450 Derek's Trex 450 Pro DFC

[Derek]

Derrick u better put that 450 in the air before u shelf it bud... Uv been work'n on it a good minute.. Time to fly! U guys still have a white out tho huh?!

Yeah man, we still have the white stuff. I have about 8" of snow in my yard and today's high temperature is only 15 degrees. I'm not flying anything outside. It's ok though, I am working tonight and tomorrow night anyway. I did see in the forecast that mid 30 tempertures, into the 40's in on the way, so hopefully I can get back to flying real soon.

 

[Ken Jackson]

That's all you got Derek. We got hit Saturday night with 8" fresh snow overnight. It fell on the glacier piles all around. Last week everything started to melt then sub zero hit again and hardened all the snow banks, then fresh powder to hide it. Don't hit one of those snow hills you'll total your car, Lol

Ken

 

[Derek]

So, I've been through Tony's videos on setting up the 3GX. Thank you, Tony, for those.

It's been a couple of days since I've been able to mess with the helicopter but I'm off today and tomorrow so I'm hoping to get to the maiden flight real soon. I got to thinking, today, that I've not enabled the Gyro menu in my DX8. It still shows "INH". I imagine that I should enable this menu so that I can make adjustments to the gyro. Am I right in thinking this or is there something that I've missed from the videos?

 

[pvolcko]

Nope, you need to enable that in order to be able to set gyro gain setting from the Tx.

 

[Derek]

That's what I thought. Thanks.

 

[Derek]

Is there a rough number that I should look to start with for the gyro setting or should I just enter a number, see what happens, then adjust from there?

 

[Slobberdog]

I think I have mine at 45%

 

[Derek]

Thanks for the starting point, Kev! I appreciate it!

 

[Tony]

I start mine out at 35% on the 3GX. But, somewhere between there and 45% is a good starting point.

 

[Derek]

Thanks for the reassurance, Tony! It's always appreciated!

 

[Derek]

So, I was going to take the 450 out for a test hover and I got to thinking...does the 3GX just automatically know how to adjust for the tail gain? I'm asking this because there is no set of wires that go to a "Gyro" port or channel. If I make an adjustment to the gyro gain, will it know? and how would it know?

Keep in mind, this is my first 3GX, so I'm learning.

 

[Tony]

You are only using Satellites, right? If so, then your gyro channel is on Aux2. Make sure in your gyro menu, your channel is set to aux2 and NOT gyro. Set it to 35% and head outside. Make sure you have a green status light on the gyro.

I know, I answered this already, but this will help someone in the future.

 

[Derek]

Yes, you answered this early but I surely don't mind you answering my question again. This may come in handy for later reference for myself.

Yes, I'm using 1 satellite rx. The "Gyro" menu is not enabled and the "Channel" is now set for Aux2.

Yes, I have the green light.

Maiden hovering coming this weekend. I have several 3S 2200mah lipos here but I order two brand new Nano Tech 3S 2200mah 45-90C lipos when I ordered the other parts. I'll get the Deans plugs soldered to the new lipos tonight.

 

[Tony]

Yes, I'm using 1 satellite rx. The "Gyro" menu is not enabled and the "Channel" is now set for Aux2.

If its not enabled, then enable it lol. But I'm sure you meant its set on Aux2 and you have enabled the gyro menu. I hope lol.

 

[Derek]

Yep...my fault...typo

My Gyro menu is "now" enabled....good catch buddy! sorry about that!

 

[Tony]

haha, sounds about like my day... Tore a transmission all the way down, then the guy tells me that he is not going to rebuild it after telling him his low/reverse clutches are metal to metal... I tossed the trans back together and left out the 2nd gear band and the bearing between the forward and direct drum. He will NOT be driving with this transmission until he pays me money for the teardown and inspection.

Needless to say, I'm a little pissed off.

Good deal on the typo lol. Had to get this back on topic. Sorry about that. lol.

 

[cml001]

Viscous!

 

[Derek]

I just did a bench test with my 450 Pro DFC. I spun it up with no main blades, no tail blades......I saw zero vibrations. Awesome!! I added the tail blades....I saw zero vibrations. Awesome!!! I added the main blades....I saw zero vibrations. Mega awesome!!! So, I take the 450 out to the yard for a hover attempt. This thing is just screaming!!!!! This is nothing like the other 450 that I flew in late 2013. I dunno if maybe the 3600kv motor that I have is too much or the 12 tooth pinion is too much but WOW! I shut it down and concluded the attempt.

I checked out "Mr. Mels Head Speed Calculator". Here are the results from my setup:


You'll see, in the image on the left...that is my setup. Battery is 35C, 3 cells, 121 tooth Trex 450 slant main gear, 12 tooth helical pinion, and 3600kv motor. On a full charge, I'm looking at a 4200 headspeed. Isn't that a bit much for a 450? Even towards the end of the flight, this calculator is showing a 3740 head speed.

What do you all think about this???

 

[cml001]

I use the same set up... I have the align ESC so I don't know what my head speed really is, but I use a throttle v curve... 90 85 90(have to look to see if that's right).. Anyhow.. She zings pretty good!

- - - Updated - - -

Just checked... 95-90-85-90-95 throttle curve on idle up... 13 pitch pos & neg.. My cyclic is at 9 degrees... Now I use the AR7200... Ur on the 3GX right.. I don't know if there are any differences between the 2 gyros w my numbers... I'm pleased with them tho... Hope that helps.

- - - Updated - - -

U could look at my flight in the video section and compare the sound.... U said urs was screaming... That was in a 45c pk as well

 

[pvolcko]

I got ~4050RPM for your high headspeed. 3600 * (3 * 4.2) * .9 * (12/121) Not sure why my number and the Mr. Mel number is so different. And that's only considering motor efficiency. You'll have mechanical losses in the drivetrain too, losses due to torque, etc.

It is high, though. 2800-3600 seems to be the range people fly at in my short research effort.

11T pinion would get you down to 3700ish RPM.