How to - 12s T-Rex 600 Setup On A Budget.

[rceccleston]

Originally Posted by jones007

Are you confident that there's not a calibration issue with your EagleTree datalogger? The plot indicates a meager 9Amps in hover - that's only about 430Watts. That seems quite low for a Trex 600 at a 1900RPM headspeed. Granted, the stock motor is not very efficient, but at 1750 headspeed, I measure about 570W in a hover. If moving to 12S really reduces power draw that much, that's a pretty nice selling point. One way to verify the calibration would be to check that the mAh replaced in the packs during charge is close to the indicated mAh drawn from them during flight.

--Kevin

Thought the low amps could be the result of lower drag caused by the absent flybar and paddles with his flybarless setup.

[jones007]

Originally Posted by rceccleston

Thought the low amps could be the result of lower drag caused by the absent flybar and paddles with his flybarless setup.

That's possible. Have you ever seen anyone post data-log charts for a heli before and after conversion to flybarless? Everyone claims power savings, and intuitively there should be some, but I've never been able to find quantified data. I'd love to see some. You save on both weight and aerodynamic drag, but probably pay a small penalty due to a slightly slower stability control loop.

There's a very strong correlation between headspeed and power required. Some time ago I was working with an old-model Trex 600e with a stock motor, trying to maximize endurance, and as a sample, with a 10-tooth pinion, and 6S pack, it went from 480W at 1590HS to 535W at 1690HS to 585W at 1780HS. Of course the motor has a most efficient RPM as well, so to do this right, you would really want to gear it in each case to operate at the most efficient motor RPM. I don't think I can go smaller than 10 tooth though.

--Kevin

[Chanq]

Here is my last flight, now with 2000rpm which flies great btw.


Average amp: ~13A


This was with 1900rpm. Average amp: ~9A


And this is one before the 12S setup. Not very clear but HS was 2100 and average Amps of 45. With V-bar!


So, I don't think my logger doesn't function properly. I also checked the mah I putted back in and it correlated fine with what the chargers said. Also on my 450 it gives the proper results. I'll guess the 12S setup is just very efficient and thanks to the V-bar consumption is very low. Please note this were only hoovers, weather is not permitting me to fly at the field. Everything comes down cold as well so that also supports the data.

All I can say is I love this bird at 12S and flybarless A HS of 2000 flies really nice, great stability and enough pop for me. Combined with the 3300mah lipo's I get a very decent flight time of at least 10 minutes. Maybe when the current goes up due to real flying it will be around 8 minutes which I think is still very good.

[jones007]

Thanks for the updates. That looks impressive. Might have to try 12S.

--Kevin

[rceccleston]

Originally Posted by jones007

Thanks for the updates. That looks impressive. Might have to try 12S.

--Kevin

I have no regrets making my T-Rex 600 12s from day one.

While it may cost more to purchase 2x 6s 3000Mah packs, in the long run, it works out alot cheaper due to the increased life cycles of the packs.

[adroc3905]

I am at the point in my 12s build where I am ready to program the CC85 HV and CC Pro BEC.
Is there anything important that I should be setting either of these two components up with using the CC data cable?

How about DX7 settings with regards to TC and PC? Idle up mode? I have the same setup as most - CC85 HV/4025-630kv/CC Pro BEC/12T pinion.
I do have a 13T waiting in the parts bin for later.
I keep reading about "fixed end points". What does that mean?

I have never bothered with Eagle Tree Logger before but I may now consider it since it seems to help maximize efficiency. Where to purchase?

Thanks

BTW anyone thinking of upgrading their frame to the Custom Heli Parts 2mm CF frame - it works great. I installed one on my 600e and the frame allows for the bigger scorp motors to fit w/o cutting. Also, mine arrived already sanded on all the exposed edges....unlike the stock ones. Very smooth.

[rceccleston]

Originally Posted by adroc3905

I am at the point in my 12s build where I am ready to program the CC85 HV and CC Pro BEC.
Is there anything important that I should be setting either of these two components up with using the CC data cable?

How about DX7 settings with regards to TC and PC? Idle up mode? I have the same setup as most - CC85 HV/4025-630kv/CC Pro BEC/12T pinion.
I do have a 13T waiting in the parts bin for later.
I keep reading about "fixed end points". What does that mean?

I have never bothered with Eagle Tree Logger before but I may now consider it since it seems to help maximize efficiency. Where to purchase?

Thanks

BTW anyone thinking of upgrading their frame to the Custom Heli Parts 2mm CF frame - it works great. I installed one on my 600e and the frame allows for the bigger scorp motors to fit w/o cutting. Also, mine arrived already sanded on all the exposed edges....unlike the stock ones. Very smooth.

Fixed end point is normal mode where the rpm of motor is increased in relation to the throttle stick, with a linear throttle curve.

Governor mode is a feature of the esc which maintains a set headspeed dictated by a flat line throttle curve, regardless of the position of the throttle stick.

[BPINE]

Originally Posted by rceccleston

Fixed end point is normal mode where the rpm of motor is increased in relation to the throttle stick, with a linear throttle curve.

Governor mode is a feature of the esc which maintains a set headspeed dictated by a flat line throttle curve, regardless of the position of the throttle stick.

I run mine with a 85 flat in idle 1 and 95 flat in idle 2 no governor that is considered fixed end points as well right?

[adroc3905]

Originally Posted by rceccleston

Fixed end point is normal mode where the rpm of motor is increased in relation to the throttle stick, with a linear throttle curve.

Governor mode is a feature of the esc which maintains a set headspeed dictated by a flat line throttle curve, regardless of the position of the throttle stick.

Ok I guess what throws me off then is the verbage. For example:

On my 500 ESP I run a 100-95-90-95-100 TC in idle up mode. It could be a flat line if I choose. I thought setting the TC like this helps maintain a constant motor RPM speed regardless of throttle position? Is this not similar to governer mode in an ESC then? Or are they still different?

[rceccleston]

Originally Posted by BPINE

I run mine with a 85 flat in idle 1 and 95 flat in idle 2 no governor that is considered fixed end points as well right?

Yes.

[rceccleston]

Originally Posted by adroc3905

Ok I guess what throws me off then is the verbage. For example:

On my 500 ESP I run a 100-95-90-95-100 TC in idle up mode. It could be a flat line if I choose. I thought setting the TC like this helps maintain a constant motor RPM speed regardless of throttle position? Is this not similar to governer mode in an ESC then? Or are they still different?

In theory, your 'v' curve in fixed end points will help to maintain a similar headspeed under load but this is not electronically monitored or regulated, so the headspeed can vary.

However, the governor built in to the esc, uses a flat line throttle curve to dictate the chosen headspeed which electronically monitors and maintains the same headspeed by automatically increases or decreasing the throttle.

Castle Creations recommend gearing at 85% throttle, for the desired headspeed, to allow a 15% over head for the governor to increase the throttle under load.

[Finless]

Made a sticky by user request!

Bob

[Chanq]

I went 13T because I use the governor. It gives a bit more headroom. The motor can handle it fine. The software may say the gearing is off for some sort of headspeed. My normal is 1900 which is accepted by the software, ilde up is 2000 which is a red number, at least says the castle software. It works great though So don't put to much energy in that. Set rpm is btw very easy. Simply answer the things the software asks and there you have your desired headspeed. I checked it with my Eagletree and it is spot on, didn't expected that. I first went with gov-low and gov-high but all that isn't necessary with set rpm. Make sure the first time you use fixed enpdoints though since it is important for the esc to know what your endpoints are.

Only things that bugged my during set up:
- Autorotation option. I had it enabled but during spool up I always have the stick in lowest position causing problems with this setting. It will 'shut down' when it reached the desired headspeed. Just a hair above the low endpoint is fine. I simply disabled it.
- Motor startup power. Since the 4025-630 is quite powerful the heli spins during spool up. Not 360gr. but sometimes at least 120gr. Due the spinning the V-bar acted odd. I could compensate it with setting the spoolup rate to slow but it takes ages for spool up then. In stead I changed the initial motor power to the lowest setting which solved the problem. Took a while to find that out though.

[adroc3905]

Awesome, thanks everyone for the input. Does the Castle software have a HS calc or should I use something like the Redyheli calc? I have no idea what my HS is currently.

[rceccleston]

Originally Posted by adroc3905

Awesome, thanks everyone for the input. Does the Castle software have a HS calc or should I use something like the Redyheli calc? I have no idea what my HS is currently.

Readyheli's headspeed calculator is good start but it can't take into account for the manufactures 5% tolerance for kv values.

[Chanq]

Originally Posted by adroc3905

Awesome, thanks everyone for the input. Does the Castle software have a HS calc or should I use something like the Redyheli calc? I have no idea what my HS is currently.

It doesn't have a calculator but you can MrMel's calculator. It works quite good. click here . You should be aiming around 2000-2100. When you got your setup worked (motor, gearing etc. ) out, you can tell the Castle Software which headspeed you want and presto, there you have it

[adroc3905]

Originally Posted by Chanq

It doesn't have a calculator but you can MrMel's calculator. It works quite good. click here . You should be aiming around 2000-2100. When you got your setup worked (motor, gearing etc. ) out, you can tell the Castle Software which headspeed you want and presto, there you have it

Awesome. thanks
Should I always use 85% efficiency for an outrunner motor? (scorp 4025-630kv)
Here are my results:

Voltage for this calculation (avg):3,552/cell with a total of 42,624
Nominal voltage: Spoolup RPM 100% throttle no governor (44,4v): 2139
Avg RPM you will see with 100% throttle and no governor: 1991
Max normal bogging applied you will see RPM at: 1745

[adroc3905]

Rceccleston - I thought I read somewhere here that you have a fan system to keep components cool. Care to go into more detail on that?

[rceccleston]

Originally Posted by adroc3905

Rceccleston - I thought I read somewhere here that you have a fan system to keep components cool. Care to go into more detail on that?

Sorry, not me, all components run a little warmer than ambient so no cooling fan required.

[Shef]

Does anyone have a governor file they can post for their 12S setup that doesn't produce undergeared results (red numbers) in the software?

Thanks.