• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

EPO Parkjet

fliteadmin

Administrator
Staff member
Admin
Moderator
#1

It's cold and windy! But it won't stop Josh and Josh from doing their jobs. Watch as they test this lil' EPO ParkJet from Hobby King. It's a fast plane that's small and easy to tote. But wait, there's more... Watch what happends when we strap a 270W motor on it's back!



 
#2
Hi Flitetest guys :)

I need some help with mine...

I bought the Parkjet (kit), I use 2 HXT900's, 30A ESC from hobbyking, an e-flite Park-250 motor and a 1000mAh 2s Lipo nanotech.

The problem I have is that whenever I launch it it dives straight into the ground with a left roll. I also tried it without motor just to see if that was torque roll but it still did the same.

First I changed the CG (from 2mm from holes to 2/3 of the holes) by putting the lipo further back but no changes. After that I pointed the motor more up (from 2° to 3-4° I think) but no changes. Next I tried trimming it to the right but no changes either. the faster I throw the more the effect, slower and without power it was less but still unflyable. I don't get the chance to get my hands on the controls.

I tried different launching methods (using finger holes and throwing straight and swinging it away by holding the wingtip) but using the finger holes was the best.

I don't really know what other things might be the cause so that's what 'd like to hear from you guys...

I've made a cut in the left wing leading edge to put the rx antenna in but I don't think that would have that much influence on the flying...

Hope you guys can help :)

Grtz, Thomas
 

ananas1301

Crazy flyer/crasher :D
#3
hey thomas,


did you try letting someone else launching the jet? You will have your fingers right at the controls then so you can compensate immediately.

Also many jets need a minimum speed to glide or whatever, otherwise they will dive into the ground, so don´t give up!
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#4
I have a Hobby Lobby Saber EDF. I had the same problem with it. I thought it was speed, and I would throw it harder, and it did it worse. I threw it higher, and it just fell that much harder. Finally I started throwing it under hand, and it works every time.

Now you could be off balance longitudinally. Put a fingertip on the nose, and hold the motor by the prop nut, and see if it falls to the left every time. You might need to add a little weight to the right wing.
 

ananas1301

Crazy flyer/crasher :D
#5
Now you could be off balance longitudinally. Put a fingertip on the nose, and hold the motor by the prop nut, and see if it falls to the left every time. You might need to add a little weight to the right wing.
That´s what I think too, if it still doesn´t work.
Try not to put much weight on. For that use less weight but the wingtip because then the weight will have a bigger effect.
 
#6
I built my bungee catapult particularly for my Parkjet 'cause that little bugger is hard to launch! I can't do it without crashing. I notice in the video that Josh Bixler throws it with his left hand so he can control the elevons with his right hand. The SkyFun is hard to launch also. It's a skill that you learn at the same time you learn repairing or replacing ParkJets - too much for me!

Here's my chrome ParkJet:

ChromeParkjet3.jpg
 
#8
It's chrome decal material that I bought from the local hobby shop. By "local hobby shop" I mean the one closest to me - about 90 miles away. Hobbies aren't popular here, the locals love deer mostly, I moved here from California so I couldn't care less about deer. I was going to use chrome iron-on film but then I'd have to use heat to apply it - might melt the EPO foam, too risky. The EPO pParkJet is my favorite plane - once you get it up in the air that is.
 

lobstermash

Propaganda machine
Mentor
#10
Oh my! I just got one of these and came back from maiden just now. I bought the kit, a 3000kv blue wonder and 5x5 tgs prop. I'm running a 1300mAh 3s and a 20A ESC. I am more than impressed. I didn't find it hard to launch, although I can probably thank my flying wing for that. I flew on full throws at first, but it was waaay to much roll. I landed it and am now on 60% throws with 30% expo.

I don't have a speedo on my phone, but I'm looking forward to the next session with glydr! What an amazing plane.

My only issues have been with the canopy and the motor mount. With the canopy, my fit isn't as good as I've seen on others. Instead of keeping it stock, I chucked rare earth magnets on the fuse and the canopy to keep it on. With the motor mount, I didn't use the stick at all. I epoxied up the mount and stuck it in, and put screws through that were just a flush fit. I then epoxied the screws in. Ideally I would have used a nut and bolt system, but hey, being resourceful can get you in the air quicker.

I'm astounded at the speed of this thing. It also flies slow OK, but I did suffer some slight damage to the right aileron on a very standard, soft, skidding landing. I'll be reinforcing the control surfaces.
 

Brian fred carr

Site Moderator
Mentor
#13
I just got one of these little flyers and had to do this with it[video=facebook;3403404641967]http://www.facebook.com/video/video.php?v=3403404641967[/video]
Am running with a 1000mah 3s lipo, 20 amp esc, 5x5E prop and I wouldnt trust those silly
magnets (2 fell out lol) to hold the canopy so I will rubber band it will try and film the maiden
 
Last edited:

lobstermash

Propaganda machine
Mentor
#14
I managed to squeeze all my electrics in, but discarded the little pieces of metal and replaced them with magnets. The thrust line on yours looks way too high... I didn't put the stick in and mounted the fibreglass mount straight in there with lots of epoxy. You shouldn't have any trouble getting balance by sliding the battery up the front.

I'll do a few pics of my setup later.
 

lobstermash

Propaganda machine
Mentor
#16
And one flat battery later after the latest fix... Didn't get enough throttle on it so landed after the toss. Motor mount disintegrated again. No amount of epoxy is going to save it. Shelved pending a new mount.
 

dusk

Junior Member
#17
This is the way I mount mine. Very solid and easy to fix after a crash. I guess that the aluminum fins help to keep the motor cool, but I don't really push mine that far.

ParkJet Motor Mount.jpg
 

Brian fred carr

Site Moderator
Mentor
#18
I managed to squeeze all my electrics in, but discarded the little pieces of metal and replaced them with magnets. The thrust line on yours looks way too high... I didn't put the stick in and mounted the fibreglass mount straight in there with lots of epoxy. You shouldn't have any trouble getting balance by sliding the battery up the front.

I'll do a few pics of my setup later.
You were right lobster the thrust was all wrong my first launch ended in a heartbeat....ditched
the stick mount and used a 90 degree piece of metal and i cant believe how fast it was on a1000mah
3s....unlimited vertical till i coudnt see it....but they are fragile....keep flying
 

lobstermash

Propaganda machine
Mentor
#19
Thanks Dusk. I'll be popping the stick in and mounting the motor on some form of metal mount attached to it. There's certainly plenty of power! I was almost tempted to pull the epoxy out again and fix the fibreglass mount, but I thought better of it. At 100mph there's no room for fragile attachments!
 

lobstermash

Propaganda machine
Mentor
#20
ARGH! I've got a new motor mount (thanks to glydr) and I was widening the holes on the motor mount, when I managed to drill out half the wire on one pole. Damn! New one on the way. Check back in two weeks and I may be flying this thing again...