Goldberg Gentle Lady Build

speedbirdted

Legendary member
Nice. Do you use some sort of jig for building a fuselage that long and thin?
I have a "sort of" jig which I have used on some other planes, it's basically just some plywood right triangles glued to flat pieces that I can then clamp to the bench to hold the fuselage sides straight, but I found I didn't need them this time and it actually turned out almost perfect. This is actually the first fuselage I've ever built with CA, normally I use PVA or 30 minute epoxy which takes a while to cure so it allows parts to be put into a jig, but CA cures quick enough that I could just hold it true with a square to make sure everything was straight. This is really irresponsible and you should never do it, but it worked here...
 

CMS_1961

CMS_1961
I was actually thinking about putting my PAW 049 diesel that I have lying around somewhere in a pod so I could make it self-launch and keep the nose. It has the RC carb on it but I could pretty easily just set up a linkage to hold it at full throttle at all times. Problem is it doesn't have an internal tank so I'd have to get one of those 3/8oz Cox tanks (smallest tank I have right now is 1oz and it gives it 15+ minutes of runtime which is too much for a glider launch) And there's also the problem of even getting fuel for the thing now that Davis Diesel is no longer a thing and Ether is weirdly hard to get here in the States...

I used to use the Cox .049 Black Widow glow motor (see pic) on a pod on my Gentle Ladys'--no throttle--runs full speed, has a tank and it would get the Gentle Lady to a nice altitude. I have no idea if they are still made, but EBAY / AMAZON might have them!! If not you could easily rig an electric motor on a boom with a 6x3 prop with a 1500 - 1800mah battery or similar.

I know you said you want to keep the nose block but so you know a good setup that works is>>> I currently have my 1100Kv motor, 6x3 prop on the nose with a 25 amp ESC and a 2200 30C battery in my Gentle Lady---works great. I typically get 20 to 30 minute flights on a good day on one battery!! I just use the motor to get to altitude and kill it.

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speedbirdted

Legendary member
Stuff came. This is just some of it: I got a few other bits which you might see in other airplanes at some point too ;)

The color scheme I've picked goes as follows, silver for the fuselage and yellow for the inner wing panels and h-stab, orange for the outer wing panels and v-stab. I was thinking about doing only one wing panel in orange to help with orientation from the ground though I don't think it'd be necessary as that would only help with orientation if the plane was inverted, and this being a 2 channel plane if it somehow ends up inverted it shouldn't spend a lot of time that way.
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All the tail feathers are done, control horns installed and hinges glued. Hopefully I can attach these with epoxy to the fuselage when it's also covered without adding too much tail weight. I've done it on other planes and it was fine, but never a sailplane, so I'll try not to be excessive.

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Also, for the sake of the fact that I've never seen anyone mention it, this is a helpful technique for sealing up edges with Monokote. Stick the monokote onto the back of the control surface but don't apply it any farther than 10-20% around the rounded part so it can still be moved easily. Hold the rounded edge at an angle against the work surface with the monokote to be cut underneath the material, then hold the control surface at angle to the work surface (this angle depends heavily on the control surface edge geometry and the amount of material you want left which is also important for reasons that will be discussed shortly.) Then you can use the edge of the control surface to get a super straight cut, but be sure to apply a bit of backwards twisting pressure on the knife so that the rear edge of the blade brushes on the control surface instead of it being damaged by the sharp end. If this is hard to understand hopefully this extremely crappy drawing will help:

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I tell you this because it is much, much easier to measure and cut off small amounts of trim coating, starting with a rough, slightly oversized piece of monokote, to get a smooth seal than meticulously measuring your pieces and then trying to do all the cutting in one go. I use almost no measuring tools when I cut and iron on monokote, as all measuring should be done when the parts are being assembled in the first place, and with these kinds of techniques, I don't need to.

Now why is the angle that you hold the part at and therefore determine the amount of excess material you have important? Well, you don't want your seam to be perfectly inline with the center of the edge; this is bad because not only does it not leave you with any excess material (so if you cut the other side of the monokote too small, you end up with patches that don't get covered at all and this is exceedingly annoying) but if you have the seam either in the center of the edge or too far recessed, the airflow over the control surface will always be trying to pull the monokote off of the control surface. This is not very important when you have a low speed airplane like a sailplane but on pylon racers that go 200+ mph, it can cause problems. I just do it out of habit for on every plane I build. So you always want more material than you need; this ensures that the seam does not have nearly as much pressure on it from air and the adhesive is under less strain to adhere to the plane. Here's another crappy drawing if my utilization of the English language is too messy:

crappy drawing 2.jpg


I'm also thinking of trying something new: Using an Orangerx reciever. Usually I use either Lemon, Redcon or old Spektrum recievers (since I'm too poor to buy new ones) plus experimented some with the fake Spektrum recievers you can get on ebay for like $16 (they tend to be hit or miss - I have some that have worked perfectly for 4+ years and others that I couldn't even get to bind) but despite my extensive purchasing habits on Hobbyking I have never bought any Orangerx products. Well, technically I have bought one, a USB simulator dongle, but I don't really count that. Something that initially turned me away from Orangerx stuff is most of it isn't satellite compatible, and I figure if I'm going to be taking this glider up to the full 700 feet the AMA allows me to ride thermals all day (uncontrolled airspace babayyyyyyyyyyyy) I don't want my signal dying. But I figure now that I have totally run out of receivers and I'm already going to be buying the batteries and servos (and maybe extra stuff like a vario?) off Hobbyking anyway I might as well buy one of those too and save the extra little bit of shipping money. So does anyone have any experiences positive or negative about Orangerx products, particularily the R615X or R610V2 that they'd like to share?
 
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TooJung2Die

Master member
Good covering tip! Wish I knew about it a few days ago when I started covering the Eaglet 250. Haven't covered the fuselage yet. There may be a straight edge or two where this will be useful. It's like watching people free hand cut wavy bevels into foam board. I always get perfectly cut bevels by laying a steel straight edge on the foam to guide the knife. It can't be too hard to use the edge of the model to guide the blade through the covering film without cutting into it. :cool:(y)
 
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speedbirdted

Legendary member
Transparent monokote is now my favorite thing in the known universe.

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I got all the wing sanding and covering done today in one go. Took probably about 4 hours though I probably could have halved that if I didn't screw up while covering the inboard panels which resulted in some unwanted wing twist - the right side had the correct 1/8" of washout while the other side was twisted the other way about 1/2" and I had to patiently tighten individual portions of covering little by little with the heat gun to correct it. I always cover the bottom first, and always from the center outwards when I have cases where I have to use multiple pieces of covering on each side. I considered going over the center joint with some filler to hide the small gap of about 1 mm, but it'll get covered by the rubber bands anyway so it doesn't really matter all that much. From a structural standpoint filling the gap doesn't mean much either as both sheeting panels are glued to the double-wide center rib so they don't have any room to move.

Why has my bench gotten even messier even though I moved all the scrap balsa off of it?

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The fuselage is also covered. I just went with silver since why not? I think it looks nice that way. I also put another layer of clear on the front underside, since every landing with this is going to be a belly landing and the extra protection won't do any harm. Silver monokote also might be the most heat-sensitive type in terms of color - the shininess of it changes significantly depending on how much you heat it and so you have to be really mindful of how much time the iron is spending over a certain area of the covering. I didn't get it anywhere near perfect this time, but I think it's the best I've done.

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Now that all the external bits are pretty much finished I figured I would put them all together temporarily for a photo. I think it looks pretty good, but I can't be the judge of my own work...

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I think tomorrow I'm going to get the pushrods built.
 

TooJung2Die

Master member
Wow. Great color combination for looks and visibility. Another classic Gentle Lady will soon take to the skies!

I have several transparent covered airplanes. Some are crystal clear transparent. On the ground I often get asked if it is harder to see them in the air. It's the opposite. They are brighter in the sky than opaque covered airplanes because light passes through. A solid color will eventually fade to black as distance increases. The airplane will become a dark silhouette. No so with transparent colors.
 

speedbirdted

Legendary member
Tail feathers went on. Nothing really interesting here - I used 5 min epoxy since I think it's a little lighter than the 30 minute stuff. Tried to use as little as possible to keep tail weight down.

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Pushrods were also built up - my skill in the fine art of thread reinforcement has atrophied quite a lot due to non-practice but I think these will do.

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Also, has anyone ever made this stupid mistake with epoxy bottles? :ROFLMAO:

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speedbirdted

Legendary member
@speedbirdted - very nicely done - this telemaster is looking great - I just recently renovated a 'moldie' which has a solid pushrod for the 3V tail - I think in the future I would use them more!
i was actually thinking about replacing them with sullivan goldenrods since I didn't know whether the pushrods would have problems with binding and rubbing against each other, since the rear fuselage gets pretty dang narrow. Fortunately some test fitting revealed this was not the case. I also considered pull-pull control because that would probably be the least heavy option and for me at least pull-pull is the easiest to set up well, but if the included setup works fine why change it?
 
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Joker 53150

Mmmmmmm, balsa.
Mentor
I also considered pull-pull control because that would probably be the least heavy option and for me at least pull-pull is the easiest to set up well, but if the included setup works fine why change it?

On classic designs like this I often like to keep the build faithful to the original design (other than modern electronics). There is something satisfying about going old-school with the builds.
 

speedbirdted

Legendary member
On classic designs like this I often like to keep the build faithful to the original design (other than modern electronics). There is something satisfying about going old-school with the builds.
That's what I wanted to do all the way through. The only change I made was that stupid elevator since it gave me a headache looking at it.
 

speedbirdted

Legendary member
Interior guts are all done. I ended up finding a spare Redcon receiver that I dropped in; there's no satellite but I think for a maiden where I keep the launch altitude on the conservative side it shouldn't be too much of an issue. The antennas are not in their final placement so don't cry about that. I still have to find a good place to mount them at a good 90 degrees.

AUW came out at 18.8 ounces, with a 700mA life stuffed as far into the nose as it would go. It's still a bit tail heavy so I will be adding ~3 ounces of nose weight which should clean that right up.

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The faceplate for the 40+ year old switch I used was also broken (my reason for using it is it was the lightest one I had lol) so I had to make this... thing... I considered not even using a switch at all since I was gonna have to pull the hatch off to get to the charging cord anyhow, but I really want to get out of the habit of juggling receiver batteries around between airplanes.

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The next you see of this airplane on here will hopefully be maiden flight footage...
 

speedbirdted

Legendary member
Looks nice and clean inside! Nice touch on the servo wire wrapping too - should cut down on any signal cross talk. :D
didn't think about that aspect of it! I mostly just do it so if I ever need to redo the cables they're always close to each other and I don't have to go hunting around the airplane to get all of them. But here there's only two to worry about so I guess it isn't as important.

I think the maiden is going to have to wait a bit.

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