HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 04, 2013, 06:38 PM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,314 Posts
Discussion
RJX X-Tron 500 helicopter kit at Hobbyking

Looks like HK is finally going to carry RJX helicopters.









EDIT: I just realized that the following pictures are of V1 and what HK is selling is the V2. The only difference seems to be that the cutout of the side frames is sturdier in the V2. There might be other differences but I can't tell from the pictures.









X-Tron 500 - Christopher Kuchinke (5 min 8 sec)


The RJX 500 FBL head is from this helicopter and if the rest of the kit is the same quality then for $224 this is a great deal.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Nov 06, 2013 at 05:38 AM.
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 04, 2013, 07:30 PM
Rchelistuff
Romania, AR, Arad
Joined Nov 2012
603 Posts
Hi Atomic Skull,
You got this or you found the pics?
Any idea about the quality of this kit? It doesn't look like Align compatible so this should be considered regarding the future spare parts sourcing...
Looking nice anyway
cofl10011 is offline Find More Posts by cofl10011
Reply With Quote
Old Nov 04, 2013, 07:42 PM
Suspended Account
Joined Dec 2012
1,900 Posts
The frame design looks really flimsy IMO...
TheKingPhisher is offline Find More Posts by TheKingPhisher
Reply With Quote
Old Nov 05, 2013, 12:57 AM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,314 Posts
Quote:
Originally Posted by cofl10011 View Post
Hi Atomic Skull,
You got this or you found the pics?
Any idea about the quality of this kit? It doesn't look like Align compatible so this should be considered regarding the future spare parts sourcing...
Looking nice anyway
No just pictures around the web. it's not a clone of anything though the head does use an Align feathering shaft and bearings (it's the same as the RJX 500 FBL head but in silver instead of black). Except for the feathering shaft and main grip bearings this thing isn't even close to Align. The mainshaft *might* be the same as Align as well but again I can't say for sure. It uses an S3M belt with a 16t pulley, a 33t tail drive gear and a 177t main gear so none of those parts are Align compatible. The RJX FBL heads are pretty good so I imagine the kit should be as well.

There seems to be a lot more dealers in Europe than in the americas.

http://www.rjxhobby.com/en/about.asp?id=3

RJX also sells parts direct to customers from their web shop though.

Quote:
Originally Posted by TheKingPhisher View Post
The frame design looks really flimsy IMO...
You are correct it does in the V1. I didn't realize there was a V2 though which is what HK seems to be selling. The side frames look a lot better in this version. Also note that the lower main bearing block, the motor mount and the upper tail pully bearing block are all a single piece and there is a CF stiffener right in the center of the frame. The cyclic servos also screw to the bearings blocks. I can't imagine that frame flexing is going to be a problem with this.

I added a few pictures from the manual that show the differences more clearly and how the frame is designed.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Nov 05, 2013 at 07:51 AM.
Reply With Quote
Old Nov 05, 2013, 11:13 AM
Suspended Account
Joined Dec 2012
1,900 Posts
Yep V2 frame looks a lot stronger however what's the thinking behind the dual spar struts? Why not use a single carbon spar that's thicker vs two thin carbon pieces?
TheKingPhisher is offline Find More Posts by TheKingPhisher
Last edited by TheKingPhisher; Nov 05, 2013 at 11:23 AM.
Reply With Quote
Old Nov 06, 2013, 01:44 AM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,314 Posts
Quote:
Originally Posted by TheKingPhisher View Post
Yep V2 frame looks a lot stronger however what's the thinking behind the dual spar struts? Why not use a single carbon spar that's thicker vs two thin carbon pieces?
Probably increased strength vs weight compared to a single thicker piece.

Also with two piece struts if the CF breaks in a hard landing they are more likely to stay functional rather than splitting in half and dumping the helicopter on it's side.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Nov 06, 2013 at 02:16 AM.
Reply With Quote
Old Nov 06, 2013, 01:46 AM
Suspended Account
Joined Dec 2012
1,900 Posts
Quote:
Originally Posted by Atomic Skull View Post
Two 1.5mm pieces spaced out like that form a box and are stiffer than a single 3mm piece would be.
Skids shouldn't be stiff though, they should be flexible...

Quote:
Originally Posted by Atomic Skull View Post
Probably increased strength vs weight compared to a single thicker piece.

Also with two piece struts if the CF breaks in a hard landing they are more likely to stay functional rather than splitting in half and dumping the helicopter on it's side.
Weight savings if any will be extremely marginal in a 500 class heli. I doubt a Goblin 500's skids are a weight problem. IMO the dual piece skids are just a bad design choice...ie too rigid and has too many parts to hold it together. In the field of engineering there's this thing called the KISS principle, I'm sure you've heard of it.
TheKingPhisher is offline Find More Posts by TheKingPhisher
Last edited by TheKingPhisher; Nov 06, 2013 at 02:26 AM.
Reply With Quote
Old Nov 06, 2013, 02:18 AM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,314 Posts
Quote:
Originally Posted by TheKingPhisher View Post
Skids shouldn't be stiff though, they should be flexible...
I revised that post with some additional guessing.

I do prefer "unbreakable" type nylon skids like gorilla gear or the Quick UK high strength skids.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Nov 06, 2013 at 02:28 AM.
Reply With Quote
Old Nov 06, 2013, 02:39 AM
Suspended Account
Joined Dec 2012
1,900 Posts
In my experience the best carbon fiber skid design would be a one piece that's not too strong but just enough to hold the heli up off the ground with a slight flex using a flexible "breakaway" mount. Think "shock absorbing" design without the weight penalty of using actual shocks.

Anyway I've actually thought about designing a shock or spring based landing strut system for a heli design I've been working on just as an experiment. It looks pretty cool and futuristic but its designed for larger 700/800 class helis where a small amount of additional weight isn't a problem. I really want to work with a manufacturer to make carbon fiber plates for my design but can't find any that doesn't charge an arm and leg for the service.
TheKingPhisher is offline Find More Posts by TheKingPhisher
Reply With Quote
Old Nov 06, 2013, 02:50 AM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,314 Posts
Quote:
Originally Posted by TheKingPhisher View Post
In my experience the best carbon fiber skid design would be a one piece that's not too strong but just enough to hold the heli up off the ground with a slight flex using a flexible "breakaway" mount. Think "shock absorbing" design without the weight penalty of using actual shocks.

Anyway I've actually thought about designing a shock or spring based landing strut system for a heli design I've been working on just as an experiment. It looks pretty cool and futuristic but its designed for larger 700/800 class helis where a small amount of additional weight isn't a problem. I really want to work with a manufacturer to make carbon fiber plates for my design but can't find any that doesn't charge an arm and leg for the service.
Problem is if the skids break away the helicopter goes on it's side. I'm thinking that double strut design is probably less likely to break completely through.

Best skids I ever used are the gorilla gear on my trex 500. I had the jesus bolt break once and the helicopter and rotor parted ways at 100 feet. It free fell to the ground and both the airframe and the skids survived.
Atomic Skull is offline Find More Posts by Atomic Skull
Reply With Quote
Old Nov 06, 2013, 02:53 AM
Registered User
New Zealand, Canterbury, Christchurch
Joined Jun 2013
131 Posts
+1 on the Gorillas. You can fold them inside out and they just go back to their shape.
tracernz is offline Find More Posts by tracernz
Reply With Quote
Old Nov 06, 2013, 03:02 AM
Registered User
Atomic Skull's Avatar
Joined Dec 2011
3,314 Posts
Quote:
Originally Posted by tracernz View Post
+1 on the Gorillas. You can fold them inside out and they just go back to their shape.
If they get bent just boil them for 5 minutes bend them back into shape and run them under cold water and they are good as new.

HK fixed the missing frame picture. When they first listed it they had this up:



That's actually an RJX X600EP, which is this.



That is not a stock photo, HK must have taken photos of the X600EP as well as the X-Tron to get them mixed up which means they're probably going to start selling the X600EP as well.
Atomic Skull is offline Find More Posts by Atomic Skull
Last edited by Atomic Skull; Nov 06, 2013 at 05:49 AM.
Reply With Quote
Old Nov 06, 2013, 09:06 AM
just gotta mess with it!
2Doggs's Avatar
North West Louisiana
Joined Nov 2009
4,830 Posts
Stiffener

Quote:
Originally Posted by TheKingPhisher View Post
The frame design looks really flimsy IMO...
But it incorporates a transverse frame stiffener, something lacking in many helis. To me, it looks like a very well thought out design.

Edit: Oops! See Atomic already covered this!
2Doggs is online now Find More Posts by 2Doggs
RCG Plus Member
Latest blog entry: Nano Tech 1800mah 4S 25-50c
Reply With Quote
Old Nov 06, 2013, 12:17 PM
Suspended Account
Joined Dec 2012
1,900 Posts
Quote:
Originally Posted by Atomic Skull View Post
Problem is if the skids break away the helicopter goes on it's side. I'm thinking that double strut design is probably less likely to break completely through..
If the skids broke then most likely it was a major crash anyway which means there was other damage to the heli. As you said if durability was the main factor you'd use Gorilla or something similar you wouldn't use rigid carbon fiber.
TheKingPhisher is offline Find More Posts by TheKingPhisher
Reply With Quote
Old Nov 06, 2013, 01:02 PM
IHW Heli Division
IntegrityHndywrk's Avatar
United States, FL, Palm Coast
Joined Mar 2012
7,260 Posts
One of the hobby shops near me has started stocking a lot of these RJX models and parts. He used to carry Gaui, Compass and Align. I've even seen some SABs in his shop for sale before. But lately he seems to only be stocking up on this RJX stuff. So apparently he likes them, at least from a business point of view.

I do seem to recall him mentioning to me that he buys FRP, G10 sheets and cuts them to the size of the CF parts on the skids using a dremel or something. I think he is on to something there if your breaking your CF skid parts from just hard landings and AR practice. The G10 is more flexible and should be more durable in that respect. But you kind of have to expect them to be destroyed in a crash no matter what they are made out of. At least on bigger helis. The only CF incorporated or full CF skids i have actually enjoyed are on my 450. But those never break because the plastic bottom frame plate takes the hit and breaks. Those bottom plates are only $3 for my 450. I don't know what the RJX skids cost. But being CF incorporated, i imagine it's not exactly the cheapest thing around. Especially if they do in fact break easily. Though for all the trouble of cutting fiberglass G10 sheets. I would imagine gorilla gear becomes worth the price real quick.
IntegrityHndywrk is offline Find More Posts by IntegrityHndywrk
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Xtron 500 RJX Kauaiguy Electric Heli Talk 8 Jan 10, 2014 01:10 AM
Sold Trex 500 fbl rjx beastx bnf ready tmr110 Aircraft - Electric - Helis (FS/W) 1 Oct 11, 2013 08:59 PM
Sold Flb rjx head 500 class with swashplate $70.00 cobrabill Aircraft - Electric - Helis (FS/W) 7 Jul 23, 2013 08:53 AM
News Toledo News -The Blade 550 X Pro Series Helicopter Kit awagar Electric Heli Talk 2 Apr 17, 2013 05:06 PM
Sold TREX 500 ESP Airframe FBL RJX + Parts $150 Shipped heli0 Aircraft - Electric - Helis (FS/W) 1 Feb 13, 2013 08:48 AM