Very Slow HK-500 Build

[rcdbutz]

So I decided to purchase a cheap HK-T500 (Trex 500 clone) kit, thanks to a link provided by Big Ern. The kit is on backorder, as well as some other parts, so it will be a slow build for sure. Either way, it should be a fun heli when I'm done and I'm sure I'll have questions for all of you 500 size owners along the way.

I went cheap on the kit, the ESC and the Gyro, and mostly Align parts on the rest. Here is what I have coming:

1 x 24k gilt terminal - K10149A-1 (K10149A-1)

4 x Align DS520 Digital Servo K10420A (K10420A)

1 x Align 500L Brushless Motor(1600KV) RCM-BL500L (KX870001A)

1 x Deans Ultra Male-Female Pack (DEANSULTRA)

1 x OUTRAGE XP25 6S1P 22.2V 2500mAH 25C - XTREME POWER SERIES - T-REX 500 (OXP25-25006)

1 x xmhobbies digital gyro G401B

1 x CNCHELICOPTER XME-60A ESC for trex450 HDX450 3dx500 HDX500 etc RC helicopter

1 x "Rhino Gear" Ultra Hardened Steel Pinions - 0.6M 13T - T-REX 500 (HR1039)

1 x Spektrum DSM2 AR6200 6-Channel Receiver Ultralite (SPMAR6200)

So, that's it for now, more to come...

[McKrackin]

That's some really nice stuff ;D

Can't wait to see it.
I think I'll do one too

[akent]

Just IMO, but the 13t pinion on the 500L with plastic head and tail?

I would recommend going lower here, unless that 500 is good with plastic.

Oh man, that made me get off the pot for an Exi 500 build thread. This thing is the best deal on the planet right now, IMO. But it is $120 more than the HK500! More metal than an Align!

[McKrackin]

Definately replace the plastic main blade grips with metal.
Plastic is actually dangerous.
You'll want to try for 2200-2400 rpm at the head and plastic grips won't hold those heavy blades for long.

[Solitaire]

HK500 is back in stock.
181 available at this point.

[rcdbutz]

OK guys, I've got the heli put together...finally. I've flown it a few times (just hovering, nothing crazy) and the plastic seems to be holding up OK. I was having issues with the power going to the receiver. Apparently those DS520 servos are pulling a lot of current, so I attached an external BEC and another battery for the Rx and now it is flying just fine. Don't sure I like the extra weight though.

Certainly learn a lot when I build these things rather than getting them RTF all of the time. What is the calculation for the RPMs I'm using? Should I go down to a 12T pinion? I really don't want to put in on the shelf while I wait for metal grips to come in the mail, but I don't want the blades flying towards me either. Anyone know where I can find some metal grips for this thing at a reasonable price?

Anywho, I'll try to get some pictures of it in here. The canopy is still just white, but I'll do something cool with it here soon. It was such a great feeling to fly the heli after I ordered the parts and the kit and put it together myself. I'll probably being doing my own builds from now on.

[elkmaster01]

RC,,,,,,,you have a 162T main gear,,,,,so 162/13T(pinion)=12.46,,,thats your gear ratio.So,,,

1600(kv)/12.46=128.41,,,,,X 22.2(v)= 2850,,,,X .9(motor efficiency) = 2565 rpm headspeed on the setup you have.

Change that to a 12T;

162/12 = 13.5 1600/13.5 = 118.51 X 22.2 = 2631 X .9 = 2368 rpm headspeed. You will drop 200 rpm with the 12T pinion,,,which,,if you are staying with plastic grips,,might be a good idea!

Hope this helps!

Randy

[rcdbutz]

Thanks Randy. The kit came with a 12T and a 13T pinion, so I figured either one would be good. I suppose I could throw the 12T on tonight, just to be safe.

[rcdbutz]

OK, so I replaced the 13T with the 12T, and it seems to fly pretty smooth, and the plastic grips like the lower head speed. I finally took some pictures:





And a nice little video of the third hover flight. The gyro is almost set right, but there's still a little wag in the tail. In the flight before this, I tried putting it in to idle up mode, but it didn't seem to like the extra head speed. I'll have to look for some cheap metal blade grips. Anyway, here's the video:

[rcdbutz]

Alright, I got the canopy painted this weekend, here is a new pic:



It's not the best, but it works. I learned that I'm not meant for airbrushing.

The metal blade grips came in the mail today too, so I'll be throwing those on, as well as put on the 13T, when I am done with work today.