Frequently Asked Questions
		I have your MHTV Video series from a few years ago. Is this the same footage, only in a DVD format? No. This is an entirely new series. Yes, the basic format is the same (rough-in the tx, set up the helicopter on the bench, then take it to the field and flight trim it), but I'm using a new radio (JR 9303) and a new machine (Raptor 50), and I'm telling you my latest setup secrets that I've developed since that time, which is mainly a new way to set up the throttle, and the new 90% throttle rule. One of the most significant changes is the flight trimming sequence. In the old series, that was only 19 minutes. In this series it's 55 minutes, so I think the flight trimming disk is much better than the old series. I've watched the flight trimming sequence a million times during editing, and I still find it fun to watch! You mentioned in the DVD foldout that shortly after the shoot you got a bad batch of fuel, and changed over to Magnum 15%. What brand of fuel gave you the problem? Cool Power 15%. What do I do if I have problems ordering from your site? Go to our Contact Page and let us know the problem you are experiencing. We will gladly help with any problems you may have. What if I want to place an order but I don't have, or don't want to use, a credit card? You may send a check or money order to Ray's HeliTech, 2433 E. Alden St., Simi Valley, CA 93065. We will send you your order once payment is received and funds are approved. Don't forget to include 7.25% tax (California residents only) plus $2.25 for shipping. I have your MHTV Video series from a few years ago. Is this the same footage, only in a DVD format? No. This is an entirely new series. Yes, the basic format is the same (rough-in the tx, set up the helicopter on the bench, then take it to the field and flight trim it), but I'm using a new radio (JR 9303) and a new machine (Raptor 50), and I'm telling you my latest setup secrets that I've developed since that time, which is mainly a new way to set up the throttle, and the new 90% throttle rule. One of the most significant changes is the flight trimming sequence. In the old series, that was only 19 minutes. In this series it's 55 minutes, so I think the flight trimming disk is much better than the old series. I've watched the flight trimming sequence a million times during editing, and I still find it fun to watch! You mentioned in the DVD foldout that shortly after the shoot you got a bad batch of fuel, and changed over to Magnum 15%. What brand of fuel gave you the problem? Cool Power 15%. What do I do if I have problems ordering from your site? Go to our Contact Page and let us know the problem you are experiencing. We will gladly help with any problems you may have. What if I want to place an order but I don't have, or don't want to use, a credit card? You may send a check or money order to Ray's HeliTech, 2433 E. Alden St., Simi Valley, CA 93065. We will send you your order once payment is received and funds are approved. Don't forget to include 7.25% tax (California residents only) plus $2.25 for shipping. I have a Futaba 9CH radio (or any other radio with "free" mixes). The program mixes are not built-in on this radio. How do I program them? The Futaba 9CH has three program mixes. Two are "straight" or "linear" mixes, and one is curveable. For our needs, we don't need the curveable mix, so we'll program it with straight lines to make it just like a linear mix. Make the first linear mix Aileron > Throttle. Select Aileron as the master channel and Throttle as the slave channel. Set the percentage on each end so the throttle INCREASES when you move the stick left AND right. I'd recommend that you start with 20% on each side. If the rotor rpm underspeeds in a roll, increase the percentage of mix, and if the rotor rpm overspeeds in a roll, decrease the percentage of mix. BEFORE YOU PLAY WITH THESE PERCENTAGES FOR AILERON > THROTTLE MIX OR ELEVATOR > THROTTLE MIX, MAKE SURE THE ROTOR RPM HOLDS CONSTANT IN A "NORMAL" LOOP. ADJUST THE BOTTOM OF "V" THROTTLE CURVE UP A LITTLE IF RPM UNDERSPEEDS AT THE TOP OF A LOOP (AT 0º PITCH/HALF STICK) OR DOWN A LITTLE IF RPM OVERSPEEDS AT THE TOP OF A LOOP (AT 0º PITCH/HALF STICK). Make the second linear mix Elevator > Throttle. Select Elevator as the master channel and Throttle as the slave channel. Set the percentage on each end so the throttle INCREASES when you move the stick forward AND aft. I'd recommend that you start with 20% on each side. If the rotor rpm underspeeds in a tumble, increase the percentage of mix, and if the rotor rpm overspeeds in a tumble, decrease the percentage of mix. Make the third (curveable) mix Rudder > Throttle. Select Rudder as the master channel and Throttle as the slave channel. Set the percentage on each end so the throttle INCREASES slightly when you move the stick right, and DECREASES slightly when you move the stick left. I'd recommend that you start with 8% on each side. This means point two would be 4% and point four would be 4%. This will give a linear line to the "curveable" program mix. If the rotor rpm underspeeds in a right pirouette, increase the percentage of mix on the right side (and adjust point four to half of what point five is), and if the rotor rpm overspeeds in a right pirouette, decrease the percentage of mix on the right side (and adjust point four to half of what point one is). If the rotor rpm underspeeds in a left pirouette, decrease the percentage of mix on the left side (and adjust point two to half of what point one is), and if the rotor overspeeds in a left pirouette, increase the percentage of mix on the left side (and adjust point two to half of what point one is). I only have two program mixes. What should I use them for? The priority is to use one for Rudder > Throttle, so you get a constant rpm in pirouettes, and use the other one for Aileron > Throttle, so you get a constant rpm in rolls. The theory is that you hover first, using rudder > throttle mix in pirouettes, then learn to do rolls (aileron > throttle mix) before you learn to do tumbles (elevator > throttle mix). With the particular combination of the Raptor 50 and the OS 50 shown in the video, we essentially zeroed out (didn't need) Rudder > Throttle mix, so in this case, you could forget the Rudder > Throttle mix altogether and set Elevator > Throttle for the second program mix. Dual Rate:  I see in the video that the JR has two D/R and EXP values for each position (POS-1, POS-2, and POS-3). Why are there two DR and EXP for each?  The 9CHPs only allows me to set one D/R and one EXP for each switch position. Those two dual rate values are for EACH SIDE of the stick throw. They change together by default, but you can move the stick to one side and set one value for that side, then move the stick to the other side and set another value for that side. There's no good reason to do this, and that's why I didn't mention it on the DVD. I see the JR 9303 seems to allow you to automatically use a dual rate based on the Flight mode.  I don't see anything like this for the 9CHPs. Would you recommend I just make sure I have some EXP no matter what position my switch is in? You can also do this in the 9C. Refer to page 36 in the manual. Look at the paragraph just above the "goal of example" box. Then look at the bottom box of the “goal of example”. You want to select "Condition" and then you can get your expo and/or dual rate with the flick of the flight mode switch. Also see the next answer below... With the Auto set for each flight mode do the D/R switches even do anything (since you have Auto for each flight mode set to POS-1)? The dual rate switches don't do anything since I've left them at 100%. If I set a dual rate switch setting to 80%, then I'd get 80% of full travel at full stick, along with the expo I've set. So the dual rate and the expo can be mixed together. You can do this on the 9C too, simply by selecting a dual rate percentage AND an expo percentage. In the 9C you want the expo percentage to be a NEGATIVE number. Throttle Curve: Is your recommendation to ignore the values specified on the Raptor manual? Yes. I would recommend that you do NOT use the numbers in the Raptor manual. This will give a helicopter with a very high head speed, which is not needed or desired. Why they suggest numbers this high is beyond me. Use my throttle curve numbers, and use your pitch gauge on the rotor blades to get the pitch I recommend on the DVD. Whatever the numbers turn out to be, that's what you want. Particular "given" numbers for pitch are nothing... You don't want to depend on "numbers" that somebody gives you. It's the DEGREES of pitch you want to see with the pitch gauge. Step back a little bit and look at the overall picture I'm trying to give you. Understand the "why." Does your book provide additional information that might be important?  My budget is pretty much busted at this point but I'm considering saving up for the book.  I haven't seen the book in any book stores and I hate buying books without "flipping" through them first. RC Modeler magazine used to distribute the book. They are now out of business. Most of the books out there are sold now; that's one reason you can't find one. Yes, the book provides additional information, but I've given you the most important stuff on the DVD. So do you need the book? No. Would it still be beneficial? Yes. I am currently working on a new edition of the book, but it’ll be awhile before it comes out… My OS 50 Hyper did not come with a thrust washer (drive hub) or woodruff key (to keep the drive hub keyed to the crankshaft). How can I break-in my engine on the bench? My “normal” OS 50 (not Hyper) came with a thrust washer (drive hub), so all I had to do was bolt on the prop and go. I just became aware of this myself when I couldn’t get another “regular” OS 50 and had to order a Hyper. Yeah, looks like you'll have to buy one... Part # 27708010 for the drive hub and part # 27708200 for the woodruff key. You mentioned in the DVD that you don’t like CCPM, but didn’t give a specific, technical reason. Is it that it’s not precise enough? Could you please explain? Good question. CCPM is precise: It's that it's not pure. And while it is simpler mechanically, it’s actually harder to set up, since you have to pay very close attention to the swashplate being level and each servo’s output arm being perfectly level at the center of the collective throw, and then carefully adjust each endpoint on the top and bottom of the pitch curve (for each servo) so the swashplate remains level at full positive pitch and full negative pitch. Here’s why the sytem is not pure: If the bellcranks to the swashplate are level, and you put in a large cyclic input, all is fine. But if you're at high collective pitch, all the bellcranks to the swashplate are angled up. When you put a large cyclic input on top of this, some bellcranks go further up, towards more differential throw, and some bellcranks go down, towards more linear throw. (Draw a picture with one bellcrank in front of the swashplate and one bellcrank behind the swashplate, just to make the visualization easy.) This means the bellcranks "going over the top" are not putting in as much throw as the bellcranks "going toward center." So at high collective pitch, the bellcranks moving down are going to put in a little more throw, and the swashplate is going to drop very slightly with a large cyclic input. The same thing happens at low collective pitch, and the bellcrank going up is going to put in a little more throw, so the swasplate is going to rise slightly with a large cyclic input. There isn’t a program mix that you can use that can fix this. Are you going to feel it? No, I don't think so. The only way you might feel it is to fly exactly the same helicopter with a Raptor 50 type collective system, and see if you could feel a difference in the collective during maneuvers. For normal hovering, where the cyclic bellcranks are around center, you'd never feel the difference in either system. That's why CCPM is fine for scale applications. But for wild 3D, I don't think it's the way to go. Does it work? Sure. A ton of guys are flying it. But nothing beats the technical purity of the Raptor 50 (and Intrepid) cyclic/collective system. It's perfect! I’m not sure I understand why you elected to use the red Raptor 30 gear to get a “non-driven” tail rotor. And again, why do you use the “Rate” gyro mode for autorotations? The reason I use rate mode in throttle hold (autos) is because I'm NOT using a driven tail rotor on my ship. Driven tail rotors suck up rotor inertia, and the average guy isn't going to be doing pirouettes in autos, so I think the extra inertia gained is far better for the average pilot. If you want to do pirouettes in autos, then yes, you need the driven t/r, and then you can use Heading Hold (for the gyro) in autos, too. If the tail rotor stops in the auto (with a non-driven t/r), and you're in heading hold mode, and the ship yaws a little bit, the HH mode will put pitch in the tail rotor. Because the tail rotor isn't turning (or turning relatively slowly), the ship won't straighten out. So the gyro puts more and more t/r pitch in the t/r, the t/r rpm slows even more or stops, and all this pitch in the t/r becomes a "drag bucket" and really increases the rate of descent. So by using the Rate gyro mode in a ship without a driven t/r, I get the best rotor inertia (for those "fluffy soft" touchdowns) and the t/r stays at flat pitch (again, in the Rate gyro mode) for minimum drag all through the auto. So to put it a little different way: In a driven tail system, the GYRO drives the t/r to keep the nose straight, and in a non-driven tail system, the VERTICAL FIN keeps the nose straight by weathervaning the helicopter into the wind. When I tried to set up the collective pitch on my helicopter (a small electric), I couldn’t get a repeatable reading on my pitch gauge. One time the pitch would be right on, but the next time there would be too much pitch or not enough pitch. What’s happening? This happens because all of your linkages (ball links) are too stiff on the balls, and you may have other things binding up (or too sloppy, as well) in the helicopter. If you loosen up the ball links and get everything smooth, and take out as much slop as possible, your pitch readings will be repeatable, like mine in the video. There is just going to be less precision in small helicopters, too. It is a combination of all of the above. I am trying to set up my collective pitch. I’ve set my endpoints to 140-150%, but I still don’t have enough collective throw. What do I do to correct this problem? You simply move out one more hole on the collective servo arm. This will give you more collective throw with the same endpoints. If this gives you too much throw, simply back down the endpoints (exactly as shown on the DVD) until you get the throw you need. Simple, huh? If there's STILL not enough collective throw, you'd go out ANOTHER hole on the collective servo arm, then back down the endpoints as necessary. Starting to understand the theory here?  :-) I noticed you set 30% expo in all of your flight modes. Why didn’t you vary this percentage for the different flight modes? As I mentioned in the DVD, these settings can be used for getting the cyclic "feel" you want. You can set one at 40% expo, 30% expo, etc. I selected 30% expo for all because I wanted a consistent feel through all my flight modes. So I think the best answer to your question is whether or not you want the same "feel" in all your flight modes. I do, so I used the same number for all the flight modes. Whether that "feel" is 30 or 40 or 45 is up to you to experiment with and play with, and if you want a soft feel around in hover, set 50% expo for example (with a "crisper" 30% expo in forward flight), or if you want a soft feel around center in forward flight, set 50% expo for example (while keeping 30% expo in a hover). I'm currently in the middle of setting the endpoints for fore/aft cyclic, and I?m not totally tuned in with the whole inches/thou's etc. Can you give me a quick estimate to the height of the plastic stop used to prevent binding of the swashplate in metric? The plastic stop is .137 thousandths, so let's just round that up to .140. That is 3.57mm. You don't even need the stop, but it just makes the setup a no-brainer. Without the stop, rest the swashplate on the bottom collar, then tilt the swashplate aft and right at 45 degrees (as shown on the DVD) until it hits the mainshaft. Set your fore-aft and left-right endpoints here, then REDUCE both sets of endpoints a few percent at a time until the swashplate does not drag on the mainshaft when you move the collective /swashplate up and down (with tx cyclic deflection still in the aft/right corner). It's that simple! Could Helicopter flyers implement the large cooling heads that are in place for Nitro buggy and race cars? It would seem to me that these engines have much less cooling available to them and run at tremendous RPM. I realize there are some space considerations, but if a helicopter were designed around these large cooling heads, maybe it would be feasible. As always, with your keen knowledge of helicopters, this thought must have crossed your mind and I would love to hear your opinion. The Hyper 50 has a "buggy head" (horizontal finned) type cooling head. In my opinion, I do not care for this type of cooling, because all the heat in the engine has to go up the "center channel" before it branches out to the horizontal cooling fins. This gives a lag in the engine heating up and cooling down. On a conventional (vertically finned) cylinder head, the heat goes from the cylinder directly to the vertical cooling fins, so the heating/cooling takes place much quicker and more efficiently. Regarding the size of the fins, if the surface area is too large, then it takes longer for the engine to come up to temperature and maintain a stable setting. So if there is not enough surface area (airplane type head), the engine will overheat, and if there is too much surface area (big buggy head), it will take too long for the engine to warm up (and cool down) as the load on the engine changes: i.e. from climbing out (high demand), to an autorotation (low demand). top
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