Go Back  RCU Forums > RC Airplanes > Giant Scale Aircraft - 3D & Aerobatic
Reload this Page >

Composite-Arf 2.3 Construction

Notices
Giant Scale Aircraft - 3D & Aerobatic Discuss all your 3D & Aerobatic giant scale airplanes right here!

Composite-Arf 2.3 Construction

Old 12-06-2004, 10:43 AM
  #1  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default Composite-Arf 2.3 Construction

Are any of you guys reinforcing the landing gear mounting on the 2.3? It looks life awfully thin plywood that the carbon gear legs are attached to. With those two piece legs, the forces are much higher on the landing gear plate than with a one piece design. Also what tial wheel assembly are you guys using? I was very surprised that one didn't comne with the kit.

jmw[8D]
Old 12-06-2004, 10:53 AM
  #2  
bhanley
Senior Member
 
Join Date: Oct 2002
Location: Sammamish, WA
Posts: 451
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

I layered the entire landing gear area with a single layer of
Kevlar cloth and epoxy and then made a 1/4" aircraft ply
plate that sits on top of and spans
the two gear pieces (side of fuse to other side of fuse and as wide
as the gear channel in the bottom of the fuse) and
is pierced by the four landing gear bolts. This requires longer
bolts. Don't remember the exact length.... Then used large
washers under the bolt heads to further spread the load over
the ply plate.
Bruce
Old 12-06-2004, 11:30 AM
  #3  
CCDave
My Feedback: (53)
 
CCDave's Avatar
 
Join Date: May 2003
Location: Frisco, TX
Posts: 241
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

John,

I am using the Graphtech 22# tailwheel bracket.
Old 12-06-2004, 03:15 PM
  #4  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

ORIGINAL: bhanley

I layered the entire landing gear area with a single layer of
Kevlar cloth and epoxy and then made a 1/4" aircraft ply
plate that sits on top of and spans
the two gear pieces (side of fuse to other side of fuse and as wide
as the gear channel in the bottom of the fuse) and
is pierced by the four landing gear bolts. This requires longer
bolts. Don't remember the exact length.... Then used large
washers under the bolt heads to further spread the load over
the ply plate.
Bruce
That sounds real close to what I was planing to do Bruce. It looks like if you land perfect every time you probably won't have any problems with the stock setup but then again who ever lands perfect? I am going with a ZDZ 80 and those motordome bolts look awful skimpy as well, I think they are 4 mm which is about 5/32". There is no provision to lock the bolts down, I can see vibration loosening them up pretty quick. I prefer using nylock type nuts on high vibration areas like this. Overall I give Comp-ARF a high score for wing attachment and stab attachment, a tad lower for the gear and motordome mounting and I am still trying to figure out why they went with such an overly complicated setup to mount the canopy? I am just geting started on this thing and am trying to think all this through ahead of time. What diameter wheels did you guys use? I was going to go with 4 1/2 " Dubro low bounce. Where can I get the Graphek tail wheel assembly, is it light?? I see this thing coming out tail heavy if I am not careful.

jmw
Old 12-06-2004, 03:28 PM
  #5  
ptgarcia
Senior Member
My Feedback: (36)
 
ptgarcia's Avatar
 
Join Date: Jun 2002
Location: Alta Loma, CA
Posts: 2,072
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

[link=http://www.graphtechrc.com]Graphtech R/C[/link], and yes, they are light. Good luck!
Old 12-06-2004, 07:17 PM
  #6  
GoeKeli
My Feedback: (18)
 
GoeKeli's Avatar
 
Join Date: Aug 2002
Location: North Hollywood, CA
Posts: 3,713
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

I did not glass or reinforce my landing gear mount. All is well after 100 flights. Nothing about this plane is meant to be crashed or abused, but it is surprizingly tougher than I thought it would be. I got the graphtech tail wheel and carbon stab tube.

joe
Old 12-06-2004, 09:06 PM
  #7  
Nyroth
My Feedback: (31)
 
Join Date: Jun 2002
Location: Linköping, SWEDEN
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

Helllo John,

I know it can be tempting to reinforce an existing construction that might appear weak.
In this case dont do it!

The Composite ARF line of aircraft is proven to be well engineered there is no need for additional strenght of the landing gear plate.

If you do choose to reinforce, The result will most likely be disastrous the day when you will have to do a rough landing.
Instead of the landing gear plate collecting all force and break like a fuse, it will distribute all force out to the fuselage and know you will have a mess to clean up. Thrust me i have seen it happen.

The following text is from the instruction manual, Please follow it , these guys know!!

The landing gear mount is strong and doesn’t need any extra reinforcement. You have an extremely light weight fuselage, and the gear loads need to be led into the structure gently. No glue joint needs to be stronger than the materials that it is attached to, as it would just result in increased weight for no advantage. The landing gear is a fairly flexible design, which works very much like shock absorbers. This plane is not made for crashing, but the landing gear will take some hard landings without problems. Do not change or modify it, as the results would only be negative. We had plenty of time and experience to engineer the strength needed in this area -and we did!

Best Regards,
Niklas Nyroth
Composite-Arf Field Rep
Old 12-06-2004, 11:51 PM
  #8  
didiwatt
My Feedback: (38)
 
Join Date: Feb 2002
Location: La Center WA
Posts: 823
Likes: 0
Received 2 Likes on 2 Posts
Default RE: Composite-Arf 2.3 Construction

I agree, leave it alone. It is stronger than the surrounding fuselage already. I have 3 extra's. I have landed all of them hard enough for the landing gear to flex up into the edge of the fuselage 1/2", damaging this area of the fuselage yet the landing gear plywood bracket assembly held. All you will be adding is weight and not gaining any fuselage strenth. Just my two cents worth.
Old 12-07-2004, 10:43 AM
  #9  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

OK, I'll leave gear structure as is. Only thing I changed in the gear department so far was to go to slightly larger diameter washers under the landing gear bolt heads. Stock ones are a bit small, not much bigger than the bolt head itself. I have superficial damage to the gear legs themselves where they chafed during transit. Not serious but would like to polish out if possible. Anybody with suggestions on this??

Thanks
jmw
Old 12-07-2004, 11:02 AM
  #10  
Nyroth
My Feedback: (31)
 
Join Date: Jun 2002
Location: Linköping, SWEDEN
Posts: 19
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

John,
You can easily fix most scrape marks with some wet sanding and then rubbing compound then end with some polish/wax.

Start out with 400 wet sand then work your way to at least 800, then compoound and polish as needed.

Good luck,

Niklas
Old 12-07-2004, 02:37 PM
  #11  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

OK, I'll try a micromesh kit we use to repair scratches in aircraft plexiglass windows. Should work fine.
Found a really cool tailwheel assembly at http://www.cactusaviation.com/Produc...els/wheel.html

jmw
Old 12-07-2004, 05:38 PM
  #12  
AJF--2
Senior Member
My Feedback: (119)
 
Join Date: Feb 2002
Location: Snow Hill, NC
Posts: 2,089
Likes: 0
Received 1 Like on 1 Post
Default RE: Composite-Arf 2.3 Construction

I have landed all of them hard enough for the landing gear to flex up into the edge of the fuselage 1/2", damaging this area of the fuselage yet the landing gear plywood bracket assembly held.
Ditto-- me too. The only thing that broke was one of the bolts pulled through the hole in the composite gear. A body washer was a quick fix at the field and I was flying inside of an hour. The fuse was fixed with some fiberglass and epoxy to the inside of the fuse and then epoxy with milled fiber to fill the hole on the outside. Will get around to painting someday!
Old 12-08-2004, 04:24 AM
  #13  
Mattyb
Senior Member
 
Join Date: Mar 2003
Location: Australia
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

Hi guys.
Am just ordering the last of the stuff I need for my 2.3 jr scheme. I can get some nice'n lite wheels but they are 4.33" does anyone know if that will fit ok in the wheel pants.

It sure is a nice model huh.

Mattyb
Old 12-08-2004, 10:35 AM
  #14  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

Matty, I think you can use up to a 5 inch wheel, I am going with 4.5 Dubro Low Bounce wheels on mine. Did you end up going with the ZDZ 60 or the 80? I was curious as to how it balanced. Also, what tail wheel did you go with?

jmw
Old 12-08-2004, 12:58 PM
  #15  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

I was going to order some custom standoffs from Aerografix http://www.aerografixs.com/ and was wondering if I need to add additional right thrust. The motor domei s slightly offset to the right on the 2.3, haven't measured the angle yet but I think the ZDZ 80 I'm usingi s going to need more. How much rightthrust are you guys usingwith the bigger engines?

jmw
Old 12-08-2004, 01:17 PM
  #16  
ptgarcia
Senior Member
My Feedback: (36)
 
ptgarcia's Avatar
 
Join Date: Jun 2002
Location: Alta Loma, CA
Posts: 2,072
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

john316,

I would order equal length stand-offs then adjust right thrust with washers/spacers as necessary as you trim your plane.
Old 12-08-2004, 02:15 PM
  #17  
stomper
Senior Member
My Feedback: (20)
 
Join Date: Dec 2001
Location: Clayton, NC
Posts: 2,249
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

These are the wheels going my Yak. 5" superLight big scale airwheels from Kavan. Take a look half way down the page > http://www.hobby-lobby.com/wheels.htm


HTH
Old 12-09-2004, 04:11 AM
  #18  
Mattyb
Senior Member
 
Join Date: Mar 2003
Location: Australia
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

John,
I ended up buying the zdz60, price was to good to pass up. it is being sent to me soon. as for tail wheel it looks like i will get the one from Precision Aerobatics aswell as the wheels which will be 4.33" . wont know how she will balance yet as am waiting for all this to come from other side of Australia. and the muffler is still 3 weeks away, but what a beauty it is.
Attached Thumbnails Click image for larger version

Name:	Fd93114.jpg
Views:	5
Size:	107.4 KB
ID:	200993  
Old 12-09-2004, 02:41 PM
  #19  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

What do you plan to do about standoffs Matty?

jmw
Old 12-10-2004, 05:06 AM
  #20  
Mattyb
Senior Member
 
Join Date: Mar 2003
Location: Australia
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

I am thinking that i will just make some out of hard wood. or go buy some solid Aluminium tube stuff from a hardware place. Make it up that way. I dont think its all to hard. People have made them out of oak dowel.
Old 12-10-2004, 08:45 AM
  #21  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

ORIGINAL: Mattyb

Hi guys.
Am just ordering the last of the stuff I need for my 2.3 jr scheme. I can get some nice'n lite wheels but they are 4.33" does anyone know if that will fit ok in the wheel pants.

It sure is a nice model huh.

Mattyb
Matty, I ended up using 4" Sullivan Lite wheels, they fit the pants perfectly. I can't see any reason to go with a larger wheel, just going to add more weight. I ditched the stock hardware and went with 10-32 x 2" axles with two locknuts and washers. This setup works great and won't come loose.

jmw
Old 12-10-2004, 10:18 AM
  #22  
bhanley
Senior Member
 
Join Date: Oct 2002
Location: Sammamish, WA
Posts: 451
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

On eng stand offs - suggest that you look at Lowes or a good hardware store in
your area for nylon spacers/bushings. Have tested them for resistance to
gasoline and for compression stability and they hold up. They are cylindrical
in shape, come in various lenths and drilled down the center. The center hole
size is varied but I tend to use 1/4" for 1/4x20 bolts. These offer a light,
simple and cheap solution - look OK as well.
Bruce
Old 12-10-2004, 10:46 AM
  #23  
john316
Senior Member
Thread Starter
 
Join Date: Mar 2003
Location: San Antonio TX USA
Posts: 447
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

ORIGINAL: bhanley

On eng stand offs - suggest that you look at Lowes or a good hardware store in
your area for nylon spacers/bushings. Have tested them for resistance to
gasoline and for compression stability and they hold up. They are cylindrical
in shape, come in various lenths and drilled down the center. The center hole
size is varied but I tend to use 1/4" for 1/4x20 bolts. These offer a light,
simple and cheap solution - look OK as well.
Bruce
Bruce, I checked those out at Tru-Value hardware last night. Cheap and light, I may go that route, thanks. For a more elegant solution if you have the bucks try http://www.aerografixs.com/

John
Old 12-10-2004, 09:03 PM
  #24  
Mattyb
Senior Member
 
Join Date: Mar 2003
Location: Australia
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

those bushings sound like a great idea. will have a hunt for them tomorrow. its not a matter of money for me but more about timing, i have 10 days off over xmas and i always have to mail order my stuff and i need it all by then so i can start building . not rushing or skimping on anything, but if there is a quicker easier way, thats what i will do
Old 12-12-2004, 12:56 AM
  #25  
Mattyb
Senior Member
 
Join Date: Mar 2003
Location: Australia
Posts: 275
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Composite-Arf 2.3 Construction

hey bruce,
What section would those nylon bushings be in. i know what they are but cant think what they are usually used for. had a quick hunt today and couldnt find any.

Matt

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.