maximum weight of RC gear for a RC convertion

[woundedbear]

I am afraid I didn't phrase my question right. Here's what I need to know, What is the maximum weight of the RC gear that can be used when doing an electric radio controlled conversion of a Guillows 1/16th scale model kit? I have 2 Tactic RC transmitters so I guess I am stuck with using one of their receivers, or am I There are other companies that make micro receivers Are any of them compatible with Tactic transmitters Tactic does make micro servos, why don't they make a micro receiver that has 6 channels to be used with their micro servos What I want is a receiver that can use micro servos that has 6 channels. One channel for each of the basic stuff, Throttle, rudder, elevator, and ailerons, plus retractable landing gear, and flaps. If I could have micro servos for the landing gear and flaps that could be programmed to move slowly, I think that adding flaps and retractable landing gear could work for 1/16th scale Guillows model airplanes. I have seen conversions where the landing snapped up and down like an on and off switch. I think this could cause instability during landing. But if the action of the landing gear and flaps were slowed down this could make adding scale landing gear and flaps possible for 1/16th scale model airplanes. But there is still the question of weight Any receivers, servos, motors, and electric power systems for a Guillows 1/16th scale would have to be very light. A 1/16th scale airplane only has so much wing area So the total weight of the finished airplane would have to be very light to work.

[dirk gently]

Check the reported weight of successful RC conversions of your particular model on http://www.rcgroups.com/forums/showthread.php?t=827861
The lighter you can make the airframe, the more wiggle room you have with the gear.
For a 1/16 size plane I would use a 16g motor, a 10A ESC 5g servos and a 450-700mAh 2S battery.

[David Lewis]

For any R/C model, max allowable gross weight depends on how good a pilot you are, how many flights you want to average between crashes, inherent stability, wing area and lift coefficient. The most useful performance parameter in this respect is cube loading (weight/wing area^1.5).

[Bill Gaylord]

Flaps aren't practical for smaller models. Under 30" span, I wouldn't bother, unless for scale purposes. Pretty much the same with retracts, where every now and then it's nice to scale out a model, but not really practical. I would ditch the Tactic. Buy on what meets your needs. That said, I shouldn't have bought my DX6, as I knew 10 model memory would get old. As for more than 6 channels and all the other newer bells and whistles, I have no need for them, so a 6ch unit with more memory would suit my needs fine. 6 channel Spektrum compatible Lemon receivers can be bought for something like $6. I simply pay a few dollars more and hit the BUY button on Ebay, from Heli-Nation, and get them in a few days.

The difference between a few grams of gear weight can easily be lost, with ballast. I rarely need ballast, which is achievable after a number of diverse types of different scales, along with careful planning. There's no benefit to using 3gram servos versus 5 gram servos, if you end up needing 5 grams of lead. As for maximum weight, it's more of a skill issue than anything else. I've flown the 190 at a bit over 14oz, if I remember correctly. Required build precision and landing speed obviously go up. Anything under 12oz should be fairly straightforward, although these are not beginner planes. You have to know what to expect, before launching the model. Forget standard weight coverings. A model can almost be sheeted with contest 1/32" and ultralight covering, and end up at the same weight. Same goes for realizing where the wood weight really comes from. Most of the Guillow's 1/4" main and leading edge spars use heavy wood, which will need to be replaced. I would concern myself with removing 5-10 grams of wood weight, achieved with lighter grade spars, before trying to shave 10 grams of gear weight. It's seems a complete waste to shave gear weight, and still have a considerable amount of iron wood in the model. Another bottom line is to fly the model. It probably won't go well at first, or at least it didn't for me. I could remember trying to observe as much as I could from watching various builds of these models fly. It really didn't help much, until I actually started flying them. I consider gear as a mis-focus, in that unless it's far out of range, it's not what makes you or breaks you. I never learned to appreciate the importance of precision settings and what a degree here or mm there could do, until I actually started flying the models. If anything, that was the most discouraging part, when I realized the precision required for some of the settings.

[woundedbear]

Thanks! David Lewis, But could you clarify this for me. How many grams (or ounces) Per 1 square per inches of wing area? Is this what you mean? The lightest Tactic 6 channel receivers I can buy are the TR624 (8.3 grams) and the TR625 (9.5 grams) they're designed for the mini size servos plugs. Things would be so much easier if there were some kind of standard or universal servo plugs I have learned from Bill Gaylord Guillows B-25 build that you can save weight by soldering the servo wires directly to the receiver. This seems to make a better connection too. But you don't want to use a wire gauge that can't handle the current going into the servo itself as this could start an onboard fire So from this comes the part that I find confusing The battery used has to supply power to the receiver, ESC, motor and the power to operate the servos. How do I determine this I have a now obsolete Flyzone Aircore power unit. It has the receiver, ESC, motor, and three servos on one removable unit. The Guillows 400 series model airplanes can be built much lighter and have larger wingspans (that equals more wing area) so I'm guessing I could use a smaller motor and a smaller lighter battery But I want to add two more servos. One for the retractable landing gear and one for flaps. That would be an ESC for the electric motor, plus 1 servo each for the elevator, rudder, ailerons, retractable landing gear, and flaps. There are so many variables to consider How is a person to know? How much power will the battery need to have to run all of these things? I know that to carry an over 8-gram transmitter, and five servos will dictate the motor needed to get the airplane into the air. And running the main servos (the ones that will draw the most power) the elevator, aileron, and rubber will draw power through the entire flight. With the landing gear and flap servos will only need power during take offs and landings (I want those two servos to move slowly as I want the landing gear and flaps to operate slowly ). This will not only look more scale but I think retractable landing gears that slam open and close up too fast will make the airplane unstable during a time during the flight when a crash is more likely to happen. My Tactic TTX600 uses a nob (that turns like a volume control on a radio ) This will make deploying the flaps better. Something that I thought of was adding a little more length to the wingspan. And adding a little more width to the wings, by using a slower taper out to the tips Not enough to spoil the scale look, just cheat a little. One of my heroes growing up was Smokey Yunick, he was always trying to make little changes to the race cars he built to give his drivers an edge. Back in the late 1960s', he built a Chevy Chevelle that is still a legendary car. Well I hope you guys can enlighten me about how to building the electronics that I will need to make the kind of RC Guillows conversion I have been wanting to do.

[Bill Gaylord]

With the B25, I still used connectors on the receiver, but eliminated as many others as possible. Standard "S" connectors are heavy, and limiting them to the receiver is a good way to save weight, as they don't have the heavy additional body that covers the female connector. As for the Tactic receivers, 8-9 grams is unacceptable, with low dollar Spektrum clones such as Lemons weighing a few grams, and selling in the $10 range. The few grams won't kill you, but it's just unnecessary dead weight. I used the GWS Pico 72MHz receivers for years, which only weigh about 5 grams, with crystal. A few connectors at the receiver isn't a killer, but they start to add up quickly if used elsewhere, with gold pin motor connectors being especially heavy. The wire gauge is another weight savings, as you don't need servos or ESCs with standard 22-24 gauge wire. Using lighter gauge such as 32 will shave weight, as well as eliminating connectors.

Using servo slow devices on landing gear can prove difficult, as they are known to reduce torque, at least with linear servos. My experience with servos in the 5-7 gram range is that they have just enough torque for micro retracts, using a single servo. The small retracts are not robust either, and will most likely break. I would consider actually using them on the last FW190 I built, only after a few really good flights with grass landings and with the gear retracted. It would have to be a near perfect landing on a hard surface, to not over stress the micro retracts at roughly 11oz AUW with 1/32" sheeted fuse, if I remember correctly. The slightly larger retracts such as the GWS "Blue" or GP10 start to become a bit heavy for the 1/16" scale models, as well as being a bit large to fit properly. In the real world, retracts are not practical for these models, and are more of a novelty. I just came across Jagdpanther9's (You Tube name) P51 build, with retracts. http://www.rcgroups.com/forums/showthread.php?t=1998803
I have this model with a sheeted fuse and wing top/bottom LE at 12oz, and it lands a bit faster. Mine could be lighter, if the fuse had been built in more recent times. His weight at 10oz lands comfortably for a skilled flyer, but would degrade quickly with much more weight.

[dirk gently]

For a plane that size I would shoot for maybe 25g/dm^2 or 8.2oz/sq. foot. More than that, while may still be flyable, will have poor survivability in an event of a less-than-ideal landing.
Also, the heavier the plane is, the faster it needs to go, which means you would be flying more away from yourself, which will give you orientation problems - very easy to confuse which way a small plane is going when looking from afar.

[Bill Gaylord]

I've flown the 190, Zero, and Spitfire at wing loadings of 14 oz sq/ft and greater. The 1/16 scale models are very manageable for grass landings at wing loadings of 14 oz/sq-ft. My models all have sheeted fuses and partially sheeted wings, which could easily be built lighter. From my experience with the series in general, about 12oz AUW is where they start to become more difficult to land, where taller grass is a benefit. I would consider landing one of these at 10oz AUW to be nearly an effortless landing. Attempting to build these models with wing loadings of less than 10 oz/sq-ft for r/c is simply not practical, if even achievable. They're not beginner planes, and if a person can't manage them for what they are, then they're simply not practical unless built ultra-light. I'm a firm believer in replacing heavy wood, while hand cutting all parts from contest wood and covering with unpainted tissue is simply not what most people desire with their builds. There was a good example of the Stuka built that way, which basically flew out of the guy's hand and floated, but didn't have much in the looks department. Of course in that case they won't be as robust, further increasing the need for good landing skill. FWIW the added wing area and deeper chord of the Spitfire makes it considerably more manageable than the other models in it's series at higher AUWs.

[woundedbear]

Thanks for your input Bill Gaylord your advice is always welcome . I would like to run something past you . If I were to add 1 and 1/8 inches of wingspan to each side of," say the P-51 kit # 402" and widen the wing some by using a different taper to the trailing edge of the wing from the wing root to the tip. Making the wing tip somewhere around 4 inches wide at rib # 12, "the stock being 3 and 3/16 inch". This is just a ballpark figure for increasing the wing area of the Guillows 400 series P-51 kit. I would want to increase the wings span and width proportionally to get a little more total wing area. A Dude that I grew up idealizing," Smokey Yunick", did some rule bending back in the 1960s', in fact, this guy was one of my heroes as a boy. Growing up in Carolina stock car racing was a big thing to us country bumpkins . This guy, "Old'Smokey", was a rebel who use to do some innovative things with the cars he built. His big dream was to win at the Indianapolis 500, he almost did it one year with a highly modified chevy small block engine. He made a crankshaft from a solid piece of Crome Moly, that gave the engine had 200 cubic inch displacement, and gave it twin turbochargers. Smokey's homemade car almost won that race but something broke in the last few laps . For some reason, I always identified with the renegade engineers like Smokey. Guys who think, well if I change this a little, do a little nipping and tucking here and there maybe it just might work. Of course, I will drill a lot of holes in the ground and will often fail miserably, but I will have a blast doing it. Hey! It could be worse, I could be flying real airplanes, Wow that is a scary thought isn't it. OK, I've had my fun with you guys. But I really want to make one of these Guillows airplanes fly with all the bells and whistles. There's something about seeing a P-51 with those barn door flaps down, coming in on the final approach. Just think about it for a second with all of that power blowing under that wing being deflecting the air downward, making a cushion of air and floating that big beautiful Mustang down to a gentle touchdown at such an impossibly slow speed. A true thing of beauty, it could work Then it could be just another one of my reseeding hair brain ideas You would think that I'd just buy one of those prebuilt foamys and be done with it. But where's the fun in that Well I want to end this with a serous question. How do the companies that make the big foamys get the servos that control the landing gear and flaps to deploy and retract them so slowly? I'm realy not being facetious here and am looking for the right answer to this.

[Bill Gaylord]

I've cheated spans a bit, but at this size it disrupts the appearance, if more than maybe 1/2". It won't make you or break you, and will only lighten the loading a small amount. If I were to do it, I would cheat the overall area a bit, as well as the span. Increasing the short chords at this size, would probably help more per unit area, than span wise. Cutting new trailing edges or capping them with a stringer to increase the chord by a few mm can help. I've done that before, and then sanded them to a taper so as to not create a flat "land" at the end of the wing ribs.

Some newer transmitter like the Taranis can be programmed for servo slow. Outside of that, a servo slow device is needed, which adds weight to the model. Of the models I've added flaps to, I haven't had an issue with instant deployment. What I did notice is that if the model already has a bit more positive incidence than it should have, it will balloon, but not so fast that you can't control it. On models where I didn't have a balloning issue, I can't say that they made much difference at spans of 3' and under. What I would do at this point is to simply start a simple 3 or 4 channel conversion, and go from there. There's a lot to be learned from flying the earlier builds, and not worth going too far with them. The earlier builds I have tend to have a number of afterthoughts, making it not worth the added effort of things like retracts, when I did install them. The Dauntless is a perfect example. Built again, I would easily be able to balance the model with a battery 50% lighter, as well as the build being lighter. I built new tail feathers, which made it balance with a still larger than cared for battery, and I lost interest in it.

[davidchoate]

While researching a twin engine kit to build I looked over some RC Group forum threads, and a couple people cheated the wing span on the C-47, and they flew, but it just did not look scale in appearance at all. If You change the scale to a noticeable degree than it is not worth it. And if You want a nice easy to fly Plane I would and have built non-scale kits designed for the purpose of being an RC Plane. I mean windshields are not used, or painted on, but in order to develope the piloting skills to fly a heavy scale plane with a high stall speed and funny characteristics in the air because maintaining a scale appearance requires not being able to set things at optimum settings for Scaled down RC. So good piloting skills are needed first. I started a Fw-190 RC a while ago and put it on hold the minute I got an idea of the AUW and was able to figure out it was beyond My Pilot skill as of Yet. Thats why You see Me doing a lot of Trainer type Kits.

[dirk gently]

I've flown the 190, Zero, and Spitfire at wing loadings of 14 oz sq/ft and greater. The 1/16 scale models are very manageable for grass landings at wing loadings of 14 oz/sq-ft. My models all have sheeted fuses and partially sheeted wings, which could easily be built lighter. From my experience with the series in general, about 12oz AUW is where they start to become more difficult to land, where taller grass is a benefit. I would consider landing one of these at 10oz AUW to be nearly an effortless landing

That's interesting to read about a completely different building style to my own. I can't really imagine how it's possible to get to 12oz in a 25 inch model. I got to 9oz in a 32inch model built for a nitro engine, the same model with an electric motor reached maybe 11oz, and I wasn't really trying to make it light, in fact, I used extremely hard balsa everywhere (because I didn't know any better).
Cheers.

[woundedbear]

Hello! davidchoate, I was hoping you would chime in on this topic, between you and Bill Gaylord I have learned a lot I see you added a Guillows Piper Super Cub 95 kit #602 photograph to your posting, How good is the wood in that kit? I bought one back around 2000 and the wood in that kit was awful One of the die cut sheets was like oak and one was the lightest balsa wood I have ever come across, needless to say, the hard as oak sheet was cut pretty good but was way too heavy to use and the lightest die cut sheet was "useless as tits on a boar hog". I will be so happy when Guillows gets all of their current kits in laser cut form and starts adding new airplanes to their line of kits It looks like to me that the 600 series would have been among the first kits Guillows converted to laser cut. I have a grand Nephew that I'd like to get into model building and aviation in general. That is one more smart kid, so far I can't understand half of what he says, you know how it is with young'ns, it's like they speak a different language There is one word he can pronounce as good as an adult "Paleontologist" that boy is dinosaur crazy The 600 series are a good kits for getting young'ns starter with the fun free flight model airplanes. Of course, it's also fun for not so young builders too And the 600 series kits make for good three channel RC flyers. But being die cut kits they're a crapshoot If all of the die cut sheets in a 600 series kit were all of the same density they would be a much better buy as far as balsa wood model kits go. Maybe I'll order one of the 600 series kits directly from Guillows Back in 2000 there were probably a lot of kits from, "the dark ages of Guillows kits ". The wood in Guillows kits has been getting better ever since they started laser cutting their kits, I think once every model builder finds out about Guillows bringing their stuff into the new century their sales will go up. Back in the day, Guillows got the reputation for producing impossible to build kits and they lost a whole generation of modelers. But now that Guillows is producing laser cut balsa wood their kits are a joy to build and as a side benefit the wood in Guillows Die cut kits has gotten better I wish Guillows would go public so I could buy stock in the company Guillows the company started the year after my Mother was born. Charles Lindbergh had flown non-stop across the Atlantic Ocean and became the first person to become a superstar. The whole country was caught up in Aviation, it was the latest thing at that time. There was a popular song about Lindbergh, even a board game, suddenly the whole country was aviation crazy I once wrote about how Guillows little rubber powered airplanes were part of my life,"summer just wasn't summer without a Guillows rubber powered toy airplane with the red propellers 58 years old and I still get a kick out of flying one of these stick and sheet winged little airplanes. I don't have a lot of money to spend but I would love to buy stock in this company, just to make sure there will always be an inexpensive way for little boys (and little girls too) to have good clean fun flying a Guillows toy airplane

[Bill Gaylord]

That's interesting to read about a completely different building style to my own. I can't really imagine how it's possible to get to 12oz in a 25 inch model. I got to 9oz in a 32inch model built for a nitro engine, the same model with an electric motor reached maybe 11oz, and I wasn't really trying to make it light, in fact, I used extremely hard balsa everywhere (because I didn't know any better).
Cheers.

Fully sheeted models weigh. I recently finished the B25 with an AUW of 7.25oz, obviously not fully sheeted. I haven't seen any examples of your building style, so there would be nothing to compare them with that I'm aware of. There was a guy who used to give Guillows advice on RCG. He always stated unrealistically light AUWs and wing loadings. It eventually became obvious that he hadn't built, converted and/or flown any of the models he commented on, if many at all. That said, as a rule, I prefer to give suggestions based on actual relevant, proven, and documented experiences, versus advice. For that reason, I don't comment much about rubber flying models. You give a lot of advice concerning r/c conversions of these models, for a guy who hasn't demonstrated proficiency with any of them, as far as I know.

[dirk gently]

Hello Bill,

reading your reply I thought my original comment must have came across as rude. That wasn't my intetnion and I apologise if it did. I'm sure your models fly great in the hands of an experience flyer.

I don't post any of my stuff here, as I don't build Guillow's models, only scratchbuilds.
I don't want to spam in this thread, but I can send some example in a private message

Regardless, I don't think the figures I quoted are unrealistic, many conversions that you can find on rcgroups are much lighter than I could achieve.