HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jul 16, 2010, 07:15 AM
Wisdom can not be granted.
Orion Pax's Avatar
Shreveport Louisiana
Joined Dec 2006
6,300 Posts
Quote:
Originally Posted by Lardog View Post
So, these #s are for a single motor/ESC then?
Yup, 1 motor and 1 esc.
Orion Pax is offline Find More Posts by Orion Pax
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 16, 2010, 10:40 AM
add lightness
PositivelyJoe's Avatar
Big time Minneapolis, Good Ol' St Paul
Joined Oct 2007
1,121 Posts
Quote:
Originally Posted by Orion Pax View Post
Bringing it down to a 5" pitch by using my already cut HL blades brought the amps down to 47.9 but my watts went up to 487. Still too much for the motor but the esc is what was hot not the motor.
Careful with 48 amps on a 40 amp esc. two things can happen:
1) it will shut down - as in thermal shut down when it gets too hot (not fun on a P-38 twin having one side shut down, even worse if it is your BEC for your rx)
2) it could start on fire.

Motors can usually handle over-propping quite a bit if it is only for shorter bursts.
PositivelyJoe is offline Find More Posts by PositivelyJoe
Reply With Quote
Old Jul 16, 2010, 10:55 AM
CD-ROM Junkie
Art Newland's Avatar
Camas, Washington, USA
Joined Apr 2001
13,859 Posts
Quote:
Originally Posted by kasra View Post
cool!
Art Newland is offline Find More Posts by Art Newland
Reply With Quote
Old Jul 16, 2010, 11:02 AM
Wisdom can not be granted.
Orion Pax's Avatar
Shreveport Louisiana
Joined Dec 2006
6,300 Posts
Quote:
Originally Posted by PositivelyJoe View Post
Careful with 48 amps on a 40 amp esc. two things can happen:
1) it will shut down - as in thermal shut down when it gets too hot (not fun on a P-38 twin having one side shut down, even worse if it is your BEC for your rx)
2) it could start on fire.

Motors can usually handle over-propping quite a bit if it is only for shorter bursts.
Yeah, that is my current predicament. The esc's can handle 40 amps for 60 sec and 50 for a 10 sec burst. The motors are rated for 440 watts. I just need to get a different prop. I have a MAS 9x7 I am going to try tonight probably.
Orion Pax is offline Find More Posts by Orion Pax
Reply With Quote
Old Jul 16, 2010, 12:20 PM
ex-noob
Lardog's Avatar
Sammamish, WA, USA
Joined Jan 2010
2,378 Posts
Quote:
Originally Posted by kasra View Post
Quick video
Great vid Kasra. The horizontal stab looks like a great mounting spot for the camera. May have to give it a try.
Lardog is offline Find More Posts by Lardog
Reply With Quote
Old Jul 17, 2010, 10:04 AM
Registered User
eroeder's Avatar
United States, TX, Frisco
Joined Jan 2004
967 Posts
Video

Quote:
Originally Posted by Art Newland View Post
cool!
Can you take a pic of how you mounted it? cool!
eroeder is online now Find More Posts by eroeder
RCG Plus Member
Reply With Quote
Old Jul 17, 2010, 10:42 AM
CD-ROM Junkie
Art Newland's Avatar
Camas, Washington, USA
Joined Apr 2001
13,859 Posts
Quote:
Originally Posted by Orion Pax View Post
Yup, 1 motor and 1 esc.
you know, this sounds like an insane amount of power for this plane.

I fly a BH Mosquito on 300 watts per side...

each to his own of course, I really enjoy my P-38 on stock power.
Art Newland is offline Find More Posts by Art Newland
Reply With Quote
Old Jul 17, 2010, 12:26 PM
Wisdom can not be granted.
Orion Pax's Avatar
Shreveport Louisiana
Joined Dec 2006
6,300 Posts
Well if the plane was all stock I would agree. I am probably going to bring the watts down per side by using a smaller prop. However the power will be needed since it probably wont weigh 29 oz. when I am done.
Orion Pax is offline Find More Posts by Orion Pax
Reply With Quote
Old Jul 17, 2010, 11:04 PM
Registered User
Omaha, NE
Joined Oct 2009
24 Posts
Hey guys, I just received my BH P-38 and began doing the necessary dry fitting and wiring etc.

During a power test everything appeared to work fine but after a few tries of lowering and raising the gear, the nose gear steering servo began to jitter by itself then got worse to the point it was sounding crunchy.

I powered down then looked around and didnt see anything I thought was out of ordinary and powered it up again - the nose steering servo began to spin inside. I take it the gear is stripped? Anyways its not a big deal just wondering if this plane is steerable with out that servo?

I have a replacement coming in the meantime but I would like to fly it if I can. Also how do you guys tune the servos to quit jittering? Thanks in advance.

Julian
~JG27AFRIKA~ is offline Find More Posts by ~JG27AFRIKA~
Reply With Quote
Old Jul 19, 2010, 12:46 PM
CD-ROM Junkie
Art Newland's Avatar
Camas, Washington, USA
Joined Apr 2001
13,859 Posts
Quote:
Originally Posted by ~JG27AFRIKA~ View Post
Hey guys, I just received my BH P-38 and began doing the necessary dry fitting and wiring etc.

During a power test everything appeared to work fine but after a few tries of lowering and raising the gear, the nose gear steering servo began to jitter by itself then got worse to the point it was sounding crunchy.

I powered down then looked around and didnt see anything I thought was out of ordinary and powered it up again - the nose steering servo began to spin inside. I take it the gear is stripped? Anyways its not a big deal just wondering if this plane is steerable with out that servo?

I have a replacement coming in the meantime but I would like to fly it if I can. Also how do you guys tune the servos to quit jittering? Thanks in advance.



Julian
One of the design flaws with this plane is that while the gear is retracted, the nosegear steering is bound up, so if you try to use the rudders the steering servo has no place to go and puts a lot of strain on the gears in the servo. Looks like the most common fix it to disable nosewheel steering through electronic mixing, that's the route I chose. If your transmitter doesn't support mixing (also have to have an open channel in receiver) some add a small microswitch to the power lead of the steering servo to disable while retracted. My P-38 needed some small tweaks to the lingages to the retracts and adjustments to the transmitters end points.
Art Newland is offline Find More Posts by Art Newland
Reply With Quote
Old Jul 26, 2010, 07:19 PM
Registered User
Hink64's Avatar
Cape Coral, Fl
Joined Jan 2010
1,253 Posts
Art,

The E-Flight retracts fix this problem pretty well.

Hink
Hink64 is online now Find More Posts by Hink64
Reply With Quote
Old Jul 26, 2010, 08:43 PM
Registered User
Omaha, NE
Joined Oct 2009
24 Posts
Quote:
Originally Posted by Art Newland View Post
One of the design flaws with this plane is that while the gear is retracted, the nosegear steering is bound up, so if you try to use the rudders the steering servo has no place to go and puts a lot of strain on the gears in the servo. Looks like the most common fix it to disable nosewheel steering through electronic mixing, that's the route I chose. If your transmitter doesn't support mixing (also have to have an open channel in receiver) some add a small microswitch to the power lead of the steering servo to disable while retracted. My P-38 needed some small tweaks to the lingages to the retracts and adjustments to the transmitters end points.
I'm using a spectrum dx6i and will fiddle with the mixer settings, thanks.
~JG27AFRIKA~ is offline Find More Posts by ~JG27AFRIKA~
Reply With Quote
Old Jul 26, 2010, 09:36 PM
CD-ROM Junkie
Art Newland's Avatar
Camas, Washington, USA
Joined Apr 2001
13,859 Posts
Quote:
Originally Posted by Hink64 View Post
Art,

The E-Flight retracts fix this problem pretty well.

Hink
Too bad the fix is almost as expensive as the plane!

I have a set... plan to put them in over the winter. My stock rtracts are still working, but getting beat up, have had to use a little CA on them in places.
Art Newland is offline Find More Posts by Art Newland
Reply With Quote
Old Jul 26, 2010, 09:43 PM
Registered User
Goodyear, AZ.
Joined Dec 2005
267 Posts
Same with mine... after 5 flights.. need to put CA in places (retracts) I also used hot glue on the nose retract area.. (screws came off, I dont know if in-flight or during landing) but 2 of them are gone, only 2 left holding it. Hot glue Fixed that area for now. I dont know for how long it will hold. I have a T28 foamy (PZ) it seems it can take a lot of beating (mine is still pristine condition) I dont know with this P38 how long the foam will last. (maybe more damage just getting to and from the field) Also with the other jet foamys at BH... dont know how durable, how long they last. I came across one person in youtube that his BH planes lasted about 10 flights then things fall apart. I would like for mine to live forever (no crashes)...
lw777pilot is offline Find More Posts by lw777pilot
Reply With Quote
Old Jul 31, 2010, 04:55 PM
Dont be divided from the truth
Dangaras's Avatar
Canada, ON, Toronto
Joined Mar 2010
3,249 Posts
I finally got the "replacement" airframe built & it was no bargain. I was sent some sort of prototype with crappy original parts.

The landing gear had additional support wires attached and they were loose so they rotated on their own, had to fix (tried to anyway) with CA, the gear doors had hinges setup so they were hinged closed!!!

I had to peel off the hinges, take them apart and put the hinges in backwards, then re-glue everything back together. Somewhere during the process it crossed my mind to chuck them and see what OP was doing for doors and follow his lead.. Then I discovered they didn't include the little fishing line jigs for closing the doors. Had to recover those from the crashed one.... After much screwing around to mount them, the new problem is the doors wont close all way because the hinges appear to be too stiff!!!!! What a croc... Just cant win.

Any suggestions for gear doors would be welcome at this point I feel like ripping them off and flying naked!!!!!!!!!!!!!

Anyway, took it out this morning for the maiden, besides some clicks of left aileron all went well, flew like a dream & I forgot how quickly it took off. It leaps off the ground in 30 feet.

Not much top end but lots of grunt with the stock motors. The Tower pros I used from hobbyking in the last one appear to have more pull and gave me a slightly higher top end... With all the messing around and other projects on the go, I don't have the time or inclination to change them out....
Dangaras is online now Find More Posts by Dangaras
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Banana Hobby P-51 w/2.4 GHz Tx/Rx cypherpix Electric Warbirds 9 Nov 26, 2008 03:32 PM
For Sale (NEW) F-Model P-38 Cowls Orion Pax Aircraft - Electric - Airplanes (FS/W) 13 Oct 30, 2008 07:22 PM
New Product New Phase 3 P-38 = EMI P-38 repackaged? shschon Electric Warbirds 16 Nov 25, 2007 11:57 AM
Discussion New E-flite P-38 pda4you Foamies (Kits) 1 Jan 12, 2007 11:04 PM
New Product New web shop, New product *EMI P-38 Forked Tail Devil * infinityhobby Product Announcements 60 Nov 03, 2006 06:48 PM