RV8ER1

Hey guys. I've been flying R/C for 40 years and always said I would never fly an ARF. They used to to be heavy lead sleds made of foam core wings plastic coated and the fuselages were some kind of blow molded plastic. However I've now been flying modern ARFs for 4 years, all electric powered. The last 2 years or so things have really improved and the performance of these new models is fantastic due to design improvements and their very light weight construction. However there is one major flaw in ALL the ARFs I've seen and that is the lack of proper glue joints. The laser cut parts fit incredibly well but the problem is they only use thin CA on all joints. Most of the important parts in the front of the fuselage are plywood and THIN CA is a poor choice of glue. If we were building these from kits we would use med. or thick CA on heavy load bearing areas like firewalls, landing gear blocks, wing/fuselage through tubes etc. I've seen ARFs have major structural failures and have had motor cages and firewalls of my own planes pull apart during high G loads.
What I do on all my new ARF builds is re-glue all these areas with med. CA . In the hard to get to areas I drip the CA (on target) into the joint and hold the plane to make the CA run down the length of the joint. Some areas I use 30 min. epoxy and use a thickener like Cabosil (to keep it from running) and use a chopstick (or dowel) and dot the epoxy along the joint and then smear it into a nice fillet. The stick allows one to reach down inside the structure. A fairly slow epoxy like 30 min. allows some to soak into the wood. This operation adds very little weight to the finished model.
I've found that an hour or so of glue reinforcement is well worth the time spent. I haven't cracked a firwall or motor cage in 2 years and I logged over 1350 flights in that time so it seems to be working. I hope this information is useful!

outdoorhunting

You got it right!! Sooo many people get an ARF & slap it together & think good enough. With a little extra work you can take a $100. ARF & make it a very good plane. I've had the "Nitro Planes" craft & the GP or other "name brand ARFs. Basically, the main difference between them are the "glue joints". They are pretty much all light weight. If they don't want to spend the extra time on them, they shouldn't gripe about the outcome !! After all, they call them ARFs" for a reason !!!! ALMOST READY TO FLY my 2 cents

TimBle

I often run some whiote wood glue over all main stress bearing joints in ARF's.

ro347

My Feedback: (13)

Has anyone found any of the no-name planes which need to be "rebuilt" however are amazing fliers? Just curious.

GarySS

My Feedback: (13)

What do you all do about wings? They are usually covered up except for maybe servo holes, or rib profiles in the root halves if so designed. Even if you can get into them through these holes you can't get really far. Remove some covering, etc????

RV8ER1

Gary
I have not been able to damage any wings, even high speed snaps, blenders etc. It's always "pucker time" when test flying a new model as we can only hope the wings are good internally. My take on this is the wings are mostly balsa and that allows better glue joints with thin CA. I have never opened up to re-glue an ARF wing, however I do like to add thin carbon fiber mat to the exposed root rib. I do this by trimming any excessive overlapping covering on the root rib. I then cut a piece of carbon mat and thin CA it to the rib using a piece of ziploc bag on my finger to press it down as I go. You then use a sharp #11 blade and cut out for the joiner tube to insert. Do not use an excess of glue as it can run down into the wing tube and cause clearance issues. This mod. will spread the bending load from the joiner tube to the entire root rib and help prevent tear-out under extreme load. This may seem excessive to most folks out there but that's how I do it.
Regarding the fuselage re-glue, it has to do with the fact that the forward fuse. is mostly plywood. Plywood does not glue very well with THIN CA. The joints tend to have very little CA to form a good bond. Some med. CA dripped and allowed to run the length of the joints will fix that right up. Just be sure to leave the canopy off until there is no more CA smell otherwise you could fog it up!!

Jason 3-Danhakl

My Feedback: (10)

I've got some bad news for you guys. ARF's do not have ANY CA in them at all. They are all built with glue that cost much less than CA and can be dispensed in a production setting.
Going over an ARF with Med CA is a good plan.

Charlie P.

I check the firewall and usually dowel it as a matter of course. I try to avoid the temptation to slather in the epoxy and tri-stock because I generally build heavy and, for better or worse, the ARFs do seem to come in light. Lighter flies better. I just assembled a Hanger 9 Saratoga 40 and only beefed up the tank area with a cross-wise retainer (the tank was loose in their built in cable-tie strap cradle and pressed the throttle linkage). I gotta say this one is built darned good. I also added a popsicle-stick stop to keep the battery from sliding backwards unnoticed as it was in a foam sandwich held by Velcro. Did not touch the firewall or other spots but I will keep a watchful eye on everything.

On the other hand, I have been leery of the last three firewalls on Great Planes models and pegged them with toothpicks or bamboo skewer dowels. I had one pull loose in flight a few years back and that was no fun - though I did land her otherwise OK. They were probably sufficient, but it's cheap insurance.

opjose

I'll often drip THIN CA along the formers and stringers, while holding the wings so that the wing root is straight up... permitting the CA to flow down.

Given that most of the forces are realized toward the wing root ( hence the tube ) anything you can get to, only helps.

Oberst

I always look inside the fuse and epoxy or CA (sparingly) any parts that's lacking hot glue or what ever they use at these factories. I just got done stripping a Discontinued Great Planes .60 Fokker and one spar in the fuse was only glued at one end and not the other, it was just hanging and if I hadn't removed the covering I wouldn't had seen it! I always add a little epoxy around the servo tray, firewall and landing gear mounts if I can get in there with the glue. It gives it extra support for those terrible landings I like to do at times.


I haven't had a structual failure from a ARF yet, Thank God! I have faith that the factory uses enough glue in the wings and places I can't get at and I go from there. If it were me and I was too worried, then I would say " Screw it " and just buy the kits.

The benifits would be that I would know that everything was glued right, plus it would help the kit sales.


Pete

TimBle

The downside to "reinforcing" the ARF is that if you do have a hard landing, the affected parts shatter making repair more difficult.
I find that if I leave well enough alone when something comes loose it's a simple matter of a few drops of medium CA and its back together.

I usually only reinforce around the firewall (had one fall out when I dropped the fuse off my benchtable) and the servo tray and landing ear area.

the rest I leave alone. I also only reinforce with white wood glue because its flexible and helps damp vibration. Beyond that, flying an ARF is an act of trust and faith.

What we have to remember is that the reinforcing is of no use if the Epoxy or CA cannot penetrate the ply. If t does not penetrate then the "reinforcing" is cosmetic and just adds weight. wood glue at least penetrates.

Luchnia

My Feedback: (21)

I realize we need to do this and I fully agree, but I have to wonder. Do we buy a new car and disassemble it and reinforce/glue/rebuild it before we drive it? Sometimes it just does not seem right that we are paying the quoted price for the RC planes and yet we have to re-do so much of them to get them to work as they are designed to work. What is wrong with this picture?

Charlie P.

That's what warranties are for. Otherwise we wait for the recalls and protection under the various "lemon laws" and hope it doesn't rust away before we can afford another.

opjose

There's the rub!

The "quoted" price is often reduced as much as possible using low cost manufacturing and labor processes.

Were ARFs manufactured the same way Kit Builders put together their planes, the costs would be at least an order of magnitude higher.

I don't see paying around $1,000.00 for a .40 size ARF do you?

I find $240.00 for the same exhorbitant.... so I resign myself to trying to pay around $100.00 instead.

For that price I know I WILL have to add some TLC before flight....

Glacier Girl

My Feedback: (4)

And price doesn't seem to determine quality sometimes. My worse was the ARF I paid nearly 800 bucks for. The formers were silicone caulked in place on the fiberglass fuse.
They failed the first time I operated the nose retract. Lucky for me it was a bench test. Have to say thou that the distributor was a stand up guy and took care of it.

But when I found the supports for the bell cranks for the Fowler flaps were never attached inside the wings it was enough for me.

I was honest and sold it to a buyer, for less then half of what I had in it, who knew up front what I had found. Never did hear back on it, so I don't know if it ever flew or not.


Have to agree with another poster, ARF stands for ALMOST Ready to Fly.

pkoury

My Feedback: (7)

How does a thin sheet of carbon mat applied to the wing root spread the wing tube load?

Charlie P.

I don't see it helping much either. But, hey, if it makes you feel better and the leading edge dowels and trailing edge Nylon bolts don't instill confidence . . . why not? 'Course, if the tube sleeve fails you're still S.O.L. in either case.

MANFRED

My Feedback: (27)

Really? You're going to compare the price of a 20K plus car to a $200 ARF, really? Besides how many cars that cost 20K plus fall apart after 4 yrs?

Luchnia

My Feedback: (21)

Absolutely! You mean I should use logic that somehow because it is cheap in price it is poor in quality? How does that work? So I would assume based on price that I must pay what range for a quality RC airplane? Where do we set the mark at via price to determine quality? 20k, 50k, 100k or 5, 10 ,15 dollars? Which would determine quality? You see this is exactly what is wrong with our country today...greed and cutting back on quality and quantity, yet charging the same. What is the saying, "Pass it on to the consumer."

When I was coming up quality meant it was designed by a good and reputable builder and sold for a decent price based on cost and reasonable investment by the manufacturer, etc., and yes, you definitely got a better product by paying a higher price, but not always.

I think cost is relative to what you buy. If GP can make the large Revolver for around 200 and it is built very well for the size plane verses some other models you pay more for (an AeroWorks 260 for example at 274$), then why would you want to pay 500 for the same plane. Now is the plane built poorly and not enough glue? That is the question at hand. Just how much does the extra glue cost and what sets the standards for what and how glue is used?

Think of it this way. A decent radio cost around 200-500 dollars. Do you have to pull them apart and rebuild them before you can get good service from a radio? They are foreign built too. If I apply the same process to my RC radio as I do my new RC planes then I need to pull my radio apart and fix it before I fly if I expect long term quality. Hmmmm....hard for me to think this way. An ARF is almost ready to fly, not almost ready to add more glue because it won't cut it in the long haul. No where in my ARF manuals do I see anything stating that I need to add or re-enforce glue joints...sort of costly removing the covering and recovering a new ARF wings so you can reglue all joints [X(]

I recently pulled an AeroWorks Edge 260 down and I was surprised at how poorly the wood in the plane was as well as the glue joints were very poor. The structural wood in the wings was very sub-par and of an extremely poor quality. This plane averages 75-100 dollars higher in price than a comparible GP plane. Most of the strength in the wings was in the covering. This simply amazed me. I was surpised after pulling the plane down that it had lasted as long as it had. It is a wonder the wings had not fallen apart in the sky during flight [X(]

I buy something my expectation is that I can use it and get good service out of it for the reasonable price I paid whether it be a 200 dollar Rev 70 or a 275 dollar AeroWorks 260.

Oberst

Chevy. Check Heads Valves Yearly.


Pete

Luchnia

My Feedback: (21)

I plan to buy a new Chevy this November so I will pull the engine and tranny and re-build/re-enforce and also re-do the body for strength so it will hold up better for the long haul. After all, since it will be a middle-of-the-road Chevy I should expect to have to re-do most everything and I should not expect it to last as long as to be relative to the cost investment.

After some thought, I should go ahead and spend an extra 50k and get something that is really going to be road worthy! Then I would not expect to have to rebuild something I purchased brand new. [X(] [X(]

Charlie P.

And if folks parked cars the way some land ARFs (or any models) there would be pieces of scrap metal all over the roads and ramps.

The American Way, and I am guilty of this myself, is to over build, over engine and over stress aircraft. Look at our fighters in real life - huge, heavy, able to carry extra ordnance for ground-attack, but usually fast and able to sustain heavy damage and keep the pilot alive. That's our mind set (and not necessarily bad). We couldn't even get one ready in time for WWII because we were making heavy duds and the Wright Brothers were suing anyone with a good idea. Other nations built light, maneuverable aircraft that could dance well but not take a hit. Cars, too. Big, heavy, lots of engine as well as trim and chrome

You could hand out two identical ARFs to two pilots and one would do 10g stunts with 3X larger of an engine than recommended and crack off the firewall at the first hard landing or shed a wing in a Lomchevak while pilot #2 may fly it like he was in it with an adequate engine and never experience a mishap.

rye

My Feedback: (10)

WELCOME TO THE HOBBIE

start out learning to fly ends up learning to fix them, now you got all the bases covered

RV8ER1

It's really simple, fly the ARFs as received from the factory or spend an hour with some med. CA or a little bit of epoxy making sure CRITICAL joints have a good bond. I just witnessed a very high end ARF landing hard and the entire firewall, motor cage and cowl FALL right off. We looked it over and found maybe 25 percent of the glue joints actually had wood to wood contact. The rest of the THIN CA simply wicked away leaving air to "hold" the parts together. We glued it back together with med. CA at the field and it flew 15 minutes later. It has to do with using thin CA to glue plywood, that is just not the stuff to use. Really, it only takes a little bit of time to do the re-glue. If you want to just fly it out of the box without extra gluing that's fine. We're not talking about adding much weight here! Maybe 1/4 oz. which my 4.5 lb models won't even sneeze at. As far as the C/F mat it's very thin but I feel it adds some strength to the root rib. May not be doing anything for me really. Peace of mind?????


Mo power.......................250 watts/lb.
Must have mo power............................................. ..............

proptop

My Feedback: (8)

I use thin CA, Aliphatic resin (yellow Carpenters glue ) and 30 minute epoxy and go over the various glue joints.

30 min. epoxy around the landing gear mount(s ) and firewall area...wing center section...high stress areas.

I use a pipette to apply the thin CA wherever I can get it...typically where I can't get to with the Carpenters glue. (I also use a small modelers paint brush to work the yellow glue into the joints.