A collection of questions about R/C Helicopters that I answer all the time. Also check the Tips page

Who maintains this website?

I do most of it (Ron Lund). In the store section John adds new products. All editorial comments are mine and do not reflect the views of anyone else unless I say so. You might visit the Who we are page.

I'm having some problems with my gyro.

Click here

What can you tell me about electric helicopters?

Click here

Is it really necessary to use a battery checker that puts a load on the battery?

Absolutely! Read the article.

Should I add a head shim to make my engine run smoother?

Read the article.

Can I use 6V (5 cell) receiver packs? Will I get increased performance from my equipment? Are there any drawbacks to using 6 volts?

All Futaba systems are designed to operate on either 4.8 volts (NiCD 4 cells) or 6 volts (Alkaline 4 cells OR NiCD 5 cells), except certain gyros which are specifically labeled for use at one voltage or the other only. A 6-volt pack does provide more torque and speed, which may be desirable in certain competition situations, or when the servos available for the model

However, while 6 volts provides more torque and speed, it also provides a significantly shorter run time for the same milliamp hours of capacity and may shorten servo life proportionally. This sounds confusing -- let’s compare the current in the battery to water in a bucket. If you have four small holes in the bucket, the water will come out at a certain rate. Add a fifth hole the same size, and you're supplying more water (increasing the current and therefore making the servos stronger AND faster); however, the bucket empties 25% sooner than when it only had four holes.

I use all digital servos. What should I do about batteries?

Read the article.

Do I need to balance?

Lipo batteries, yes. Your helicopter, no.

Today's helicopters are manufactured a lot better than when Ray Hostetler wrote his first manual in which he suggests that everything should be balanced by the builder.

I do think it's a good idea to weigh things that oppose each other, such as paddles and blade grips. This is quick and easy with a beam balance from the local pawn shop. Careful measurement of the flybar and paddle installation is all that's necessary on the flybar. Obviously the blades must be balanced carefully.

The fan might be the exception. However, it's not unusual for a guy to do more harm than good when he goes to balance his fan. I was working with a customer last year that had a foaming problem. He had dial indicated the fan and it was right on. We went through all the steps and narrowed it down to the fan. He said he had balanced it. Since he was at his wit's end and ready to throw in the towel, I agreed to balance the fan for him. When I got it, it had about twenty holes in it and they were spread out all over half the fan! I balanced it, sent it back and that fixed the problem. Most of my material removal was directly opposite the average of his. I think if he would have just installed the fan as is, he wouldn't have had a problem.

I have a method for balancing fans. It seems to work well and all the equipment only costs a couple bucks. I'll boil it down.

You'll need a fingertip prop balancer, collets to hold the fan, two razor blades, a cheap level, a way to remove material from the fan, a pencil, some CA glue and a couple blocks of wood that are the same size.

I glue the razor blades to the blocks of wood so the edge is just a hair above the top surface and parallel to it. I space them out on a level surface so the blades are parallel with each other and just far enough apart to catch the very tip of the balancer.

I put the fan on the balancer and set the assembly on the razor blades. The heavy side should theoretically go to the bottom. I mark the high side with a pencil or marker. Then, and I think this is extremely important, I rotate the fan on the balancer about 90 degrees and check it again. After doing this a few times, if the mark is in the same area, I take the average of the marks and remove a little material from the side of the fan opposite the average. I repeat this until I can set a 2mm flat washer on any of the fan blades and have that blade sink toward the bottom. Once you do this and dial indicate the fan to .001 or less, you can just about eliminate the fan as a source of vibration.

I hear guys talk about Differentialall the time. What is it?

I've created an illustration that should make it clear. Click here

I have this great new gyro and it doesn't seem to work very well. What do I do?

There are quite a few links and tips on this website that can help. The Gyro page is a good place to start. Run through the Tail Rotor Troubleshooter

What is the best way to break in my new engine?

The new way

Metallurgy has changed in the new crop of engines. It is now recommended to set the mixture only a few clicks rich from the max power setting. During the first one hour of running, do not load or overspeed the engine. It's as simple as that. Doing autos is still a good way to spend that first hour. The idea is still to heat and cool the engine. We highly recommend that you don't run the engine blubbering rich. This doesn't allow the engine to heat up and could cause premature bearing failure.

The old way

I would imagine you all have your favorite ways, and some of you don't bother. Those of you who don't bother are missing the boat. I was in that group for a long time. I figured it didn't make any difference anyway. WRONG. An engine that is broken in properly vs. one that is slam dunked from day one will have up to 30% more power over it's lifetime. That's an estimate, but it's from a good source. Curtis Youngblood, well known for having really powerful engines, shared his quick break-in procedure with me. I've tried it and it works really well, is quick and doesn't keep you from flying immediately. I've added a couple things that I do when I want my engine to work really well. I'm assuming you can tune your engine and you have the throttle/pitch curves set up properly.

There are basically two types of engines today. Ringed and ABC. For the most part the break-in is the same for both, however on an ABC engine, substitute a rich, but solid two cycle for rich. Running a ringed engine really rich doesn't hurt anything, but in an ABC engine, you aren't doing it any favors by running it slobbering rich. The only thing that wears is the connecting rod. An ABC engine must get up to temperature to run right. Unless it gets to temperature, it won't ever break-in.

I'm going to try to keep this really simple, but bear with me. Needless to say, the first step is to install the engine. Before you do, make sure you've removed the back plate and inspected the inside for foreign material. It's not a bad idea to put a few drops of fuel in it and spin it around a few times. Not too much. Make sure you've dial indicated your fan/clutch to make sure there isn't excess run out. If you don't know what I'm talking about, buy Ray's Manual and read it. It's hard enough on an engine during break-in. Don't add a foaming fuel tank to your work.

Set your needles to the recommended setting. Pinch off the fuel line to the carb and fill the tank full. Remove the glo plug and spin the engine over very briefly to make sure there's no oil in the combustion chamber. You don't want to break your rod before you hear the engine run. Install the glo plug, open the fuel line and light the plug. Start the engine. If your engine doesn't start immediately, don't spin it until you wear down the battery on your starter. Find out what's wrong and fix it. Either the glo plug isn't lit or it's not getting fuel, simple as that.

Once you have the engine running and tuned for a slightly rich mixture, especially the idle. Hover it for about 30 seconds and set it down. Let it idle for about 20 seconds and cool off. Repeat this, adding 30 seconds to each hover until the first tank is gone. Don't run the tank dry. The idea here is to heat it up and cool it down, which is a very important part of break-in. If at any time the engine starts to go lean, shut it down immediately and find out why.

Refuel and now follow these three rules for the next 15 tanks of fuel.It's ok to fly around, even do small loops and rolls. No high power maneuvers...period. Just follow the rules.

  1. Don't overload the engine. No full throttle...period.
  2. Don't over speed the engine. If you can't descend without over speeding, auto it in, or don't go high to begin with.
  3. Don't run it lean

That's it. You'll notice the engine making more power toward about the tenth tank. Don't be tempted to overload it until you've finished the break-in.

Keep the fuel clean. Keep dirt out of the engine and you'll have a long lasting powerful engine.

My Raptor 30 V1 goes out of track and has even bent the feathering spindle in flight. I heard you had a fix. Could you share it?

If you get the woof and poof, which is what we call the major out of track condition, it can bend the axle in flight. To make sure it never does this is simple. Here are the steps:

  1. Reverse the blade grips so the control balls lead instead of follow.
  2. Turn the seesaw over and turn the paddles 180 degrees.
  3. Reverse the collective servo.
  4. Fine tune your pitch curve.

The machine feels better and you don't have to worry about the blades going out of track.

I currently have an OS SX that is probably a good five years old. I don't do very wild things with the heli, but plan on working toward more advanced aerobics. Which engine would be a good choice?

Get one of the new .91 engines. OS and YS both make a good one. You'll probably need to change your gear ratio to something around 8.5 : 1. If you don't want to change gear ratios and you think a .61 is enough engine, ask us if we have any .61s around. We might, although they're getting rare. Another alternative would be to try one of the new .55 class machines such as the Fury 55 or T-rex 600. They will do any trick in the book.

What receiver battery setup do you recommend?

It took a while for me to come around but now that I've used them for a couple years, there's only one setup I even consider... regulated Lipo. I'm using a 2S 4350mah pack with an Align 2 in One regulator on most of my stuff.I can fly all day long and not worry about charging my battery or having a Ni-starter. I'm telling you, it's great.

If you're still running analog servos, you can still get away with a 4 cell NiCd pack around 1400mah. That'll get you 4 good solid flights, probably 5.

I'm learning autos and I've had too many boom strikes, is there a way to make learning autos less expensive?

Oh yes. There's really never a good reason to have a boom strike, though I've had my share too.

For more details read my article on autorotations.

My Raptor 30 wobbles when I add throttle, but when it breaks ground, it's smooth. What's wrong with it?

This seems to be normal behavior for the Raptor 30. It seems to be a case of too much friction between the landing gear and the ground. Once the head starts spinning at a high enough speed, it centers itself, the blades swing to their normal position and everything smoothes out. I say fly off a smooth surface and don't spend a lot of time at quarter throttle on the ground. Get rid of the skid stops so the gear can move a little. I don't see how skid stops help anything except contest fliers who need to prevent sliding or minor yaw changes when lifting off.

My NiCd battery doesn't seem to last very long. It starts out at 5.4 volts and then drops to 5.0 volts pretty quickly.

Sounds normal to me. The meat of the pack is between 5.0 and 4.7 volts. It will drop relatively quickly to 5 volts and then stay between 5.0 and 4.8 volts for a long time, depending on the capacity of the battery. Onboard battery monitors are a great tool for making sure you get the most out of every charge. We like the Gem more than any of them. It's easy to see while you're flying and gives you just the information you need. Once the receiver battery goes below 4.8 volts, the flashing led goes solid and it's time to recharge. Most machines can finish a flight if the battery is at 4.8 volts at the time of takeoff. If the Gem is on solid sitting on the ground, charge up. When you're flying, you'll see it go solid at times, which indicates there is a load on the battery. Don't worry too much about this since it's perfectly normal. Today's servos draw a lot of current,

If you don't have an onboard monitor, check the voltage right after flying. It's important that your voltage meter puts a load on the battery while it's checking it. There's not much reason to use more than a one amp load unless you want to be ultra conservative. If the voltage is 4.8 with a one amp load, you should be good for at least one more flight, maybe several more. It depends on what servos you use, how free your control system is and the weather. In cold weather, batteries just don't want to give up the current like they do when it's hot.

I seem to be having a problem with the collective on my new heli. It seems to be binding. On the bench it works great, but with the head speed up in a hover it is very sluggish..... lots of stick movement to go up or down. On the bench it is set for 9 degrees at full pitch, but from the couple of flights I have gotten on it , it isn't getting anywhere near that in flight. I have a Futaba 9202 on the collective, which should be strong enough. I even tried a 6v battery, trying to get more servo power, and it got no better. I am starting to think that I have assembled something in the head wrong, but if I have, I can't find it. Maybe you have had or seen this problem before and can tell me what I have done wrong.

I would suspect that you have the thrust bearings turned around. The smaller inside diameter thrust race must be on the outside, closer to the blades. This would account for the good movement on the bench, but sluggishness in the air.

Do you ship fuel?

No we don't.

I bought a kit from Ron's Heliproz South and I have a part missing. What should I do?

If you are missing a piece in your kit, the correct thing to do is to call the manufacturer/distributor of the kit. Click here for phone numbers

Normally, there won't be a problem and they'll get the part our to you right away. If you do have a problem, call us and we'll make sure you get taken care of.

I recommend you inspect the kit right away. I get some muffin tins and start going through each bag to make sure everything is there. It takes a while, but if you're pressed for time, you don't want to be held up when you discover that a part is missing from step 33!

My Helicopter is vibrating today, but it was smooth yesterday, why?

Normally a buzzing fin is caused by a change in the way the engine is running. If the temperature or humidity has changed, a click or two on the main needle might do the trick. If it's cooler, the air has more density. The denser the air is, the more fuel you need to give the engine. The more fuel your engine uses, the more power it's going to put out, that's why they run stronger on cool days and at lower altitudes. So if it's warmer than yesterday, lean the engine a click or two and see if that helps, and visa versa. Also, make sure you aren't drawing more air into your fuel mixture via a perforated clunk line or a loose pressure fitting.

Things that cause lower frequency vibrations are loose boom supports, worn head dampeners, loose bolts, play in the main shaft bearings, cracks in the frames, blade tracking, bent mainshaft or feathering axle, or anything else that might have been damaged in a hard landing or even bumped going from the house to the car.

One thing I can almost guarantee...it isn't a balance problem. If it was smooth yesterday, it should be smooth today unless you managed to chop a couple inches off one of the blades.

What do you think of the Raptor?

I get this question a LOT!

I think the Raptor is a terrific little helicopter. It flies great, and it's pretty tough. The parts are available and cheap. It autos very nicely and is fully aerobatic, yet can be set up just as easily for a beginner. What more could you ask for? Click here for more Raptor info.

My tail won't lock in a hover. The nose moves slowly from side to side. What's wrong?

This is a tough one. It's not hunting, I call it looking around . Any mechanical binding will cause this. This includes resistance in the control system, or the thrust bearings in the tail rotor blade grips. Check these things out first. The control rod should have no resistance except what the servo creates. Unhook the link at the servo and make adjustments until it's silky smooth. The thrust bearings should be in good condition and installed properly. The most common error is putting the thrust bearings on backwards. The larger inside diameter race always goes on first, or, put another way, is always closest to the t/r shaft.

My clunk line has rotted out, what should I replace it with?

Any small flexible silicone tubing will work for Nitro fuel. At this time Aerotrend has stopped making fuel line so things have changed. We have several alternatives so give us a call.

Do I need to enter my credit card every time I place an order with the online store?

Sorry, yes you do. The software we use won't allow anything else.

How many days does it take for online orders to be processed?

This will explain it.

What happened to Rick's R/C Helicopters?

Long story...read the article.

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