Exi/Trex 500 *Tray Mod* for using 3300ma+ 6s

[akent]

I had been running 2 x 2200ma 3s batteries in series with my Exi 500 for a while, which are my 450 batteries. I could get 6 and a half minutes on a charge, but the recharge sometimes would put these batteries near the danger zone for discharge. My homemade cable for this was rather long, and stuffing it up under the canopy was a pain to do.
I wanted longer flights, plus, I didn't want to worry about capacity and stuffed adapter wires maybe doing something bad.

So, I found some 3300ma 6s 20-30C batteries for $87 over at Hobby City. These are amazing. I haven't pushed them to the limit yet, and I flew tonight for 9 minutes! I am setting the timer for 8 and a half minutes though. I have put back varying amounts into these batteries so far, depending on how I fly, but none even close to the danger zone! I really believe that you could probably do 8 minutes of 3d with these batteries!
This time is about my limit for forward flight anyway...My nerves are pretty much shot by then!
Maybe someday I'll get jaded. Not yet!
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Anyway, These big ole batteries will just barely fit with squeezing the canopy over it, and it puts pressure on everything under there.

I searched and found a mod that works beautifully. This is not my mod, but I was thinking along similar lines.
Only two holes need to be drilled. It allows the battery tray to lower into the space under it and can allow even bigger batteries than this to be installed! This entire tray mod took me less than 5 minutes to do!
A huge bonus is that with this battery, placing it all the way against the servos will net you PERFECT CG!

This battery is definitely heavier than the others, but I can't tell a difference in flight at all. But I'm not doing 3d yet, with this bird.

Everything feels exactly the same as with the small batteries, other than the CG. Now it's not tail heavy.

As I may have mentioned before though, I think these 500's can lift small children without much trouble...
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Here's what the modded tray looks like with the big ole battery on it:

[akent]

To perform this mod, you need to remove the stock battery tray.

There are two screws in front and two inside the canopy rubber standoff.

I don't have a picture of this removed. Sorry.

Then you need to measure 5/16" below the original top screw hole on each side and drill the same size hole there. On my heli, the hole size was 0.1".

Then reinstall the tray with the front bolts through the new lower holes. Don't tighten them up too much yet.

[akent]

Then on the rear of the tray, take the original screws inside of the canopy standoffs and just screw those into the slot that the strap goes through!! How simple is that!

The rubber around it will center itself there.

[akent]

Then just tighten it all down and you are done!

[akent]

Or, if you prefer!

[akent]

A couple of notes:

I have the Align 60A Esc mounted below the battery tray. I did this as I like to be able to bring the heli out to the flight line with the canopy on and then connect it up. I found that if the ESC were on the better location for cooling (the side of the frame), that I couldn't do that.

I have found that the ESC still runs very cool, at least with this stock 500L motor. But again, I'm not doing 3d yet with it!
Kent

[Solitaire]

Pretty simple indeed. Thanks Kent.
That big ole 3300 is sure a brick.

[akent]

IT IS a BRICK, Sol!!!
Good analogy.

The 2x 2200ma 3S batteries are maybe 2/3 the length, but otherwise the same dimensions as this, so you can still run them with this tray mod. You just need to move them forward to make the CG work. I had the little batteries as far forward as I could get them before. Imagine that.

Hey Sol, what's the status of your 450 and 500?
Kent

[McKrackin]

I also moved my ESC under the battery tray.
I did it for purely aesthetic reasons though ;D

[Solitaire]

Finless's Trex 500 video on electronics placement shows his ESC under the battery tray as well.

Kent
I'm embarrassed to say the 450 has been on hold for two months. Basically together other than a fried Rx (my stupidity). Put it on hold due to the Spektrum fiasco. Still going back and forth with Horizon on the Dx6i, waiting for the RMA. I think they are hoping to stall me until it's out of warranty in June. Who knows.

Backup plan was to buy Doozer's repaired one, which just arrived last week. Now I just need to find the time to get back at it. The 500 was just shipped yesterday, although it was purchased last Fri and I still need to get a few more goodies for it.