ART Hobby Glider pick help...

[RobertTHaas]

i was looking at the art hobby glider website and i am very impressed with some of their designs/prices.. i usually design my own stuff but i want something i can fly around and not get crushed if it breaks.. so im stuck between 2 gliders. SKY-V 2M and BOAR 2M.. which one do you guys like..? is the SD7080 a better airfoil for thermaling..? i want something i can high start and just thermal.

http://www.arthobby.com/shop.html

[fly1milehi]

I have the JK Thermik with the HN1033 airfoil and I would take the SD7080 over that one so my vote would be the Sky and probably in the cross tail not the vtail
greg

[Freakflyin]

I chose the Serenity for just that purpose... it's light and versatile.

Mike

[ptglass]

Question - Are the aerilions already cut out on these models? Just looking at the pictures, I can't tell.

[OhioPete]

If they are built the same as my Hybrid DLG then no, you have to cut them out. There is an extra section of balsa imbedded in the wing foam under the sheeting that matches up to where you cut the ailerons out. This way you have a nice hinge point.

[Freakflyin]

I believe that all the Art Hobby planes require you cut them out. It was easy using a metal straight edge and a very sharp knife and saw.

[screamin' eagle]

You have to cut ailerons/flaps on all the arthobby planes. It's very easy to do with a #11 xacto knife. When I was a noob builder it scared me but it's really quite simple.

[ptglass]

I'm sure it's not all that difficult, but most ARF's already have them cut out and all you have to do is hinge them. I would be a little worried I might make a mistake and trash a wing!

[RobertTHaas]

will the sky glider kit or any art hobby kit handle the winch ok? are the wings strong enough?

[Batmanwpg]

will the sky glider kit or any art hobby kit handle the winch ok? are the wings strong enough?

I have a Boar.
I haven't winched mine but I do launch it off a 3M Hose Monster HiStart and can only see a slight bend in the wings on a hard launch.
They should take a medium winch launch but you will have to glass the centre joint with a couple of layers of glass. I used three layers of glass all of different length and all tapered with the peak of the taper at the airfoil high point. The last layer of glass is a .6 oz finishing cloth. These spar-less wings are actually pretty strong. The SD7080 may give you a stronger wing being it is thicker than the HN1033. The fuse has to be re-enforced also. Sand the inside of the fuse first before assembly to remove the gloss surface. I have one heavy layer of glass on the inside from just in front of where the wing sits to about 1" past the TE of the wing. The fuse is weak in the area underneath the wing saddle. You'll also need that re-enforced to keep the tow hook from ripping out.
Throw the tail in the garbage. They are too thin and cause dead banding. Replace them with thicker wood that has a Drela tail airfoil carved in.
As far as flying, I like the Boar. It will thermal well and has good run speed. I did a few other mod's as well to make it better.

[kkw]

will the sky glider kit or any art hobby kit handle the winch ok? are the wings strong enough?
I have the Blejzyk range here in Australia. They are very similar, Blejzyk having manufactured for Art Hobby for a time, but he builds stronger (and better in my opinion) models. We have a 2m span comp running in Australia, and around 85% of the competitors are all flying the First. These gliders are launched F3J style on single and reflex hand tow. Also get winch launched regularly. I have seen them break 150lb line on launch, but have never seen one even come close to breaking on launch. I have seen a few Art Hobby Boars here, but they are definately not as strongly manufactured. They have also been strongly reinforced with glass or carbon at the wing join. The First has no extra reinforcing required at all - anywhere. The wings don't flex at all, or not visibly at any rate. If you get an Art Hobby kit, then I suggest that you just watch what happens on launch, and go stronger from there. I am sure that they will handle a bungee/high start launch o.k.

[vol-haut]

Question - Are the aerilions already cut out on these models? Just looking at the pictures, I can't tell.

Art Hobby tried supplying the wings with the ailerons cut but they found that the aileron pieces arrived at the customer's door warped out of shape. The epoxy in the wing is actually still gaining strength after it has left the factory. This combined with changing humidity makes it impossible for Art Hobby to cut the ailerons at the factory. It's actually a good idea to have the kit sit around the house a few weeks before cutting out the ailerons.

[ptglass]

Thanks for the info - I never would have thought of that.

[fly1milehi]

warping ailerons because the epoxy isnt cured???

I cant imagine that the epoxy is still gaining any bond strength after its been manufactured and shipped to the united states there is no way that it is still curing. Epoxy is a chemical reaction and once it has bonded and hardened its done doing that.

I would suspect that if pre-cut ArtHobby ailerons were warping in shipping/transit that its a humidity issue because the wing skins are still raw wood, ie., not sealed to keep moisture out. The expoxy essentially seals the wood on the side it is applied to so the unfinished side is free to take on or release moisture and expand or contract.

[vol-haut]

warping ailerons because the epoxy isnt cured???

I cant imagine that the epoxy is still gaining any bond strength after its been manufactured and shipped to the united states there is no way that it is still curing. Epoxy is a chemical reaction and once it has bonded and hardened its done doing that.


Call Andre and argue with him.

[OhioPete]

I don't know the specific cause but I had a warping problem with one of the ailerons on my Hybrid. No matter what I do I can't seem to get all the twist out. It's minimal now but still noticeable. Haven't flown the plane yet so I don't know the affect it'll have on the flight performance.

[Forest Flyer]

Aileron Warping

I’ve built several Art Hobby gliders and I have been pleased with each. I need a sheeted wing that can withstand the rough conditions in my airfield, and Art Hobby wings fit that bill. However, aileron warping after cut-out has happened many times. My impression is that there are certain stresses in the wing that unload in a “warping” way in the ailerons when they are cut out of the wing.

My approach has been to cut-out the ailerons and let them sit for a few days - it is the first thing I do with a kit. Once they stabilize (if they warp), I “un-warp” them back into shape by suspending them at the both ends and placing a weight in the middle. It takes a surprising amount of weight and several hours to do the unwarping, since the ailerons are quite strong. Once the ailerons are slightly warped the other way (they always bounce back a bit), I put them aside to assess their stability. If they re-warp a bit, I repeat the procedure until they are stable and in the right shape. I have not had them re-warp after reaching final stability.

This length of this (very simple) procedure is why I cut-out the ailerons right way, so I have the time to reshape them if they warp. BTW, there was minimal warping (if any) in the ailerons of the Thermic (Castor) wing that I just built. I should also note that the wings themselves are rock solid in holding their shape.

FF

[Forest Flyer]

is the SD7080 a better airfoil for thermaling..? i want something i can high start and just thermal.

Robert,

I’ve mentioned this elsewhere, so I’ll just paste it in below. I hope it helps.

.... As for the HN 1033 vs. the SD 7080 airfoils, I have an Andromeda (a Boar-E) with each of them. Both are pretty good thermaling wings. However, the HN 1033 is clearly a thinner and thus faster wing, and as a result it is the better choice for windier conditions. The SD 7080 wing can really slow down for thermaling in light lift, and it can carry weight a bit better than the HN 1033. The SD 7080 might not be the best choice for a very light plane ... not sure about that, but I can say that an Andromeda at 24.5 oz with the SD 7080 wing is a great thermaler, but not with a wind much above 10 mph (under windier conditions - say 12 - 16 mph - it does well with a larger battery pack that brings it up to 29 oz). I have also flown the HN 1033 wing down to about 25.5 oz, and its performance is also pretty darn good in a light plane. It might be the best overall wing for you.

FF

[RobertTHaas]

how do the art hobby wings handle winch launch, or do they need to be modified for that?

[Forest Flyer]

how do the art hobby wings handle winch launch, or do they need to be modified for that?
Don’t know, as I fly only electrics. That question has, however, came-up on another forum recently, and there was no definitive answer (but it was not the main topic of the thread). In any case, the fiberglassed wing joint is quite strong, and I have put my planes through some pretty rough aerobatics without any problems whatsoever. A strong winch launch is another matter, though.

Maybe someone else here can be of some help.

FF

[screamin' eagle]

I have also been struggling with the 7080 vs. 1033 question on the ArtHobby planes. I primarily fly slope, and need an electric 2m or so plane as a slope lift tester/light wind sloper/thermaler/slermaler. I have owned two ArtHobby Falcos with the HN1033 on the slope and have loved their performance.

The model I really want now is the Sky-E, 1.7 M, but I want the HN1033 instead of the SD7080 unless there is an issue with the increased wing loading from the electric motor and gear. I think the HN1033 will be better for my application.

What do you folks think?

[Forest Flyer]

The model I really want now is the Sky-E, 1.7 M, but I want the HN1033 instead of the SD7080 unless there is an issue with the increased wing loading from the electric motor and gear. I think the HN1033 will be better for my application.

Is there a 1.7 M version of the HN1033 wing? I may have misundertood you on your other thread, where I got the impression that you might be going for a 2M wing. In any case, as far as I know, the HN1033 airfoil comes in only in the 1.5M, 2M and 2.5M wings.

FF