Multiple packs -start up sequence question - RC Groups
Thread Tools
Dec 10, 2017, 03:51 AM
Ldm
Ldm
Registered User
Discussion

Multiple packs -start up sequence question


Guys a little help please. I am assembling my largerst electric plane to date.
1) I know i turn on my TX then receiver power second then plug in the 2x6 cells packs
2) My question is about my light system. My lights plug into a custom board that is powered by a separate lipo and the board is plugged into a port of the receiver.
I assume I need an on /off switch between the light system board and the receiver in order for the board not to draw from the flight packs and also for the ESCs not to see the power from the separate lipo for the lights.

I flying the system in parallel so both ESCs will have the red wires disconnected and I just want to make sure my start procedure is correct .
1) TX -Turn on
2) Receiver pack turned on
3) plug in lipos for motors
4) Turn on switch for lipo power to lights
Sign up now
to remove ads between posts
Dec 12, 2017, 04:47 PM
"I will return" Federico
rclad's Avatar
I would suggest an arming plug for the main packs. Here is my start up and shut down checklist, for use on any electric set up with 6s and larger battery packs: Electric Start Up and Shut Down Checklist

I use this checklist for my 87" Extra as well as the 55".
Dec 14, 2017, 03:29 AM
Ldm
Ldm
Registered User
Agree and in my plans , but I will tell you that I have never ever experienced your problem with my Spectrum system nor have I seen the issue with Futaba .
All the safety measures in the world would still not prevent your system issues when actually being close enought to the plane pre-flight and final turn on of the system.
When I make the final power up , I am close to the plane, away from the prop and pointing to the field but a TX that overrides the receiver is telling you something else is wrong.
I have seen or heard of this on the major brand radios or even flying electric on an older FM system.
I like your process and redundancy but still would be concerned and look to the TX /receiver for other inherent problems.
Dec 20, 2017, 10:08 AM
"I will return" Federico
rclad's Avatar
Swamping the receiver by getting too close with the transmitter may be just the nature of the beast, and certainly can be a safety issue, but I don't think it indicates a problem with the system. Plenty of users have documented this issue, and it only occurs when the the two are within a couple feet of each other. Apart from that the Taranis Plus radio has performed flawlessly for me for hundreds of flights over the past two years.
Dec 20, 2017, 11:02 AM
Ldm
Ldm
Registered User
I have total respect for your comments and concerns however I will tell you that at my club our director of safety only flys electric and all high powered.
To say that he is ANAL on safety, start up and AMA suggestions on safety would be an understatement.
We have a safety update in every monthly meeting led by our director and this element of TX distance from the receiver /plane had never ever been addressed as an issue, random issue or passing concern.
Perhaps its been pure luck that the wing span of a plane has the final arming process with the TX on the ground or work station at a significant distance from the receiver ? Perhaps its just a matter of time but we have 30% of our club flying electric including me flying electric all the time.
I am only challenging this report because I have seen so many urban legends grow from one brand, one situation into something that never is repeated outside a brand or field/unique situation.
I think what your stating is a good habit and a safety element ( all good ) but sincerly I should be the leader of the pack with my TX litterally 12” from my plane at time when arming the model and I have never had a glitch.
Sorry sincerly not trying to be a PITA , but I think I take safety and redundancy to the extreme and I also personally believe that also comes with brands that are proven outside the RC community and in non -RC applications.
We are seeing more and more value products enter the marlet and with the entry comes new levels of learning the reliability and elements that my not occur with the proven brands.
IN closing I am not a brand snob, I have used many non branded value products in my planes but I have learned a valuable lession with TX, receivers, and certain battery’s that there is a reason for the cost of brand equity.
Dec 20, 2017, 05:49 PM
"I will return" Federico
rclad's Avatar
Quote:
Originally Posted by Ldm
Perhaps its been pure luck that the wing span of a plane has the final arming process with the TX on the ground or work station at a significant distance from the receiver ? Perhaps its just a matter of time but we have 30% of our club flying electric including me flying electric all the time.
I am only challenging this report because I have seen so many urban legends grow from one brand, one situation into something that never is repeated outside a brand or field/unique situation.
Could you elaborate on what you mean here? I'm not clear what you are trying to say.

From what I understand Frsky made a trade off in making a transmitter with enough power to have excellent range (1.5km LoS) that unfortunately will overpower, or swamp, the receiver at really close range. By close range I mean only inches away from the receiver, not feet. Keeping the transmitter 2-3 feet away is a safety margin, not the actual impact range on the receiver. I completely agree with you that this is a serious safety issue, but it is a real one for all Taranis transmitters and by no means an "urban legend." As long as users are aware of it and employ Fail safe I think it's an acceptable trade off for the great range it provides.
Dec 20, 2017, 07:21 PM
Ldm
Ldm
Registered User
What I was trying to say is that perhaps my TX does not override my receiver because it’s always 24” min distance from the receiver just based on the size of the planes I fly.
I dont wear a neck strap with electric flight so my TX is never less then 24” from the receiver, does this make sense ?
Dec 20, 2017, 11:37 PM
"I will return" Federico
rclad's Avatar
OK, that makes sense now. Thank you.

Back to your original post: How's your plane coming along? Did you decide on a switch for the lights? Installing lights is a lot of work, but sure look nice when flying at dusk. I hope yours hold up better than my Super Cub. One of the landing lights failed after less than fifty flights.
Dec 21, 2017, 01:51 AM
Ldm
Ldm
Registered User
Thanks !
Yes I am using a switch simply because I know I dont need one but I feel like it allows me to know the system is operating as far as my separate power supply is concerned.
Thanks to you and others I know its not a safety issue but at least I know the condition of my battery based on my switch light monitor.

I know what you mean on lights not working, this set was the most expensive investment I have made in lights but the leds are extremely bright so I am hoping for durability.
In the addition I really the power/regulator box that is provided for light set up.
I am also going to test a super cheap LED system in another plane, the super cheap system is $14.00 vs $125.00 . The $14.00 system says “leds” lol but I find it hard to imagine the QC will be in the same league.

Overall this is where a I am at with the model . I am testing my props to see watts ect because there is so many opinions and power system being used its amazing. Stock Tower suggested 2x32s , when you read the max load on the 32s , they wont even cover the total weight of the model at its lightest assembled weight 16lbs . The 32s are rated at 7 lbs each !
I went with Power 60ties and plan to fly scale at a reduced speed.
So all that is left is :
1) Add Callie graphics
2) panel lines
3) weathering
4) CG and prop test
Obviously not in this order
Dec 21, 2017, 07:33 AM
An itch?. Scratch build.
eflightray's Avatar
An A-26 cockpit ?

Looks fantastic.

Ray.
Dec 21, 2017, 09:01 AM
"I will return" Federico
rclad's Avatar
Nice detail in the cockpit. Looks like an A-26 Invader.

If AUW is only 16 lbs for a twin, then why 2 x 32s? Isn't 2 x 4s 4500 mAh the recommended battery set up? My 21 lb Extra 300 uses 12s 6000 mAh and has unlimited vertical with almost 300 watts per pound. But that's needed for scale aerobatics (IMAC). A scale wardbird only needs about 100 watts per pound.
Dec 21, 2017, 08:46 PM
Ldm
Ldm
Registered User
Thanks guys !
As far as power , I am using 2x60ties , I have not tried the props yet on a Watt meter , that is my next step in my build process.
I am not useing the rimfire 32s , my point is that Tower suggested 2x 32 and it you look at the specs on the rimfire 32s , they are suggested for a 7lb plane max.
At the stock specs on the 32s , they will not even conver the stock weight of the plane,
Dec 22, 2017, 12:43 AM
"I will return" Federico
rclad's Avatar
Sorry, I misunderstood what you are trying to do. Have you tried ecalc to see how the two Rimfire 60s will work out? Going up in motor size means adding more cells 5-6s vs. 4s. Both will add weight to an already heavy wing loading. I just ran some numbers on Aeroplayin's PAR calculator (see here). It looks like the original Rimfire 32s will actually perform better, since the plane will be lighter. You would get about 115 watts per pound with an AUW of 16.5 lbs. You don't need 1:1 thrust to weight for a scale warbird. Has anyone flown this plane with two 60s?
Dec 22, 2017, 03:25 AM
Ldm
Ldm
Registered User
For a total stranger you make a lot of assumptions lol .
1) this is a 90” wingspan model and wing loading is very light
2) the Rimfire 32 have in fact been report ( even on the tower site ) as low power /inefficient
3) two at my field and at least three in the thread useing 60ties and the plane flys great at 1/2 to 3/4 throttle
4) I not only used ecal to pre-determine what I wanted to do and that provided the options so i am useing a watt meter to determine final numbers.
5) I will be running 2 x 6 cells in parallel , XT 90ties connections, 90 Talon ESCs in the wing for ideal cooling . I have two Capacitators ( one on each ESC ) to compensate for the length of the wires to the fuselage. As far as deferring to experts for the set up I was on the phone with castle many times and they love the set up ! .
So I am clear on my system.
60 size x 2 x 90 size ESCs x 2 6 cells packs, this is not my first rodeo just my first large twin.
In my research ( pre -purchase ) I found that in Europe this models stock suggested power system is 2 x 45 or 2 x 60ties ( never ever menthioned 2x32s.
One of the Tower techs said the 2x32 were suggested as a minimum fun fly system to keep the budget down in two expenditures for the plane.
As you know its not about what you need per pound when you know how to use the throttle but you can not fly the entire flight at full throttle and that was ( some of ) the early reports on 2x32s .
So while 2 x 32 may work on an ecal ( by the way not ecal always accurate ) in the real world a motor rated at 7 lbs max x 2 = 14 lbs . The model at its lightest is 16.2 lbs .
As a warbird rc modeler you always have two choices for CG, add function weight or add dead weight.
With the exception of my scale details everything added has been funcational.
The reason why my assemblies go slow ( besides work lol ) is that I will not make any of the moveable weight elements like lipos, flight packs ect permanent until I set the CG .
As an example of clear thinking and planning, The 60ties with the stock motor standoffs will surely add weight ahead of the CG . However once my CG is attempted with the stock stand offs , I have multiple options if I am not happy with the results.
I can , 1 ) use shorter standoffs, virtually mounting on the firewall . 2) move the main flight lipos back almost 2 to 3” by removing a non -critical low fuse former , set the packs and re-build the former with a variation.
All of my additional electronics are placed for optimum lateral weight , lipo left , light control box right ect,
So no worries on the power system and in fact every plane I fly ( every single one ) has been upgraded in funcational power .
Some examples- VQ 60 size Dauntless ( stock is 45 size ) but guys were adding 4 to 6 oz on the nose lol . Upgrade to a 60 , remove wood for a 6 cell and wala, no dead weight ! Plane fly great despite many skeptics , wing loading is wing loading , what really counts is where is the weight coming from if added weight is needed.
FW190 -73 “ , move all the servos in the wing ahead of the CG , turn them on there side and go up in 4/40 rods supported internally , made the same type mods in the fuse .
Final weight 15.5 lbs vs 19 pounds stated by many .
So in closing I am good and I have zero worries on how this plane will fly.
My search now is for one simple motor standoffs ( Aluminum tube type ) in two sizes for my expetect tweak that will be needed once I get to the CG
Dec 22, 2017, 09:38 AM
An itch?. Scratch build.
eflightray's Avatar
As a slight comparison.

My B-25, (scratch built in balsa), is 93" span, flying weight 9lb -11oz, (has weighed considerably more as it first flew with brushed motors, belt drives, and Nicad cells).

Now uses E-Power GT 2826 710kv motors, and turns 12" x 8" props, 6900 rpm on 3s Lipo per motor. Not exactly fast, but quite scale like in flight.

Ray.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion JSM Xcalibur start up question Tronn Jet Turbines 7 Apr 23, 2017 06:54 PM
Discussion RC Question- gear starting up on its own idealmethod Dock Talk 4 Sep 26, 2016 09:36 PM
Help! Naza-M NO Start-up Sequence and Can't Connect to Computer Craig9080 Multirotor Drone Electronics 0 Jun 14, 2013 12:30 PM
Help! Naza-M NO Start-up Sequence and Can't Connect to Computer Craig9080 Multirotor Drone Talk 0 Jun 14, 2013 11:56 AM
Discussion B17 Start up sequence--The real one!! fnlrun Electric Warbirds 3 May 19, 2011 11:09 PM