ameyam

Hi,

about to assemble a Aeroworks Yak 120 for 3d. I know there is a forum for that but it doesn't answer one question- how do the 120ax, dle20, dle30 and turnigy 26hp-s 26cc stack up for this airplane for 3d? Can someone advice?

Ameyam

speedracerntrixie

My Feedback: (29)

The best performing engine you could install would be a YS 115.

ameyam

I have these engines with me but no YZ. I would prefer to go gas now because its very expensive to run synthetic glow fuel in the larger sizes

Ameyam

ahicks

My Feedback: (2)

I'd go with a DLE 20, knowing full well it's going to have limited 3D capabilities. It's too heavy. And if you'r considering going 30cc, it will totally overwhelm the airframe from a power perspective, and still leave you with wing loading too high for 3D.

Fun to fly plane? Yes. 3D? Not in my opinion. -Al

speedracerntrixie

My Feedback: (29)

Al, couldn't agree with you more. The YS is the most expensive to buy and operate however is the lightest power plant for that size airplane and the most powerful. The guys using the 115 for pylon are spinning a 14x14 a tad higher then 10K. For 3D work it would easily spin an 18x8.

ahicks

My Feedback: (2)

SR, I think this is more about the weight/design of that plane? Not sure the 115 is going to be a lot of help? What does it weigh? To help this plane out, it would need to be significantly lighter the the DLE 20 - which is at something close to 29oz. all up? If not, he's spent much more money - and it's still going to be overweight/shy of wing area when considering 3D work? -Al

ameyam

Actually my bigger problem is the length of the engine. I believe the distance from the front of the cowl to the firewall is about 145mm whereas the dle30 is 162mm. The dle20 will fit correct but I dont think its got the grunt. Plus they said it will not be able to get the required CG

I believe they said on the forum its best to keep the airplane under 10lbs which is 4.2Kg. I was thinking about the OS GT22 as well but that one is 998g and the dle30 is 1090g which seems counter productive. Unless you feel the GT22 is more suitable...

I have a spe 26 available for purchase as well but the local response I got regarding the engine was not very good. Its 1050g, so in the same range.

Or should I build the airplane and then select the engine based on what gives me the recommended CG?

Should I bite the bullet and put the 120ax in?

Ameyam

ahicks

My Feedback: (2)

Ameyam, that plane is going to be over 11lbs with a DLE 30 up front. Mine was closer to 11.5lbs (if my memory serves me correctly), though I'm pretty sure I could get it a little lighter using lessons learned since building that one. The 20 should come in around 10.5lbs.

Regarding balance, not sure what "they" tried when trying to balance the plane with a 20 on it? I haven't done it, but my bet is that it IS possible? Rudder and elevator servo placement, tail vs. midship using pull/pull, along with battery placement, generally will balance about anything like this?

Keep in mind when comparing glow vs. gas the size of the fuel tanks are easily doubled when using glow, and the glow tank needs to be very close to the engine? This affects CG when looking at take off vs. landing weights (take off nose heavy, land tail heavy?). -Al

ameyam

Hi,

you need to pass on those "lessons"

meantime, about getting it to lose weight, do you think CF is in ordeer?

For the engine, I am going to test and see. If nothing, atleast I can expect it to be a crisp flier?

And, should I be looking at the GT22 at all?

Ameyam

kerwin50

I put my DLE 20 in a 68 inch Goldwing Yak.
It had an OS 120 in it.
The DLE 20 gave it more power, but I still find for 3D flight I need to swing a bigger prop.
I am thinking about a DLE 30 for it.
I have a DLE 30 in a GW MX.
It flies so much nicer.
I'd go with a DLE 30

Tony Iannucelli

My Feedback: (193)

A 30 is a lot of engine for that airframe. Don't forget the vibration. What good is 'saving some money' if it all ends up in a trash bag and/or destroys your servos. The YS will vibrate too, but they are wonderful engines. The 120 AX would be an excellent choice; low vibes, great power, easy handling. Good luck with whatever you choose. I've seen three of them at the field, and they all fly great with those different power systems.

ameyam

The dle20 I have swings a 18x6. But I think what everyone refers is that the midrange rpm is lower than the 120ax, hence the thrust in the hover.

Couple of years ago I and a friend imported a couple of cartons of klotz 100. It was not available locally and we both had reliability issues with plain castor. Premix fuel was also not available then (its available now- Rapicon). He used up his when he put his 120 on the GW Sbach 20cc (Same airplane as Kerwin's, just newer). After he crashed his airplane from a deadstick out of hover, he moved to 30cc. I, on the other hand developed back problems and was out of the hobby for a year. Now I still have 4 or so bottles of klotz and I can always get more if I need. So no harm in going for the 120 if its reliable enough.

Ok. What I am going to do is, decide on the engine as I go along. Then if I have reliability or CG problems, I will retrofit the dle30 if it comes to that

Ameyam

kerwin50

On my GW Yak my buddy had a OS 120AX on it swinging a 16/8 prop. When I bought it from him I put my DLE 20 on it. With the DLE 20 swinging an APC 17/6 prop she out performed the OS in all aspects. There was no way the OS could pull this plane out of a hover like the DLE 20.
The OS will not swing an 18/6. My DLE 20 will though it seems to be the happiest with a 17 inch prop.

ameyam

Actually, the GW is a much lighter airfreme

I actually selected to open up the Phoenix Yak over the AW for now. Simply because it was in a paper box, so more moisture effected. Its heavier than the AW & smaller at 66". So a dle20 is in consideration. If the turnigy 26 comes by then, I will use it. They tell me its about the same as the dle

Ameyam