Project Bush Demon

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

Arkan

Well-Known Member
Joined
Jun 6, 2021
Messages
72
Ty for the chart. I will make my wife run the math, I just had a flash back from high school algebra class.... lol

I knew going into this I was going to have to do a lot of math... that was the part I was not looking forward too....
 

Arkan

Well-Known Member
Joined
Jun 6, 2021
Messages
72
Okay been giving thought to the power plant... originally I was thinking a Rotax 915si but have I countered a cheaper option. Yamaha Apex... c company called SKY TRAX makes a gear reduction box for this engine, but if you add a turbo to this set, your talking over 200 hp...

My concerns are Duribility. That is a high RPM engine, at cruise I understand it is running 6000 rpm. I know those motors are made for snow mobile and motor cycles... but maintaining 6k has to be hard on it.
 

Voidhawk9

Well-Known Member
HBA Supporter
Joined
Mar 26, 2012
Messages
581
Location
Timaru, NZ
Yamaha Apex... c company called SKY TRAX makes a gear reduction box for this engine, but if you add a turbo to this set, your talking over 200 hp...
Yes, but only briefly. Last I checked even the 300hp model was rated for only 160hp continuous.
 

Arkan

Well-Known Member
Joined
Jun 6, 2021
Messages
72
Still, there is something to be said for modern auto, motorcycle, and even race tech in experimental aircraft. Viking aircraft enriched uses Honda four cylinder engines, fuel injection, turbos, and such and makes a quality product for kit planes.

for home builders on a budget, looking into alternative eninges, like the Yamaha apex, or a Viking like modification on a small four or v six aluminum block auto engine, is worth looking into, the advantage of reduced cost and ease of access to parts makes it an attractive option.

At higher altitudes, where is thinner, NOS can be used, to maintain performance. I am not talking about a power shot, but a metered or controlled release to offset the lack of oxygen.

I am really looking at cheaper alternatives for a power plant for this design. Does anyone have suggestions?
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
14,958
Location
Memphis, TN
My opinion is no engine is cheap.

If you go a different way than the crowd, you generally have to pay with personal talent to fix issues. If you go with the crowd, you pay running price.

Expectations. What do you expect to do and how do you handle it? Watching Trent Palmer’s YouTube and he has blown engine and borrowed one to get home. Friend of his had a spare flown in to fix out in the middle of nowhere.

A VW flyer has different expectations than a 0-360 one does. It’s a realism question, not what’s cool. WW 1 engine’s life is about 50 hours. They were usually shot down way before. A regular airplane engine is trouble free for 1500-2000 hours from fresh as long as it doesn’t sit around. Sitting kills engines. I think the VW guys are in the 800-1000 range for a good one. Yamaha Apex, an intriguing I don’t know. Experimental can mean same as certified in reliability or it can mean Ginny Pig suit tailored to fit.
 

ToddK

Well-Known Member
HBA Supporter
Joined
Jan 13, 2016
Messages
487
Location
Shweaty Texas
Life is short. Learn to fly now. Even if you can’t get a medical. Learn to fly because ultralights are a blast. Your life will be greatly enriched much more by hanging with buddies at the airport, flying and living. You will also learn what you like about airplanes in terms of configuration, performance, and handling.
 

Arkan

Well-Known Member
Joined
Jun 6, 2021
Messages
72
My opinion is no engine is cheap.

If you go a different way than the crowd, you generally have to pay with personal talent to fix issues. If you go with the crowd, you pay running price.

Expectations. What do you expect to do and how do you handle it? Watching Trent Palmer’s YouTube and he has blown engine and borrowed one to get home. Friend of his had a spare flown in to fix out in the middle of nowhere.

A VW flyer has different expectations than a 0-360 one does. It’s a realism question, not what’s cool. WW 1 engine’s life is about 50 hours. They were usually shot down way before. A regular airplane engine is trouble free for 1500-2000 hours from fresh as long as it doesn’t sit around. Sitting kills engines. I think the VW guys are in the 800-1000 range for a good one. Yamaha Apex, an intriguing I don’t know. Experimental can mean same as certified in reliability or it can mean Ginny Pig suit tailored to fit.
Your right, there is no cheap engine. Like everything else in aircraft design, it is a trade off. Going different from the crowd can be a good thing though, Viking aircraft engines uses 2020/2021 Honda auto engines. You need a part, it is at the local auto part store, with say a rotax, you order it and wait for it to be shipped over seas.

The standard Piston Aircraft engines is air cooled, but yet even my lawn mowed now days is water cooled, all automotive engines are water cooled, even Harley is moving to water cooled engines. Other than saving weight, is there a reason aircraft engines have not moved in this direction? Honestly, I have a theory on this, aircraft engine builders don't make the quantities of engine as say the automotive industry. The R&D budget has to be limited, not only this but the machining tools, milling machines, and such are limited to the type of engine they have been building. Switching to water cooled engines would require a wholly different set, walking into a factory and changing everything and they are going to sell what, 1000 or 2000 a year? It would take a long time to recoup that expense.

And yes I watch Trent Palmer as well. The engine he lost was a Roxtax, and I think the buddy of his who had the extra engine flown out to him was flying Rotax as well. Another video I watched someone had one cylinder go out and it had to be replaced on a hilltop. Honestly, as someone who has never flown, that's my biggest fear, is losing an engine and no place to land... and as for the VW powered planes, no thank you..... I owned VW Beatles in HIgh School, I had three... as much as I know the engines and how to work on them I would never trust them in the air. They were too fickle in the cars, let alone in the air.


Life is short. Learn to fly now. Even if you can’t get a medical. Learn to fly because ultralights are a blast. Your life will be greatly enriched much more by hanging with buddies at the airport, flying and living. You will also learn what you like about airplanes in terms of configuration, performance, and handling.
On my to do list, I want to learn, but it takes a lot of money, flight instructors are not cheap and aircraft rental is even more expensive. Private pilot requires at least 40 hours in the air under instruction. That's the minimum, on average it takes 60 to 70. If I could, I would go all the way and get my commercial ticket. Funding it on my salary, just is not possible. Desire and willingness can only take you so far.

So, I want to learn, getting in a position where I can afford it is my goal.
 

TFF

Well-Known Member
Joined
Apr 28, 2010
Messages
14,958
Location
Memphis, TN
Unless you have a buddy, training in your own homebuilt is probably not going to happen. Most CFIs are on career tracks to be airline pilots and blemishes to their record are avoided. Flying an unknown homebuilt is a risk to their future.

Spending $150 once a month for an hour of flying gets you in the game and after about 10 or so lessons you will have a handle on what is expected flying wise.

Don’t start adding up money. It is a spending hobby. Some days I can buy and sometimes I can’t, but I don’t track spending. You will never go far if you do because even if someone gave you a plane and gave you instruction, you will spend a lot of money.

Getting into flying is not like buying a fishing boat or buying a collector car, it’s running a race team. Money goes out and value only goes down. You have to like the fun more than that.
 

ToddK

Well-Known Member
HBA Supporter
Joined
Jan 13, 2016
Messages
487
Location
Shweaty Texas
Also, trust me on this. After putting 1000 plus hours in on your build, you are not going to risk wrecking it as a student pilot. All you really need to do is get to solo. At that point you have sufficient skills to not kill yourself. And you can fly locally solo, and chop away at your training as you can afford to. That could happen in 10-20 hrs.
 

rbarnes

Well-Known Member
Joined
Aug 28, 2015
Messages
401
Location
Texas
Engine alternative: Yamaha APEX snow mobile engine with skytrax gear box

I think you guys are missing the point. ..... I came up with this idea of designing a plane as a form of mental gymnastics.
Get this book
Yes it is worth $130. It will answer pretty much every question you can think of right now.
 

pylon500

Well-Known Member
Joined
Dec 26, 2003
Messages
383
Location
Taree Airport Australia
Just having a quick read through, and I think we all started with the dreams you have.
Then depending on our circumstances, and with a little exposure, we start to find which direction best suits us, and work towards that goal.
That said, those of us that have 'got there', can look back and see how things could have been a little more straight forward and thus easier.
I was a modeller, designed and built my own (kits were expensive in my day), worked my way up through hang gliders to sailplanes and got stuck in (Australian) ultralights.
I never went into GA, too expensive and couldn't see the point. Not practical for travelling (weather, cost, end point mobility), actually figured out that if you want to go less than 300 miles=drive there, if you want to go further=buy a ticket.
That is not to say I don't mind the idea of flying a light aircraft/ultralight all over the country as I do that for the challenge, and make sure I've got the time for it to go wrong.
End result, I've got over 4,000 hours (in 40 years) as an ultralight instructor, have built a few of my own designs (and flown 92! other types in my time), and can see I'll probably run out of time before finishing all my thought of projects, but I'll try to use this background to offer my unprompted suggestion to where I feel your flying need would most effectively drive you and say;
Go and buy a second hand 912ULS powered Kitfox, and find someone to teach you how to fly it.
The Kitfox is not the hard and fast ultimate choice, there are others of it's ilk such as Avids, Heinz STOLs or Savanahs and the like.
The truth is, watching the Mike Patey or Trent Palmer youtubes are a con. EXTREMELY few people spend all their time flying out to 100 foot long sandbars just to try and wreck their airplanes.
Most are happy to just fly around the patch and go over and visit the next airport on a good day. To most of the weekend 'fun' flyers (in LSA and ultralights), a 100 mile trip, and back, is an ordeal.
Getting something easy, cheap and common is usually the best way to 'get a foot in the door', and you tend to find that used aircraft that have lost all their 'showroom' value, can be bought and then resold later for almost the same price, so you've only paid for your flying, and had the exposure to better determine which way you REALLY want to go...
And sure, if you want to build something (that's why we're here after all), then you can still do that while you're learning to fly, and maintaining proficiency for when you get your dream project finished.
OK, time for me to get back to my turbo Yamaha powered, all metal, retractable military replica project, which I hope flies and handles as well as my Foxbat, just a bit faster. 😎
 

Arkan

Well-Known Member
Joined
Jun 6, 2021
Messages
72
I am working on a design for the mental exercise. Keeps my mind busy so I don't stress too much on other issues. I don't have the money for flight lessons, let alone buying build materials... but anyone can draws lines or even a plane, making it correct, adding control detail, dementions, figuring lift, designing the plane around the proper CG, and doing so with a desired performance in mind. That takes time, that keeps a mind working out the problems. I am using the forum for a sounding board, a way to express thoughts or even figure out solutions.

I am not building a plane, if I had the money to do so I would spend it on flying lessons and airplane rentals. Around here to get a CFI runs 150 an hour and the plane is usually 200 an hour. Least that what I have found, there is one school, (Summit) and thier prices are the same.

I hate to say it, but aviation is an expensive hobby. I do not see me being able to afford to get a pilots license, and if I did, I would be lucky to be able to afford to fly once a year. So please, let's keep the discussion to design. If I ever get my license, and somehow can afford to build a plane, it won't be a STOL. No place around here to use one, now if I lived some where it could be utilized, then yeah. If I had a license, and could afford any plane, I would get one I could fly about 700 or 800 miles in so I could spend time with my Son, it is a 13 hour drive to see him, so other than video chats and phone calls, I only get to be with him a few times a year. So back to designing....
 

Victor Bravo

Well-Known Member
HBA Supporter
Joined
Jul 30, 2014
Messages
9,201
Location
KWHP, Los Angeles CA, USA
Arkan, if you would not buy or build a STOL airplane (in post # 35 above) then what is the purpose of designing Project Bush Demon as your mental exercise... as opposed to Project Acro Demon, or Project XC Demon, or project Cargo Demon, or project Pylon Demon?
 

Arkan

Well-Known Member
Joined
Jun 6, 2021
Messages
72
Arkan, if you would not buy or build a STOL airplane (in post # 35 above) then what is the purpose of designing Project Bush Demon as your mental exercise... as opposed to Project Acro Demon, or Project XC Demon, or project Cargo Demon, or project Pylon Demon?
because it is a challenge. In RC' s I have designed and built fast planes, acrobatic 3D flyers, piper and Cessna look alikes, and delta wings. Problem with RC building is this, I can take any rc plane, slap a larger motor on it, increase the control surfaces, and make it fly. Hell I took a flat piece of square foam board, added vertical uprights, cut in Eleverons, glued a wooden motor mount and a quad motor and flew it. The principals of flight are the same, weather your flying RC or real planes, but rc materials are so light, with a bad design, you add enough power and you can still make it work.

STOL planes I felt would challenge me, stimulate my problem solving skills, and make me think outside of the box. Also, I would love to live somewhere that a STOL would be a practical choice, but here where I live, no they would not be. Since I don't have a pilots license, and don't have the funds to build a plane, why not design something that is challenging, something I respect, and take the enjoyment and mental challenge.

VB, you have a lot of knowledge, and are the argumentative type of person I like, you make people think. Just remember though, a persons motivations to do anything are their own, I don't mind answering, but the a-hole biker in me almost answered "because I want to....". Nothing but respect for you, and please keep challenging me to think, that is my purpose on here, and with the design I am working on. Just remember we all have free choice, and why someone is doing something Ike this is their own reason, don't question their motives, question the the design, question the technical aspects, but don't question why..... when I am finished with this design, my goal is to have a set of plans I could hand to anyone, and they would be able to build one hell of a STOL plane. Maybe if I could win the lottery, I could build it one day. Who knows what the further holds,

So, here lately I have been giving some thought to how to deploy the leading edge slats. I was thinking on use of a torsion arm and an electric actuator, just deployed and stowed? Any thoughts?
 
Top