Al's TDR Project

[ZuvieleTeile]

Originally Posted by CyprusFlyer

Mode TX% RX% RPM Pitch
Norm 30% 26% 1420 -3/+13 (Throttle 0 to 26% in first 25% of stick).
FM 1 30% 26% 1420 -13/+13 Linear
FM 2 58% 55% 1710 -13/+13 Linear
Hold Put about 15% in and did the AB switch when I programmed Mode 4, pitch linear same as last FM 1&2

As you can see there is 3-4% difference between TX and what Jlog tels me the ESC receives. I am not going to calibrate because its only a relative thing anyway.
You can see a dip on the graph, tested the auto bailout, worked very well. I obviously didnt let the blades stop! The ESC cannot measure RPM if its not providing power.

Well nothing flew off and killed the neighbors cat or made strange noises so no excuses not to fly then.

Would you mind posting one of your .lov files here? Possibly with all flight modes.

[CyprusFlyer]

OK, not many of interest, just HS calibration/ground running, but kept this one that I showed as a picture a few posts back. Just curious why the interest for you seasoned guys?
All flight modes just switch between the 2 HS for now.

[ZuvieleTeile]

Thanks for the file.
For some reason I can't open it in LogView.
Tried it with a different device setup (JLg-1) but still out of luck.

[CyprusFlyer]

Strange, new to these so may have cocked up or there is something ime not doing right. Here is the raw text file direct off the SD card then for import into LogView.

[ZuvieleTeile]

Got it running now. Thanks.

Looks good so far. Highest PWM was 85%, so there is plenty of headroom for the governor and some more head-speed too.
There is one bigger spike at around min. 3:40, where you pulled about 1200 Watts.
What did you do there? Having fun?

[CyprusFlyer]

Ah thanks, so checking the health of my system, thanks appreciate that. So, PWM Motor is Pulse Width Modulation for a switch mode type input for the power duty cycle?

BTW that power peak was caused testing the Auto Bailout, have to be VERY careful using that, purposely had the blades tight but it does kick. Shame you cant alter the fast spool up rate like you can with Castle ESC's.

Good to go for tomorrow, cant wait.

[CyprusFlyer]

TDR would not fit in the truck or car sideways, had to pull my finger out and sort something out for the weekend, just some bits of wood, bungee and hooks etc.
TDR is very tail heavy without batteries and blades folded back, wasnt happy hanging it all off the skids whilst moving so a bit of pipe insulation helped there.
Photos on Show you TDR photo thread, thats it, if the wind doesnt get up too much, fly tomorrow!

[ZuvieleTeile]

Nice setup in your truck there.

I always transport my TDR with batteries. Too tail-heavy and unstable otherwise.

You are correct in the PWM.
This is the "output" of the ESC.
As you can see, it does not correspond the the TX output.
At about 65 to 70% TX we have already 100% ESC/PWM.

Nice thing in the JLog is when you look at the PWM battery relationship.
You can see easily that the voltage goes down over the course of the flight and the PWM goes up to keep your programmed headspeed (if you fly on governor).
If the PWM is up to 100% for a big part of the flight, either through maneuvers or through declining battery voltage, then your gear ratio is not optimal.
It also depends of course on what headspeed you fly the most.
I like to fly around 1600 and my PWM never reaches 100%
If I go up to 1850 and do some hard flips or full pitch climbs, then PWM dips into 100%.
That's ok, as long as it does not do it for a longer period of time.

The health of the system setup can also be seen at 'Temp PA", that's the internal temperature of the ESC. Should be below 100 degrees at all times.

[CyprusFlyer]

Thanks that makes perfect sense, will monitor for a while and check the parameters, I like the analysis bit, easy to spot things that otherwise might miss.. Did the same with the Castle stuff to work out a safe flight time, will have to keep it simple for tomorrow, just go for 6 mins and see what the packs end up on although expect 9 - 10 mins is viable at low HS taking it easy with 4.5A packs.

Truck worked out well, just have to work out where to lash the generator etc and yes decided to transport the TDR with a fully charged pack, ready to go.

Just got hold of some silicon grease from a diver friend (O Ring grease), so grease her up for tomorrow.
Completed a random bolt test for tightness, checked all links wiring, Vbar setup again and pitch V Tx curves, tail blades and Gyro sense blah blah. BTW that Pure Silicon Grease used by divers is great, "Tenacious" indeed, in fact like s*** to a blanket lol.

Another snippet, the top battery plate I bought with the lower did not work out, however,it fits perfectly as a battery plate for Logo 500/600, sticks out enough to get the CoG correct, lucky or what!

A few beers and early night then maiden flight tomorrow

[Groucho_]

Originally Posted by CyprusFlyer

Just got hold of some silicon grease from a diver friend (O Ring grease), so grease her up for tomorrow.

You were supposed to use that silicon grease on the four O-Rings in the head...

[CyprusFlyer]

Yes you are correct, used some other silicon grease for that, this stuff looks good for the gears too.
Cant remember who, someone else mentioned they used it too for lubing the gears, this stuff I can get down at the bay locally at the Scuba shop.

[Groucho_]

I have a tub that I bought in 1997 for the O-Rings in my scuba gear. That's 1997 not 2007. It just never empties...

[CyprusFlyer]

That the Maiden flight then, went absolutely perfect, spooled up, increased collective, into an almost hands free hover, tail working perfectly and flew around for a while great, unbelievably stable what a machine, some photos below.

But.....Joined the "Lets do something stupid and wreck the TDR" club
Second flight, started the same, some flips rolls gentle stuff, then I lost it! Went into a banked turn that was obviously too far and low, only one mistake in the bank and I made two. Lost orientation for a second and pushed in the wrong correction, I relive the moment but alas no time machine, just very angry with myself.

Lessons learned, respect the speed and keep within a height distance line of at least 30 degrees, this heli can cover a lot of sky so needs accounting for. Mybe I am not quite ready for it yet so need to take it easier.

Damage assessed and not alarming at all:
Blades of course including Tail
Main shaft gear stripped
Canopy skuff and small crack, pealed of decals using hot water, easily repaired touched up and new decals.
Most of the ball links gave up and saved the servos.
1 skid plate and 1 bent skid.
1 Flybar link guide
1 lower side frame

Cost about 170 Euros + Main blades - expensive day out - telling the wife dismantling for fun!

Boom survived without a scratch, surprised, I went in almost knife edge, blades took it then skided along the canopy so a glancing blow, expect the canopy flexed like hell and saved a lot.

Stripped the head and mechanics, nothing bent at all, all servos check under stress, full travel, no apparent damage. Very lucky I think, into this again since January, lots of flights on my 550 but first crash had to be this one, just a setback, parts ordered, back in the air soon

PS blame Groucho, saying all was smooth here lol

[DT75]

That's too bad. I feel sorry for you.


I would advice you to excange the main shaft while you're at it, just as a precaution.

It is a cheap "insurance", imo.

[CyprusFlyer]

Yes agree, ordered it and feathering shaft with end bolts, cant be too careful.

[ZuvieleTeile]

Same here.

I had the same problem in the beginning of TDR flying.
This lady covers a lot of sky very quickly.
This is really a point where I had to get used to.
She just speeds silently away . . .

[Groucho_]

I'm actually really quite upset after reading of your misfortune...

It all sounded so promising before you said 'But'...

Could I maybe suggest you give some thought to installing an SK-720?

Things may turn out differently next time something like this is about to happen with the SK-720 helping out...

[CyprusFlyer]

Lol, just after that did occur to me, self leveling, however, shouldnt have been so stupid but thanks, very happy with it despite the setback, playing to an audience was probably a factor too! (Jan does warn about that).
Boom didnt escape after all, stripped it and creased slightly where it clamps in the frames, luckily managed to get the TT and bearings out smoothly. Have a spare so no problem.
Boom and skids rebuilt, spare gear bolted on, another week for the parts and rewind to square one :-)

[Mercuriell]

Words can't express the frustration I feel for you after such careful build and set up - well they can but I can't type them on a PG-13 forum !!!

My fave helis - all 700es have all had mishaps on the first few flights - almost like a christening and gone on from strength to strength after

[CyprusFlyer]

Thanks John and all for the support, appreciated.
A few beers last night got me over the "trauma" and off to fly the 550
Order for parts is off and total cost with blades is about 300 Euros, so thats a 10% hit, not that bad really, main shaft bearings not 100% so ordered them too.

Canopy to touch up, suppose I need a small amount of GF/resin, body filler and spray paint, decals with the spares, not one of my better skills, its all black so hopefully easier.

Pleased that it did fly straight off and nicely and there was not a technical problem, in fact married up Jlog and Vbar logs, found the flight from reset to "Aileron sensor out of range" etc, nothing to worry about.

So we can fix the Heli and do something about Dumb thumbs to fly another day.

I talked about the "Bath tub Curve" in one thread, higher probability of technical failure at the start and end of life. Obviously applies at the start to flying skills then. Take it extra easy for a while.

But thanks again.