700 T-Rex 700E build
- Thread starter pvolcko
- Start date
Island Breeze
Senior Rc-Help Member
Looking good..I never thought I will be posting here on the 700's. can't wait to see your bird and breeze's fly..oh and mine..lol
Got a bit more done on it. Busy weekend and my 300X mishap put the build back burner again.
Have female bullets on the esc. Installed the elevator/ail linkage rod and levers. Got the cyclic servos in (dry fit on the horns and elevator/anti-rotation arm until I get them powered up and centered). Got the BEC side of the EC2 connector I'm going to be using on, as well.
I'm contemplating wiring routing. Things look very busy up around the elevator and main shaft with the motor/esc wires. But I don't want to extend the ESC motor leads. Not sure what I'll do there.
Servo routing should be fine. Just have to put an extender on the tail servo. Probably on the ESC throttle line too, just thought of that.
Planning to run the BEC off the main batteries, so will have to put a tap on the ESC power leads. Probably run 14ga from there forward to the BEC and then EC2 connector to the BEC. Gives me the option to go with flight battery or maybe a failover/backup circuit to run both if the main supply dies in flight.
Gaba, hopefully you'll see this. Did you run the battery connection to the ESC out the back? Seems the most direct and most likely, but I've also seen people run them out the middle between the two packs and put a short extension on the ESC power taps. And since you had the KDE nose/mount without the tray locking mechanism, I'm assuming you velcro strapped both front and back of the pack block to keep them from shifting around?
Have female bullets on the esc. Installed the elevator/ail linkage rod and levers. Got the cyclic servos in (dry fit on the horns and elevator/anti-rotation arm until I get them powered up and centered). Got the BEC side of the EC2 connector I'm going to be using on, as well.
I'm contemplating wiring routing. Things look very busy up around the elevator and main shaft with the motor/esc wires. But I don't want to extend the ESC motor leads. Not sure what I'll do there.
Servo routing should be fine. Just have to put an extender on the tail servo. Probably on the ESC throttle line too, just thought of that.
Planning to run the BEC off the main batteries, so will have to put a tap on the ESC power leads. Probably run 14ga from there forward to the BEC and then EC2 connector to the BEC. Gives me the option to go with flight battery or maybe a failover/backup circuit to run both if the main supply dies in flight.
Gaba, hopefully you'll see this. Did you run the battery connection to the ESC out the back? Seems the most direct and most likely, but I've also seen people run them out the middle between the two packs and put a short extension on the ESC power taps. And since you had the KDE nose/mount without the tray locking mechanism, I'm assuming you velcro strapped both front and back of the pack block to keep them from shifting around?
Yeah, that or use some zap goo to secure it.
And I like the vote of confidence "... during its life inside...". Way I've been flying lately it may well be a very short life in this thing.
Well, I'm much more careful with the 550 and will be even more so with this bird, so maybe it will have a long life of seclusion tucked away in this monster.
And I like the vote of confidence "... during its life inside...". Way I've been flying lately it may well be a very short life in this thing.
Well, I'm much more careful with the 550 and will be even more so with this bird, so maybe it will have a long life of seclusion tucked away in this monster.
coolgabsi
Super Mod & DEAL KING!
Yes both front and back were velcrod . It's a bit tricky at first... You have to push the packs all the way in far ahead, put the read Velcro, then using the front Velcro push the packs against the rear Velcro and tighten it down.
My esc was over sized and yes on the back with its leads (series connection) across the boom. I didn't use extensions per say. I extended my battery wires. (As you can see on turnigies)
I highly recommend a cap pack like I have. The wires are more than 11 inches total from farther most battery to the esc solder. You need a bit of protection on that so it doesn't create a huge ripple .
Castle makes it and also yge makes it... See what design suits you. I was using yge as I could strap it across the boom.
Fly safe!! have fun!
My esc was over sized and yes on the back with its leads (series connection) across the boom. I didn't use extensions per say. I extended my battery wires. (As you can see on turnigies)
I highly recommend a cap pack like I have. The wires are more than 11 inches total from farther most battery to the esc solder. You need a bit of protection on that so it doesn't create a huge ripple .
Castle makes it and also yge makes it... See what design suits you. I was using yge as I could strap it across the boom.
Fly safe!!
have fun!I need to find some detail pics of how the motor wires (esc to motor) are best routed. I can figure out the rest, but there is not a lot of room through the top of this thing on inside or outside of frame.
Got to doing some ikon setup tonight. Got as far as swash leveling and getting the head put on. LT'd the servo horns and elevator arm and end screws on the AIL/PIT control arm pivot. Next is blade zeroing, min/max collective and cyclic. Then onto tail setup.
Got to doing some ikon setup tonight. Got as far as swash leveling and getting the head put on. LT'd the servo horns and elevator arm and end screws on the AIL/PIT control arm pivot. Next is blade zeroing, min/max collective and cyclic. Then onto tail setup.
Yup same problem I have the ESC wires are 5 inches the motor wires are 2 inches. I want to mount the ESC on the back of the helicopter instead of inside the canopy for airflow. I'll be extending the esc motor wires 5-6 inches to go down the taibox then under the main gear and back up to the motor so a total of 11-12 inches of motor wire. No other clean way to do it that I saw. I could route them down the side of the helicopter but I'd still need to extend them about 5 inches. I'd prefer to rout them inside the helicopter then a giant wart on the side of the helicopter. I did contact Castle Creations and asked about extending these wires that total length they said it should be fine.
coolgabsi
Super Mod & DEAL KING!
you dont have to extend the wires at all bro. the wires go from inside the frame to the esc.. with the esc motor wires (3 phase side) going towards the swash. Thats how I mounted it. I kept one outside the frame so i could disconnect it when needed. Its easily routed for the 120.. 160HV has thicker wires so it was harder.
For your setp xokia, you have the DFC.. you should actually have more space inside the frame than the V2 that Paul and I dealt with.
I really recommend not using too long of wiring to the motor. That just introduces inductance in the wires and will cause shabby throttle control. When i extended my battery wires, I actually had to put a capacitor pack on that battery side to get the ripples down.
instal the motor in a way that the three phase wires are pointing inside the frame and then route them using zipties clear of the servos / main shaft. and the rest of the way is your ESC
For your setp xokia, you have the DFC.. you should actually have more space inside the frame than the V2 that Paul and I dealt with.
I really recommend not using too long of wiring to the motor. That just introduces inductance in the wires and will cause shabby throttle control. When i extended my battery wires, I actually had to put a capacitor pack on that battery side to get the ripples down.
instal the motor in a way that the three phase wires are pointing inside the frame and then route them using zipties clear of the servos / main shaft. and the rest of the way is your ESC
I'm pretty sure I either have the same space or less space. I dont know that sticking caps on the DC side of things would do anything at all. Ripple is an AC thing and any current spike on the DC side would drain the cap instantly. So unless that spike last for only few pico seconds its likely the cap doesnt have enough storage to affect anything. Its more likely getting a battery with a lower ESR would improve ripple more then trying to add caps. Just my $.02 but if it works for you great. The wires that came with the new trex 700 are really short. The only possible way you could mount the ESC on the back would be to route the wires down the center. And you would have to route all 3 down the center on the same side. There is not enough length to route one a different direction nor enough room to route it down the outside of the helicopter.
I specifically asked about the indcutance as well as the RC delay for extending the wires the amount I want and CC said it should be fine. That is why I provided them the total wire length. Now if the guy on the other end of the email knew what he was talking about that's another story I dont know. I will try it if it doesnt work I'll do something else.
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coolgabsi
Super Mod & DEAL KING!
I hope you know that I am familiar with Electronics and AC and DC current when I say what I say. Castle itself has a "cap pack" its not A capacitor but 6-7-9 capacitor banks.. made my YGE also.
You have a castle now, you go and open the castle log after flight. see "RIPPLE" there in the graphs. The ripple is generated on those DC wires because they are 8 or 10AWG wires. The load is CONSTANTLY being varied on the motor throughtout the flight. Yes the Capacitors will actually discharge as soon as load is applied, but oyu are not considering the fact that the capacitors are connected in parallel to the batteries and there to support drop in voltages caused by the inductance in those wires. you sy pico second ripples, open up your casltle graph and you will see milisecond ripples.. The ripples should not exceed more than 2percent of the total voltage of the system at that moment. any more than that, and you are running a risk of esc seeing low voltage and shutting the system down.
I have been at numerous fun flies, talked to numerous people who have actually been a victim of that because the wires from the battery solder point to the ESC solder point were longer than 11 inches-12 inches and longer.
Now you say that inductance is an AC parameter not DC. I know, but you are varying the curren intake on the esc side by a lot.. your motor could be using anytihign from 30A to 120 A withing a matter of few miliseconds sometimes. That "varying current" demand and load causes inductance to be a parameter in this DC system (atleast battery to the ESC) ..
Cap pack link form castle's own website :
Castle Creations | CC CapPack
YGE ESC company one i use:
YGE Cap Pack 7 | RotorQuest.com - Best R/C Helicopter Source in Canada
So yes these companies designed their product, and if I dont know what I talk about.. I bet they know.. and they market it right ?
Now that said. you extend your battery leads and will you see it in the first flight. May be not. Will you see it at all.. MAY BE NOT AT ALL
But.. I would rather protect my electronics power plant from a "may be" with a protection cap pack which costs me 20 bucks than to repair a fallen bird. if talking to a person not familiar with all the inductance jibber jabber.. the protection point in and of itself is good enough to use it.
Now you are extending the wires from ESC to motor. I want to let you know, I did not doubt for a moment, your understanding of all this,If castle gives you the green light.. I say go for it.
I have to put this info here BECAUSE this is a learning website. We have people who are Electrical engineers here who understand the nitty gritty of this topic to people who know nothing about this, and are easy to be mislead.I want to have this info out there. if you would like I will post my castle log here with all the ripples I see and how low it is with using the cap pack cause capacitors help the esc by making it see a "full tank" ( like a nitro header tank)
then you go fly without one, and we can compare ripple by ripple on the graph.. I am confident in this cause I did this to my own setup and get to the results
Choice is ofcourse the fliers
You have a castle now, you go and open the castle log after flight. see "RIPPLE" there in the graphs. The ripple is generated on those DC wires because they are 8 or 10AWG wires. The load is CONSTANTLY being varied on the motor throughtout the flight. Yes the Capacitors will actually discharge as soon as load is applied, but oyu are not considering the fact that the capacitors are connected in parallel to the batteries and there to support drop in voltages caused by the inductance in those wires. you sy pico second ripples, open up your casltle graph and you will see milisecond ripples.. The ripples should not exceed more than 2percent of the total voltage of the system at that moment. any more than that, and you are running a risk of esc seeing low voltage and shutting the system down.
I have been at numerous fun flies, talked to numerous people who have actually been a victim of that because the wires from the battery solder point to the ESC solder point were longer than 11 inches-12 inches and longer.
Now you say that inductance is an AC parameter not DC. I know, but you are varying the curren intake on the esc side by a lot.. your motor could be using anytihign from 30A to 120 A withing a matter of few miliseconds sometimes. That "varying current" demand and load causes inductance to be a parameter in this DC system (atleast battery to the ESC) ..
Cap pack link form castle's own website :
Castle Creations | CC CapPack
YGE ESC company one i use:
YGE Cap Pack 7 | RotorQuest.com - Best R/C Helicopter Source in Canada
So yes these companies designed their product, and if I dont know what I talk about.. I bet they know.. and they market it
right ? Now that said. you extend your battery leads and will you see it in the first flight. May be not. Will you see it at all.. MAY BE NOT AT ALL
But.. I would rather protect my electronics power plant from a "may be" with a protection cap pack which costs me 20 bucks than to repair a fallen bird. if talking to a person not familiar with all the inductance jibber jabber.. the protection point in and of itself is good enough to use it.
Now you are extending the wires from ESC to motor. I want to let you know, I did not doubt for a moment, your understanding of all this,If castle gives you the green light.. I say go for it.
I have to put this info here BECAUSE this is a learning website. We have people who are Electrical engineers here who understand the nitty gritty of this topic to people who know nothing about this, and are easy to be mislead.I want to have this info out there. if you would like I will post my castle log here with all the ripples I see and how low it is with using the cap pack cause capacitors help the esc by making it see a "full tank" ( like a nitro header tank)
then you go fly without one, and we can compare ripple by ripple on the graph.. I am confident in this cause I did this to my own setup and get to the results
Choice is ofcourse the fliers
Thanks for the info, Gaba.
I was screwing with things some more last night and think I figured out what I plan to do. If I have the ESC motor leads coming out the "top" then I end up with a lot of wires jammed into the area under the ESC plate. With the large elevator/anti-rotation arm there I'm not keen on this layout. So I tried flipping the ESC so the motor leads come out the bottom and I run them under the mounting plate. It is more or less a straight shot to the motor's leads. There is a canopy mount screw head that I'll have to protect against (probably wrap the bundle in velcro there), and this will not allow for easy access for disconnecting the motor wires, but there are a couple zip tie points along the way, it keeps everything in a more or less straight run and it is all inside the frame. The bad side of this is that the esc power leads are on the top. I'll have to fold to a side and bundle with the ESC in a velcro strap or zip tie.
Still playing with it. Hopefully come up with a final plan tonight.
I was screwing with things some more last night and think I figured out what I plan to do. If I have the ESC motor leads coming out the "top" then I end up with a lot of wires jammed into the area under the ESC plate. With the large elevator/anti-rotation arm there I'm not keen on this layout. So I tried flipping the ESC so the motor leads come out the bottom and I run them under the mounting plate. It is more or less a straight shot to the motor's leads. There is a canopy mount screw head that I'll have to protect against (probably wrap the bundle in velcro there), and this will not allow for easy access for disconnecting the motor wires, but there are a couple zip tie points along the way, it keeps everything in a more or less straight run and it is all inside the frame. The bad side of this is that the esc power leads are on the top. I'll have to fold to a side and bundle with the ESC in a velcro strap or zip tie.
Still playing with it. Hopefully come up with a final plan tonight.
coolgabsi
Super Mod & DEAL KING!
http://s55.photobucket.com/user/rttpanningen/library/700e wiring?sort=3&page=1
and also another pic attached:
see of this helps. Wish I had taken a pic of my wiring but mine was very very similar. THis is from a fellow 700 owner
and also another pic attached:
see of this helps. Wish I had taken a pic of my wiring but mine was very very similar. THis is from a fellow 700 owner
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My intent wasn't to pove anyone wrong that's why I said if it works for you great. Your voltage drop will be the voltage dropped across the ESR of the battery. As the current changes the voltage will drop proportional to that ESR. And yes I know you are a fellow EE. Much of this depend on how long those current spikes are and I have not logged that data myself so I don't have the complete picture. I can say that the capacitor bank is only able to dump a small charge since the voltage only fluctuates by a small amount. Most of the charge will stay in the capacitors. Since its an AC motor you may get a short enough on off time to make a difference.
Companies will sell whatever people are willing to buy. The large 1.5 farad capcitor in car stereos come to mind. There was a guy named Richard Clark that went into a long explanation of why they dont work (in car stereos as a stiffening cap) and was considered a guru by some and hated by others. I dont wish to repeat that here so I will say if it works for you great. I also don't have enough data to really draw any conclusions. Although I do think if you chose batteries that had lower ESR values you would see a bigger improvement over adding "stiffening" caps.
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Take pictures you have the same problem as me. I'm also curious as the total length of your wires from the ESC to motor. If your standing behind the helicopter I intend to run the wires down the right side of the tail box then its a straight shot under the main gear to the motor. I think when I am done it should be 10-12 inches max total length.
Tony
Staff member
Gaba, your inner electronics engineering geek is showing 
I completely agree though. Caps work for that split second burst that the motor is needing but the connection can't handle. It's something like the sump on an aquarium (you had to see this coming!). When you increase the water flow (power to the motor) the sump allows a little extra water to fill the aquarium until it can equalize again (letting off the power).
I completely agree though. Caps work for that split second burst that the motor is needing but the connection can't handle. It's something like the sump on an aquarium (you had to see this coming!). When you increase the water flow (power to the motor) the sump allows a little extra water to fill the aquarium until it can equalize again (letting off the power).
If you're trying to solve a fundamental current supply/flow issue due to undersized wiring or underpowered supply with caps, no that will not work. Taking the car stereo example. They will supply for a quick high draw sub hit, that would overpower your power system. However, they will do nothing to help you on a sustained tone (and by sustained we're talking a more than half a second or so) that is overburdening your system.
Applied to a heli, I suspect they will help on a very short duration current draw spikes (as long as they are spaced out enough) and as long as you are not critically restricting current flow such that the caps can't recharge. Basically if you are on the borderline between under supplying and being okay, they will make a difference. But if you have too long a run or too high a resistance in the bats or line to the ESC, the cap isn't going to do anything for you since it isn't going to supply makeup current long enough to cover the induced ripples and may not have enough time to recharge before the next current draw induced voltage dip.
Assuming the batteries are capable of delivering the current needed and also assuming there isn't really a true "short" duration current spike scenario in play with a heli, you'd probably be better off putting larger gauge wire from the bats to the ESC, trimming supplied leads down and replacing with larger wire as needed.
The cap is a stent, sometimes a bypass is called for.
That all said, I don't know if this heli needs a stent or a bypass. I'm running a lower current ESC than Gaba was. My flying is more tame by comparison. I'll inspect the esc logs once I finally get it in the air and see if there's any issue with ripple or under supply and decide then.
Applied to a heli, I suspect they will help on a very short duration current draw spikes (as long as they are spaced out enough) and as long as you are not critically restricting current flow such that the caps can't recharge. Basically if you are on the borderline between under supplying and being okay, they will make a difference. But if you have too long a run or too high a resistance in the bats or line to the ESC, the cap isn't going to do anything for you since it isn't going to supply makeup current long enough to cover the induced ripples and may not have enough time to recharge before the next current draw induced voltage dip.
Assuming the batteries are capable of delivering the current needed and also assuming there isn't really a true "short" duration current spike scenario in play with a heli, you'd probably be better off putting larger gauge wire from the bats to the ESC, trimming supplied leads down and replacing with larger wire as needed.
The cap is a stent, sometimes a bypass is called for.
That all said, I don't know if this heli needs a stent or a bypass.
I'm running a lower current ESC than Gaba was. My flying is more tame by comparison. I'll inspect the esc logs once I finally get it in the air and see if there's any issue with ripple or under supply and decide then.Sorry guys I didn't meen to derail the thread was just thinking out loud. Bad engineer bad
Caps can be used as stiffening devices they provide deminishing returns but they do work assuming they are of the ultra low ESR variety placed as close as possible to the load and the "charge" time is longer than the "discharge" time. Caps dont create current they store a charge and that charge must come from the battery. That being said my only comment was to highlight the ESR of the battery plays a bigger role in this not to say these caps dont work. I do not have enough data to say anything other than that really. I dont even have my 700 together yet.
Caps can be used as stiffening devices they provide deminishing returns but they do work assuming they are of the ultra low ESR variety placed as close as possible to the load and the "charge" time is longer than the "discharge" time. Caps dont create current they store a charge and that charge must come from the battery. That being said my only comment was to highlight the ESR of the battery plays a bigger role in this not to say these caps dont work. I do not have enough data to say anything other than that really. I dont even have my 700 together yet.