Trex-500 HANGAR - Page 22

hancockdw · Nov 04, 2009, 10:43 AM

Quote:

Originally Posted by RotorJockey

LOL,

Doesn't matter to me, Dave!

The first thing I do is cut the connectors off any way and install Deans.

BTW, the last 2 battery orders I have placed, they've sent me free bags of Deans style connectors.

Not sure they will for a single pack, though.

Fred

I guess they're trying to get rid of those fake Dean's since they can't sell 'em anymore. Actually I'm using the XT60s on my bird (or I will if it ever gets finished). I think they look pretty good!

hancockdw · Nov 04, 2009, 10:46 AM

Quote:

Originally Posted by RotorJockey

jmpwnd,

That's our point! (Me & Prozac)

Just because the battery is capable of higher draws doesn't mean that's what's being drawn, just the capabilities of the battery. Higher C rating on a battery is not going to have any effect on the rest of the power system.

The motor and ESC determine the draws and the battery just needs to be capable of delivering at least that much.

If you have a little overkill on the battery capabilities it doesn't have to work as hard, won't overheat and won't puff.

And we shouldn't trust the C rating on the label! I have 3000mah 20C batts, which *should* be OK for me at least early on, until actually learn to fly this thing. But are they actually 20C? I wouldn't bet on it.

Dave

hancockdw · Nov 04, 2009, 01:17 PM

I watched the Finless Bob build videos. Bob put the ESC under the battery tray. But I notice in the flight review video he was using a pair of 2200mah 3s batts. I'm going to run (as I said earlier) Turnigy 3000mah batts on a lowered battery tray. BEC will go somewhere on the side, rx and gyro on the radio tray and the top of the boom block, I suppose.

With this arrangement will I be OK WRT CG? Would the ESC work mounted sideways on the bottom tray under the main gear, or is that too close to the rx?

Dave

raynet11 · Nov 04, 2009, 01:23 PM

Quote:

Originally Posted by hancockdw

I watched the Finless Bob build videos. Bob put the ESC under the battery tray. But I notice in the flight review video he was using a pair of 2200mah 3s batts. I'm going to run (as I said earlier) Turnigy 3000mah batts on a lowered battery tray. BEC will go somewhere on the side, rx and gyro on the radio tray and the top of the boom block, I suppose.

With this arrangement will I be OK WRT CG? Would the ESC work mounted sideways on the bottom tray under the main gear, or is that too close to the rx?

Dave

I used the stock mount location, no issues, I guess if your tail heavy under the tray would be good but I'm using 3000mah packs so that wasn't a worry

(keeping it from being nose heavy was instead.. )

RotorJockey · Nov 04, 2009, 01:35 PM

Quote:

Originally Posted by hancockdw

I watched the Finless Bob build videos. Bob put the ESC under the battery tray. But I notice in the flight review video he was using a pair of 2200mah 3s batts. I'm going to run (as I said earlier) Turnigy 3000mah batts on a lowered battery tray. BEC will go somewhere on the side, rx and gyro on the radio tray and the top of the boom block, I suppose.

With this arrangement will I be OK WRT CG? Would the ESC work mounted sideways on the bottom tray under the main gear, or is that too close to the rx?

Dave

Dave,

Your CG will be fine.

I've lowered the tray on both of mine and have flown up to 3300mah Flight powers. The bigger batteries tend to get warmer because due to the size there is less circulation around them.

With the tray lowered, I still mounted the ESC on the bottom of the battery tray without any problems. I did it just to have a cleaner appearance.

Fred

hancockdw · Nov 04, 2009, 01:42 PM

raynet: I presume you mean that your ESC is strapped to the side of the frame?

rotorjockey: Thanks. So you balance OK that way with no trim needed?

Looks like I have options! I like as neat an installation as possible, but it can be a pain routing things. The wires on the ESC are kinda short!

Dave

Rickn816 · Nov 04, 2009, 03:46 PM

Quote:

Originally Posted by RotorJockey

Dave,

Your CG will be fine.

I've lowered the tray on both of mine and have flown up to 3300mah Flight powers. The bigger batteries tend to get warmer because due to the size there is less circulation around them.

With the tray lowered, I still mounted the ESC on the bottom of the battery tray without any problems. I did it just to have a cleaner appearance.

Fred

I like my ESCs in the rotor wash. They can get warm.

Rick

hancockdw · Nov 04, 2009, 04:08 PM

Quote:

Originally Posted by Rickn816

I like my ESCs in the rotor wash. They can get warm.

Rick

Good point.

Dave

RotorJockey · Nov 04, 2009, 08:02 PM

Quote:

Originally Posted by Rickn816

I like my ESCs in the rotor wash. They can get warm.

Rick

Which is why I did temp checks on mine to be sure they weren't getting too warm.

105 degrees is the most I've ever seen. That was after a very hard flight.

The only time it's in rotor wash is when you're at a hover.

Fred

prozac · Nov 04, 2009, 08:59 PM

Quote:

Originally Posted by jmpwnd

This is interesting, as the 40C packs would give a max continuous current of 106A compared to the Align 500L motor, which runs at a max continuous current of 35A with bursts to 45 - 50A. In fact, this article at Trextuning.com does a comparison of the Align, Medusa, and Scorpion 500 motors and shows max current draws of 50 - 55A...although this is on a 5S power system, but the spec reads as follows:

Align 500L Motor Specifications:
-Input voltage: DC11.1V-22.2V 3-6cell Li-Po
-Max continuous current: 4S 45A/55A(30sec), 6S 35A/45A(30sec)
-Max output power: 650W/800W(30sec)
-KV value: 1600KV
-Dimension: spindle 5x36x61.1mm
-Weight: 200g (prox.)

To me, it would seem rather excessive to use a 40C pack (even though in this case, I think they're cheaper!

), but I didn't think about how their discharge rates vary with number flights logged. Prozac, do you see a noticeable difference in the low versus high C packs? Are you saying that after only around 20 cycles, you see an obvious difference in the peak current capabilities of the pack? This is definitely a consideration that I had not previously made...

Still learning here, so let me know what you think. Thanks!

I've run some packs that were supposed to be 25c. After only a short time the packs were getting very hot, puffing, and the head speed sounded slow. Using a better pack (the new hyperions) you can hear a difference, the packs don't come down as hot, and generally preform better (less bog on collective changes). heat is the biggest killer of a Lipo.
Another thing to think about, is not just power out. Your pack has to put out more than 800watts of energy to get 800watts from the motor. there are losses in the system. Just something to consider. Nothing scientific.
Also, my esc is under the battery tray, never hot. motor gets hot.

raynet11 · Nov 05, 2009, 08:38 AM

The Hyperion G3's are amazing, my Mini Titan used to beat packs of all brands into submission. Picked up some G3 2200's and not only do the packs come down cool as can be the heli now has stump pulling power , more power then I know what to do with. I will be ordering two 6S packs for my Trex 500 and Sniper II this spring along with Hyperion's 200watt charger so that I can cook them at 3C , I'm charging my 2200's at 5C , the packs charge so fast that I can fly till the cows come home or at very least until my Tx battery goes dead..

jmpwnd · Nov 05, 2009, 10:44 AM

Prozac and Fred,

Alrighty! I'm convinced...I'll check out the 30C and 40C batteries.

That makes sense to me...I'm not interesting in wasting money on batteries that are going to lose their "kick."

Also, an update: I should be getting my ESP kit in the mail today or tomorrow!

I can't wait!

Cheers,
-->Justin

RotorJockey · Nov 05, 2009, 10:53 AM

Quote:

Originally Posted by jmpwnd

Prozac and Fred,

Alrighty! I'm convinced...I'll check out the 30C and 40C batteries.

That makes sense to me...I'm not interesting in wasting money on batteries that are going to lose their "kick."

You won't regret it.

Also, an update: I should be getting my ESP kit in the mail today or tomorrow!

I can't wait!

KOOL, Keep us posted on the build!

Cheers,
-->Justin

Tip: If you are going to do the battery tray mod, clamp both halves of the frame together and make your cuts and drill your holes before you assemble the frame. Makes it ALOT easier.

Fred

RC Man · Nov 05, 2009, 12:09 PM

That’s exactly the way that I do it also. Get a new set of frames. Bolt them together. Then trim and drill them before assembly.

jmpwnd · Nov 05, 2009, 03:36 PM

Do I need to drop the tray with the 2650-30C and 40C packs? I thoght the concern was for the 3000mAh packs. I think I just read that Align just released a new frame that doesn't need to be modded...someone over on helifreak said that they've been shipping them in the recent (5-6 weeks) kits, too. I'll have to dig back through the thread when I get home tonight to figure out which packs need the mod though before I do anything. Thanks for the advice!

Nov 04, 2009, 01:17 PM	#318
hancockdw Wing Count: 3 fixed, 3 rotary Join Date: Jun 2007 Location: Near Dallas, TX Posts: 1,707	electronics placement I watched the Finless Bob build videos. Bob put the ESC under the battery tray. But I notice in the flight review video he was using a pair of 2200mah 3s batts. I'm going to run (as I said earlier) Turnigy 3000mah batts on a lowered battery tray. BEC will go somewhere on the side, rx and gyro on the radio tray and the top of the boom block, I suppose. With this arrangement will I be OK WRT CG? Would the ESC work mounted sideways on the bottom tray under the main gear, or is that too close to the rx? Dave

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Nov 04, 2009, 01:42 PM	#321
hancockdw Wing Count: 3 fixed, 3 rotary Join Date: Jun 2007 Location: Near Dallas, TX Posts: 1,707	raynet: I presume you mean that your ESC is strapped to the side of the frame? rotorjockey: Thanks. So you balance OK that way with no trim needed? Looks like I have options! I like as neat an installation as possible, but it can be a pain routing things. The wires on the ESC are kinda short! Dave

Nov 05, 2009, 08:38 AM	#326
raynet11 Sponsored by Team Me Join Date: Aug 2005 Location: Montgomery, IL Posts: 6,400	The Hyperion G3's are amazing, my Mini Titan used to beat packs of all brands into submission. Picked up some G3 2200's and not only do the packs come down cool as can be the heli now has stump pulling power , more power then I know what to do with. I will be ordering two 6S packs for my Trex 500 and Sniper II this spring along with Hyperion's 200watt charger so that I can cook them at 3C , I'm charging my 2200's at 5C , the packs charge so fast that I can fly till the cows come home or at very least until my Tx battery goes dead..

Nov 05, 2009, 10:44 AM	#327
jmpwnd Justin is back after 10 years! Join Date: Oct 2009 Location: Redmond, WA Posts: 78	Prozac and Fred, Alrighty! I'm convinced...I'll check out the 30C and 40C batteries. That makes sense to me...I'm not interesting in wasting money on batteries that are going to lose their "kick." Also, an update: I should be getting my ESP kit in the mail today or tomorrow! I can't wait! Cheers, -->Justin

Nov 05, 2009, 12:09 PM	#329
RC Man A man with too many helicopter Join Date: Feb 2001 Location: Illinois Posts: 10,714	That’s exactly the way that I do it also. Get a new set of frames. Bolt them together. Then trim and drill them before assembly.

Nov 05, 2009, 03:36 PM	#330
jmpwnd Justin is back after 10 years! Join Date: Oct 2009 Location: Redmond, WA Posts: 78	Do I need to drop the tray with the 2650-30C and 40C packs? I thoght the concern was for the 3000mAh packs. I think I just read that Align just released a new frame that doesn't need to be modded...someone over on helifreak said that they've been shipping them in the recent (5-6 weeks) kits, too. I'll have to dig back through the thread when I get home tonight to figure out which packs need the mod though before I do anything. Thanks for the advice!