kkelly
Member
I hadn't thought of that. We tend to have windier conditions here (right next to the Rockies), so it could benefit from the additional weight.
My first balsa build in 30 years
- Thread starter kkelly
- Start date
kkelly
Member
Almost there! The servos arrived today, and I'm going to scavenge the rest of the electronics from a Simple Scout that's due for retirement. Shaping the nose turned out to be less anxiety-inducing than I expected. It still needs some details smoothed out, but overall I'm happy with how it looks. I've sanded most of the airframe. There's just a little work left to do on the wing and some tweaks to the wing saddle so it sits straight and then I can cover it. There are a few gaps and dings (oops) that need filling. Can I really use drywall mud on those like some have claimed or am I better off with a wood filler?
Speaking of covering, it looks like that market has changed dramatically since I last built a model. Back then Monokote was pretty much the only option, at least where I lived. Now there are almost too many choices. Can someone recommend a film that will provide some durability against a grass field without being too heavy? I think I'm going to go with the same color scheme as Stevens used in their photos (red with white trim) rather than trust my very poor visual design skills. If I cover everything with red and then put white film over top in places will the red bleed through? I thought I saw something about a film specifically for trim work that won't let the color underneath show, but now I can't find it.
I'm tempted to convert the wing to a screw mount. Am I asking for trouble if I do that?
FlyingTyger
Elite member
I recommend Hangar 9 Parklite covering. The heavier films like Monokote and Ultracote have more shrinking force and may warp this airframe. The chinakote coverings like Neucover have less shrinking force but are still heavier than the Parklite. The AeroLite that Stevensaero sells would be fine too, but its more than twice the price of Parklite. Mine was covered with white Parklite and I did find it fairly transparent. I would not recommend putting it over the red. On mine, I cut the stripes from sign shop vinyl. The little bit of weight there wont make much difference. Any stick on trim sheets or even the Cricut vinyls you can find at a craft store will work well.
I coverted mine to a bolt on wing using two 1/8" dowels at the leading edge and a pair of 4-40 bolts at the trailing edge.
kkelly
Member
That's the one concern that's making me hesitate on using a hard mount. I still occasionally have a rough landing that a drags on a wing. I'm probably better off sticking with rubber bands for now, and maybe by the next model build I'll be a good enough pilot that screws are safe.
kkelly
Member
It looks like Monokote is still the only thing anyone around me carries, so I'll have to order the covering. Fortunately lots of online shops carry Parklite.
CA hinges are turning out to be difficult to find. The local shop can't order them from any of their suppliers, and almost every online store that lists them is out of stock. Are they falling out of favor?
These came with the kit. I have no idea what they are.
CA hinges are turning out to be difficult to find. The local shop can't order them from any of their suppliers, and almost every online store that lists them is out of stock. Are they falling out of favor?
These came with the kit. I have no idea what they are.
FlyingTyger
Elite member
Yes. Thats exactly what they are for. Bend the pushrod into an L, then slide through the horn. Those will slid over the end and snap onto the shaft.
FlyingTyger
Elite member
You could always use the covering has a hinge. I believe that is what I did on mine.
kkelly
Member
Ah, I see. I hadn't noticed until now that the elevator and rudder pushrods in the kit had L bends and not Z bends on them like the aileron pushrods do. What's the benefit of using those clips over a Z bend?
kkelly
Member
I have done that before, but I wasn't happy with the results. If I had to go that route I'd probably just use tape like the plans suggest.
speedbirdted
Legendary member
It's much easier to remove the pushrod from the control horn if necessary. To remove a Z-bend from a control horn often necessitates detaching the control horn from whatever surface it lives on, and this is obviously not possible if it's glued in as is often the case.
If you have threaded clevises on the servo end it can also make adjusting them much easier. Often times reaching into a fuselage to undo a clevis from a servo is very cumbersome, so instead you can undo the connector on the control surface end, slip the pushrod out of the control horn and rotate it on that end to adjust the amount the pushrod is threaded into the clevis on the servo end.
kkelly
Member
I got a watt meter today and tested out my planned electronics setup. At full throttle on 3S with an 8" prop it peaked at 106W and just under 10A, so I have plenty of room to play around with different prop sizes while staying under the ESC's 30A limit.
The plane is running a bit on the heavy side, but I don't think it's going to be an issue. With electronics but without covering it's 529g. The plans say the average flying weight is 482g. 62g of the overage is attributable to the larger 3S 1300mAh battery I'm planning to use since I already have the power train for it. Parklite is 36g/m2, so at a guess I'd say it will add in the vicinity of 40g.
I found a local shop that carries Parklite, but they didn't have any red in stock so I'll have to order it. The guy there suggested I use Ultracote instead since I fly off grass, but I didn't want to risk the warping @FlyingTyger mentioned. Like almost everywhere else I've looked they had an empty spot on the wall where CA hinges would be. I picked up a pack of very light (< .25g each) nylon hinges on their recommendation, but I'm not sure I'll use them. There's one more local store I'm going to check with tomorrow. I did find these online: https://www.motionrc.com/products/b...0-pack?variant=31475130433649#description-tab, but they're on the small side and I'm concerned they may not have enough gripping surface inside the balsa.
All I have left to do at this point is a little more sanding, cover it, install the electronics, and then wait for the weather to cooperate so I can fly again. It's been a couple months since we had warm weather coupled with enough nice days in a row for the field to dry out.
The plane is running a bit on the heavy side, but I don't think it's going to be an issue. With electronics but without covering it's 529g. The plans say the average flying weight is 482g. 62g of the overage is attributable to the larger 3S 1300mAh battery I'm planning to use since I already have the power train for it. Parklite is 36g/m2, so at a guess I'd say it will add in the vicinity of 40g.
I found a local shop that carries Parklite, but they didn't have any red in stock so I'll have to order it. The guy there suggested I use Ultracote instead since I fly off grass, but I didn't want to risk the warping @FlyingTyger mentioned. Like almost everywhere else I've looked they had an empty spot on the wall where CA hinges would be. I picked up a pack of very light (< .25g each) nylon hinges on their recommendation, but I'm not sure I'll use them. There's one more local store I'm going to check with tomorrow. I did find these online: https://www.motionrc.com/products/b...0-pack?variant=31475130433649#description-tab, but they're on the small side and I'm concerned they may not have enough gripping surface inside the balsa.
All I have left to do at this point is a little more sanding, cover it, install the electronics, and then wait for the weather to cooperate so I can fly again. It's been a couple months since we had warm weather coupled with enough nice days in a row for the field to dry out.
speedbirdted
Legendary member
An AUW of 1.25 lb with a power output of 106W equates to 84.8 watts per pound which is quite acceptable for a trainer type plane. Though, you can probably increase the prop size and/or pitch maybe an inch or two to get some more wattage and thrust without running into problems with outstripping the ESC's maximum amperage output or burning up the motor.
Piotrsko
Master member
Go find yourself a tynar FEDEX envelope, they are kinda odd fabric looking meant for papers, but thry don't tear and CA glue into wood nicely. Put the hinge together, adjust to your heart's content, then apply CA thin. Only down side is ugly coloring FEDEX uses might be visible but that covers with your favorite sharpie ink.
kkelly
Member
I forgot about watts per pound (I'm learning a lot from everyone in this thread). I'll definitely try a larger or higher pitch prop if performance is an issue.
I think I know the material you're referring to. If I can't find CA hinges at the last place in town I'll seek out one of those envelopes.
TooJung2Die
Master member
@Piotrsko must've had a keyboard error. He's talking about Tyvek mailing envelopes you can get for free at FedEx and the post office. USPS Priority Mail envelopes are made from Tyvek, a non-woven synthetic cloth. It is my favorite CA hinge material. It is extremely tough stuff and impossible to tear. The Tyvek hinges will be nice and floppy, unlike the stiff commercial CA hinges. Tyvek wicks CA glue into the slot like magic.
The only downside is there is printing on the envelope but you can cut out the print-free areas. I never found a commercial CA hinge material that is superior to Tyvek.
kkelly
Member
About an hour before your post I found CA hinges on SIG's website and ordered a bunch. They call them "Easy Hinges", which I guess is why I couldn't find them earlier. A local shop that carries the same hinges and gets them straight from SIG can't get them right now, so I was surprised they were listed as in-stock. Maybe they're not and I'll get an email about it tomorrow. Either I'm about to have hinges for years or I'll get a Tyvek envelope.
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