DA85 on pipe! Results please.

[sprice50]

DBcaster - any tach results?

[dbcaster]

PAU 27 3Db prop 6400 rpm.

[sprice50]

Wow DB, that's great! I actually tached 6350 on a 27B Vess vs 6450 on the Mej 28x10 first time out which was surprising, so you should get around 6500 on the 28x10 Mej. My pullout was a lot better with the Mej and spoolup was same. Hovering has a little more gyroscopic effect with the Mej. The Mej is way quieter than the Vess.

[dbcaster]

That sounds good. I am not sure how the PAU compares to the Vess but the prop works very well. It is definately not quiet though. I had to send my 85 in due to the fact that the base gasket is leaking from all four sides already. This is my second 85 and my second one with the base gasket leak. I sure hope they figure it out soon because pulling the engines off after each gallon is a real pain.

[sprice50]

DB - strange about the base gasket. How bad a leak are we talking here? I don;t think mine has any issues.

[dbcaster]

Bad enough that I cannot even tune it. If yours isn't leaking, it sounds like you are one of the lucky ones so far.

[sprice50]

Yes, I have never had a problem. I'm glad about that! Haven't bothered with needles sine first run. Seems strange to me that a gasket would leak. What causes something like that?

[Henna_Ojisan]

I've been really lucky so far too - I do have a slight film but nothing that is affecting the tune.

My buddy has not been as fortunate and has sent his back to DA- seems it's not happening to all of them.

[dbcaster]

Here is thread with more info. Da 85 base gasket ooooooze
It has been said that only some of them are leaking. Unfortunately both of mine do.

[Henna_Ojisan]

Alright gents - as promised, I installed my Eagle Tree Logger and was able to grab some in flight data. I have the magnetic pickup sensor affixed to the ignition sensor and I'm using the hall sensor magnet as the source for my logger. I also have a thermistor between the 3rd and 4th fin on the cylinder head. I have the logger in line after my batt-share before the rcvr and servos. Works great for picking up mAH per flight as well as for tracking servo current draw.

I've got a couple graphs below and can display a wide array of data - let me know if you are interested in something and I'll see what I can do.

Summary of data:
** 88 Deg day, 40% Humidity, ~750' above sea level. Mixed IMAC and 3D.

- 6625 RPM on Mej 28x10 on ground
- 7246 RPM in flight (same prop - unloads ~600 RPM)
- Max CHT - 245 deg F. (extended hover and dropped to 190 once on the wing)
- Avg CHT - 175 deg F.
- Max current - 9.5 Amps (Servos - 6-5955's, 1-8711, 1-5965, 1-225MG)
- Avg current - 1.15 Amps

[3D-Seth]

I got the chance to run a DA 85 on a Grieve pipe (broken in), with a Mejzlik 27x10 on 89 octane gas @ 100:1 Amsoil. Tached it on the ground at 6440 RPM. Pretty ballistic if you ask me. It really shows in the air too.

Seth

[3D-Seth]

Great info Henna! Thanks for sharing!