HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 07, 2010, 03:00 AM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Discussion
OMP EG Aircraft 85-100 CC Extra 300 - Electric Conversion

Hi All,

After smashing my 103 3dhs Extra, I was able to pick up this OMP for relatively ship price. A guy I know had purchased it and decided it was not for him so I was able to get it at cost for $875 NIB. Apparently, OMP will sell you this plane shipped for that price to your local GreyHound Bus station making this one of the cheapest 100cc airframes around


So to begin lets go over how its packed and what you get. The plane comes in 1 large box so the wings and fuse are packed together. I actually like this setup because the shipping is cheaper and you have less cardboard to throw away after your done unpacking (I kept my box however, in case I ever decide to re-sell mine later).

So First off we have the the plane, fuse, wings, and hardware bag along with the cowl. Everything looks pretty good, 1 thing that was disappointing was that the hardware is NOT socket / hex screws instead they are el-cheapo Philips However the ball links and rods (titanium) were made well, so are the g10 control horns.

The hardware kit also includes control arms for servos, these aren't as nice as SWB/MPI but they work alright. You need a circular horn where you can drill 4 wholes fro the micro screws to attach the main horn.

Lastly is the spinner, which is a bit disappointing....While it is a spinner its cast aluminum and fairly heavy. I also don't think it has been balanced, and it says "SD Model" on it I will see how this works, if it appears to be un-balanced then the replacement will be from either MPI or Tru-turn.

I'll be posting more as I go.
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Sign up now
to remove ads between posts
Old Sep 07, 2010, 08:14 AM
Barefoot Birkinsomething
rcbirk21's Avatar
United States, CA, Hayward
Joined Aug 2004
9,451 Posts
subscribed, looking forward to what you think of the quality compared to the 3DHS 103 Extra, really like OMP's raven and yak so this would be perfect if you could compare the quality with that of your (former) extra
rcbirk21 is offline Find More Posts by rcbirk21
RCG Plus Member
Latest blog entry: Joe's Battery Contraption
Reply With Quote
Old Sep 07, 2010, 11:36 AM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Ok so next up I inspected the wings, rudder, and other extremities. They all look pretty good and didn't have any wrinkles. OMP already has the inner servo bay cut-out for you on both wings, so I guess you could set this plane up with a single servo. However, unlike the 3dhs their are only 2 servo bays inner and outer, no middle :/ Basically you need to use 2 servos in this plane otherwise I would think you would get aileron twisted near the end.

I decided I wanted to go with a removable rudder setup so if I ever decide to sell the plane it would be easy to put back in its original box. Setting up the removable rudder was fairly simple: Remove the stock hinge pins by grinding them down with a dremel and then run some pushrod wire down through them. I put an L-bend at the top of the rudder and secure it with some light CA. This should keep it in place and allow me to remove the rudder if I need to in the future.

ON to the wings:
The wings are fairly straight forward. Although I'm a bit disappointed that OMP does not give you wing bags, I am to use the ones form 3dhs and they work fine. 1 Thing to note that OMP does give you a spinner and servo arms, however, given the choice I rather have wing bags over stamped arms/cast spinner. But Anywhoo... I decided to go with the stock hardware as it was made to the right lengths and matched up perfectly with the plane.

I'm going to be using 7955TG servos through out the plane with a 7950 TG on the rudder, these servos include 1 circle horn that you need to use to mount the included servo arms with. Their is a catch, however, you need to dremel and sand down the top of the horn so that is flush with the horn body (The top has a small indention and its too big for the horn to slip on to, hence it has to be sanded down smooth).

I tried to get the horns aligned as perfectly as I could, however, they were not 100% centered (about 90%). I'm hoping this doesn't effect the operation to severely, especially the wings as I'm using dual servos. OMP has pictures of the red X-horn being used in the manual, that would have been nice expect the 7955 series doesn't include these red x-horns :/

The other thing I'm concerned about is the plastic spline of the horn it self wearing out and slipping. I have had this happen before on a 1/4 scale plane were the plastic spline just eroded away against the titanium gears. Hopefully this won't happen, but if it does I'll be replacing these included arms with some 1.5 inch SWBs/MPIs

So I was able to get both wings but together, went by pretty much event free, 1 of the things to note however, is that even though the wing is pre-hinged and glued its not perfectly Align. I had the same issue with 3dhs, it doesn't seem to make a huge difference, but had I been gluing the plane my self I would have made sure the aileron is dead center with the main wing.

Another important thing to note is that the included g10 Arms are way to long and need to be trimmed / cut so that they fit the wing. OMP gives you about 10 horns (2 per servo) and they are all the same size so have a cut-off wheel ready when you do this step. The inner servo needs about 1/4 length cut-off where as the inner needs about 3/4ths cut-off

Lastly, for extensions, I recommend 24 inch for the outside bay, and just a 6-9 inch for the inside bay. OMP includes servo extension secure connects to keep the servo wires intact so that's a plus.

Will be adding more tomorrow including my motor mount and elevator setup.
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Old Sep 07, 2010, 11:59 AM
Bigger is better
ibange's Avatar
Austin TX
Joined Jan 2001
909 Posts
Looks like a fun build. You might put a copy of this thread over in the giant electric planes section, I'm sure they would love to see it there.
ibange is offline Find More Posts by ibange
Reply With Quote
Old Sep 07, 2010, 12:33 PM
Huckfest or bust!
cryhavoc38's Avatar
United States, WA, Woodinville
Joined Mar 2007
8,057 Posts
Love this!

Love the fact that others recognize that there is more to life than 3DHS planes!


EG Aircraft are one of the top of the line planes that can be purchased out there and they are very light in comparison to other "scale" manufacturers who make planes for not only the weekend flyer, but for competition work above basic and sportsman levels.

regarding the use of the hitec plastic horns with the EG metal arms...don't..too much of a hassle.
use the MPI, Secraft or MWP metal arms. This will make life much more simpler.


regarding the use of phillips head screws versus cap head hex bolts.

While the screws are perfectly functional, I hear ya regarding the preference over 4-40 bolts. I just purchased them from the local hardware store and use those instead of the screws. This is one area where EG should make a standard, although my last 50cc MX-2 had both types in the bag.

Oh and regarding the 7955tg's.

Hitec has officially certified these to be HV capable and will fully warrant their operation at HV voltages.
cryhavoc38 is offline Find More Posts by cryhavoc38
Last edited by cryhavoc38; Sep 07, 2010 at 12:38 PM.
Reply With Quote
Old Sep 07, 2010, 03:50 PM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Well I have already made all the arms, if they become an issue I already have replacement SWBs on hand.

Yes bolts would be good, 3mm bolts like Extreme Flight would be great, I don't think we will be getting 4-40 as everything overseas is metric .

I got all the materials to mount the motor I will be setting that shortly, the build is moving along nicely with no major hurdles.

I did notice 1 thing with the cowling, it has blind nuts in it for the top and middle mounts, however, the lower mount only has a hole and the airframe it self has the blind nuts. This will be interested, in fairness I do prefer the split cowling of the 3dhs extra, but this one not bad either.
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Old Sep 07, 2010, 10:04 PM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Ok so got some more stuff done today:

1, First is the mounting of the motor, I will be using a NEU 1527 2D w/6.7:1 HD gear box motor. This a motor that's rated to a max 4500 watts for 30 seconds but people have successfully pushed this motor to well over 6500 watts without an issues. I plane on getting around 6200 Watts with either a 26x12 prop or a 27x10 prop (the prop will be a wooden xoar prop). After the 3dhs extra crash I sent in my motor to be looked at and I had a spare lying around so I will be using this motor in the OMP extra.

The motor mount I used is a maddogrc NEU motor mount. Now this motor mount is designed for a NEU1521 motor, but I was able to adapt it to fit the the longer NEU 1527 by using 3/8 inch nylon spacers. 1 thing to mention, the Mad Dog Mount had indents on each side so lining it up with the stock motor box was fairly easy. I drew a tracing of it and then drilled out the holes.

You will notice I have added silicon caulking around the edge of the motor and the wires. This is to dampen the vibration and to isolate the motor from touching / rubbing the mount and creating unwanted Rf noise (The same was done with the nylon spacers on the stand-offs)

The mount was mounted a bit different than the manufacturer intended, this was done to compensate for the clearance of the cowling so that it matches the height of the motor. In this case I have screws from inside the plane going into the back of the motor mount stand offs (the stand-offs have 6mm threads in them). This worked out pretty well and the mount was very sturdy. I then screwed (directly into the wood) 4 6mmx20mm screws into the firewall itself through the outer holes of the mount. These weren't needed but I didn't like the open holes so I filled them. The holes in the firewall were made a little smaller than the screws, so in effect the firewall was acting like a big nylon lock nut as well this made the mount even more sturdy.


Now its time to mount the speed controller, which turns out is fairly simple. With all the extra room available that would have been other-wised used by canisters, mounting the speed controller has many options; I chose to mount it underneath the motor mouth and some small screws and lock nuts. The speed controller mounted up properly and appeared very sturdy. I can also get a temperature reading form inside the fuse because the exposed throttle servo bay is directly underneath the esc.

I will wire up the speed controller to the motor later on, for now I wanted to see if the cowling lined up properly. Well, the motor mount is lining up fairly square, working with this 1 piece cowling is rather annoying as the mounting ring requires a VERY long screw driver and tiny hands. I prefer the 3dhs split cowling over this any day.

Finally after mounting the cowling it was time to see how close or far my mount attempt was. Well It wasn't too bad, the motor was pretty much centered, however, this great planes 10 mm prop adapter was not exactly sitting kosher with my motor. Unlike the Esprit Models mount that I had on the 3dhs the great planes mount stuck out about between 1/8th and 1/4th of an inch. I will probably need to order a different prop adapter for this plane.

Now moving on to the spinner. Well I have decided NOT to use the included spinner. It is just really low quality and its made for a 12MM shaft. I will be ordering an MPI 4 1/2 inch spinner as its replacement.

Ok So that is all for now, More to come later as I work on the elevator servos and rudder.
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Old Sep 08, 2010, 09:05 PM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Got the rudder done. Some comments on the rudder:

1, The brass tubes supplied for the pull-pull are VERY tight, it was quite a chore to get the pull-pull wire through them, It took me almost 40 minutes just working on this.

2, The Rudder install went be fairly event free, my removable rudder works great, I tested and and the rudder comes out easily.

3, EG did a good job of including a paper tube to keep your electronics seperate, this gives the rudder and the pull-pull set up plenty of room to play around without worrying about getting tangled in the elevator wires. The tube is big enough to house the servo connector clips.

4, Lastly I decided to keep the using the EG aircraft hardare, if their is anyone horn that I am worried about, its this one because I am only using 1 servo and I"m not sure how this can handle the load (the plastic spline of the circle arm).
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Old Sep 08, 2010, 09:11 PM
Barefoot Birkinsomething
rcbirk21's Avatar
United States, CA, Hayward
Joined Aug 2004
9,451 Posts
Quote:
Originally Posted by Alkaline View Post
Got the rudder done. Some comments on the rudder:

1, The brass tubes supplied for the pull-pull are VERY tight, it was quite a chore to get the pull-pull wire through them, It took me almost 40 minutes just working on this.

2, The Rudder install went be fairly event free, my removable rudder works great, I tested and and the rudder comes out easily.

3, EG did a good job of including a paper tube to keep your electronics seperate, this gives the rudder and the pull-pull set up plenty of room to play around without worrying about getting tangled in the elevator wires. The tube is big enough to house the servo connector clips.

4, Lastly I decided to keep the using the EG aircraft hardare, if their is anyone horn that I am worried about, its this one because I am only using 1 servo and I"m not sure how this can handle the load (the plastic spline of the circle arm).
ok, so far, just based on quality, which plane do you like better, the OMP or the 3DHS extra?

really like the looks of some of the other OMP EG planes and have always wondered on the quality compared to 3dhs. not trying to say 3dhs is the best, but i have built quite a few of their planes and find it hard to go back to china arfs that i must replace all the hardware and nothing fits right
rcbirk21 is offline Find More Posts by rcbirk21
RCG Plus Member
Latest blog entry: Joe's Battery Contraption
Reply With Quote
Old Sep 09, 2010, 12:36 AM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Well so they seem to be similar, I can't really compare because to me its all about the flight quality and if I have to work twice as hard to get a better flying plane than so be it.

The only thing I would say is that I really rather have wing bags then the spinner/arms that were included, other than that they are pretty much the same. Ohh better screws would have been nice like allen head screws carbon steel/stainless.

I also think the OMP seems a bit heavier, the firewall is VERY beefy would have no problem putting a 85cc and letting it shake and bake this plane all day, so if you are looking for a single cylinder I would go with OMP over 3dhs.

Lastly the cowl setup is better on the 3dhs, now this may be bases solely on the design as the 3dhs is an extra 330 while this is an extra 260/300.

But on thing I will definitely say, at 875.00 shipped you would be over $200.00 cheaper, and could easily buy spare wing bags and other things.

Final decision will come down to flight quality, and as far as I'm concerned that's really what matters.
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Old Sep 09, 2010, 06:52 AM
Barefoot Birkinsomething
rcbirk21's Avatar
United States, CA, Hayward
Joined Aug 2004
9,451 Posts
Quote:
Originally Posted by Alkaline View Post
Well so they seem to be similar, I can't really compare because to me its all about the flight quality and if I have to work twice as hard to get a better flying plane than so be it.

The only thing I would say is that I really rather have wing bags then the spinner/arms that were included, other than that they are pretty much the same. Ohh better screws would have been nice like allen head screws carbon steel/stainless.

I also think the OMP seems a bit heavier, the firewall is VERY beefy would have no problem putting a 85cc and letting it shake and bake this plane all day, so if you are looking for a single cylinder I would go with OMP over 3dhs.

Lastly the cowl setup is better on the 3dhs, now this may be bases solely on the design as the 3dhs is an extra 330 while this is an extra 260/300.

But on thing I will definitely say, at 875.00 shipped you would be over $200.00 cheaper, and could easily buy spare wing bags and other things.

Final decision will come down to flight quality, and as far as I'm concerned that's really what matters.
awesome, keep up the good work!
rcbirk21 is offline Find More Posts by rcbirk21
RCG Plus Member
Latest blog entry: Joe's Battery Contraption
Reply With Quote
Old Sep 09, 2010, 10:38 PM
Registered User
United States, LA, Baton Rouge
Joined Jan 2005
568 Posts
Mounted the wheels and landing gear today, some comments:

1, 1 of the nuts for the landing gear road was totally messed up :/ had to go to the hardware store to get a replacement.

2, the Rear tail wheel setup just doesn't make sense in the manual, they have the tail wheel assembly pushed way to far forward, I think I'm going to revise this with the position I feel it needs to be.

3, The tail wheel bushing and sleeve are made out of aluminum and its very easy to strip them. I really just rather have steel, I'm going to see what I can use to replace these.
Alkaline is offline Find More Posts by Alkaline
Reply With Quote
Old Sep 10, 2010, 07:35 AM
Registered User
USA, SC, Easley
Joined Sep 2009
481 Posts
What kind of weight are you hoping for and what battery set up will you use? I am using a 2215 but my plane is 30lbs, hope yours flys well because on my next plane I will shot for lighter set up.
yellowbird2800 is offline Find More Posts by yellowbird2800
Reply With Quote
Old Sep 10, 2010, 08:12 PM
UAV R&D Pilot/MC/PO
Sukhoikid's Avatar
Joined Jun 2006
770 Posts
You will love this plane. I have the Yak in the same size with a DA-120 on the front and it has handled that engine just fine!
Sukhoikid is offline Find More Posts by Sukhoikid
Reply With Quote
Old Sep 10, 2010, 09:47 PM
I used to be all thumbs...
NumbSkull's Avatar
United States, KS, Pittsburg
Joined Mar 2005
7,061 Posts
Nice build. I cant wait to see how the motor works out. I was following your posts on the 103 with the 1527.
NumbSkull is offline Find More Posts by NumbSkull
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question Flitework Extra 300 LP Flying Bulls Electric andriesa84 Electric Plane Talk 1 Nov 15, 2011 07:23 PM
Discussion Electric EG Aircraft 89" MX-2 BulletMaster Australia 32 Feb 07, 2011 03:33 AM
Discussion Team OMP Extra 300 50cc Build Sukhoikid Giant Scale Airplanes 1 Dec 25, 2009 10:56 PM
Sig Extra 300 Electric Conversion jerrythercpilot Electric Plane Talk 0 Jun 03, 2005 08:58 PM
Electric conversion CAP 232 or EXTRA 300 chrisc Aircraft - Electric - Airplanes (FS/W) 6 Sep 14, 2002 07:40 AM