700 Extreme build

[corona007]

Wow, Glad I made this choice in my new kit.

Outstanding workmanship. Can't believe how quick this build is going.

Just need placement of electronics...

It seems it could be a pain to plug and unplug electronics, I'm planning lipo placement under boom, Inside frame.

Is anybody using a switch to power electronics straight 2s lipo?

[rcmarty]

I'm not sure there are many that use a power switch on the rx lipo power.

The internal workings of even the jr hd switch have rather small pieces of metal to pass current from.

It looks like you have some 8917's in there. There as super power hungry as some but still up for condiseration.


The theory is to eliminate as many failure points as possible.

Myself i use the deans plugs on my setups. Take 3 HD servo leads to the radio gear ( either side of cyclics and another to the sbus rx ) to the deans connector and then the battery has the matching deans. The normal hd deans are drasticly overrated for the job , but more importantly is they take a bit to pull apart ( therefore won't come undone in flight )


On the other side of the coin , i had a debate going with anther member about using a 2s2p rx pack. This way if one cell were to fail it could save the heli.
Not certian that ir would , i guess it depends on how the lipo fails (as rare as a lipo rx failure is) in the open or closed postion and how it would affect the other in parallel cell.
I've had one motor lipo fail a cell , cell went to 0 volts but still passed current and voltage (less that cell of course ) In this situation , with proper mah logging of flights i can see the heli being saved by relying on the other cell to maintain 7.4 volts to the radio gear. A regular rx pack would drop to 4.2 volts and there's a good chance that's not enough.

Martin

[chrisansilver]

Originally Posted by corona007

Wow, Glad I made this choice in my new kit.

Outstanding workmanship. Can't believe how quick this build is going.

Just need placement of electronics...

It seems it could be a pain to plug and unplug electronics, I'm planning lipo placement under boom, Inside frame.

Is anybody using a switch to power electronics straight 2s lipo?

I am using a 2s straight to power electronics on my L700. I have it mounted under the frame on the rear and have switch mounted towards the top on the Left side. I also am running a Scorpion BUG just in case.

[corona007]

Thanks guys...

I'm thinking of getting different servos.

What would you guys recommend bls255 or bls 156?

[RyanW]

There is a photo in another post showing how Kyle has a 2s LiPo mounted on the back upright frame support. It seems to be simple and easy to get to. No reason to have a switch when the plug would be accessible with the canopy on.

[whytlotus]

If at some point you plan on using a heatsink on your esc, flip it over and then run your wires. I use BLS 156 on mine . They are more than adequate.

[Mathias]

I am also running a 2S 1300mAh pack directly. I will add a couple more power cables to supply the electronics from the EC3 plug just in case, though.

[corona007]

Originally Posted by whytlotus

If at some point you plan on using a heatsink on your esc, flip it over and then run your wires. I use BLS 156 on mine . They are more than adequate.

I fly 3D and do a few hard maneuvers throughout a flight but not the entire flight.
So is the heat sink necessary?

BTW, I picked up some bls156's
I guess I'll have some 8917HV for sale. lol

[Mentalic]

Originally Posted by corona007

I fly 3D and do a few hard maneuvers throughout a flight but not the entire flight.
So is the heat sink necessary?

BTW, I picked up some bls156's
I guess I'll have some 8917HV for sale. lol

I ended up installing a heatsink on mine because of running 753's was causing high temp alarms. To install the heat sink you have to flip the esc over so there is the reason for the suggestion of wiring it that way.
Don't like switches and use deans for power, WR bec, small 2s450mah ran to a WR battery buffer. The buffer is really just a diode switch with LED's.

[Jesse Kavros]

I am curious as to why you would be selling the 8917s for the BLS156HV's. While I have run the BLS157s on my heli and had no issues at all, I am now using the 8925s(european version of 8917s) and my efficiency is almost exactly the same as a matter of fact. The BLS156s I feel, will be a bit too slow, just my opinion though. The BLS157s I had, obviously had plenty of torque running on a direct 2s lipo(all 513oz/in ), but I felt the speed was a bit too slow.

Therefore, I sacrificed a little bit of torque for speed, and overall have a happier flying machine that still will have a great locked in feel. Now if we were talking about an 800 I would say go with higher torque servos, but for a 700(even with its weight) I would opt for a faster servo with a little bit less torque.


Keep in mind I have run 8717HVS, BLS157HVS, and 8925HVS on my 700 and have conclude with the 8925 as being the all around good servo(for my flying), with a good speed of around .07 or .06 and torque of about 230 oz/in on a 2s lipo, that is a good amount of torque for this machine while retaining higher speed.


Just my results of testing and thoughts.


Jesse

[rcmarty]

I went with the 8917 because they were a bit less and had a 3 yr warranty

I wanted some bls futabas but even on Black Friday I was we'll over 500

Why ...

What are your thoughts on the heats ink for stock setup running on the 30-35c range ?
( 80-90f)

Martin

[corona007]

Originally Posted by Jesse Kavros

I am curious as to why you would be selling the 8917s for the BLS156HV's. While I have run the BLS157s on my heli and had no issues at all, I am now using the 8925s(european version of 8917s) and my efficiency is almost exactly the same as a matter of fact. The BLS156s I feel, will be a bit too slow, just my opinion though. The BLS157s I had, obviously had plenty of torque running on a direct 2s lipo(all 513oz/in ), but I felt the speed was a bit too slow.

Therefore, I sacrificed a little bit of torque for speed, and overall have a happier flying machine that still will have a great locked in feel. Now if we were talking about an 800 I would say go with higher torque servos, but for a 700(even with its weight) I would opt for a faster servo with a little bit less torque.


Keep in mind I have run 8717HVS, BLS157HVS, and 8925HVS on my 700 and have conclude with the 8925 as being the all around good servo(for my flying), with a good speed of around .07 or .06 and torque of about 230 oz/in on a 2s lipo, that is a good amount of torque for this machine while retaining higher speed.


Just my results of testing and thoughts.


Jesse

Well I read somewhere in a couple of spots that the 9817 were really power draining hungry.
And I had cash burning a hole in my pocket, lol


But now that you mention all this I will probably stay with the 8917.
I'm sure the site will take the return.

I have seen your flying so I feel safer taking this advice coming from a pro!

Thanks you Jesse....

[rcmarty]

The big power servo's out there these days can draw a fair bit of current.

Some are better than others while some have better specs.

The power demands is why many are choosing to run a rx pack instead of a bec.

There are some servo's out there (align hv for ex) that are too much for even a high quality bec like the WR unit.

I'm sure the next generation of servo's will be a rx pack only deal , or the next generation of bec needs to be built.

Either way the 8917 and futaba bls (and many other) servo's are all a great choice.

I'd assume it would also take a great deal of skill to be able feel and/or benifit from the small differences in the servo choices out there. If you have this talent then it's extra money well spent. If your talent is getting there then that opens up for debate on the extra costs. (maby an extra battery would be more effective at this time)

From what i've read on the 8917 there a great servo. Kyle has had great success with JR servos of this caliber. Kyle's dad commented that the 8717hv and the equivelent to the 8917 they run are good to 1200 + flights.

Martin

[Jesse Kavros]

Not a problem, just glad to help and share the results from my findings.

If you ever need any help, go ahead and drop me a pm and I will do my best to get the questions answered!



Jesse

[dahld]

There was a question a few posts back asking if the ESC heat sink was really necessary for 3D flying (using the stock 713mm blades). No it's not. I say this as Kyle flies in some vary hot conditions throughout the year (Bakersfield, Calif.), and we've yet to ever get an overheat warning (no heat sink installed).

It's needed on the Logo 800 swinging the larger 813 disc, and even the 753's will cause the ESC temps to climb some. But with 713's...no problems.

And the comment about JR servos lasting a long time. As hard as they get abused on the 700 (talking about the 8717, 8917, 8925 series), I'm amazed even to this day how long they last. Not that there aren't other good makes that are durable as well...I'm not starting a VS. thread. But it's amazing to me the servos can routinely go 1000+ flights (never had a failure under 1200 flights). Once installed, they are the last thing on the heli we worry about.

(-: Dave

[corona007]

Wooohoo, Finally done!

[corona007]

Finally got to properly maiden this, Did 3 flights. Opened her up on the third.
Absolutely amazing machine. And really fun to fly.

[rcmarty]

I got the chance to lean on the heli today.

Took all i could throw at it and come out like a champ.

I've got some minor tweaks to do but i know this is going to be one nice heli.

Martin