CHAWKJIM

What should this DA 100 idle at and what should its RPM be at full throttle ? Is a two blade prop better than three blade prop? Should I use CARBON FIBER or wood prop?

MikeEast

My Feedback: (3)

Roughly with a 26x10 prop it will idle at about 1700 RPMS give or take, and it should max out at 6500-6700 RPMs. That is just based on my personal experience with the engine here at sea level. It will idle lower than that, but I see no need to tempt fate in the air.

Wood props are fine. If its well broken in it will turn a 27x10 or 28x10. If its new try a 26x10.

fancman

My Feedback: (16)

Looks like you're in over your head. [] Why not call DA and ask the mfg. [X(]

Tired Old Man

My Feedback: (1)

The best idle rpm is the one where the plane does not roll on a paved surface at low throttle. That's correct for the plane/engine/prop combination. Everything else is influenced by the propeller used and it's size. As to what the prop is made of, it doesn't matter as long as it's a well made propeller and will stand up to the engine load.

Hooked-On-RC

My Feedback: (16)

RPM's can be misleading too. Depending on several issues such as the altitude you fly at (flying field distance above sea level) the prop size you are using, the mufflers or canisters you are using, the engine tuning, fuel you are using as well as oil you are mixing, how well the engine is broken in etc etc. If there is one thing I have learned about these forums over the years, everyone reports "incredible" numbers when it comes to a planes weight and it's full out RPM.

By that I mean, you could have two different guys with the exact same plane (ARF wise that is) with the exact same on board equipment, set up exactly the same way, same batteries, same serovs, same engine, spinner, everything the same, identical planes for all intensive purposes and one guys plane will be 3 pounds lighter than the other guys...Plane weights and RPM's are like fishing stories...

nitro wing

My Feedback: (1)

I can see that.usually because people use unreliable scales and tachs.
As Pat said,an rpm,where the engine is not racing or pulling away at idle on the ground is ideal.
I have never used a tach,but somehow all my engines run stronger than other peoples,have reliable low idles,rarely need tuning and last for many years.With some use,one can read an engine and get them tuned to max performance without any gadgets.
Once you run the engine and fly it for a bit,you will become acustomed to the way it sounds and reacts.The DA 100 is a reliable engine.
It should respond well to fine tuning and staying that way.
A 3 blade is considered less efficient than a 2 blade,and 3 blade Carbon will usually cut down noise level somewhat.

Taildragger726

Hi Jim, Are you "up and running again"? I was asking about you at the field today.
I will be glad to meet up with ya and put the tach on my DA 100. It works pretty well. Using a Vess 27B.
PM me.

CHAWKJIM

I felt good enough to start my plane today. I'm not suppose to pick up anything more than a gal of milk. I just finished my comp arf 260 extra. I have not flown her yet. Few more days. Here is a picture of her.

yarom

My Feedback: (82)

As written above here, idle is where you feel it is right for you, yet reliable enough to sustain.

DA indicate you need to use a 27x10 during break-in, with 1:32 Ashless Lawnboy, or equivalent.

After the engine is broken in, you can mount a 28x10, with 1:50 and up synthetic oil (I use 1:80 Amsoil).

CF Props are almost always better than wood prop in terms of performance, but way more expensive. I've had good experience with XOAR and NX wood props, yet I prefer PT Model or Mejzlik CF props, which I find more to my liking in terms of overall power band.

MikeEast

My Feedback: (3)

DA recommended a Vess 26B for break in when I got my last new DA fall of last year.

Aerobat

My Feedback: (6)

Mine idles at about 1300, maxes out at about 6500 with a Mez 27x10.

Tired Old Man

My Feedback: (1)

One thing great about a DA. It's an engine in any of their sizes that anyone can successfully run with a minimum of effort. Those that understand engine tuning and are willing to experiment with different props for their airframe and flying styles will obtain a lot more performance than those who don't, but all will have a reliable engine that provides good power.

PiccoLino

Even though this thread is old enough to likely make my comment useless, I'd like to say that the stories you recalled about the weight and RPM are definitely a fact but with some exceptions. I myself experienced quite the opposite in a few occasions. For instance in two identical ARF boxes (H9 33% Edge 540), even by the colour scheme, that my friend and I bought from the same hobby shop at the same time, we found in the wing tubes only a weight difference of 175 gr (~ 0.4 lb). Similarly I have found that the wood density is not consistent, both plywood and balsa. Have you ever watched those videos where you can spot the wood stock area of the ARF assembling factories in Southeast Asia?

For the idle (I own a DA 100 myself), by a three positions switch in my radio I have set it for the following different conditions: 1 - flying (1,650); 2 - landing in zero wind (1,450); 3 - landing into some 8 knots and above wind (1800).