Protection for your 4 in 1 controller

SSG Scott · Jan 31, 2006, 10:59 PM

Here is the mod we came up with while in Iraq to protect your 4 in 1 controller and minimize damage to your rotor head and main drive gear as well as your motor.

If you have any questions just ask! Scott.helmann@us.army.mil

-Scott

P.S. If your running the normal stock 370 motor with a 8 or 9 tooth pinion and an 11.1volt lipo battery- then use 7.5 Amp for the motor protection.

Clarifyling notes: If your measuring current with one of the popular current meters- the actual current flowing to the motor is less that you are reading on your meter (as the speed control is sending pulses to the motor to vary the speed.) These fuses are rated at 7.5 amps at a continous steady DC current.

If your running your motor extremely hot (not recommended) (11.1 Volt lipo, 10 or 11 tooth pinion, stock 370 motor) You can also use a 10 Amp mini blade fuse. Your not leaving much room for protection for your controller (max rating is 10 amps). But what the heck its up to you.

Our tests show that the normal stock 370 motor with a 9 tooth pinion and 3 cell lipo batteries with the canopy installed and dual motor heat sinks - runs about 110 degrees above ambient temperature (test results after about 10 minutes of hovering). Why you would want to run this little motor any harder with a 10 or 11 tooth pinion doesnt seem like sound power equipment and power management to me.

If your running brushless- then we have a slightle different mod for you. Install a 10 amp fuse in the power lead of your brushless main motor control.

ShuNut · Feb 25, 2006, 04:02 PM

Good idea, but can u explain more.

1. Asin is it for when u crash to stop the motor ?
2. I'm asuming this can be done on other E-Helis, is that right ?
3. + how come there are no replys here ?

cat5 · Feb 25, 2006, 04:17 PM

Thanks SSG, maybe I could use the mod later on. Though I haven't use it, my dilema is could you burn out the fuse during flight before you burn it in a crash

SSG Scott · Feb 27, 2006, 01:25 AM

Quote:

Originally Posted by cat5

Thanks SSG, maybe I could use the mod later on. Though I haven't use it, my dilema is could you burn out the fuse during flight before you burn it in a crash

Good question- There is nothing that is very mysterious here as it is just physics and electronics. Your not going to blow your fuse in flight -it isnt going to happen and here is the results of our testing and why. The only way to get the motor current to spike up high enough to blow the fuse is to hit something or have something catastrophically come apart and fail in your motor or jam in your main rotor drive gear.

Here is what we did before full flight tests. We performed bench tests with a regulated 9.0 volt, 10.0 volt and 12.0 volt 40 amp power supply (to insure ample voltage and current was always available- the military is great for having cool test equipment available) We ran tests and the results showed that even with fast application from full up to full down (in 3d mode) of the collective you can not get the current to spike up high enough to blow the fuse. for furthur tests and for fun -We even took a large fan and blew it against the rotor system to simulate a massive amount of air moving through the rotor system to create additional load and couldn't get the current to spike high enough to blow the fuse.

Bottom line- you certainly dont need to apply this to your heli. If you have a couple of crashes and get tired of replacing drive gears, motors and perhaps your 4 in 1. Well then consider giving it a try. Heck- try testing all this yourself. Any good engineer will want to follow up with testing of his own to verify the results and I encourage it! I am sure it will make you a better and much more knoledgeable modeler in the process!

Good luck and happy flying!

-Scott

SSG Scott · Feb 27, 2006, 01:26 AM

Quote:

Originally Posted by ShuNut

Good idea, but can u explain more.

1. Asin is it for when u crash to stop the motor ?
2. I'm asuming this can be done on other E-Helis, is that right ?
3. + how come there are no replys here ?

Sorry about not replying sooner. I have been busy with work, life and outside commitments and only occasionally get a chance to check in here.

-Scott

Vario3 · Feb 27, 2006, 09:04 AM

Thanks Scott. Nice PDF doc. It's in my library already!

neilswolf · Feb 27, 2006, 12:21 PM

I have no doubt that this mod saved my 4-in-1 last weekend. It did exactly what it was supposed to do when the wind pushed my CP2 into my house. I had a standard 8amp glass fuse (all I had around the house at the time).
The only damage was the blown fuse. Replaced it and kept on flying!
Thanks SSG Scott!
Neil

ShuNut · Feb 27, 2006, 01:07 PM

So can this be done on a T-Rex ? or any other bigger E-Heli ?

cat5 · Feb 27, 2006, 04:45 PM

Thanks Scott for your testing

SSG Scott · Feb 27, 2006, 11:50 PM

Quote:

Originally Posted by ShuNut

So can this be done on a T-Rex ? or any other bigger E-Heli ?

I am sure it could. I do not have a T-rex to test it on so I have no idea what the limits of normal current draws might be. You could try different values and keep going up until you cant get it to blow by applying full power (while having it anchored to the ground) and doing all the other possible crazy things you can think to do with it.

As a side note- I still occasionly blow fuses during crashes. I was flying at the local college gym Sunday and after a couple of hours of flight time I was getting pretty bold and was just about at the end of my battery pack. I was doing highspeed downward spirals from the very top of the ceiling and didnt have enough power left to pull out at the bottom. As I approached the floor I pitched the heli forward, applied full collective and expected to fly out of the manuver (like I had done many times before). At full forward speed the heli started tapping on the floor with the rotors until I broke a blade and snapped off a pitch change arm on the top of the head. The fuse promptly blew as the nosed over helicoptor and parts slid accross the floor. After an oops- I didnt mean to do that! I picked it up and there was no damage to the motor, speed control (4 in 1) or the main drive gear. I put in a new fuse and swapped out the main rotor assembly and was back in the air 20 minutes later.

-Scott

ShuNut · Feb 28, 2006, 12:02 AM

Ok thx for the info.

And nice story.. I think i will have to try this when i get my Rex.

LuckyDuc · Feb 28, 2006, 09:52 AM

Very good idea. I have smoked 2 main motors and gears because of crashing in idle up mode. I was fortunate not to have ruined the 4 in 1, but I think it was purely luck. I'm off to buy some fuses

Thanks!

LuckyDuc · Mar 01, 2006, 12:28 PM

Seeing that I'm not electronically inclined...Does it matter what wire you solder the fuse to in a brushless motor setup?

SSG Scott · Mar 01, 2006, 01:27 PM

Quote:

Originally Posted by LuckyDuc

Seeing that I'm not electronically inclined...Does it matter what wire you solder the fuse to in a brushless motor setup?

If you want to protect (fuse) your brushless motor and brushless motor controller - put the fuse in the power lead of your brushless controller. With a 3600KV motor and an 8 tooth pinion I am using a 10 Amp fuse.

Update 18 April 06- for brushless upgrade we like this motor best of all the ones tried so far. Use a 9 tooth pinion and you will have more power and the rotor speed wont bog down at full pitch and you get about 20% longer run times (takes about 1 amp less at hover than the stock motor) http://www2.towerhobbies.com/cgi-bin...?&I=LXLZA4&P=7

You dont want to put a fuse in one of your brushless wires as the motor will still try to run with power applied through the other two wires and you still risk damaging your motor.

Good luck and happy flying!

-Scott

Zeta Phoenix · Mar 01, 2006, 07:49 PM

What about using one of these for the tail?

http://www.allelectronics.com/cgi-bi..._1A-2.5A_.html

I ordered a few a while ago, and now I cant find the ATM, but when I do I can do some tests.

Only concern I can see, you cannot see when you blew the fuse (as it auto resets), but then you do not need to replace the fuse each time.

Idea, put a LED with curent limmiting resistor in parallel with the breaker, so when voltage is applied and the breaker is blown, the LED will light.

-Jon

Jan 31, 2006, 10:59 PM	#1
SSG Scott Registered User Join Date: Jan 2006 Location: Rapid City, SD Posts: 724	Protection for your 4 in 1 controller Here is the mod we came up with while in Iraq to protect your 4 in 1 controller and minimize damage to your rotor head and main drive gear as well as your motor. If you have any questions just ask! Scott.helmann@us.army.mil -Scott P.S. If your running the normal stock 370 motor with a 8 or 9 tooth pinion and an 11.1volt lipo battery- then use 7.5 Amp for the motor protection. Clarifyling notes: If your measuring current with one of the popular current meters- the actual current flowing to the motor is less that you are reading on your meter (as the speed control is sending pulses to the motor to vary the speed.) These fuses are rated at 7.5 amps at a continous steady DC current. If your running your motor extremely hot (not recommended) (11.1 Volt lipo, 10 or 11 tooth pinion, stock 370 motor) You can also use a 10 Amp mini blade fuse. Your not leaving much room for protection for your controller (max rating is 10 amps). But what the heck its up to you. Our tests show that the normal stock 370 motor with a 9 tooth pinion and 3 cell lipo batteries with the canopy installed and dual motor heat sinks - runs about 110 degrees above ambient temperature (test results after about 10 minutes of hovering). Why you would want to run this little motor any harder with a 10 or 11 tooth pinion doesnt seem like sound power equipment and power management to me. If your running brushless- then we have a slightle different mod for you. Install a 10 amp fuse in the power lead of your brushless main motor control. Attached Files fuse protection for your heli.pdf (713.0 KB, 7315 views) Last edited by SSG Scott; Feb 01, 2006 at 12:31 AM.

Feb 25, 2006, 04:17 PM	#3
cat5 Registered User Join Date: Aug 2005 Location: Portland, OR US Posts: 966	Thanks SSG, maybe I could use the mod later on. Though I haven't use it, my dilema is could you burn out the fuse during flight before you burn it in a crash Last edited by cat5; Feb 25, 2006 at 04:22 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale E-flite 4 in 1 controller for Blade CP $50.00 shipped NIP	nakman8	Aircraft - Electric - Helis (FS/W)	4	Mar 18, 2007 10:15 PM
Sold E-Sky 4-in-1 controller for FP helis	preston_brown	Aircraft - Electric - Helis (FS/W)	1	Apr 12, 2006 11:54 PM
Question Twister/honeybee:- 4 in 1 controller	welshlad	Micro Helis	8	Jun 20, 2005 10:51 AM
Where to buy esky 3D 4-in-1 controller box?	Skycat	Micro Helis	7	Dec 17, 2004 04:24 PM
help on esky cp 4-in-1 controller box	Skycat	Micro Helis	8	Nov 16, 2004 12:40 AM

Feb 25, 2006, 04:02 PM	#2
ShuNut Hotep Join Date: Dec 2005 Location: UK Posts: 2,324	Good idea, but can u explain more. 1. Asin is it for when u crash to stop the motor ? 2. I'm asuming this can be done on other E-Helis, is that right ? 3. + how come there are no replys here ?

Feb 27, 2006, 09:04 AM	#6
Vario3 Registered User Join Date: Oct 2005 Location: Southeast PA Posts: 2,791	Thanks Scott. Nice PDF doc. It's in my library already!

Feb 27, 2006, 12:21 PM	#7
neilswolf Registered User Join Date: Nov 2005 Location: California Posts: 236	I have no doubt that this mod saved my 4-in-1 last weekend. It did exactly what it was supposed to do when the wind pushed my CP2 into my house. I had a standard 8amp glass fuse (all I had around the house at the time). The only damage was the blown fuse. Replaced it and kept on flying! Thanks SSG Scott! Neil

Feb 27, 2006, 01:07 PM	#8
ShuNut Hotep Join Date: Dec 2005 Location: UK Posts: 2,324	So can this be done on a T-Rex ? or any other bigger E-Heli ?

Feb 27, 2006, 04:45 PM	#9
cat5 Registered User Join Date: Aug 2005 Location: Portland, OR US Posts: 966	Thanks Scott for your testing

Feb 28, 2006, 12:02 AM	#11
ShuNut Hotep Join Date: Dec 2005 Location: UK Posts: 2,324	Ok thx for the info. And nice story.. I think i will have to try this when i get my Rex.

Feb 28, 2006, 09:52 AM	#12
LuckyDuc Registered User Join Date: Dec 2005 Location: Formerly Denver. Now West Bend, WI Posts: 2,044	Very good idea. I have smoked 2 main motors and gears because of crashing in idle up mode. I was fortunate not to have ruined the 4 in 1, but I think it was purely luck. I'm off to buy some fuses Thanks!

Mar 01, 2006, 12:28 PM	#13
LuckyDuc Registered User Join Date: Dec 2005 Location: Formerly Denver. Now West Bend, WI Posts: 2,044	Seeing that I'm not electronically inclined...Does it matter what wire you solder the fuse to in a brushless motor setup?

Mar 01, 2006, 07:49 PM	#15
Zeta Phoenix Formerly P4 Hover Join Date: May 2003 Location: San Jose, California, United States Posts: 356	What about using one of these for the tail? http://www.allelectronics.com/cgi-bi..._1A-2.5A_.html I ordered a few a while ago, and now I cant find the ATM, but when I do I can do some tests. Only concern I can see, you cannot see when you blew the fuse (as it auto resets), but then you do not need to replace the fuse each time. Idea, put a LED with curent limmiting resistor in parallel with the breaker, so when voltage is applied and the breaker is blown, the LED will light. -Jon