flyinwalenda

My Feedback: (5)

http://www.rcuniverse.com/forum/fb.asp?m=11354686

flyinwalenda

My Feedback: (5)

I got the engine back today. They received it on 5/20 , worked on it 5/29 and completed it 6/3. They stated the crank pin deterorated and that also damaged the roller bearing .They also said the piston and liner was a bit scored but said that was probably due to a lean run. They rebuilt the engine in lieu of replacing it due to no stock on complete engines. So everything but the case, carb and head was replaced. They also said it ran good after break-in but I can't believe they ran over a gallon of fuel through it to break it in . Maybe they did.
I don't agree with the lean run because I was always erring on the side of rich even from the break-in and I received a few comments about running it rich.
I will reinstall it and see how it performs.

flyinwalenda

My Feedback: (5)

I got the engine remounted and I took a closer look at it.  The slop in the prop hub that was present  before I sent it in is gone now. Tight as a drum and it is the original hub.  When I took it off ,the hub and key looked fine but it had a lot of side-side slop after it was  pressed onto the crank.
I'm sticking with the story of the early batches of cranks not being built or heat treated properly.
I'll take it up tomorrow and see how it performs.

georgee

Thx guys for the informations.

Cheers [8D]

hairy46

My Feedback: (1)

Good thread I see one of these in my close future!

flyinwalenda

My Feedback: (5)

I've run about 3 tanks through it since I got it back. It started right up on the 4'th flip and there was not much much residue so I guess Horizon did break it in! I am still treating it like a new engine though.
The tuning was right on and it sounded good and flew well but it's not quite where it was before the problem occurred but it is slowly getting better just like before. Time will tell but I'm hoping it was just a defective crank that caused the issues

superfli

My Feedback: (42)

I am currently putting this combination together. I want to power the servos with a Life 2200 6.6v battery. Can this same battery power the ignition as well?

Thanks,

Superfli

cwhitacre21

My Feedback: (4)

Hi, I put the fuel tank in mine today. I'm not sure about the third fuel line. Would this be a fill valve line? Instructions fall off right here..

All else is good so far. Thanks!

superfli

My Feedback: (42)

Yes, the 3rd. line is a fill line.

Superfli

flyinwalenda

My Feedback: (5)

It will work but you are going to have to closely monitor the pack after each flight so you can determine when the pack gives up. Remember LiFe packs hold their voltage throughout the discharge curve as capacity keeps droping and then both voltage and capacity drop off .
I'm running 2200's for the ignition and receiver and get around (4) 30 min flights with some capacity left. Just keep the battery extension feedig the ignition away from other wires,receiver, etc.

Cherokee Flyer

What a nice flying airplane!, fun to just shoot touch and go's with. I don't have much to say about engine issues, as I just put a Saito 72 in it and have justbeen flying it. But again, what a great flying machine!!!!

L.

AA5BY

Brian... monitoring LiFe batteries after a flight with a load voltage test might not be the best advice in keeping with your reminder about the sharp discharge curve. The suggested management scheme is to determine the consumption per flight and apply it to the battery capacity.

Secondarily, one might get some degree of fore warning from real time telemetry but the jury is not in on its value or even what the right warning voltage should be set for. Real time might be of some value but after flight testing will not help if the sudden drop off occurred during the 3rd minute of the last flight.

When I converted to LiFe, I asked what voltage to set as the warning voltage and received suggestions of 6.3V. At the time I was setting up a giant scale in a new transmitter and dealing with the learning curve of the new transmitter and in addition, the setup was more complicated than normal. So, I'd program and test and at some point got a voltage warning from telemetry and switched immediately to the other dual battery to finish what was being tested and then followed up with a battery charge.

The charge required replacing around 1270 mah in a 1300 mah battery. That seemed too close to the batteries capacity and I changed the warning voltage to 6.4. Since, I've flown several LiFe batteries to around half capacity without any false warnings from reading brown voltages. At what capacity level a warning would come with the 6.4v setting, I don't know. It might also be very near the end of the battery capacity, hence why I say I think the jury is still out on the value of telemetry warning. I am however convinced that after flight load testing is of little or no value.

ahicks

My Feedback: (2)

I would suggest careful logging of flight times over the span of 2-3 flights - then charging to see what it's going to take to top off the battery? With that info in hand you can then mess with the number/length of YOUR flights to see what it's going to take to get down to something around half the LiFe's capacity. That level commonly assumed to be safe.

All that said, I have a 70" Revolver with a DLE 20 in it, running a single A123 powering everything. Servos are 100+oz. digital (power hungry pigs!), and using the process above, found I can fly the heck out of that plane for 2 evenings (6-8 flights) on a charge easily - on less than 50% of the battery's capacity!

The key take away point here is there are a TON of variables to factor in to what percentage of YOUR battery YOU are using. It's not fair to assume what my plane is doing will be duplicated by what you're doing at all? You really need to pay attention for a few flights to get a feel for what YOU have going on. -Al

hairy46

My Feedback: (1)

Ordering one by Monday, as I get older you start to enjoy the simple things in life, like tricycle gear"

AA5BY

I ounce again agree with Al to apply the variables of a given situation. As mentioned above, I've had no telemetry warnings at a 6.4v setting and have flown some batteries down to half capacity. However, many of my planes have dual flight batteries and it might be that a giant scale using a single flight battery might brown out and false trip the telemetry when set to 6.4v.

I've three planes with one battery serving both flight control and gas ignition and have flown only one of those down to slightly beyond half capacity without a brownout and false warning. It has a 10cc engine and six digital servos but is less than a six pound plane and though it is a funfly plane and has large control surfaces, they are not set up too wild. It has a 1300mah battery and has on several occasions been flown to consume around 700mah. It consumes about 170mah per 10 min flight or abt 17mah per min and thus seems safe for four ten min flights and might get pushed for a fifth some day or I might exercise it beyond the fourth flight until getting telemetry warning and note how much recharge is required.

flyinwalenda

My Feedback: (5)

H'mmm I didn't state to 'load test" LiFe packs ....because you can't due to the rather constant voltage on the discharge curve. I said to "monitor" the packs after flights . How someone monitors the pack is up to them. I determie how much is put back into the pack after an x-minute flight and set a baseline and then monitor it after 3 x-minute flights, etc, etc...

ahicks

My Feedback: (2)

Darnit! Seems like we're all on the same page then! Love the idea of learning something new regarding this stuff.... even a new way of approaching the same old thing! ;^)

AA5BY

Brian... my apology for the misunderstanding.

AA5BY

My curiosity is piqued regarding the capacity point at which a telemetry alarm will sound with a 6.4v setting.

flyinwalenda

My Feedback: (5)

No problem !
I too can't figure out how a "Voltwatch" type voltage monitor device or telemetry can be dependable using LiFe packs. If someone is depending on them to monitor the "voltage" for flight time /duration time before recharging then they may be in for a rude awakening whe the packs capacity plummets !  Better off to set a baseline on your plane and pack and just don't go beyond it.

AA5BY

As noted above, real time telemetry might be of secondary value to the monitoring you outline. My guess is that a 6.4v warning will still be too close for comfort to the end of capacity but if it happens at a point with enough capacity to get on the ground... then it will be of secondary value.

ahicks

My Feedback: (2)

Due to "lessons learned" regarding NiMh pack problems I was having early on when first messing with bigger servos and single battery packs (and brown outs), I would rather not depend on the voltage telemetry to tell me I should be on the ground, not in the air! Too much of what was happening depended on the load that was on the receiver buss at any given time? E.G. knife edge flight vs. level cruise? And then, this wouldn't happen on the first flight. The problem didn't show intil the second or third. I actually got to the point I could recognize a brown out fast enough where I could neutralize all controls (even if headed straight at the ground!), allowing the receiver enough voltage to continue on again, then moving controls only enough to level the plane and get it on the ground!

This is with the voltage telemetry on an Aurora A9 that was brand new at the time. Cost me a Funtana and a couple of very close calls with another plane to learn waiting for the alarm to go off to tell me I was in trouble was way too late! Actually, it wasn't until after loosing the Funtana that I even figured out I had a voltage issue? When the identical problem occurred with a second plane, that's when what was happening dawned on me (while flying). I neutralized the controls and got it back down on the ground in one piece for the first time.

Back then, if you mentioned you suffered from a brown out, most thought you were off your rocker. It wasn't until later that it started happening often enough with similar setups where it was recognized for what it is most often. The low amperage capacity of the NiMh battery chemistry. -Al

AA5BY

To be certain there is clarity... I'd not depend upon telemetry voltage over applying consumption rate to battery capacity.

ahicks

My Feedback: (2)

Then I'm not sure what you're trying to do by monitoring voltage?

By the time the voltage drops to the point there could be an issue powering your flight pack, the voltage level is dropping like a brick, no? That would be way to late for a warning?

AA5BY

My thought is that real time voltage under flight loads might be of secondary value to keeping track of consumption/capacity (not a substitute). LiFe is new to me and fairly new to modelers. Will capacity deteriorate? Will voltage fall off on one cell quickly leaving one cell hanging tough a little longer? With aging and senses not as acute as once upon a time, will I personally mess up and fail in the primary effort to keep track of consumption?

I've no illusions that voltage monitoring should be the prime management scheme... but I'm not yet ready to conclude that real time telemetry monitoring has no value, though I concede that traditional expanded scale load testing has no value and in fact would present a danger if attempted.