MJD

My Feedback: (1)

It helps when the servos don't need to use half of the available torque just to be able to move the aileron at all. That way they can use it to fight aerodynamic loads instead. Maybe the horn fatigued from the constant load from the hinges. Are the Phenom hinges more forgiving than the Whip?

MJD

Details 4 Scale

My Feedback: (3)

Ok guys since were going to discuss servos and Mike's design,

Here goes. First, the original Whiplash hinges were live hinges, meaning they were vacuum bagged when the wings were made. They were part of the skin of the wing. This made the Whiplash very quick to manufacture. The first examples were Kevlar hinges and they didn't work quite like I had thought they would, so the torque for the servos was raised to compensate for my lack of forthought in the design. Later models had a much better, but still not perfect design. The problem on the Whiplash was in keeping the hinges rigid in vertical displacement while allowing freedom of movement. It's much harder than it would seem. The thickness of the surfaces on the Whip were about .250 at the hinge. Not much room to stiffen the airframe there if the hinges were too loose. The first design had super loose hinges, but didn't do well at real high speeds. Flutter was a big problem, hence the stiffer hinges. The Whiplash also had what is called an open bottom hinge design. The lower surface of the wing was slotted to allow the upper hinge/skin to move. The Phenom on the other hand uses Hvy Dty Robart hinge points and yet the surfaces are very tight and the hinges are free to move because they are pocket hinge lines.
Mike, I was not poking fun at your design at all. In fact, I've been following the tread with great interest to see your progress. I like it very much. It appears to be a solid design. What I was refering to was the difficulties and drawbacks that occur on any delta design made like the DD. Yes the wing loadings are far less than the Phenom, but their top speed is limitted by the rigidity of the airframe. The covering can only be stretched so tight. As the cover airframes passes through the air, the pressures on the surfaces are constantly changing, and making a bunch of drag doing that. With the Phenom or Whiplash, the molded design sacrifices a little weight for rigidity. The airfoil can be much thinner, but yet remain very rigid and unchanging. The only thing I can guess about Crazy and ChuckL's Phenom's must have to do with the launch itself. The airfoil on the Phenom is only 5.5%, which is very thin! Delta's can be very fast with thin airfoils, but with the wing loading being higher, they need more airflow over the wings for the control surfaces to have effect. I noticed this very much with the Jett .50 powered Whip. Spinning the small prop combo, take-offs were kinda hairy until the plane built a little speed. Once on step, it was a bullet, and even though my Phenom weighs more than the Jett powered Whip did, it actually has a better take-off profile with my measly OS.40 on it using a 9-7 prop. Go figure.
I wish I knew what was wrong with Crazy and ChuckL's Phenoms, but I havent a clue. It just makes no sense. Both of them seem to have built beautiful versions of the Phenom, but for some un-explained reason are having/had problems with them. I personally plan on building another Phenom over the winter with a Jett .60XL up front. Maybe I can figure out what happened to their's. Having designed the Whip and now flying the Phenom, the Phenom is better. The finish is immaculate and the parts fit is nearly perfect. I gave up on built up airframes a long time ago. I just don't have the time when I have to re-build them. Molded is much faster. I didn't say, better! I am definately not knocking anyone's attempt at any type of new design. I have been doing this for over 30 years and have designed and built a bunch of airplanes for myself as well as some kit designs. I'm all for what you are doing Mike, I think it's great. Keep it up. The only thing that I wish is that when problems seemingly arise with someones design. Especially a design being sold by a company , that maybe when things can't be explained, they just can't be. Would you immediately blame a company for a crash of an aircraft on the first take-off, simply because it was a new design and never flown, only to find out later that it could have been the radio or something else and nothing to do with the design at all. I know you are only raising the issue of what might be going on with the Phenom, but I know that I along with guys like Razor are not having any problems what so ever, so if it were the aircraft, they would all seemingly have the same issues. I believe that should be the real issue here. What is the common link in ChuckL and Crazy's Phenom. I know they both used the Jett .60XL, different pipes, but both have the same problems. They can't get a good take-off. You would think as Rudeboy said that with the .60XL, there should be enough power to go straight up on take-off.
I personally think the Phenom is great, that's why I'm building a .60XL powered one this winter to find out for myself what might be their problem. Russ' website video and Razor's video are proof enough of the soundness of the design. I think the other issue's need to be explored and explained before any conclusions can be made. Sorry again if I came off as picking on your design Mike. Not the intention at all. [8D]

Dan

Mike Connor

My Feedback: (5)

Dan,
Thanks for your thoughts. You are not the only one that took what I said a couple of times as harsh criticism of a design. In my mind it was just having fun when I made a comment about the Phenom and Whip being boat anchors to Combatpigg. There were a few other things I said that were also taken wrong so I will blame myself and try to be more careful in the future. The design of the Whip and Phenom are more durable then my design or a Dust but at the cost of weight. It can still fly well and this works out better for some folks. My Delta would have serious problems after a couple of landings on a dry lake bed. If you build an airframe to a point it wont be destroyed in a crash it will be too heavy to fly. We can all choose a balance that works for us.

It sounds like you put a lot of R&D into the Whip and ended up with an airframe many wanted and still do. Most of my R&D was done before the prototype was ever built. I would not call it plagiarize but I took good ideas from several designs and put them together. I feel lucky that with two prototypes flying and a few other overpowered ones holding up and flying well I see no need for a design change because of problems. A fully sheeted Q40 powered Demon will fly soon I hope by one of my customers. Full sheeting only adds 3 oz to the weight. I will start my third prototype soon that will be over powered and have large winglets and no vertical fins on the center section. My Delta project is a hobby and does not have to put dinner on the table. I do not want to sell one to someone that will not be happy with it. I do enjoy promoting my kit but one of these days I will probably give the whole thing away to someone that wants to do it. It is more work then most realize to kit a plane.

Good luck with your future projects and I hope there are no hard feelings. What you said is not even close to a problem for me. I try to keep RC a fun part of my life.

Details 4 Scale

My Feedback: (3)

Thanks Mike,

Good luck with your design. You're sure right that most people have no idea what it takes to make a kit a reality. Fully molded aircraft are three times the work at first, compared to a built up airframe. You get the pleasure of making it three times instead of once. Plug. mold and actual model. They cost a lot more to manufacture as well, so I don't expect the demand to be huge for fully molded airframes of this type. They are fun though.

Dan

combatpigg

My Feedback: (3)

D4S, What is your take on the Phenoms that won't fly? I used to build FG boats as a summer job in High School and know that getting FG goods to come out at identical weights is not an exact science, especially when the end user does his own paint job. At some point I think the weight can become too much for reliable hand launches with the given wing area. Especially if a guy is fooling around with a speed prop instead of a 9x7 or 9x8.

Razor-RCU

My Feedback: (50)

Okayyy...So how much more will the Jett-60 guys Phenom have to way over mine (OS-50SX) to makle weight an issue? Seriously...LOL

Chuck said he used all types of props. either of these guys needs or needed to use a dolly if launching was an issue, that way they could at least get it airborn for a minute to check CG and other settings-