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Sep 28, 2012, 01:10 PM
Upstanding Member
Kurt's Avatar
Originally Posted by headlessagain
Hi Kurt
have you seen this video?
Thanks Andy, I did see that one a while back. Not very many X-wings with operating "Xs" out there!
It would be SUPER cool to do that with the RJ, but I'm afraid the necessary equipment to do it (at least one, better two MG servo, stout hinges, and should sand down the top of the bottom wing, bottom of the top wing so they closed relatively tightly together) would be quite heavy. For now I'm going to stick with either single wings, or fixed x-wings, maybe try moveable ones on the next frankenstein-Radjet
The canards also kind of ruin the effect for me, I'd much rather not have them even if it mean only ok pitch control.

Originally Posted by mocio
Hi I have a Radjet 800 what glue i have to use to build them, I want also put u carbon fibre in wings??
+1 on gorilla glue, I put a thin cocktail straw, split on one side to about 1/2" so it could be rolled to a smaller diameter on the end, and secured with electrical tape, in the end of the bottle's tip to squirt glue about 6" deep in the CF wing hole (made by heating up a thin brass rod with a MAP torch, then carefully pushing it along the bench so it would bore straight down the middle) then let the glue run down to the end.
Make sure to wet the CF a bit before pushing it in the hole if it's not a humid day, Gorilla Glue needs a little moisure to cure.
I used 4mm CF tube I think, one piece running straight through the fuselage and out to about 75% of each wing. It's a very good idea to do - I've had 3 pretty hard core crashes and other than ripping off the wing tip tanks no other damage to the wings at all.

Originally Posted by PeterVRC
So all in all, it still fulfills a pretty realistic take-off and landing process for those too.
That's a good point, but there's still a great feeling taxiing back to you after a nice landing which even a bullseye belly land won't quite match
I'm trying out fixed gear on the Sportjet for the first time tomorrow, if I can't stand how they look in the air I'll just rip them off.

Tried out a quick mod to my busted up Radjet #1 today: servo mounted keychain cam. Plugged the servo into Rud, upped the extant to 150% for almost 180 degree L/R movement, slowed down the movement to 2s so it's not too quick, and dialed in a big dose of expo.
In flight it was a bit tricky to recalibrate the mind that rudder doesn't do anything to the flight, only the camera, but the video came out looking very cool!
There was a strange sound about 1/2 through the flight, brought her down to find the 2826 motor very loose! Opened up the hatch and the bottom two motor mount bolts were totally gone, top two holding on by a few threads
Don't know what happened to the two bottom ones, they were nowhere to be found inside.... big day at the big field tomorrow, may have to run out to the hobby store this afternoon to get some more.
tally ho!
Last edited by Kurt; Sep 28, 2012 at 01:37 PM.
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Sep 28, 2012, 04:42 PM
Upstanding Member
Kurt's Avatar
Couple frame grabs from the servo cam. I took her up pretty much to the edge of my eyestight for the first one - the shore of Lake MI is 6.5 miles away accd to Google Maps.
The left/right panning works very well!
Once the weather gets too cold to do much outside I'll put together a compilation video.
Sep 29, 2012, 03:27 AM
Registered User
Thanks for answer. But what kind of gorrila glu I have to use? There are many types of thih glue?
Sep 29, 2012, 06:07 AM
Upstanding Member
Kurt's Avatar
I used this one, but the white version should work as well:

Use it sparingly, it will expand with moisture, you can put a piece of clear tape over the joint to help keep excess from coming out of the joints.

I have about 6 different glues for various RC plane joints: hot glue gun (<$10 from Walmart) that sticks very well to foam, but cools quickly! 15 minute 2 part epoxy for wood and plastic, CA, Gorilla super glue, white and brown Gorilla glue.... it's always a bit of a guess whether it will work, so if possible do a test glue first and be patient, let whatever glue you use dry completely if possible before flying!
Sep 29, 2012, 03:15 PM
Turbine pilot
setxws6's Avatar
^ Every thing Kurt just said. I wouldn't use Epoxy on foam, it's too heavy. CA burns most foams and I've never had good luck with foam safe CA. So that leaves Gorilla glue or hot glue gun. And glue gun is a heavy glue too and doesn't allow for a super tight bond, it's more of a quick fix. Gorilla glue bonds very well to the Radjet foam. It also fills in all the imperfections. Like Kurt said, apply the glue, join the pieces together, then use a masking tape over the entire seem. This will help keep the pieces together while it dries and as the gorilla glue expands it will keep it tight with the seem or joint.
Oct 02, 2012, 03:57 AM
Registered User
My two Radjets have been dormant for quite a while now... awaiting the motor system upgrades....
The first one is ready to test fly now.

I cut a much longer hatch, and joined it to the stock hatch. That way I have full access to the battery area - seeing large batteries need to go well rearwards and are quite long batteries too. (4S 1800mAH 35C Nano)

I put on a slide-catch mechanism, to lock down the hatch and assure it can never come off. The front end has a tongue that feeds into the nose area foam.

The Turnigy Deluxe 40A ESC sits in the rear end lower fuselage half, and gets clamped down snugly by a plwood strip that runs forwards from the motor mount, to where the fuselage top remains. I will make up a 'plastic upper half', like the fuselage shape, to cover the ESC area - but it will also airflow thorugh that area, over the ESC.
But for test flights it will remain open as it is now.

I will probably test 3S first.... I haven't done any Amp/Power tests yet. So I will do that before the weekend, to make sure it all 'adds up' to be workable.

This Radjet uses the Turnigy 2826/6-2200kv motor.
The other one has the Turnigy 2836-2350kv motor.

Oct 02, 2012, 06:30 AM
Registered User
MartinT's Avatar
I made the rear deck removable so I can change motors et al.

Used the original motormount, but instead of glueing it to the fuselage it is clamped in position by the original foam pieces, and kept in place by 2 screws and some pieces of wood. (pieces cutoff from big paint stir sticks)
The wood is rounded (curved) on the edges, so as to follow the concave fuselage form.

And in honor of the topic title, I changed the decals a bit...

Oct 02, 2012, 12:12 PM
Turbine pilot
setxws6's Avatar
Cool ideas PeterVRC and Martin T! Peter what prop will you be using with the 3s and 4s on those motors? Let us know the data when you put the watt meter on.
Oct 03, 2012, 03:15 AM
Registered User
Gee, you could test things all day... all week.... the many combinations!!
I did my first tests.....

Turnigy 2826/6-2200kv
APC 5 x 5 (reverse) Prop (just because that was all they had in stock then)

Interesting results:

4S 1300mAH 45c Nano
25 Amps 350W
AUW 495g Thrust 600g 1.21 : 1
Motor Temp 50degC areas

4S 1800mAH 35c Nano
24 Amps 320W
AUW 545g Thrust 670g 1.23 : 1
- Huh? Less Watts but more thrust? I rechecked them twice. I don't know why this occured.....

3S 2200mAH 40C Turnigy
20 Amps 225W
AUW 545g Thrust 510g 0.94 : 1

3S 1300mAH 25C Nano
18 Amps 195W
AUW 460g Thrust 495g 1.08 : 1

All were pretty good results, versus the stock Radjet (I think?).
The 4S have more thrust of course, but the motor gets a lot hotter too! That will be OK if you use it at 80% mainly, and then have fun at WOT for short periods.

It really need more props to test. Probably 5 x 4.5 (diam/pitch) for a start.
If you really wanted to work out optimals.
I liked the 3S 1300mAH 25c Nano results, as a good 'sport' power result.
Above that, either 4S battery was much the same - just more flight time, but heavier, for the 1800mAH of course.
I will test fly them all soon.......

I am not sure what props I have (a lot of various types), so I will see what I have, and when to test those.....
Oct 03, 2012, 07:16 AM
Upstanding Member
Kurt's Avatar
good stuff!

Peter - how are you testing for A/W/thrust?
Any change of trying out a 6x4?

I'll be doing some tests as well with a wattmeter on the twin,but last time I checked my 2826-6 2200kV (before killing my RJ #1 ) I seem to remember 4S being somewhere around 35A. I only flew it once on 4S, motor made popping noises occasionally and came down VERY hot, but man did she scream!

Nice job Martin!
What kind of tape is that on your RJ? Some kind of rip-stop tape?
Oct 03, 2012, 08:43 AM
Registered User
harlyquin76's Avatar
AERO 5 (Rc planes) (13 min 52 sec)

Cant remember who suggested it ( i think Kurt ) but about 3 mins into this video is my Radjet 800 with the 2200kv
Best idea ever, Thank you....
Oct 03, 2012, 09:10 AM
The ground is my Enemy!!!
Jose5x5's Avatar
Originally Posted by harlyquin76

Cant remember who suggested it ( i think Kurt ) but about 3 mins into this video is my Radjet 800 with the 2200kv
Best idea ever, Thank you....
Cool video, sure was moving fast! Was that 3 or 4 cells, what size prop,esc,and battery?
Oct 03, 2012, 09:31 AM
Registered User
harlyquin76's Avatar
Originally Posted by Jose5x5
Cool video, sure was moving fast! Was that 3 or 4 cells, what size prop,esc,and battery?
Thanks and sorry forgot to say, 3 cell apc 6x4 prop and an otter 40amp esc
Oct 03, 2012, 11:15 AM
The ground is my Enemy!!!
Jose5x5's Avatar
I was thinking about picking up the Radjet, and wanted to upgrade the motor. I have read good things about 2826 and the 2836. Just didn't know which one to go with. I think I might just go with the 2836 since it's rated up to 4cells and knowing after a few flights I will probably want to go even faster. Just wish Hobby King shipping was cheaper. Is there some here in the US you can get an equivalent motor as the 2836?
Last edited by Jose5x5; Oct 03, 2012 at 12:12 PM.
Oct 03, 2012, 01:51 PM
Registered User
Cid156's Avatar
Originally Posted by harlyquin76

Cant remember who suggested it ( i think Kurt ) but about 3 mins into this video is my Radjet 800 with the 2200kv
Best idea ever, Thank you....
Thank for the video. I have this motor in stock but I was planning to order a 2836 2350kv motor. After seeing this video and the tests results in 4s, i will definitly try it.

Just need to crash the plane equipped with the 2826

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