danamania

Bob, here is what I have in the Ice2 HV80 at maiden with the Advance :

cmoulder

Dana, after tomorrow (hopefully) and Sunday I will know more.

I'm a bit 'slow' at times, but it is gradually dawning upon me that without data we are simply throwing crap against the wall to see what sticks. Hence the irresistible compulsion to install the HV80.

It has gobs of power and looks quite robust in build. Seems that at least part of the explanation for its efficiency comes from the tight tolerance in construction. The space between the stators and the windings can't be more than about half the diameter of a human hair. I hope those bearings hold up!

danamania

danamania

If by data, you mean numbers, sure. But I cracked the throttle (no curve) and the Nuance was lifting into the air before I got half way. Wow I kept pushing the stick up, just in case, but the deed was done and the beast was airborne while I was still thinking about moving that stick up. Anecdote, yes, but that's some holy crap we are "Advancing" against the wall LOL. OT here, but the Nuance thread has some similar stories about this motor LOL. Forgive me, its my first Pletty and I am a bit giddy!

can773

My Feedback: (1)

Bob
Where is your cg now?

cmoulder

Center of the wing tube, which is 6-3/8" (162mm) from the LE at the root.

can773

My Feedback: (1)

Should be fine there, adjust stab to take any trim out and that should get it very close, that is where mine is, and I carry no pitch mix in knife and just a little roll at high rates for the F stuff.

cmoulder

I will try that. I have a tiny bit of up elevator trim which results in a bit more push than I am used to when inverted.

Tony Iannucelli

My Feedback: (193)

Very, very nice aircraft. What's the over-under on how long it will be before Hobby King is selling these? Saw it happen with the BD-5 and the GP Rifle.

can773

My Feedback: (1)

Hi Bob,

Generally I trim to get the KE as close to 0 coupling as possible, and adjust rates/expo to get the inverted feel I want.

cmoulder

I got to work on the throttle curve yesterday and it is MUCH better, utilizing the entire range now and smooth throughout with a little flat spot mid-stick RPM of 3700. That might be adjusted up or down once I actually fly it like this. Downloaded data logs were very encouraging with very modest. Amp draw at 6200 rpm. Even with a PT 20x15 current was only 71 amps.

danamania

Nice! If it is not too hot after work, I will take the Nuance/Advance out for a few more trim flights. Will actually be interesting to see the performance given the heat and that will give me ideas for a curve, or not. The basic airframe trim situation is very close, so I hope to form more of an impression about this new motor sooner rather than later. Actually, the coming heat wave is just the ticket to get the Advance set-up tuned before the next contests: I gotta find the silver lining somehow, LOL!

cmoulder

I put up about 10 flights Sunday with 90-95 deg temps and no issues with component overheating. Motor was a few degrees above ambient and the ESC log read a max of 141deg although upon landing it wasn't the slightest bit warm. I am, however, glad that I made the additional vents in the fuse belly because without them the vent intake/exhaust ratio would not have been much more than 1:1 instead of the preferred 1:2 or 1:3.

While installing the HV80 I took the opportunity to solder the motor and ESC wires and get rid of the connectors and a good bit of wire, and also move the ESC a few inches forward so that it is located under the motor, which helps with the CG when using lighter batteries. The LG fix is holding up well although at some point I hope to repair the fuse damage from the LG collapse. Kinda 'Band-Aid'ed' over for now and that's okay because it is purely cosmetic and not structural.

I added a touch of down elevator at idle (3%) but the KE on both sides was so close with no mix that it didn't make sense to try to tweak it in the blustery/bumpy wind. Plenty close for me as I am only flying AMA advanced... no P or F on my horizon for a long while yet, if ever!

can773

My Feedback: (1)

Hi Bob,

Were you having trouble with cooling? Or just added the outlet for your own comfort?

I have no additional outlets except the fuse sides, and was just flying down in Toronto in some very hot weather (~90-95F) without any troubles. Motor and batteries were fine, ESC was pretty warm but operated fine all weekend, so just curious if your setup requires more cooling.

cmoulder

Chad, I anticipated a possible cooling issue based upon intake:exhaust ratio.

Don't know if this would have been an issue, but there's an easy way to check - I'll tape over the additional exhaust vents and check the data log for ESC temps and check the motor and batteries as well.

can773

My Feedback: (1)

Hi Bob,

That would be an interesting experiment if you dont mind doing it I would very much like to know the results.

cmoulder

Will do! I won'tbe able to fly again until the AGS contest next weekend but will make it a point to do so.

Should be good and hot, therefore a valid test.

Jetdesign

My Feedback: (8)

There is nothing good about this. This is insane. I am not going outside. I don't even think I will go to work tomorrow, unless my AC breaks down, in which case I will be working overtime through next week.

The Caelestia is such a sweet looking airplane. I am looking forward to seeing some on Muncie. Hopefully I will not melt before then, and I will find some time to venture outside to practice.

VerneK

I'll take 100 degrees over snow any day.....

Verne

cmoulder

A lot of people feel this way, LOL!

Fortunately my personal temperature range is quite wide, so as long as it isn't raining and/or very windy I am happy... or happy enough. Nice thing about that is it opens up a lot more flyable dates!

cmoulder

Graph below from today. Seemed to make NO difference, so the additional outlets are not necessary, at least not for ESC cooling. I hoped to check the motor and batteries with an IR thermometer but the battery was dead. However, still to the touch they felt very much within normal range.

Ambient temp about 87degF. Max tem measured was 118degF and that was on one of the flights with the outlet open!

cmoulder

On a completely different tangent about a couple of important lessons learned, let me just say first I am somewhat lucky to still have the Caelestia in one piece!

Shortly after take-off in the third round at AGS the motor just stopped. I was very fortunate that I had enough altitude to circle back for an uneventful landing. It took a few minutes to identify the culprit, but it turned out to be a defective arming plug for the MPI AntiSpark arming plug.

I like the way the unit works, but the arming plug itself was the problem. It was one of a few spares I bought at the time I purchased the unit, because I could just imagine losing that small part and how that loss could really ruin a weekend. I have the APP contacts and housings and the crimper and could have made my own, but they were cheap enough that I simply ordered them.

It turned out that this particular plug had not been crimped adequately and there was no solder or anything else keeping the wire in place except a little friction, and with the lack of sufficient contact area the last few strands of wire were burned out with the arcing. As anybody who has used an APP crimper knows, this is not the way a proper crimp looks.

I am using the Dimension Engineering VHVBEC as primary power, but thankfully the LiPo battery back-up and Tech-Aero reg took up the slack. Without them, the Caelestia would have been history!

MTK

Bob,

I am finding out in my gas experiments that simply opening exhaust outlets doesn't mean much. One thing I am incorporating in Delta is ducted outlets....fluid dynamics will create a low pressure area around each outlet and literaly draw out the hot air. Inlet to outlet ratio of 1:1 works well in this type of set-up. Ill be posting photos in the Derivative thread

cmoulder

Matt, I would like to see how your ducting is designed for the Derivative (Delta?) and how the low pressure outlet works. I suspect that the recessed exhaust vents Chad designed into the Caelestia fuse work in this manner.

The ability to log accurate data while flying is fabulous, IMO. Now, we don't have to wait for a smoke trail or to draw inferences from temperature checks after landing or by checking battery state.

A lot of myths are being busted. This is one significant misconception that has been cleared up for me.

cmoulder

Photo of Ken Velez' Caelestia at the Paradise contest last weekend.

Ken has got the model dialed in pretty well to his liking and says he plans to get another as a back-up.