RedWing MX2 Build
#851
Thread Starter
My Feedback: (18)
Join Date: Jan 2004
Location: Peru,
IN
Posts: 748
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Two weeks ago I had a bad landing where the plane went over at the runway end. No external damage was evident even the prop was intact. Next time an attempt to start the engine was made I found the throttle servo was not working. When the cowl was removed to replace the servo it was found the engine box have suffered extensive damage during that last incident. The firewall was broke around one of the engine mount bolts, and both top and bottom engine box panels were broken.
The fact is the whole airplane is built extremely light and any small incident may cause damage to the structure, especially when you take in consideration the size and quality of the construction material. For example the engine box is constructed of 1/16" ply and the firewall is just a 3/8" thick. For that reason I decided to take the opportunity to do some structural reinforcement of the entire engine box.
First off I removed all the broken pieces, and proceeded to make new parts form the old ones, except on the firewall instead of using 3/8" ply I used 1/4'. The reason for using 1/4" ply for the firewall was that I intended to add 1/8" of carbon graphite lamination. My composite materials provider (Aerospace Composites Products) was running short of .007" Unidirectional Carbon Fiber Laminate material so I ordered one yard of .5 ounce carbon graphite tissue. I then laminated two 1/64" pieces of Obechi veneer with the CF tissue on both sides with finishing resin. After this lamination's where cured I added them to both sides of the 1/4" ply firewall, with a finished thickness of 3/8" . I could have used 1/16" pieces of ply to laminate a 3/8" panel that would be virtually indestructible but the fact is if the firewall don't break something else will so that's is a perfect example of over-engineering. Finally I laminated the rest of the box panel with CF tissue in both sides rest and reassembled the using 1/4" hardwood triangle stock to reinforce the interior corners.
One important point to keep in mind when building CF lamination is that the lamination's must be cured while under pressure. Some folks use vacuum bagging for very large surfaces (i.e. glider wings) but for small flat parts to press the part between two solid wood planks will do the trick. If one desires a very high modulus the part must be cured under pressure at a higher temperature inside an industrial autoclave which is outside the budget of most hobbyist. In my case I press the parts between aluminum plates which I coat with Partall a low VOC polyvinyl alcohol which acts as a barrier between parts and mold surfaces. Then I cure them inside my kitchen oven at 125 degrees F.
The fact is the whole airplane is built extremely light and any small incident may cause damage to the structure, especially when you take in consideration the size and quality of the construction material. For example the engine box is constructed of 1/16" ply and the firewall is just a 3/8" thick. For that reason I decided to take the opportunity to do some structural reinforcement of the entire engine box.
First off I removed all the broken pieces, and proceeded to make new parts form the old ones, except on the firewall instead of using 3/8" ply I used 1/4'. The reason for using 1/4" ply for the firewall was that I intended to add 1/8" of carbon graphite lamination. My composite materials provider (Aerospace Composites Products) was running short of .007" Unidirectional Carbon Fiber Laminate material so I ordered one yard of .5 ounce carbon graphite tissue. I then laminated two 1/64" pieces of Obechi veneer with the CF tissue on both sides with finishing resin. After this lamination's where cured I added them to both sides of the 1/4" ply firewall, with a finished thickness of 3/8" . I could have used 1/16" pieces of ply to laminate a 3/8" panel that would be virtually indestructible but the fact is if the firewall don't break something else will so that's is a perfect example of over-engineering. Finally I laminated the rest of the box panel with CF tissue in both sides rest and reassembled the using 1/4" hardwood triangle stock to reinforce the interior corners.
One important point to keep in mind when building CF lamination is that the lamination's must be cured while under pressure. Some folks use vacuum bagging for very large surfaces (i.e. glider wings) but for small flat parts to press the part between two solid wood planks will do the trick. If one desires a very high modulus the part must be cured under pressure at a higher temperature inside an industrial autoclave which is outside the budget of most hobbyist. In my case I press the parts between aluminum plates which I coat with Partall a low VOC polyvinyl alcohol which acts as a barrier between parts and mold surfaces. Then I cure them inside my kitchen oven at 125 degrees F.
#852
RE: RedWing MX2 Build
Excellent Carbon Fibre work you have done on your MX2.
The models are indeed designed to be light and while they fly great, theydon't stand up very well tounexpected 'ruff up'. I too went through a process of reinforcing my engine box and certain areas behind the firewall. Thiswasafter finding out that my firewall broke around one of the engine mount bolts just as your did. Over the course of a couple evenings Itraced, cut and glued 1/8" pannels on the firewall and all remaining sides (top, sides and bottom. You will also observe from the pictures that, as added security, Iused wood screws to secure the new firewall plate to the original one and larger triangular stock to secure the engine box to the fuse.
She's been flying GREATever since and has survived many more of those unexpected 'ruff ups'.
Thanks for sharing.
DaleD.
The models are indeed designed to be light and while they fly great, theydon't stand up very well tounexpected 'ruff up'. I too went through a process of reinforcing my engine box and certain areas behind the firewall. Thiswasafter finding out that my firewall broke around one of the engine mount bolts just as your did. Over the course of a couple evenings Itraced, cut and glued 1/8" pannels on the firewall and all remaining sides (top, sides and bottom. You will also observe from the pictures that, as added security, Iused wood screws to secure the new firewall plate to the original one and larger triangular stock to secure the engine box to the fuse.
She's been flying GREATever since and has survived many more of those unexpected 'ruff ups'.
Thanks for sharing.
DaleD.
#853
Thread Starter
My Feedback: (18)
Join Date: Jan 2004
Location: Peru,
IN
Posts: 748
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Looks like your firewall broke exactly like mine. I also noted that with the DLE engine you need to enlarge the hole in the firewall quite a bit. I run an Evolution 26 and the carb is up front so I don't need to enlarge the firewall hole so much which inevitably will weaken the firewall some more. I will keep that in mind for my next 30cc MXS-R which I plan to run a DLE to reinforce the firewall right out of the box.
In any case you did a very good job in strengthening your engine box, it should give you many more flying hours. As you mentioned this is a very light model so it need to be handled with more "finesse". Thanks for sharing
In any case you did a very good job in strengthening your engine box, it should give you many more flying hours. As you mentioned this is a very light model so it need to be handled with more "finesse". Thanks for sharing
#854
Join Date: Mar 2005
Location: Haines City, FL
Posts: 242
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Hi everyone:
I have this plane build and setting up the servos already got the wing ones set and ready.. but been trying to bust my head with the elevator servos..
I'm using 2 hitec 5625mg servos and an ems servo reverser with a JR Spcm receiver on my JR8103 radio.
The problem I have is I have both elevator halves neutral and the linkage also dead center like tim said in the video the servos arms are in 90 degree position..
Now when I connect to the servo reverser the servo connected to it has more deflection than the other one.. and if i change the servos vice versa the same thing happens...
Been raking my head trying to figure this out and its allways at full deflection when one notices it more.. theres allmost 1/4 inch or so of difference between the 2 halves..
What am I doing wrong???
I have this plane build and setting up the servos already got the wing ones set and ready.. but been trying to bust my head with the elevator servos..
I'm using 2 hitec 5625mg servos and an ems servo reverser with a JR Spcm receiver on my JR8103 radio.
The problem I have is I have both elevator halves neutral and the linkage also dead center like tim said in the video the servos arms are in 90 degree position..
Now when I connect to the servo reverser the servo connected to it has more deflection than the other one.. and if i change the servos vice versa the same thing happens...
Been raking my head trying to figure this out and its allways at full deflection when one notices it more.. theres allmost 1/4 inch or so of difference between the 2 halves..
What am I doing wrong???
#855
Senior Member
Join Date: Oct 2006
Location: winston,
MO
Posts: 1,378
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
I am just using a single elev servo. I had a similar issue but it was the futaba 9c so I elected to pull one of the elev servo's and add the elev joiner wire.
#856
RE: RedWing MX2 Build
Iam not totally familiar with your transmitter nor receiver but I thought I would share how it is that Iset up my MX2.
Iam using a Spektrum DX7 with 7 channel receiver. Iuse two separate servos on the elevators and Ihave one plugged into ELEV and the other into AUX2. If Irecall correctly Ihad to do a mix for ELEV to AUX2. My set up works perfectly without any issues as you described. If you havereceiver capacity, Iwould suggest that you use a separate channel for the second servo.
Hope this helps
Dale
#860
Senior Member
My Feedback: (4)
Join Date: Oct 2007
Location: St. Louis,
MO
Posts: 1,320
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
I have no doubts that a DLE 20 will fly this plane... but, don't expect it to have super performance. You would probably need to put everything up front to get the CG correct, and it will probably just sit in a hover (no pull out). Now, this is if you get it as light as posible. With a DLE 30 this plane is a monster, so a DLE 20 should be able to fly it, sport like, no 3d.
#861
Senior Member
Join Date: Sep 2008
Location: Mumbai, INDIA
Posts: 2,224
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Thats the objective. Its too large now for my transportation system so I dont want to open it up right now. I hope my LHS is getting some of Goldwing's 26cc airplanes so that I can use my DLE20 on it
I do have a OS GT33 waiting though. What do you think. Should I go for it?
Ameyam
I do have a OS GT33 waiting though. What do you think. Should I go for it?
Ameyam
#864
Join Date: Mar 2005
Location: Haines City, FL
Posts: 242
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Well guys fixed the servo problem...
But I dunno maybe cause i bought this plane somewhere else I got the lemon of the pack, cause this one is filled with problems all around.... Wings don't fit right , got a dle that sticks out 1 1/4inches out from the cowling... Canopy don't seal right though that I fixed easily...had a wing screw come glued with epoxy from the factory...
So slowly fixing It to be able to fly It...
On my opinion if you're gonna buy this plane buy It from Tim, everyone here has gotten lots of help from him and from what I've read he checks the planes before he mails them out.. unlike where I bought It..
But I dunno maybe cause i bought this plane somewhere else I got the lemon of the pack, cause this one is filled with problems all around.... Wings don't fit right , got a dle that sticks out 1 1/4inches out from the cowling... Canopy don't seal right though that I fixed easily...had a wing screw come glued with epoxy from the factory...
So slowly fixing It to be able to fly It...
On my opinion if you're gonna buy this plane buy It from Tim, everyone here has gotten lots of help from him and from what I've read he checks the planes before he mails them out.. unlike where I bought It..
#865
Senior Member
My Feedback: (12)
Join Date: Sep 2008
Location: Grants, NM
Posts: 189
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Finally finished mine and got it maidened. It's been a long strange trip. From the initial trashed box (yet the plane survived intact somehow) to the problems with the CF tube (nothing would fit, so lots of sanding) and the engine choice issues, it's been quite a haul to get this thing done. I reinforced the landing gear mount with wood diagonals epoxied in, boxed up the engine mount, and powered it with an OS 1.60. All the frustrations floated away as the plane pulled off the ground at 1/3 throttle. It's as good a plane as I had hoped for. Of course, the stock tailwheel tiller came loose on the first landing which was a no-bounce greaser. I'll fix that with a threaded rod and some loctite.
But I do have a question: what's the preferred CG? I like to set my birds up so that when throttle is reduced, the plane takes on a slight nose-high attitude without pilot inputs. What CG are people flying this thing on?
But I do have a question: what's the preferred CG? I like to set my birds up so that when throttle is reduced, the plane takes on a slight nose-high attitude without pilot inputs. What CG are people flying this thing on?
#866
Senior Member
Join Date: May 2008
Location: Valencia, SPAIN
Posts: 534
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
ORIGINAL: Cpt Crash
Of course, the stock tailwheel tiller came loose on the first landing which was a no-bounce greaser. I'll fix that with a threaded rod and some loctite.
Of course, the stock tailwheel tiller came loose on the first landing which was a no-bounce greaser. I'll fix that with a threaded rod and some loctite.
Get to your LHS.. buy a standard tail wheel assembly... you know the ones that have the plastic hinge that screws to the underside.. and it is just one contiual iron rod bent to shape?.
Its the ones where the tail wheel obviouly goes on a "horizontal part" then it goes vertical so you push a bent part into the rudder when you build a plane?
Well get one of those.. but cut it shorter and bend it at 90 degrees so it goes along with the rudder like the one in the kit.....
I had endless problems with tail wheels for this plane untill I did this......
#867
RE: RedWing MX2 Build
ORIGINAL: ceecrb1
Dont bother..
Get to your LHS.. buy a standard tail wheel assembly... you know the ones that have the plastic hinge that screws to the underside.. and it is just one contiual iron rod bent to shape?.
ORIGINAL: Cpt Crash
Of course, the stock tailwheel tiller came loose on the first landing which was a no-bounce greaser. I'll fix that with a threaded rod and some loctite.
Of course, the stock tailwheel tiller came loose on the first landing which was a no-bounce greaser. I'll fix that with a threaded rod and some loctite.
Get to your LHS.. buy a standard tail wheel assembly... you know the ones that have the plastic hinge that screws to the underside.. and it is just one contiual iron rod bent to shape?.
Take this advise, you will be happy.
Ihave been replacing what I think are inferior tail wheels on models with this http://www.sullivanproducts.com/Land...rMainFrame.htmThey works great.
Congratulations on getting your MX2 into the air. Ihave quite a few flights on mine now and I am enjoying her more each flight.
DaleD
#868
Senior Member
Join Date: May 2008
Location: Valencia, SPAIN
Posts: 534
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
yeah shes a real confidence builder!!
Best purchase I ever made in my RC flying... I've had mine over a year and i've REALLY advanced with it, i'm far far better for having it.
To be honest after getting my MX2 I reduced my entire stock.. Now I only own a dle20 powered scale plane, a trex 500 and the mx2... I just dont need anything else!
Best purchase I ever made in my RC flying... I've had mine over a year and i've REALLY advanced with it, i'm far far better for having it.
To be honest after getting my MX2 I reduced my entire stock.. Now I only own a dle20 powered scale plane, a trex 500 and the mx2... I just dont need anything else!
#871
Join Date: Mar 2005
Location: Haines City, FL
Posts: 242
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Thanks.. Well a little ingenuity on my part and some combined knowledge of me and my dad equals we'll come up with something... Fixed the problem and as of now the plane has 40 flights in it and flying perfectly.
Maybe for this thursday i'll switch out the break in prop for a xoar 19x8 or a 20x6 falcon.. depends how the weather is..
Maybe for this thursday i'll switch out the break in prop for a xoar 19x8 or a 20x6 falcon.. depends how the weather is..
#873
Join Date: Mar 2005
Location: Haines City, FL
Posts: 242
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
If you mean on how I fixed the problem that the dle 30 sticks out 1 1/4 out of the cowling front.. after a lot of prototypes i used a Huge block of light balsa I had laying around and made a donut which I sanded till it just fit flush with the cowling reinforced with light fiberglass primed and painted till it somewhat matched the color of the plane and installed.
That's about it.. thought it took me about 2 weeks till it looked how I wanted..
That's about it.. thought it took me about 2 weeks till it looked how I wanted..
#874
RE: RedWing MX2 Build
Would love to see pictures of your engine installation. I'm trying to appreciate why your engine spinner back plate ended up 1.25" from the front of the cowl. Did you cut a hole in the firewall to accommodate the carb?
Nice job on the modification.
DaleD
Nice job on the modification.
DaleD
#875
Join Date: Mar 2005
Location: Haines City, FL
Posts: 242
Likes: 0
Received 0 Likes
on
0 Posts
RE: RedWing MX2 Build
Here's the picture i have before i made the modification. I did not cut out or touch the firewall, minus reinforcing the back of it with 1/4 inch plywood and fiberglass.
As you can see the engine sticks out 1 1/4 inches out from the cowling so thus i made that modification to hide that from showing cause it looks horrible.. and still surprised no one at the factory that makes this plane has modified or changed this plane to acommodate the DLE30 rear carb like the one they show in their own manual... But oh well i fixed their mistake with a little creativity
As you can see the engine sticks out 1 1/4 inches out from the cowling so thus i made that modification to hide that from showing cause it looks horrible.. and still surprised no one at the factory that makes this plane has modified or changed this plane to acommodate the DLE30 rear carb like the one they show in their own manual... But oh well i fixed their mistake with a little creativity