RE: CMP 120 Zero ARF Build thread
 

Nice work!

RE: CMP 120 Zero ARF Build thread
 

I like that you distributed the weight long multiple ribs, and its hard to tell from the pic but did you replace the existing ribs ? or add doublers to the balsa stock ribs ? I didn't feel the ribs were strong enough on there own so I took this extra precaution, also I noticed that you shortened the what would be the strut length by moving the retract up to its new location shortening the stance and potential prop clearance what are you running engine and prop wise ?

looks great nice clean set up ! keep the pic coming !

RE: CMP 120 Zero ARF Build thread
 

New ribs are made from ply 5 mm thick (here we call it "plane ply" with 7 cross layers), and they are glued to existing balsa ribs.
Under the place where retract will be is screwed block of hard wood. Wheel's are du bro 4", and strut's are Robart 500 series
1/2" (12.70 mm). Yes i have shortened them, to exact size as they should be (i hope so). As a result i have to cut all
ribs to last, made of ply, in the middle.

The ribs are first made of cardboard and after that of light plastic, and than, finally from ply.

http://img517.imageshack.us/img517/5899/dscn1563v.jpg

http://img72.imageshack.us/img72/3465/dscn1596.jpg

http://img189.imageshack.us/img189/5545/dscn1594z.jpg

A lot of fitting is made because i wanted to get wheels as much to front on lending so it would not roll over.

http://img26.imageshack.us/img26/6271/dscn1593d.jpg

now the wheel is going to be in front of wing.

http://img7.imageshack.us/img7/4469/90551440.jpg

Strut is cut and spring too.

http://img169.imageshack.us/img169/9682/dscn1571.jpg

And this is how i have made round shape for wheel. I have put 3mm balsa
in water for several min, and then usling light pressure bend it over the can,
that is larger than wheel.

http://img232.imageshack.us/img232/3933/dscn1559.jpg

When dry it should look like this

http://img232.imageshack.us/img232/8724/dscn1560py.jpg

http://img535.imageshack.us/img535/2286/dscn1561mw.jpg

On this picture is original and new setup.

http://img687.imageshack.us/img687/8865/dscn1550w.jpg

@ZERO-322, Because i have read a lot of threads on many forums, i am thinking to
start a new thread with all information that can be helpful for other people.
This is my first plane that i am building in such way and i have a lot difficulties
like when somebody ask which type of retracts someone is using, the answer is Robart,
or Siera or... but wich of many models that they have? motor? Yes it is Zenoah? Which Zenoah?
The list goes on and on. That is reason that i am trying to take as many photos and
this days i will try too start new post.

Best regards

And yes, it will be Zenoah ZG-26-SC with Magneto-driven CDI ignition system.
Why? I think that it will be enough weigh in front CG so i will need no lead in
front.

http://img177.imageshack.us/img177/2205/12448782.jpg

http://img177.imageshack.us/img177/8786/z10ei.jpg

http://img62.imageshack.us/img62/2741/93033429.jpg

RE: CMP 120 Zero ARF Build thread
 

Very cool!!!!

RE: CMP 120 Zero ARF Build thread
 

Hello
Nice to see all your buildings and plane and I am following this thread when ever there been an update. Keep up your good work!

I post some pictures abut I year in [link=http://www.rcuniverse.com/forum/m_9002289/mpage_2/key_/tm.htm]Page 2[/link] and i have not completed my Zero yet. I have made all the panellines and rivets on the wing and have some problem whit the gear doors but i gut to get them to work.
My engine will be the ROTO 35 FS and that motor will give me power to swing a 3-blade prop.

Hopefully i would get my Zero to fly next year
I got at poster on my building wall that says "Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning."

Over and out. /Gezuz

RE: CMP 120 Zero ARF Build thread
 

@zero 322( or anybody), is it possible to take some close up pictures of sliding canopy.
I am thinking to make one (not as realistic as you did, but only to place inside pilot, instruments
for retract preasure, fuel, baqttery, switches,...

RE: CMP 120 Zero ARF Build thread
 

here you go, the sliding canopy was made by cutting the existing stock canopy into its respective 3 parts the by gluing 2 plastic C channels to the fuse on the center section of the canopy then by taking a short length of plastic I beam to the inside bottom of the sliding section, then by running them through each other they slide, it slid better before I painted though so you may want to use garfite to lubricate < I'll post some more pic tonight or tomarrow

RE: CMP 120 Zero ARF Build thread
 

Still working on the flaps. I was able to hide the linkage inside. Just used a regular control horn and trimmed it. There is just enough room between the ribs for a standard servo. Made servo cover out of thin ply. Had to use an EZ fitting to be able to adjust the push rod. Glassed the bottom of the flap to give it a little extra strenght as the trailing edge is thin.

RE: CMP 120 Zero ARF Build thread
 

I put mine together several months ago and have still not had a good flight. The thing wanted to climb at 45 deg as if it is tail heavy. I've got an SV-26cc engine on it and it is balanced out at about 150 mm. I mucked around with the CG and added (and later removed) shims to the engine to add down thrust.

I finally put an incidence meter on it and found the stab at 0 deg and the wing at +2 deg! The wing fit perfectly with very little slop at the LE notch so I never dreamed it was that far off. Anyone else have this problem? How to fix it?

I ended up heating the area with my heat gun and bending the fiberglass. I then added shims to the wing on either side of the notch, and on the saddle of the fuse, heated it up again, and installed the wing. I now have about +1/4-1/2 deg wing incidence. Will fly it again to see if that helped. If anyone wants pics of the fix, let me know.

RE: CMP 120 Zero ARF Build thread
 

R bean you've inspired me my friend and I will keep the pic you posted as a refrence so that when I get to this point I'll have the visual aid to guide me thanks for sharing please keep up the great work and post away !

X man sounds to me your also a little tail heavy I balanced mine at 140 mm and shimed the engine down just a tad for some down thrust and she flew fine, none the less I would love to see the fix you refer to so please by all means post away,

On this one I have ordered a a yellow zero cowl which is a perfect match diameter wise but is a about 1.25 inches longer then the stock cmp one provided, it will allow me to add a battery box against the fire wall and leave me with plenty of room to do a scale exhaust I've been dying to try, moving the engine forward that much will also greatly reduce any dead weight need to get the CG

RE: CMP 120 Zero ARF Build thread
 

Help ! guys someone anyone I'm stuck on these inner gear doors, I can't seem to come up with a viable solution to actuate the smaller gear doors I've tried hinging a small bent wire to the door so that when the gear retracts it would take the other door with it and gravity would just let it open, however there was way to much slop and the door would not hold tight when closed, I then decided to try and actuate it with a mini servo but have no clue how to set it up to work with the room I have to work with, I've tried magnets and springs, bent pushrods in all sorts of configurations with no avail, anyone how has set this up and gotten it to work please please please share with me how, some pic and a detailed how to would be greatly appreciated ! bonus if it pertains particularly to this model

thanks
Mike

this is what I'm working with so far

RE: CMP 120 Zero ARF Build thread
 

brain fart LOL

RE: CMP 120 Zero ARF Build thread
 

@zero-322, I have found some solutions on net like on this pictures

RE: CMP 120 Zero ARF Build thread
 

I tried balancing it out to 140 mm with shimming the engine and without but it still needed 1/2 the throw of down elevator to fly straight. What is your wing incidence? Mine was +2 deg.

RE: CMP 120 Zero ARF Build thread
 

Misha Thanks so much ! I think the third pic from the left is the fix I was looking for, its amazing on how sometimes we can get stuck on the simplest of things and yet other times build unbelievable works of art without thinking at all LOL

x man I haven't checked the incidence on mine don't have a meter to check it ( I haven't been building/bashing very long ) are you balancing the model inverted with gear extended and fuel tank empty ? I will tell you that when I first got mine there were two large cracks at the leading edge notch to the almost very center of the fuse, once I repaired this with some glass and epoxy the wing fit was very tight to the saddle with no slop at all and quite the oposite actually

RE: CMP 120 Zero ARF Build thread
 

Vasek,

Actually no. I left the cross piece off there because there is plywood to support the horn and I think it is stiff enough and I want to be able to inspect the horn and clevis.

RE: CMP 120 Zero ARF Build thread
 

Rbean Will you be glassing the wing ? if so what method are you considering ? I'm leaning toward the water base poly myself

RE: CMP 120 Zero ARF Build thread
 

Zero 332,

Not planning on glassing the wing, havn't done it before, don't want to add weight. I have basic airframe assembled and it weights 7 lbs with servo but less landing gear and radio. I put it on the cg meter and will need about 74 oz up front to balance. Might use a 25 cc conversion with magnito as I need the weight any way. Batteries, cowling and prop weight 18 oz plus about 4 oz of misc equip up front leaving 52 oz for the engine. Why spend money on the light weight DLE 30 when I need more weight up front? Total weight est. is 13.5 to 14 lbs.

RE: CMP 120 Zero ARF Build thread
 

Glassing a wing is not hard at all, the poly method leaves very little additional weight if any at all and provides unsurpassed strength to the airframe, you can do a search on here for the how to, and if you consider all the mods you've done to the wing it wouldn't be a bad idea (help to tighten everything up), however if if you don't glass the wing it will still look great ! zero's were beat up and very much looked that way, so as long as you don't forget to weather yours a bit it should come out looking pretty good.

If ya like when I get to that stage and hopefully soon I will gladly post how to with some pic I plan on doing panel lines and rivets this time around so its not that much of a stretch. however now thanks to you I'll be attempting the split flaps you illustrated above, you also inspired me to do hidden linkages on the alireons so we'll see how it goes and I'll post my progress

RE: CMP 120 Zero ARF Build thread
 

I read the threads and watched videos re glassing and took notes. Looks like something I could do. But have already installed flaps and alerons. I think I'll try stripping and glassing an old ARF were the covering is in bad shape to see how it goes, but maybe I'll paint this one.

RE: CMP 120 Zero ARF Build thread
 

I've started the engine installation. I aquired a 25 cc conversion with electronic ignition. Weights more than some of the lastest gas engines made for RC planes. Weight is about 56 oz. I test ran before installation and it turns a 16-8 Master Airscrew three blade prop 7,800 rpm. This should be enough power for scale flying. I'm still going to need to mount the ignition modual, ignition and receiver batteries in front of the fire wall for the thing to balance.

RE: CMP 120 Zero ARF Build thread
 

Hi all, I own a CMP 120 Zero as well. I accidentally shoved something through the wing and am delighted to see all this creative work.. She will be flying again soon. One of the contributions I think I can make is that I have discovered a drop in retract option that is electric. The new Lado retracts will drop right in place and Lado has the Oleo struts to go with it. The proper length I believe is 200mm.. Long strut for this plane, the biggie is that it fits and there is a retract combo that does not require the beautiful work I have seen here. Installing those retracts and flaps is a loving creation to augment this arf. The Lado retract option can be viewed at www.magnumrc.com. The reliability and scale operation of Lado's are impecable. My two cents worth after the Oleo's arrived.

RE: CMP 120 Zero ARF Build thread
 

Love the lado's but I'm running an old set of 60-1 back when Doug was at the helm, I will most definately be purchasing a few sets and some actuators from you soon ! as far as the oleo's they seems to be really nice but far from scale for a zero maybe if they were offset I would give them a second look probably even purchase a set or two , any chance of an offset strut being offered in the near future ?

RE: CMP 120 Zero ARF Build thread
 

R U thinking of using the straight oleo or does Lado make also some offset style oleos?

RE: CMP 120 Zero ARF Build thread
 

I think that that "beautiful work" is MUST DO. Even with perfect lending, there is big risk of braking wing ribs
that are holding the retracts or fixed gear. They are too weak. Also, landing with flaps is much easier than without, and
much safer. My friend has a plane without flaps and it is very difficult to land it on short field.