So I've been building an ultralight

[danny_galaga]

This has taken away virtually all my gaming time, including C64 projects I had going.

But if I ever finish this thing, it will make for some fun aerial 'road trips' 

[wp34]

That's really cool Danny.  I've always been fascinated with Ultralites as well.  Keep us posted on your progress.

[danny_galaga]

Yeah like I say I've been fascinated with ultralights since I was about 15. Longer really, because I loved the movie 'Those magnificent men in their flying machines' and at least one of those aircraft (Demoiselle) would now be considered an ultralight.

The Bushcat is not like the ultralights I used to dream of but it will be a hell of a lot more practical

[pbj]

I used to see a guy flying around in a go kart strapped to a parachute.  Looked fun.

Do they make an ultra lite that can fly with a 400lb passenger?

[danny_galaga]

Yes and no. If this 400lb person learns to fly they can fly in a Bushcat with a 75lb passenger

[Howard_Casto]

What if we only put one butt cheek in the seat?   

[whammoed]

Very exciting and ambitious.  I see one issue though.  That garage is too clean.

[DaOld Man]

Good side project there Danny_galaga. Looks like it will be a lot of fun.

[danny_galaga]

Good side project there Danny_galaga. Looks like it will be a lot of fun.

It will be fun when it's finished 

I really haven't enjoyed building it as much as I thought I would. Right now being the exception, because I am working on the control panel, err instrument panel 

[Howard_Casto]

You are using airplane grade screws and stuff aren't you?  We'd prefer it if you don't die. 

[danny_galaga]

I'm using what's supplied in the kit. The most critical bits are aircraft grade and the rest is whatever. For instance the brakes are from Matco who have been making aircraft parts for maybe 100 years. But the choke lever is a bicycle gear shifter.

Anyway, I'll put a four leaf clover in it somewhere. What could go wrong 

[pbj]

Have you flown it yet?

 I think about this project from time to time, and what I’d do in case of a malfunction.  I suppose panic just enough to make it look like I half heartedly cared whether or not it crashed. 

I’m hopeful this isn’t a suicidal mission in slow motion....

 

[nitrogen_widget]

He's amongst the big boys now

https://dannygalaga.blogspot.com/2020/08/21-big-move.html?m=0

Damn.
You built an airplane faster than I tiled my shower.

[bobbyb13]

He's amongst the big boys now

https://dannygalaga.blogspot.com/2020/08/21-big-move.html?m=0

Damn.
You built an airplane faster than I tiled my shower.

The girls just asked me what I'm laughing so hard about.

This project is awesome.
There is a small airstrip 3 miles down the road from me and I see a lot of small airtraffic as a result.

Really looks fun!

[danny_galaga]

Have you flown it yet?

 I think about this project from time to time, and what I’d do in case of a malfunction.  I suppose panic just enough to make it look like I half heartedly cared whether or not it crashed. 

I’m hopeful this isn’t a suicidal mission in slow motion....

 

 

The main things that would give me the willies is a structural malfunction. Engine failure is not so bad. I read a good article once about what to do in unusual situations (engine failure is pretty straight forward) like what if the ailerons got stuck while you were rolling. Sharper people than me have gotten out of situations where I'd just think 'oh, well. This is how it ends'...

[Vocalitus]

Looks like a nice project.

Just don't end up like James Horner.

[danny_galaga]

Looks like a nice project.

Just don't end up like James Horner.

Had to look that up. He was flying a pretty powerful aircraft. Power is not a thing I'm going to have to wrestle with in my ultralight 

[Grasshopper]

Danny, I realise this might sound silly, but can you fly?

[Stingray]

You rule, Dan.

[danny_galaga]

Danny, I realise this might sound silly, but can you fly?

I believe I can fly 

[danny_galaga]

Still working on it 

[Vocalitus]

Still working on it 

Still working on what? - lets see some progress pictures.

I hear horse glue is better than goat glue so use that on the wings.

[danny_galaga]

Well I put the hinges on the sub door frames. So there's that.. Also starting to think about buying the engine now. Just as well because I've been saving rubber bands but I think it would be a PITA to wind up

[bobbyb13]

What exactly do you put in one of these for an engine anyway?

I would imagine you won't get enough altitude to have major issues with oxygen percentages...
Or will you?

Now I'm thinking about it, what type/octane fuel (assuming no need for a turbocharger-)

I love this project

[Vocalitus]

Well I put the hinges on the sub door frames. So there's that.. Also starting to think about buying the engine now. Just as well because I've been saving rubber bands but I think it would be a PITA to wind up

Electric engines perhaps?

https://aerospace.honeywell.com/us/en/learn/products/electric-power

[danny_galaga]

There are now some electric options, And a company named Pipistrel actually sell electric aircraft, but it's all way beyond my price range. And the range is not enough since we plan on doing a bit of touring in this thing if I ever finish it.

Most popular engine for ultralights now (as opposed to microlights, which are smaller and are what ultralights were in the 80's) is the Rotax 912. It's about 1.2 litres. 100 HP. Twin carb or fuel injected. You can also get a turbo charged version. But why make it more complicated. Bobby, most ultralights are capable of going over ten thousand feet. But the licence I converted to actually restricts ME to ten thousand 😄 highest I've ever flown was 8000, which was easy. But low and slow is more fun 😎

[bobbyb13]

Gets chilly at 10k ft I bet!

Thanks for sharing this project here.

Stoked to learn some about this stuff through your efforts!

[danny_galaga]

Fitting windscreen and left door. Damn hard to see out that screen though 

[danny_galaga]

What exactly do you put in one of these for an engine anyway?

I would imagine you won't get enough altitude to have major issues with oxygen percentages...
Or will you?

Now I'm thinking about it, what type/octane fuel (assuming no need for a turbocharger-)

I love this project

Picked up last weekend. It's from the plane I hire to keep my skills up. Which is cool because it means I have 15-20 hours on this engine already 🙂

[bobbyb13]

Very cool.
Looks remarkably like an old Beetle engine!

And if this came out of the plane you were flying previously... what happened to THAT plane then...?!

[danny_galaga]

Funny story 😄

There were two planes at the place I hire from. This engine's hours were nearly up. The engine in the other plane had a lot longer to go. But THAT plane was damaged in a rough landing. Airframe was written off but engine was fine. Hire aircraft engines can't go over 2000 hours. But private can. These Rotax engines are good for over 4000 hours. So I get the engine that was nearly ready to be replaced, and the hire plane I was flying continues on with the lower hours engine

The funny story continues though. They 'borrowed' back my carbies because the butterfly valve shaft in the other engine got bent in the rough landing. So today I hired the plane and I'm STILL flying it with bits of the engine inow own 😄

[nitrogen_widget]

so what is the difference between and plane engine and say an engine used for a ground vehicle?
i've got a 20HP engine in a lawn tractor.
I don't think you can put it in an airplane.

intake and exhaust manifolds along with carbs are different i assume?

[danny_galaga]

You could definitely put that engine in a small ultralight. How reliable it would be is a different matter. Rotax got into the aircraft game because in the 80's when ultralights we're still a new thing people were using whatever they could get their hands on. From go kart motors to largechsinsaw engines. Rotax made two strokes for snow mobiles etc which turned out to be a good match.

People often say 'that motors not very powerful, my car engine would be much better'. But there are several really important differences that make car engines not as useful as it would first seem. First of all, propellers are most efficient at around 2500 rpm. So a lot of plane engines are designed to develop power around that speed. Rotax design their engines more like a car engine, and then add a reduction gearbox, roughly 2:1. Propellers might be more efficient around 2500 rpm, but it turns out petrol engines are most efficient around 5000rpm.

The other major thing a car engine spends most of its time at a fairly low power setting. To drive on the highway might take 20 per cent of its power for instance. But an airplane might be cruising at maybe 75-85 per cent power, ALL DAY. Not just that, on smaller aircraft especially, on take off you are using 100 per cent power until you level out. That could be five minutes. Imagine a drag race that was five minutes long!

To illustrate how seemingly under rated an aircraft motor seems, I learnt to fly in a Piper Warrior. I think from memory it had a Lycoming 0320 in it. That's pretty close in capacity to a Chevy 327. But the Lycoming only developed 150hp, AND only 4 cylinders! Like I say though, it could run all day near the top of its range.

[RandyT]

You could definitely put that engine in a small ultralight. How reliable it would be is a different matter. Rotax got into the aircraft game because in the 80's when ultralights we're still a new thing people were using whatever they could get their hands on. From go kart motors to largechsinsaw engines. Rotax made two strokes for snow mobiles etc which turned out to be a good match.

Not sure if it's true, but I also heard that some Rotax engines were shown to be so reliable that they were actually approved by the FAA for ultralight use.  I had a couple of rough looking sleds I planned to fix up which had good running Rotax engines.  When I decided that I didn't like cold, I seriously considered pulling and selling just the motors because, to the right person, they were worth more than the sleds. 

So, has anyone heard of someone crazy enough to use one of the HF Predator 20hp 2-cyl engines in an ultralight?  Being a Honda clone, they are surprisingly decent.  But you wouldn't catch me leaving the ground with one.  I think geared-down 2-strokes would be better.  Not much to talk about on the low-end, but when they get up into their power band, they can be insane relative to size and weight.  I had a 2-stroke, 3-cyl Kawasaki bike in my younger days, that I wish I kept.  Then again, if I did, I might not still be here to talk about it

[nitrogen_widget]

You could definitely put that engine in a small ultralight. How reliable it would be is a different matter. Rotax got into the aircraft game because in the 80's when ultralights we're still a new thing people were using whatever they could get their hands on. From go kart motors to largechsinsaw engines. Rotax made two strokes for snow mobiles etc which turned out to be a good match.

People often say 'that motors not very powerful, my car engine would be much better'. But there are several really important differences that make car engines not as useful as it would first seem. First of all, propellers are most efficient at around 2500 rpm. So a lot of plane engines are designed to develop power around that speed. Rotax design their engines more like a car engine, and then add a reduction gearbox, roughly 2:1. Propellers might be more efficient around 2500 rpm, but it turns out petrol engines are most efficient around 5000rpm.

The other major thing a car engine spends most of its time at a fairly low power setting. To drive on the highway might take 20 per cent of its power for instance. But an airplane might be cruising at maybe 75-85 per cent power, ALL DAY. Not just that, on smaller aircraft especially, on take off you are using 100 per cent power until you level out. That could be five minutes. Imagine a drag race that was five minutes long!

To illustrate how seemingly under rated an aircraft motor seems, I learnt to fly in a Piper Warrior. I think from memory it had a Lycoming 0320 in it. That's pretty close in capacity to a Chevy 327. But the Lycoming only developed 150hp, AND only 4 cylinders! Like I say though, it could run all day near the top of its range.

running all day is probably top of the list of things you want your personal aircraft to do.

[danny_galaga]

You could definitely put that engine in a small ultralight. How reliable it would be is a different matter. Rotax got into the aircraft game because in the 80's when ultralights we're still a new thing people were using whatever they could get their hands on. From go kart motors to largechsinsaw engines. Rotax made two strokes for snow mobiles etc which turned out to be a good match.

Not sure if it's true, but I also heard that some Rotax engines were shown to be so reliable that they were actually approved by the FAA for ultralight use.  I had a couple of rough looking sleds I planned to fix up which had good running Rotax engines.  When I decided that I didn't like cold, I seriously considered pulling and selling just the motors because, to the right person, they were worth more than the sleds. 

So, has anyone heard of someone crazy enough to use one of the HF Predator 20hp 2-cyl engines in an ultralight?  Being a Honda clone, they are surprisingly decent.  But you wouldn't catch me leaving the ground with one.  I think geared-down 2-strokes would be better.  Not much to talk about on the low-end, but when they get up into their power band, they can be insane relative to size and weight.  I had a 2-stroke, 3-cyl Kawasaki bike in my younger days, that I wish I kept.  Then again, if I did, I might not still be here to talk about it

Because it's in a different class of rules, I'm pretty sure the FAA have nothing to say about choice of engine. In fact, Rotax stopped making their 2 stroke airplane motors recently, which always had the disclaimer that they didn't meet regulations and it was up to you what you did with it.

I think the rules are simpler for ultralights because you can't cause as much havoc in an accident and also to encourage new ideas.

Just had a look at that Predator engine. That would work well in a microlight for sure. I think the class in the USA is called Part 103. You might use a belt drive to reduce the propeller speed 🙂

https://www.eaa.org/eaa/aviation-interests/ultralights/getting-started-in-ultralight-flying/about-faa-part-103-for-ultralights

[RandyT]

I think the rules are simpler for ultralights because you can't cause as much havoc in an accident and also to encourage new ideas.

Just had a look at that Predator engine. That would work well in a microlight for sure. I think the class in the USA is called Part 103. You might use a belt drive to reduce the propeller speed 🙂

https://www.eaa.org/eaa/aviation-interests/ultralights/getting-started-in-ultralight-flying/about-faa-part-103-for-ultralights

I guess so!  There's more rules for flying a $50 drone than an ultralight 

[danny_galaga]

I think the rules are simpler for ultralights because you can't cause as much havoc in an accident and also to encourage new ideas.

Just had a look at that Predator engine. That would work well in a microlight for sure. I think the class in the USA is called Part 103. You might use a belt drive to reduce the propeller speed 🙂

https://www.eaa.org/eaa/aviation-interests/ultralights/getting-started-in-ultralight-flying/about-faa-part-103-for-ultralights

I guess so!  There's more rules for flying a $50 drone than an ultralight 

Yep, for part 103 microlights you don't even need a licence 😲

There's no such category in Australia, so to fly that same microlight here needs and ultralight licence, which is similar to GA (general aviation) but with some restrictions- only one passenger, much lower weight, no aerobatics or night flying etc.

[danny_galaga]

The 'control panel' is nearly done 🙂

[pbj]

If you crash and die can I have your didgeridoo?