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Old Sep 06, 2012, 05:51 PM
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Australia, TAS, Claremont
Joined Jul 2012
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Originally Posted by SimonChambers View Post
I thought about the 420, as it kinda looks a good size to squeeze in my girlfriends car (MX-5/Miata) when we're going back to her parents for the weekend. But then if the 800 flies better, then I'd rather go for that. The 800 does look like it would make more sense - but then when ever has buying planes made sense?

What's the recommended Prop over stock on the 800? Would I have to extract and replace the ESC from the PNF version to a higher current version for it?

Cheers,
Si.
I use an apc 6x4 prop on my 800 with the standard motor/esc with no problem.
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Old Sep 06, 2012, 06:49 PM
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Australia, VIC, Melbourne
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MrMurder, something is definitely amiss there. The Radjet is an extremely simple plane, and flies fine - fantastic even.
To 'spin off left' can only be an aero mis-alignment, or via control.
I haven't flown mine in a while, but I don't recall even having any torque roll (left) at launch - or not notable at all - and it just flies off easily with a weak 'push'.

A nuisance to rebuild something if you don't have any faith in the next flight anyway! (The 50mm F-35 from HK is a severe test of patience in that way!! LOL). But you can rest assured it SHOULD fly fine, so it is just a matter of checking over to find the reason yours does not.
I can only think a few reasons in the list:
1) Something warped... wing. And I can't even think of any other 'amiss as it came' possibility. (Fin/s ?)
2) Incorrect servo mixing. So your elevators are working, but the ailerons are amiss.
This happens to people surprisingly often.
3) Pilot error.... would seem unlikely. Especially if you are flying other aircraft fine.
But, it is in the list of possibilities.

You also gave it a 'good throw', even at 45deg... which should be ok, and passable to try to offset such an issue. To at least give it more time to get to faster speed and stabilise.
The only problem with that is if it does NOT fly away fine... the crash is worse. LOL

I suggest you need someone else to have a look at it before flying it. They might find the thing that is amiss. Maybe so obvious that you "can't see it for the trees". LOL
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Old Sep 07, 2012, 03:10 AM
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Quote:
Originally Posted by PeterVRC View Post
MrMurder, something is definitely amiss there. The Radjet is an extremely simple plane, and flies fine - fantastic even.
To 'spin off left' can only be an aero mis-alignment, or via control.
I haven't flown mine in a while, but I don't recall even having any torque roll (left) at launch - or not notable at all - and it just flies off easily with a weak 'push'.

A nuisance to rebuild something if you don't have any faith in the next flight anyway! (The 50mm F-35 from HK is a severe test of patience in that way!! LOL). But you can rest assured it SHOULD fly fine, so it is just a matter of checking over to find the reason yours does not.
I can only think a few reasons in the list:
1) Something warped... wing. And I can't even think of any other 'amiss as it came' possibility. (Fin/s ?)
2) Incorrect servo mixing. So your elevators are working, but the ailerons are amiss.
This happens to people surprisingly often.
3) Pilot error.... would seem unlikely. Especially if you are flying other aircraft fine.
But, it is in the list of possibilities.

You also gave it a 'good throw', even at 45deg... which should be ok, and passable to try to offset such an issue. To at least give it more time to get to faster speed and stabilise.
The only problem with that is if it does NOT fly away fine... the crash is worse. LOL

I suggest you need someone else to have a look at it before flying it. They might find the thing that is amiss. Maybe so obvious that you "can't see it for the trees". LOL

thanks for your input pete. i agree,a fresh set of eyes on it might notice something i have not,sometimes you just get so wrapped up in something that you can not look at it subjectively anymore.
in the cold light of day i have decided not to give up on it just yet (but im sooo close! lol)
there must be a reason it wont fly. i dont think its me. im no pro but i can fly planes and helis,so its not as if i dont know what im doing (most of the time!) and i never did like giving up on something when i know it should be working!

the only thing i have not tried is having someone throw it for me being as i always fly alone. i will have to try and persuade my brother to come down the field with me and launch it. but tbh,the amount of footage i have seen of other people launching theirs with no problems at all leads me to think that i shouldnt need someone to throw it for me,there is no reason i should not be able to do it myself.

i will get to the bottom of this ifit kills me.......or the radjet
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Old Sep 07, 2012, 07:40 AM
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Well, I put my Rad 800 together last night. Just waiting on some HK LiPos to arrive and should be good to go. I went straight with an APCe 6x4 as suggested on this forum. Can't wait.....weather looks good, just need mr postman to get up bright and early tomorrow and deliver my package of batteries!

Mrmurder, I am with Peter on this, there must be a logical reason. Stick with it, although I appreciate it must be so frustrating. In the past, when I have had a model that veers so aggressively to one side there has been a visually apparent warp.

I noticed putting together my Rad last night that the is potential to build a twist into one wing if the locating features in the wing roots are not quite lined up.

Can I suggest that, to rule out a rigging problem you look at each side of the trailing edge and ensure that where they line up with the trailing edge either side of the motor (the fuslelage section). Do the same with the leading edge, there is a mould line which runs down the leading edge and should line up with the mould line on the forward fuselage. If these 4 points are all lined up then there shouldn't be a rigging problem.

To rule out a wing-twist problem, look at the aircraft from the front or side and see if the tip tanks are parallel with the fuselage. It should be pretty easy to spot a serious warp.

If all this is OK, check that with the sticks neutral, BOTH ends of each elevon line up with the trailing edge of the wing. This will rule out elevon twisting or elevon asymmetry.

If all this looks good, it really should fly. This bit may sound daft but I have done it.....check the elevons go the correct way. Although they are elevons, they still work in the same sense as ailerons I.e. stick left should result in the left elevon going down and right going up.

I have to apologies if you have done all this, and I am trying to teach you to suck eggs, but a methodical process like this has worked for me in the past.
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Old Sep 07, 2012, 02:34 PM
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Bristol,UK
Joined Feb 2007
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Simon
T3chDad did a version of his X-41 denoted the X-43 as it had thrust vectoring - see this thread
http://www.rcgroups.com/forums/showt...00#post8643657
Re the death spiral and overpowered planes. Have a look at this full size F-15 video
F-15 flying with one wing by an Israeli Pilot (6 min 5 sec)

Andy
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Old Sep 08, 2012, 08:21 AM
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United States, IL, Cary
Joined Jul 2011
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Quote:
Originally Posted by mrmurder1975 View Post
thanks for your input pete. i agree,a fresh set of eyes on it might notice something i have not,sometimes you just get so wrapped up in something that you can not look at it subjectively anymore.
in the cold light of day i have decided not to give up on it just yet (but im sooo close! lol)
there must be a reason it wont fly. i dont think its me. im no pro but i can fly planes and helis,so its not as if i dont know what im doing (most of the time!) and i never did like giving up on something when i know it should be working!

the only thing i have not tried is having someone throw it for me being as i always fly alone. i will have to try and persuade my brother to come down the field with me and launch it. but tbh,the amount of footage i have seen of other people launching theirs with no problems at all leads me to think that i shouldnt need someone to throw it for me,there is no reason i should not be able to do it myself.

i will get to the bottom of this ifit kills me.......or the radjet
MrMurder,
A few other things to try/check:
1) Do you have your TX set to use elevons?
2) When you take off are your elevons set to be 8-10 TX clicks down stick?
3) I carved a finger hole, for my index finger, in the fuse thru the skid plate. Makes the launch much easier.
4) The ailerons/elevons do not need to be exactly at the same level with each other. If it rolls left on launch, set the trim more right stick before launch. I had the same roll issue on launch because I insisted on keeping the ailerons level with each other. After changing the trim (to look uncomfortably uneven) launches are mostly level. How much adjustment to trim required depends on the side-to-side COG.

Hope this helps!
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Old Sep 08, 2012, 11:08 AM
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United States, NY, New York
Joined Oct 2010
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Quote:
Originally Posted by mrmurder1975 View Post
thanks for your input pete. i agree,a fresh set of eyes on it might notice something i have not,sometimes you just get so wrapped up in something that you can not look at it subjectively anymore.
in the cold light of day i have decided not to give up on it just yet (but im sooo close! lol)
there must be a reason it wont fly. i dont think its me. im no pro but i can fly planes and helis,so its not as if i dont know what im doing (most of the time!) and i never did like giving up on something when i know it should be working!

the only thing i have not tried is having someone throw it for me being as i always fly alone. i will have to try and persuade my brother to come down the field with me and launch it. but tbh,the amount of footage i have seen of other people launching theirs with no problems at all leads me to think that i shouldnt need someone to throw it for me,there is no reason i should not be able to do it myself.
i will get to the bottom of this ifit kills me.......or the radjet
hand launching maybe easier for others .ive been flying all sorts of wings from 16inch up to 48inch for over a year . i love wings . to this day i have not had a successful hand launch they all wind up with my plane taking a dirt nap. i always get a fellow member to hand launch it for me .hence why i put that under my avatar,


you may need to get someone to toss it for you untill you trim it out and get profiecent in launching. .this is just my opinion.
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Old Sep 08, 2012, 04:19 PM
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Bristol,UK
Joined Feb 2007
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Launched my brothers Radjet for him this evening. Stock apart from 6x4 prop and it went away cleanly from a side arm launch. Didn't discuss throw it, just let it go nice and level. He did a tail slide and pulsed the power to recover from it. Touch and go for a moment but had plantly of height
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Old Sep 09, 2012, 01:28 AM
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Headless....amazing vid! Never seen that one before!
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Old Sep 09, 2012, 02:36 AM
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Joined Feb 2007
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Quote:
Originally Posted by Simon1013 View Post
Headless....amazing vid! Never seen that one before!
and an amazing, gutsy pilot. Hit afterburner in what appeared to be a terminal spin He was obviously at more than 3 mistakes high
Forgot to mention that the 6x4 prop gives the stock set up some extra oomph. Plane now had good vertical performance even from a low speed pass and pull up. Not much faster but guess I'll just have to get mine in the air and run them back to back. The 1300 3S Nano-tech 45/90 c pack came down such slightly warm. My non stock HK Parkjet was much faster so it's a shame HK don't offer the Radjet kit in the UK
Andy
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Old Sep 09, 2012, 05:16 AM
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Australia, TAS, Claremont
Joined Jul 2012
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Quote:
Originally Posted by headlessagain View Post
and an amazing, gutsy pilot. Hit afterburner in what appeared to be a terminal spin He was obviously at more than 3 mistakes high
Forgot to mention that the 6x4 prop gives the stock set up some extra oomph. Plane now had good vertical performance even from a low speed pass and pull up. Not much faster but guess I'll just have to get mine in the air and run them back to back. The 1300 3S Nano-tech 45/90 c pack came down such slightly warm. My non stock HK Parkjet was much faster so it's a shame HK don't offer the Radjet kit in the UK
Andy
Yeah thats the same for me with the prop, no real speed improvement but makes the thing fly better.
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Old Sep 09, 2012, 04:10 PM
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Had a bit of a maiden flight setback today. Used 5 min epoxy to glue the wings on but did a 'structural test' and the wing fell off. The epoxy had no adhesion whatsoever to the foam.

No big problem because I managed to peel all the residue off in about 5 mins but it seems epoxy on this foam is not the way to go. I have built EPP models before but this is EPO isn't it? I foolishly assumed that they would handle the same.

Any advice as to what glue to use on EPO? Need something with a bit of gap filling capability since the wing root doesn't fit perfectly to the body. Oh, and because I am in the UK, something from B&Q would be ideal :-)
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Old Sep 09, 2012, 04:47 PM
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Bristol,UK
Joined Feb 2007
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Firstly sand down all joints and lightly score and prick so that the glues has something to grip onto. Re glues, have a look at this HK thread http://www.hobbyking.com/hobbyking/f...KW=glue%2C+epo. I used HK own foam glue on my HK Parkjet http://www.hobbyking.com/hobbyking/s...rge_100ml.html and worked really well. It's similar to UHU Por. You might be able to use Evo-stik timebond or their contact adhesive but test a small area to ensure your model doesn't vanish in front of your eyes.
Multiplex suggest their own Zacki Elapor Glue for their models. It's a non-foam safe CA glue and certainly held the nose cone on my powered Blizzard. Some say just use medium CA with kicker and others consider CA to be too brittle
Andy
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Old Sep 09, 2012, 05:23 PM
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Gorilla Glue works great
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Old Sep 10, 2012, 08:45 AM
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Australia, QLD, Rubyanna
Joined Aug 2012
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Himax 2815 2000kv

Hi all, stuck this 2815 2000kv motor in my rjet after you guest it a low alt slow stall that turned into the DDS, atleast what I saw of it. Just after buzzing around hard on the stock motor/esc from the parkjet for to long the esc over heated and I was low over trees and too slow speed, no power, it nosed into the road. Didn't see it but there was a car waiting up the road, all good and still got it not like rattlesnake (think that's right).
18amps 250watts - 2250 3s 6x4 apc and on 4s
23amps 350watts - 1800 4s 5x5 apc,
I think the 4s was at storage voltage not fresh charge, should be a reasonable increase from stock I'll see soon enough. Happy landings.
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