I purchased an Epic LT 1.20, and am trying to get all of the materials together to assemble it. I have 2 questions and could really use some advice. I plan to fly this plane in a pretty scale like manner, no fancy aerobatics or anything like that. Probably a lot of low passes, and touch and gos.

1. What size servos are needed for this plane? It requires a 1.20 engine, but doesn't appear to be any bigger or heavier than most .60 size planes. The instructions are not clear, but it calls for 10 servos. I assume they go as follows.
2ea Ailerons
2ea Flaps
1ea Rud
2ea Elev
1ea Throttle
1ea Front Steering
1ea ??????

2. What type of retracts do you recommend for a plane like this. The plane will weigh between 10 and 11 Lbs, and the right and left wings are seperate when removed. This will be my first experience with retractable landing gear. The plane is built for a rail type landing gear installation.

This is a nice plane, but there is hardly any info out there. I have found a couple of threads on rc groups forum that don't really offer much info beyond electric motor info.

Thanks for any help.

The control surfaces on this plane are relatively small.

That means there is normally not a lot of torque due to the air, on the surface and servo.

You might even get away with standard servos if you configure the linkages for maximum mechanical advantage.

However if you want to play it safe and keep the costs down, you could use a high torque inexpensive servo such as the Hextronics 5010's ( approximately 9.00/ea ) which produce about 130oz/in or more of torque.

Given the thin wings and weight of the plane, you'll want to go with beefy landing gear, preferably of the shock absorbing variety.
You'll want something that will help prevent the gear from ripping out due to impact....

e.g. either sprung wire gear, or gear with an offset scissor type shock absorber that deflect back and up on impact.

I don't have this plane and I do not believe the elevator uses two servos, rather the other servos are allocated to each of the retracts. If you use pneumatic retracts you will not need so many.

Thanks for the info. I have been looking at these retracts, but am not sure if they are big enough.
http://www3.towerhobbies.com/cgi-bin...?&I=LXJZE2&P=0
Robart does not even list these on thier website, so I cannot find any weight ratings.

I am also looking at these as an alternative, but with the added expense of having to buy RoboStruts, they are not my favorite option.
http://www3.towerhobbies.com/cgi-bin...?&I=LXNCY5&P=0

Then there are these. I know I would be pushing it on the weight limit for these retracts, but for 1/4 the price they seem like they would be worth a try.
http://www3.towerhobbies.com/cgi-bin...&I=LXMJK2&P=0#

The couple threads I found on this plane were all electric conversions. The one source that listed the weight of his plane stated that it was 11lbs 6oz. I know glow setups are lighter than electrics, but I don't know how much difference there would be on a 1.20 sized plane.


Any thoughts, or advice would be greatly appreciated.

The 3/16" wire struts are rated up to 12lbs.

From the three you've looked at I would choose the FIRST because those wire struts have the in-line "sping" bent into the wire.

That sping will help to absorb the shock of landings and purposely deform temporarily.

I would go with that.

You'll also want to beef up the mounting area as much as possible.

Some people merely slop on a lot of epoxy and/or TRI stock hardwood on the existing blocks.

Unfortunately that does NOT spread the load out.

What you want to do is to increase the area where the torsional forces are applied.

Remember that the long gear strut acts as a "lever" against the wooden support block.

What you want to do is to prevent that support block from tearing out.

The best way to do so is to increase the size of the surrounding wood supports onto the wing.

I typically install hardwood strips to lengthen the supporting area, thereby spreading out the load over a larger area. Two or four strips and a few tri stock angle pieces go a long way in beefing things up, and add little weight.


The last option you gave seem to be servo actuated gear. This will be more complicated than using pneumatic landing gear.

With Pneumatic gear the only extra thing you'll want to get ( other than what is in the kit and the actuation servo which can even be a mini or micro servo ) is a set of pneumatic "quick release" connectors.

That will permit you to quickly disconnect the wings from the pneumatic lines.

Thanks for the reccomendations. I really appreciate it. I was leaning towards the first set as well, I just wasn,t sure that the wire would be able to handle the weight.

That wire might be prone to bend a lot if it were not for the spring "curl" in it.

The spring absorbs most of the shock and prevents it from being transferred to the base of the gear where it will do a lot of damage.

All too often I've seen people toss out sprung wire gear and mount either straight wire or straight struts.

Then they spend all their time reparing the landing gear mounts or struts.

In your case the gear will bend back and revert to a normal position on a hard landing.

At very worst you'll need to rebend the gear slightly, something you can do at the field, or at worst merely replace the wire strut. If you have a heavier duty wire bender you can also make your own, which I often do.

The closer the curl is to the wing the better. This puts all the leverage on that part of the wire.

With gear it is always a good idea to try to anticipate where all the leverage and shock will be asserted or transferred to. A bit of forsight saves a LOT of hassle later.

I think you'll do better with the spung gear.

Many ARFs come with sprung gear to avoid having to resort to very strong, expensive and more exotic systems to take the abuse.

Thanks again for the info.

Have you ever messed with these wire strut covers.

http://www3.towerhobbies.com/cgi-bin...?&I=LXAFZ9&P=0

They are pretty inexpensive, and look like they could dress the plane up a little bit more.

Actually I have and they work well to dress things up, especially considering the price..

You may want to avoid the type pictured at the top with the angled gear, as it is hard to match the strut wire to the plastic bend.

The straight ones are easy to install and you can cut a slot to encompass the wire spring.

The Robart web page has a PDF file that shows how to do this.

I recommend you get the plane flying before you install them. They can be easily retro-fitted later.

I Used All Hitec HS475BB Sero's

Nitro Planes Moster Power 110 Electric Motor

85 High Voltage ESC

Robart 555 Retracts

The Plane Flight Really Nice And There's More Power Than Needed . With This Set Up.

[youtube]http://www.youtube.com/watch?v=bT098sGEHKs[/youtube]