A few weeks ago the RX crash box was mentioned by me in A post and I was asked to show photos of one. Many years ago you could buy these as A kit from Tower and they worked out great and were very cheap. Today I make them for almost all the planes I build and they have helped save quite A few RXs for some race planes I have built for club members. Sometimes I add A screw down top to them too but this one is open and held in with velcro and sits in cut out foam with sides added then I epoxy it onto servo rails or stringers.

Good Idea. I have done similar with 2mm coroplast before. I also like to have a way to retain the servo wires so they don't rip the pins off the receiver in a hard crash.

For servo wires I found some really cool clear plastic hook things that connect to the fuse sides with two sided tape, very strong tape too. They help clean up all the wire mess and the bay comes out very nice looking. This plane I'm working on now won't be ready for A couple more months at least, it's just in the process of getting everything installed and mounted at this point. Then I take it apart again and fill and sand then glass and paint. With my own planes I have no time frame so I don't ever get in too big of A rush, it could be done in A week or two if I was just going to cover it.

I agree. They are a Great Idea!

Great planes still makes them, and Tower still sells them.


[link=http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXJ779&P=0]Great Planes Receiver Guard Protective Case [/link]

These work great and I have one question. Don't you want the majority of the foam to be placed fore and aft of the receiver to help absorb impact shock?

The receiver is so light that I don't think it would really move that much in a crash.

Austin

My crash box is called "airplane".

Answer for Ed: Yep. The RX is just sitting in the bay for the photo and I didn't give it any thought at the time I took the picture. At this time I'm still moving things around before hard mounting to get the CG or close to it.

Austin,
I had a couple of crashes that toasted the receivers. You could shake the case and hear little parts inside rattling. <g> In a slow sport plane I would agree with you. A fast big warbird can really mess up the equipment inside. I've never done a receiver box. But I would call that a good idea. <g>
Edwin

I have never used one, I do wrap the receiver in 1/2 foam rubber taped to hold the receiver secure and placed in a plastic bag, with the opening taped or tied shut. Then I either wedge the receiver in some secure location, or I use thread or cable ties to tie it somewhere to keep it from moving around. I guess I've always thought in a bad crash there is simply going to be the possibility of damage to the radio components and I will need to replace or repair those damaged components. I have a hard time justifying the added weight of the crash box and have some doubt as to its' ability to keep the receiver from being damaged, anyway. Now, this is my opinion, only. Obviously some of you think differently and I think this is exactly right!

Hello Mode One. Please don't take this wrong at all I am not knocking you I am curious I guess because I just don't understand the added weight thing. I understand in the electric side less weight is of the utmost importance but in the Nitro side I can understand how weight would matter if you were adding a pound or 2 pounds but the crash box is only a few grams or ounces at most. In my experience the servos, battery, and receiver are the last things you put in. So your heave stuff, minus the battery, are already in the plane. So how would the flight box weight hurt the plane. Again just curious. I am building a kit and the flight box I thought was a pretty good idea. Thanks for your thoughts and input.

A person should build to fly. If you build to crash... well. I try not to tempt karma by making comments like these but I read this once and the phrase stuck with me.

somegeek

The only reason for this post was because I used the words Crash Box in A build thread and got hit with PMs asking what the heck it was. It's just one of those things you either do or don't do. If I have the room for one then I do, if not I don't worry about it and do things differently.
Found out Tower still sells them and they make A good one for little money.
This wasn't any debate. If you like the idea go for it, if not forget it. This is what one looks like.
Nuff Said.

Since it appears people think I'm trying to get into a ruckus here, I will simply state my opinions on crash boxes have been pretty much explained. I also said: "Obviously some of you think differently and I think this is exactly right"! Like you say, a crash box might weigh only a few grams and it makes sense to you to make one and I think this is fine!

Amen brother-Good idea if you have room-Why not? A question above said Rx's don't have any weight. It's not the RX flying around you have to worry about AS MUCH as say the battery coming loose in a hard landing and smacking the RX. I think this is what grey beard puts them in for. A major crash-nothing should probably be reused. Thanks for posting-i was one of them that wanted to see it.

Odd that this should have happened after I posted this but my 12 year old student had A glitch of some kind?? Not A pilot error, I think it was A bad switch but we will never know for sure.
No crash box but the RX had A good foam wrap. The battery was several inches behind the servos and RX. The plane hit on it's nose from A couple hundred feet and the battery knocked everything out in front of it. Would A crash box have saved the RX, who knows but it couldn't have hurt.
Like French said, it taint the hit as much as the weight of the hammer!!

I don't think anything would have saved that sucker. Well maybe a steel box. I have seen batteries break loose on just a hard landings that messed things up inside. I will be building a box for my Giant Super Sportster-Putting a new 2.4 in it, have plenty of room. At 100 bucks for an RX-good insurance.
Yes it's an ARF!

Mark, this one looks OK inside but for A hundred bucks it's going to Radio South for A new case and check out. The crash left A very large hole in the desert floor. I haven't opened up the engine yet but I'm thinking the crank may be gone. Broke one ear off the engine case and sheared off the mount screw on the same side. For eighty bucks he can get A new 6ch RX and I will set him up with one of my old scratch built Bipes. The kid is so good I can't stand to see him grounded.
Nothing wrong with an ARF, I love them. Friends that have gotten into them keep giving me there old kits they have laying around doing nothing.
What you got that you will never build??
OK, just fishing A little.

How about a giant Telemaster-Haven't started on that one?





Just kidding!

? What ? Repeated below?? My name is Mark too, this is confusing, who else is Mark?

I also attempt to get the receiver aft of all the rest of the heavy items in the airplane. This does a few things. 1). It helps protect the receiver from damage by having all the other stuff hit first, instead of pounding on the receiver. 2). It get the antenna away from the servos and other wiring which might reduce radio range or cause glitching. 3). It arranges the heavier items forward where the weight is generally needed and the lightest component (the receiver) aft where it's weight is easy to compensate for. I may not always be able to get it to be the farthest aft and sometimes will only be able to get it under the servos, where at least it will run neck and neck smashing into other stuff.

Thinking about this, I don't ever recall having an airplane where I mounted the battery aft of any part of the radio. Considering the dynamics of what transpires during a crash, I just wouldn't put the battery in the back. If you ended up nose heavy and moved the battery aft to achieve a balance, keeping the battery forward could be compensated by so little weight in the tail as to be almost inconsequential.

Hay Mark, been there and done that. Built one as A club trainer, three of us learned to fly on that plane. What A kick in the wind, you can get them to fly backwards.
Mode, in most cases I can mount the RX above any of the other parts or all the way back. In this case the battery had to be mounted aft of the wing right at the former before the fuse aft section started.
I also have A race plane built for A friend with the battery all the way back in the fuse just in front of the stab. Reason: A 3 pound plane fully loaded until the engine, muffler, spinner and prop were installed then it hit 4.5 pounds. It's still A little too nose heavy. As someone posted, this plane isn't built to crash, just go real fast and turn left.

Grey Beard-i heard alot about the Telemaster, Bought one last year thinking of a winter project-you know with a bunch of mods but still keep it lite. Got side tracked with with others. Going to go into 3-D this summer a little. By the way check out the 3-D forum under NJ1 combat to 3-D, this is the plane i said wouldn't make 50 (flights) also the color-it is visable.

I'll go take A look. I play with 3-D like most guys with way too much power but have never built A plane just for 3-D. I can stand my Kaos and Hots on there nose and even get A roll or two out of them and do A lot of the other stuff but any little kid with A plane can do it all better. Been to A number of free style meets but get draged with it after A few minutes. That was until I saw Chip Hyde fly at the Castle IMAA event, big difference from watching him and other pilots, I never took my eyes off his plane when he would put on his show. It's fun to try though, I'm just not all that fast anymore, I'll stick with tearing up the sky for fun and IMAC for serious learning.
Good luck to you with it though.

I gotta agree 100%. If your looking for power to weight ratio, EVERY gram matters. If you start thinking, oh it's only a little added, here and there, it starts adding up quick! Just my opinion.