a .130 flex cable on 12 cells or less.
3. Use a 12XL to 14XL or larger motor with direct drive on catamaran, mono hulls 29 inches (1/8 scale)and above. Most hulls have a min/max recommendation for how many NiMH batteries it will handle.
4. Use a 10XL to 6XL and L series motors with direct drive on 28-inch to 20 inch (1/12 scale)or less hydro type, catamaran or mono hulls. These motors have a higher rpm/volt rating and use fewer batteries. This allows for high speeds with less weight and motor torque.
5.Use a 12S to 6S series motors with direct drive on 19-inch (1/16 scale) and smaller hydro type, catamaran or mono hulls. These motors have a higher rpm/volt rating and use 6-8 cells.
6. Limit the loading of your controller to 60% amps and 75% voltage of its max ratings, 14 cells and above, due to current surges and boat weight.
7. Limit the loading of your controller to 70% amps and 75% voltage of its max ratings, 12 cells or less.
8. Design your boat to run with the “wide-open” amps at your motors "maximum" efficiency rating.
9. Install floatation in your hull, unless you are a certified scuba diver.
10. Grease and maintain your flex cable regularly, to keep it turning freely.
11. Make your flex cable metal tubing long enough to cover most of the flex cable, to prevent blowouts.
12. Use an ammeter to measure motor load. I suggest two different brands.
a. The "Watts Up" meter from Offshore Electrics. Look for it under, Tools.
It is a “peak recording”, ammeter for $50. It is very simple to use.
b. The Eagle Tree Micro "data logger" for $70 at Eagle Tree Systems. It will record your amps for the entire boat run and has add-ons for temp, display and rpm. It gives very detailed information and also works with a computer or an attached display.
http://www.eagletreesystems.com/MicroPower/micro.htm
13. Start amp testing with a small prop and move to larger ones until it is loaded to the motor maximum rating and not overloading your controller guideline. The larger your prop the higher your amps will go.
14. Use an infrared temperature meter to measure equipment maximum readings.
15. The maximum temperature reading for a controller is 150 F, the motor is 150 F and the batteries are 150 F. Always try to keep the controller and motor as far below these readings as possible with water-cooling, but the best way is lowering your amps.
16. Keep the receiver away from your battery wiring and run these wires perpendicular from each other if possible to minimize interference. Twisting receiver cables can also minimize interference.
17. Brushless controllers are more efficient when running them wide open.
18. Leave the controller "timing" option at factory default/low. It will not increase your speed by changing the setting, but will make the controller run hotter.
19. The first link below is to the FE Calc program. Download it to your computer for free. It is great for simulating a setup for your boat. Remember these guidelines when considering your maximum amps for your controller. This program does not calculate all of the variables, so start testing with a smaller prop than it calculates for your desired setup. You can add more equipment to the program if yours is not there, by adding it to the text file that comes with it.
Example: Use the second link below to get all of the Feigao motor information. Some are listed below.
http://www.rcboataholic.com/fe_calc.htm
http://img.diytrade.com/cdimg/85838/692728/0/1082223033.jpg
Feigao 540-12S 2958 2.1 .0136 B-Less 12 8 300g
Feigao 540-8S 4436 5.5 .0060 B-Less 8 8 300g
Feigao 540-9XL 1853 2.5 .0092 B-Less 9 16 372g
Feigao 540-10XL 1668 2.3 .0114 B-Less 10 16 372g
Feigao 540-12XL 1390 1.9 .0164 B-Less 12 16 372g
Feigao 540-14XL 1191 1.2 .0223 B-Less 14 16 372g
20. Using a transmission can soften current surges and make your setup more forgiving. You can load an 80-amp controller to 80% of its amp rating and 80% of its voltage rating. It makes for a very versatile setup, using different ratios. You can use any motor with a trans in a cat or mono hulls, but the trans also lowers your reliability. (Gears)
To use the FECALC for transmission setups, just divide the RPM/Volt value by your selected gear ratio;
Example: 10XL with an rpm rating of 1668 per volt and you are running a gear ratio of 1:33 to 1,(60-prop/45-motor), divide 1668 by 1.33 which gives you 1254 rpm, so if you look in the text file for a 10XL 1668 change the 1668 to 1254 and save." then reopen FECALC and "calculate".
I wrote this guideline, hoping it will help everyone to have a positive new experience with a brushless boat. Run fast, stay dry and don’t let the smoke out. ReddyWatts
Updated 10/14/2006.
1.Use no more than 8 inches of total wire between the batteries and the controller.
2. Use a .150 flex cable or larger on 12 cells or more. Use a .130 flex cable on 12 cells or less.
3. Use a 12XL to 14XL or larger motor with direct drive on catamaran, mono hulls 29 inches (1/8 scale)and above. Most hulls have a min/max recommendation for how many NiMH batteries it will handle.
4. Use a 10XL to 6XL and L series motors with direct drive on 28-inch to 20 inch (1/12 scale)or less hydro type, catamaran or mono hulls. These motors have a higher rpm/volt rating and use fewer batteries. This allows for high speeds with less weight and motor torque.
5.Use a 12S to 6S series motors with direct drive on 19-inch (1/16 scale) and smaller hydro type, catamaran or mono hulls. These motors have a higher rpm/volt rating and use 6-8 cells.
6. Limit the loading of your controller to 60% amps and 75% voltage of its max ratings, 14 cells and above, due to current surges and boat weight.
7. Limit the loading of your controller to 70% amps and 75% voltage of its max ratings, 12 cells or less.
8. Design your boat to run with the “wide-open” amps at your motors "maximum" efficiency rating.
9. Install floatation in your hull, unless you are a certified scuba diver.
10. Grease and maintain your flex cable regularly, to keep it turning freely.
11. Make your flex cable metal tubing long enough to cover most of the flex cable, to prevent blowouts.
12. Use an ammeter to measure motor load. I suggest two different brands.
a. The "Watts Up" meter from Offshore Electrics. Look for it under, Tools.
It is a “peak recording”, ammeter for $50. It is very simple to use.
b. The Eagle Tree Micro "data logger" for $70 at Eagle Tree Systems. It will record your amps for the entire boat run and has add-ons for temp, display and rpm. It gives very detailed information and also works with a computer or an attached display.
http://www.eagletreesystems.com/MicroPower/micro.htm
13. Start amp testing with a small prop and move to larger ones until it is loaded to the motor maximum rating and not overloading your controller guideline. The larger your prop the higher your amps will go.
14. Use an infrared temperature meter to measure equipment maximum readings.
15. The maximum temperature reading for a controller is 150 F, the motor is 150 F and the batteries are 150 F. Always try to keep the controller and motor as far below these readings as possible with water-cooling, but the best way is lowering your amps.
16. Keep the receiver away from your battery wiring and run these wires perpendicular from each other if possible to minimize interference. Twisting receiver cables can also minimize interference.
17. Brushless controllers are more efficient when running them wide open.
18. Leave the controller "timing" option at factory default/low. It will not increase your speed by changing the setting, but will make the controller run hotter.
19. The first link below is to the FE Calc program. Download it to your computer for free. It is great for simulating a setup for your boat. Remember these guidelines when considering your maximum amps for your controller. This program does not calculate all of the variables, so start testing with a smaller prop than it calculates for your desired setup. You can add more equipment to the program if yours is not there, by adding it to the text file that comes with it.
Example: Use the second link below to get all of the Feigao motor information. Some are listed below.
http://www.rcboataholic.com/fe_calc.htm
http://img.diytrade.com/cdimg/85838/692728/0/1082223033.jpg
Feigao 540-12S 2958 2.1 .0136 B-Less 12 8 300g
Feigao 540-8S 4436 5.5 .0060 B-Less 8 8 300g
Feigao 540-9XL 1853 2.5 .0092 B-Less 9 16 372g
Feigao 540-10XL 1668 2.3 .0114 B-Less 10 16 372g
Feigao 540-12XL 1390 1.9 .0164 B-Less 12 16 372g
Feigao 540-14XL 1191 1.2 .0223 B-Less 14 16 372g
20. Using a transmission can soften current surges and make your setup more forgiving. You can load an 80-amp controller to 80% of its amp rating and 80% of its voltage rating. It makes for a very versatile setup, using different ratios. You can use any motor with a trans in a cat or mono hulls, but the trans also lowers your reliability. (Gears)
To use the FECALC for transmission setups, just divide the RPM/Volt value by your selected gear ratio;
Example: 10XL with an rpm rating of 1668 per volt and you are running a gear ratio of 1:33 to 1,(60-prop/45-motor), divide 1668 by 1.33 which gives you 1254 rpm, so if you look in the text file for a 10XL 1668 change the 1668 to 1254 and save." then reopen FECALC and "calculate".
I wrote this guideline, hoping it will help everyone to have a positive new experience with a brushless boat. Run fast, stay dry and don’t let the smoke out. ReddyWatts
Updated 10/14/2006.