Wing Teardown and Modifications for the Rockhopper - Episode 6

[@JeffGillis1]

Ian, you sir, are a Rockstar! Your dad is too. Your attitude to just get after it and do whatever needs to be done is Super Inspiring. Your videos capture the Spirit of home built aircraft, innovation, creativity, verve and fearlessness.

[@ianslife210]

Thanks Jeff, we try!

[@scotabot7826]

Yes, I agree with everything you said, but I also know from experience that the "fearlessness" portion of the excitement can get you into deep deep doodoo before you know it, and in some cases it has been bad, real real bad! There is a super amount of solid engineering that must be done, and things figured out, or it;s one big crap shoot!!!!

[@scotabot7826]

Super Glad to see you wised up and pulled all the covering off. It would have not been smart at all to try and save any of that covering, for a multitude of reasons!!!!!! Now you can see what you have, and what your doing, and have a properly covered wing when you are done.

[@matthewmoilanen787]

Just like my son, talking while the old man is moving along on the project ha ha. No seriously, I was a Master ASE and a Crew Chief in the Air Force so actually when there's some cutting to do we both feel better with the old man on the tools so don't feel bad. I'm sure he probably enjoys it as much as you!

[@pappybo49]

Excellent video. Good instruction along with informative videography. Keep it up, you’re doing fine. I love the new rib design.

[@jarenbelrose1552]

I just picked up a heavy hauler. This is a great video. Do you have a follow up showing the completed work and what you think of the changes?

[@Skypics234]

Just some info for you as you redesign my Avid. 1st you are correct that the resins can handle ethanol. However, the tans are 14 gallons each...not 10. You are correct about the under chamber , however the aircraft was designed for slow stall and by the way the stalls are nothing more than a bobble at about 35 MPH with flaps. Yes there is a huge increase in parasitic drag at 100 plus. That said, at 10,00 MSL my cruise was 110 MP TAS. The flaperons were used on many German planes in WW2 and worked well for them. Kitfox still uses them and with 32 foot wingspan they cruise at 125 MPH with the flat bottom wing. Most likely the loose rib to spar contact was caused when I hit a cement barrier that took out the left gear. The Avid started with a Rotax 582 and then was changed to the Jabiru 2200. I flew it for many hundreds of hours and enjoy every one. Good luck on your project. I currently fly an Avid MK4 with the 14 gallon tanks and under chamber wing with flaperons. I fly back country strips and this Avid fulfills that mission with stalls at 38 MPH, cruise at 97 MPH TAS at 75% power and burning 3.0 GPH down low and 2.6 up high leaned out. John M

[@Skypics234]

I miss printed. Tanks can't take ethanol. That said, you may find it hard to get auto gas at airports on trips. So you could have used avgas and you would have 28 gallons. On 234cv I could fly 10 hours with Jabiru power. However, the bladder only lasts 3 hours. I'm only 5 8 and the leg room was barely adequate for me. Glad to see you moved the seat bulkhead back for more room. When I totaled 234cv I had a Avid MK4 in two weeks. It does have more room, but not enough for you. Also, you can't have big feet or your toes hit the firewall crossbar. Great to see my trusty Avid evolving.

[@sthomas1018]

Great video! I feel like I learn something new every time I watch.

[@goldknight40]

Thanks for these videos. I just picked up a Merlin GT used kit and planed on making many of the same changes you mention. ( Flaperons ) Cant wait to see how you change over to Flap and Alerons

[@ianslife210]

I looked at one of those not too long ago! Interesting aircraft. Hey address many of he fuselage concerns I have in their interpretation.

[@deep6thisdeep6this92]

excellent video! clear explanations. am pondering a completely amateurish question... why rebuild the salvaged wings rather than just build them from scratch? the modifications appear to be very significant. for instance, the wing ribs (i'm so ignorant i don't even know for sure, what they are called) appear to have no surface, neither all of the top or any of the bottom, nor the leading nor trailing edge, that you wish to have. modifying all of them would appear to constitute a product with multiple pieces and necessitate more work, with a possibly less dependable structure, than building them from scratch. anyway, i'm enjoying your videos and am looking forward to watching more.

[@ianslife210]

That's a question I have considered myself on a number of occasions. At the end of the day the rockhopper is supposed to be a budget build and starting from scratch would add (yet another) additional cost to the project. New spars, new spar attach fittings, more wood for ribs, it all adds up. The flip side of that is the question of if I get a lot better product for my money... something I'm still not absolutely sure of. For the moment I am moving forward with the plan to rebuild these wings but if at any point I decide that the end result is not coming out as I like then I will drop back and look again at building new wings from scratch.

[@jimchuk8511]

Could have probably sold the wings and flaperons for $2500 or more. I got that much for a set of covered A model wings without tanks. That would have bought all the parts for new wings. To late now....Keep at it though, it will be interesting to see how it all works out. Jim

[@alanewald9209]

I agree dont do this it's almost as bad as that guy who built a home depot airplane and used an electrical box for a joystick gimbal. When you're done you wont want to fly this. You just fucked up a couple good wings. Building a wing can be done for what you would have gotten out of that and you can add slats and whatever else you want. Please dont kill yourself man.... People care about you.

[@midnight-studios]

What can you tell me about the two aluminum tube spars? What type of aluminum..thickness? Thanks so much!

[@deeeeeds]

I've said this before (as I work my way through this series) but the CAD stuff is just the most interesting thing to me. Do you have any resources for where you can learn about airfoil designs? I've tried digging in before but the knowledge is... thick.

[@ianslife210]

The problem with understanding airfoils is that mine is based on decades of competing and designing model aircraft. That gives me an innate ability to judge what changes to an airfoil will do to its stall performance. Sadly that’s hard to turn into easy to digest knowledge.

[@brianphillips7235]

I really like this build

[@FeoCustomWorks]

Hey. Can you share the blueprints for this plane? Please.

[@outlawflyer7868]

ok,very cool video and i am deeply interested as to see how this is all gonna come out. what I want to know is how were you going to make the new modifications to the spars with the old covering that you planned on keeping in the first place? Oh and let your pops know to always wear a mask around any kind of dust! What kind of aircraft is this?

[@ianslife210]

There was not going to be any spar modifications other than inspection per my original plans so I didn’t plan to pull the covering but my airfoil changes forced my hand and it all came off. Thanks for the warning about dust! He largely stayed out of the cloud but he did edge in closer than I would have liked while I was focused on working. The plane is a modified avid B. If you watch my first video in the series you’ll see how this all started.

[@dmitrytoushe4533]

Maybe I don’t understand something, but why didn’t you just use CFRP to print a new wing on a 3D printer?

[@rizwanrafeek3811]

If you have to tear down the wing this much, isn't is easy to build new from scratch?

[@daisybeagle6259]

Reynolds number dude, Reynolds number!

[@ianslife210]

I wish I was better at turning the numbers on airfoil charts into real world data but I’m not so I rely on my instincts. Those instincts designed several competition winning model aircraft however so I’m fairly comfortable with my choices.

[@LightAndSportyGuy]

A wire wheel in a high speed angle grinder will make unwanted fiberglass go away very quickly.

[@PDZ1122]

I hope you have some engineering understanding. No, I don't mean fabrication, I mean engineering. Your new tanks, for example will take the place of the drag struts - have you done any calculations on if they will buckle under fore and aft loads? You're really opening a can of worms. Does your new airfoil have a significantly different center of pressure at either low or high angles of attack? I could go on.

[@scotabot7826]

I have been wondering these kind of things myself. We are not dealing with a radio controlled model that will be flying with the pilot standing on the ground. I hope he has at least called the aircraft kit manufacture and asked a few questions! I pray he understands the can of worms he's opening up. I certainly don't mean for my comments to be taken as a attack or "trolling", as these are very serious things that must be addressed!!!

[@WerewolfSS1]

Hey Ian, Loving your videos but wanted to chime in. You may wish to reconsider doing metal tanks in the wings. Kitfox's and Avid's originally came with aluminum tanks. But it was found because the tank is bonded to the wing its part of the structure. Twisting of the wing over time will lead to stress cracks and eventually fuel leaks. This is why they went to fiberglass tanks as the fiberglass tolerates the stress of twisting as it has a bit more give. You can read up about this on the Team Kitfox forum or the Avid Flyer forum. Would hate to see you do all this work and have to go back in and redo it a few years down the road.

[@ianslife210]

I’ve seen a few aluminum tank birds with various methods to avoid that problem but ironically I’m already considering fiberglass tanks to make my mounting easier so this is just one more reason. Thanks for the suggestions!

[@tenlittleindians]

Since your changing the leading edge shape anyway, now would be a good time to consider the pop out slats used on the Just aircraft. It may even end up less work just to adapt their system rather than starting from scratch. Here's a link to a video that shows these slats: kzbin.info/www/bejne/qZSmgqWHa8R_rpY

[@ianslife210]

I’m not a big fan of the pop out slats actually. I’ve spoken extensively with Steve Henry who is a just aircraft dealer (Wild West aircraft) and he prefers the highlander to the super stol in no small part because of the pop out slats. I will be including mounting points for fixed slats or a cuff so I can play with airfoil addons later but noting “active”.

[@jhaedtler]

So your just bolting on a set of Cub Wings! That would have been easier!

[@ianslife210]

Closer to rans wings than cub and I did actually go look for a set of s6 or s7 wings but I was unable to find any.

[@mdjuwelstudent9101]

ধন্যবাদ

[@edwinkania5286]

You did not rip apart your KitFox!??!!!

[@ianslife210]

Oh no! This is a different plane. Check out the first video in the series and I tell the story of getting this one.

[@JeffGillis1]

Hi Ian, I checked your "about" profile on KZbin and you've not listed an email. so I will field these questions here. I'm interested in connecting with anyone with aerodynamics mathematical skills who would be interested in running some numbers. My hope is that this triggers your interest and this exploration, albeit academically, will be of some mutual benefit to you and your community here. Here is my thesis, our wing ( fill in the measurements of your will and use that) needs to be modified to be an advanced airfoil that is both able to fly super slow to maximize STOL characteristics, yet @ elevation needs the ability to fly FAST. My personal goals are to create a wing mod that can land with a stall speed 160 knots. This is a topic I've been pondering for some time. Your removal of the fabric from your wing and subsequent modification was most inspiring, as you knew from experience that the current airfoil was not what you wanted so you brilliantly used that wing as a foundation for a newly adapted airfoil that both gave you the performance you were seeking but also would exceed the current wings 100mph limitations. This inspired me to write this. Mod 1 concept: split self-expanding leading edge; So I really like the split self-expanding leading edge that can be seen on a Just Air Super STOL, as the leading edge naturally pulls in tight at speed, yet in slower application extends out to transform them the shape of the wing to leverage a more aggressive airfoil for extreme STOL circumstances. I really like this and wish Just Air offered it as a kit. Mod 2 concept: Performance "Fowler" style flaps In Alaska, it is not uncommon to hear the term "Fowler flaps". These basically extend out when deployed to an array of preset, ideal setting as well as an extreme full flaps extension that propagates landing in

[@ianslife210]

Jeff, I have a decent set of opinions about wing design and what you’re looking to do but I’d have to discuss your platform further before I could really offer an opinion. I tell you what, send me an email at [e-mail] and we can talk about it further.

[@JeffGillis1]

@@ianslife210 Cool, I will email you, my friend.

[@travisw9071]

I would think at this point fully re cover with orotex. Ha yup you just ripped it all off

[@travisw9071]

What size tubing are the spars? 6061 T6?

[@travisw9071]

Also fyi your new airfoil looks a lot like my minimax

[@alanewald9209]

I think your rib design will be weak. If you fly this the way you say you will build it please make sure to film the first flight I wanna see what happens🙃🙃🙃

[@ianslife210]

If you’re concerned about the butt joints on the ribs don’t worry, they will be fiberglass reinforced across the joints for strength.

[@alanewald9209]

That sounds like alot of wieght now... I really do like your videos keep it up though. Not enough people putting out ideas like this

[@ianslife210]

We’ll see how it weighs out but I think I can keep it light. Time will tell!