1/2a Stealth Sport RC Plane

NEW222 Mon Nov 11, 2019 7:39 pm

So, this plane pretty much took from sticks and sheets Friday afternoon to this as of a few minutes ago. I had seen this airplane many years ago in a magazine and had wanted one. So, back in 1998, I got the LHS to order me the kit. A few months later I thought I would scratch build one. So, I traced the tail parts to paper and cut out the horizontal stabilizer and elevator. Now fast forward to a couple weeks ago. I was looking for something and came across the tail I cut out over 20 years ago. So that then rekindled my thoughts and said I had to build one. So, I had the plans digitized for any future use, and I also scanned in the instruction book for future as well. Over the past couple weeks I printed out a tiled copy of the plan. Cut out the parts I needed and made templates as required. Then over a couple trips to the LHS I bought the required balsa, almost (as one can see I still have one more sheet to buy for sheeting the fuselage). Anyways, all I have left is to sheet the fuselage, glue on the tail assembly, and glue on the wings. Oh, and make the ailerons. I strayed away from bought hinges for this as hinges are not cheap here, and I do not like any of the factory made hinges for 1/8" balsa. So, I had reverted back to sewn hinges on the tail. I like them for ease of doing, they have minimal hinge gap, they are very 'free', and lastly, they are easy to do on 1/8" balsa! Hinging the ailerons, I am still on teh fence on what I will do. I may try sewn hinges there as well, but will see when the time comes. As for finishing, I am new to flying these nitro powered beasts, so hate to invest a bunch of money in covering, so I had decided to dope the fuselage, tail booms, and tail then paint with flat black spray paint. As for the wings, I will cover them with doculam, scuff them up good, and paint with flat black as well. It is a Stealth... I will then give it a shot of satin clear to protect it if I think of it. So that's my story, and where I am at now. Thsi is the part I hate most coming up shortly. Installing controls. It calls for full size radio gear and receiver (2 servos, full size 72mHz receiver, 4 cell AA battery), but I will be ammending ths as I go along. The only thing I will need to buy is a couple of servos. I have a few 9 gram servos, but do not think they are enough for this, as the ailerons run off of one servo. Anyways here are a couple of pictures. I will get the aileron rods hopefully this week so I can continue with this.

dirk gently Tue Nov 12, 2019 4:23 am

I use 5g servos for all 1/5A stuff, if I can help it. The rule of thumb for general sports flying is:
take the weight of the plane in g
you want twice as many g*cm of torque in your servo.

For example for a 300g model, a 0.6kg*cm servo should be sufficient, the 5g servos I use have 0.9kg*cm, if I recall correctly, so there's plenty of wiggle room. I tend to run both ailerons out of a single 5g servo (via torque rods) without an issue.

balogh Tue Nov 12, 2019 6:01 am

It really looks good, and unless you are sure about the dope, I would rather suggest oracover, with polyurethane proofing of the engine cowl neighborhood prior to covering. What size of engine are you contemplating? I see the mount screw pattern is fit for a tanked 049 like Black Widow, or, a reedy with external tank? I would recommend a more powerful 049 engine than a Bee as the stout front area of the fuselage will add some drag that you may want to handle with a Black Widow, or, a reedy having at least a No 1 cylinder or even better, a TeeDee 049/051 cylinder/piston combo..

I would also strengthen the tail booms, if rectangular, with carbon strips glued to the internal face, all along from tail to body, just in case...at least the tall grass area where i fly my planes can take its tolls on a lose or weak appendix of my planes like the horizontal stab, unless strengthened, that tends to hook up in weed when landing.

Looking forward to seeing further pics as your build advances.

Levent Suberk Tue Nov 12, 2019 8:52 am

An interesting design. First published in Model Airplane News Magazine in October 1993 issue, then kitted by House of Balsa. I had that issue.

66 Malibu Tue Nov 12, 2019 10:41 am

If I recall correctly, HOB suggested use of the Cox .049 Dragonfly to power the 1/2A Stealth.
When I get time I'll dig my kit out to confirm.

Levent Suberk Tue Nov 12, 2019 11:07 am

Yes, Cox Dragonfly or Black Widow:

https://www.worthpoint.com/worthopedia/house-balsa-ultimate-backyard-flyer-1817879074

Dave P. Tue Nov 12, 2019 2:56 pm

I scratch-built two of these in '93 from MAN plans with canopies purchased from the guy that designed it. The first one got ate by a tree but it flew so nicely and was so quick and easy building that I built another. I still have that one, but after a couple of moves and a couple decades bouncing around in the garage rafters, it's a little beat up. I'm still trying to decide if it's worth repairing or not. The main issue is that the tailbooms have warped a bit so the horizontal stab isn't square anymore.

The first one I used hardwood dowels for the tailbooms, the second one used fiberglass arrow shafts. Carbon fiber was not readily available then, but I would use it now without question. Both were covered with Monokote. The first one in white and metallic purple, the second with charcoal as in the construction article.

It's a nice flyer, not at all fast with that relatively thick wing. Our cat chewed up the hatch that had the canopy on it, so I built another just out of plain sheet. The difference in performance was remarkable. The drag of the canopy made much more of a difference than I thought it would.

i don't think you have to worry about the servos not being strong enough. It's not fast enough to cause aerodynamic pressures that would even slow a 5 gram servo down. Both of mine used a single Futaba mini-servo with Sullivan flexible pushrods to drive both ailerons as depicted in the MAN plans. I used a Dragonfly with no throttle or muffler on both airframes. It is adequate, but not much more. It could use a strong tank-mounted Tee Dee and even then it won't be over-powered. Brad and Mauricio would both be bored to tears.

I'll post a couple pictures of number two when I get home this evening. You guys can help me decide whether to repair this one or just scratch out another. I have templates which I scanned and saved to PDF if anyone would like a set. I tried to paste them to this post but being the tech-challenged analog guy that I am, I couldn't make it work. I'd be glad to email them if anybody wants.

NEW222 Tue Nov 12, 2019 4:15 pm

Ok. Thank you all for the replies and advice. Where to start.... Well, my 9 gram servos are cheap Turnigy TG9 servos, and is why I am a bit hesitant to use them, but if the concensus is that they will work, I will probably give it a try!

The finish. Not 100% sure yet on the finish, but am still really leaning to the rattlecan paint over top of dope, or, if I get ambitious, I will use WBPU before the paint then I can apply it and sand it inside this winter..... Wings will be the doculam as was my original plan, but, if a roll of covering finds its way to me, I would probably use it. On the other hand, the doculam is strong, and light.

Engine... Well, since I do not have a Dragonfly, I built it as per plans for the afforementioned Black Widow engine, so that is what will be bolted up for the maiden. Or something else strong running like it.

As for the tailbooms. I went as per original and used 5/16" dowels as per the plans. I had read about using arrowshafts, but with the nose being heavy, I decided to go with the dowels for weight. Hopefully it works as planned.

And Dave P. While pictures will be most welcomed, I will say before hand, rebuild it and let it fly again! Very Happy

Also, I have the HOB plan scanned as well as the manual scanned in .pdf format as well should anyone like to build one. A PM with e-mail address is all it takes. Smile

NEW222 Tue Nov 12, 2019 4:20 pm

So I just detetected a warped TE on one wing panel in the center. May have straightened out when ailerons are installed but am not sure. So I 'wet down' the TE area in question and put a scrap piece of 1/8" square spar underneath and lightly clamped the tips down to a hard surface to see if I can help it straighten. Picked up the fuselage sheeting today, but I just realized I clamped my wing to my cutting area so sheeting will have to wait till tomorrow, or later this evening. Got to laminate some other balsa for teh triangle nose blocks, and can at least make those up and glue them on. Sorry I have no pictures of the warp. I tried taking a few, and nothing could turn up a clear enough picture of it to show.

Dave P. Tue Nov 12, 2019 6:57 pm

One method for straightening that TE is to slit it length-wise , pin it down straight (don't forget the wax paper!) and glue it with thin CA. It doesn't always work, and it can make hinging a real pain later on, but I've saved more than a few doing that.

NEW222 Tue Nov 12, 2019 7:18 pm

Well. I just took my wing off of its board, and 95% of the warp is now gone, and will be good enough now! Yay me, a win! Winner winner, chicken dinner! I could possibly get it better, but I don't want to risk anything.

Dave P. Tue Nov 12, 2019 8:42 pm

As she sits right now, with 25 years of garage patina. It's actually not as bad as I thought.

This is with the canopy set on top. It adds a lot of drag, but it looks good. That's what my wife says about me.

The plans are the MAN plans, blueprints actually. I don't know if the HOB kit came with two sheets, but the second sheet from MAN is an exploded three-view. Kind of cool touch, I thought.

To get it flying again, I have to repair the right wing leading edge and cut off the arrow shafts, drill them out and replace them with carbon fiber tubes. I also need to get some charcoal monokote for a couple patches. What do you think?

NEW222 Tue Nov 12, 2019 9:45 pm

Yours looks great. For what you describe for overall damages, I would say fix it and fly it personally. Yes, the HOB kit has teh plan, and a 3d view of the complete model. I did not get that sheet digitized as to build it I only needed the plans.

Oldenginerod Thu Nov 14, 2019 1:15 am

Dave P. wrote:It adds a lot of drag, but it looks good. That's what my wife says about me.

What was that? Your wife says you look good in drag? Affraid or WOW!

Dave P. Thu Nov 14, 2019 2:21 pm

Uhh, yeah. I guess that didn't come out right, did it?

Hmm. "didn't come out right". That's kinda screwy too.

I guess I ought to avoid self-depricating humor altogether. Huh...

Or maybe avoid posting after a few beers?

Nah. What fun would that be? Beer Cheers

NEW222 Tue Nov 19, 2019 8:40 pm

Dave P. Can I bother you for a picture of your plane insides so I can see the aileron linkage that you used. I am at a point where I am ready to do something with the ailerons, and am having a hard time deciding what to do. Original style, or go individual servos in each wing. I just drilled the holes for the tubes, but they do not seem to want to bend as nicely as I would like. That is when I thought about dual servos. Thank you.

Dave P. Wed Nov 20, 2019 7:36 pm

Here's a picture of the airplane after removing twenty years of dust, bird squeeze and the hatch. I use Sullivan Gold-N-Cable with an EZ connector in the middle. Solder threaded couplers at the ends of the cable after installing the pushrod, servo and EZ connector.
These are the flex cables a lot of folks use for throttle linkages. This picture shows only the cable in place, no connectors or clevises. Sometime in the past beyond memory I must have removed and lost the original pushrod. I have no clue why.

I use a heat gun to bend the outer sheath into shape.

This picture shows how it looks with the sheaths installed. The application here is speed brakes on a nearly finished flying wing. For your ailerons, you would use a single cable and connector in a push-pull arrangement, like in the first picture.

The radius I have here is a lot tighter than needed for your ailerons. Some may tell you not to use cables for flight controls as they can flex under pressure. That's pretty much true if they are unsupported for more than a few inches, but they are really strong in a short run. The Stealth isn't fast enough to worry about cable flex.

This is the same kind of installation used on air brakes on a flying wing I built in '94.

.
This airplane flys at well over 100mph and the cables have never shown the slightest flex. This picture shows the air brakes deployed. This airplane has many hundreds of flights, most at very high speed and with abusive use of the brakes.

I'd recommend going with a single servo and a single cable pushrod. Keep it as light as possible.

I hope this is helpful. I'd be happy to help with more detail if you'd like.

NEW222 Wed Nov 20, 2019 8:03 pm

Yes, that helps some, thank you. First, I was going to try the cabels, but was worried and did not think they would be able to, or be strong enough to 'push' the ailerons. So, you have proven me wrong there, and I like it as I think they would be easier to install. Secondly, if I may ask, did you place your servos 'across' the fuselage? My plan shows one servo each mounted to one side of the fuselage running front and back. This is why I think I was having issues of making the ailerons work with one servo, but your placement looks better to me. If you like, I can email you my plans as reference to see if and where any changes are between your and mine. Thanks again.

Dave P. Wed Nov 20, 2019 8:55 pm

A real quick sketch of how I did mine. The innards are kinda beat up after a couple different radio installs and teaching my son how to crash a couple times.

The trick to using cables is to make sure the sheaths are securely anchored at both ends. Get it all installed and working correcly before covering.

Hope this sheds some light. If you'd like, I'll write up a step-by-step of how to install and trim the aileron servo, cable and sheaths.

NEW222 Tue Dec 03, 2019 6:15 pm

Well, I had been busy the last short while, and I did get some more work done on the Stealth. I did have a couple small rods that I used for the ailerons, so will be going the way it was designed. I also covered teh wings with doculam as I have an abundance of it, it is light, and it is strong. I will be sanding them and painting them along with the fuselage when it is all assembled. The only thing I was not sure of is whether or not to cut the tubes flush with the wing. But now after seeing your pictures, I think I should have done that as I see yours are. I was just worried about teh inner rod being stron enough on its own, then again, after seeing yours, it is only a 1/2a plane. So that will be the next step, followed by gluing the wings to the fuselage. I would like to have this done before the weekend, but I cannot promise.

Dave P. Tue Dec 03, 2019 7:01 pm

Looking good! If you're using metal cables, they're plenty stiff to cut the tubes flush. If you're using Gold'n Rods, the yellow plastic ones, make sure to insert the wire pushrod in past the point where the tube is anchored when the aileron is fully extended. Cutting the tube flush is fine if you do that.

What is Doculam? I'm not familiar with it but it looks really light.

Dave P. Tue Dec 03, 2019 8:27 pm

Wait a minute, Doculam is the stuff they use to laminate things like driver's licenses, right? How do you shrink it? A bit of time with a heat gun? How well does paint stick to it? Is it fuel and castor proof? Inquiring minds want to know...

NEW222 Tue Dec 03, 2019 9:04 pm

You're close. Doculam is the stuff used industrually. Used in bluprint shops and such, maps, etc. Much thinner than that of laminating pouches for licenses and such. Lighter than Monokote and the like as well. But with soem added benefits. Stronger, especially if you get the thicker stuff, but I have the low/mid weight stuff from what I remembered. Also, it will not sag and such like other plastic coverings in teh sun or such. Once it's on, it stays the same, nice and tight. It is truly fuelproof on its own in clear. Some have painted the glue side with floral spray paint, then applied and it is then colored. I, along with others also use a scuff pad on the outside good and then paint it with whatever you desire. I use rattle can paints, just like I do on other balsa planes. As for applying it, I just use my covering iron set as high as it goes. Doesn't burn through like other covering either, so holes are pretty hard to achieve, unless you really try!

If you have a drafting or blueprint firm nearby, you may want to ask if they have any and they may give you some, or buy some for cheap. If I am not mistaken, Staples or such may also have a machine with it as well if they laminate larger things. I was fortunate enough to find a printer/laminater dealer that also serviced machines. They had a partial roll on hand that had some damage and they offered it to me cheap as it was just sitting there. So, you may also want to search for laminating supply dealers/repair places as well should you decide to try it out.

This was just a quick search.

NEW222 Tue Dec 03, 2019 9:10 pm

I just did a search for 'doculam on rc planes' and lots of stuff popped up if you want to read some more on it. I have had nothing but good luck with it. The only thing is it does not go around curved surfaces/corners very nice. If I was going to worry about how it looked, I would just use a brand name film on the tips or such.

Dave P. Tue Dec 03, 2019 9:12 pm

Boy, I learn something new everyday. This Site Rocks!

I've got a blueprint shop nearby that prints plans for me. I will definitely ask them about it. Thanks!

Sponsored content

1/2a Stealth Sport RC Plane

1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

RE: 1/2A Steath RC plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane

Re: 1/2a Stealth Sport RC Plane