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Not sure if this is a start to a reliability issue?


911hillclimber
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Sleep on the decision.
If it feels floppy tomorrow, a skewer (spell), I know I’m crap myself, will be needed. But probably not. Good enough.

A learning curve, your airframe is in the last chance saloon, God’s waiting room, area of its life. Don’t worry.
I agree, don’t throw money at it, but tight with money can be self defeating. Repair it, instructor can have a go. 
Two results. 
1. Repair techniques advanced.

2. instructor, if not observant enough before liftoff,  might have an entertaining time after it lifts off. That is serious, look what he does, checks, pulls, kinterrogates you.

 

Before I get jumped on, I fly over dead ground. If it hits the deck, deer sometimes, and more often hares are under the aircraft. The local hares do 12 portions at a dinner table. I thank my whippets for that knowledge.

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@911hillclimbera potentially easier reinforcement would be carbon strip. You just need to cut a single 'slot' with a knife, push the carbon in, and run some appropriate ca in. Quick, neat, strong.

 

Do agree with advice re new fuselage though.... much better bet in the long run.

 

Keep your chin up. And keep asking us for advice......

 

 

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Thanks to all as ever!

This would be a mine field without the forum!

 

Decided to do a simple strengthening mod and with 1mm ply, two side strips down the nose and under the c of g about 35mm wide, and 200mm long to cover the cracks and fractures just bonded back together. A simple attempt to stress the nose to the cabin-back resulted in no movements but i can help 'sensing' the motormount is tilted back slightly so will add a washer to the 2 uppermost motor mount points to bring it down a touch.

 

Parts will need a flash of satin blue which I happen to have to 'hide' my surgery but this is definitely the last song for the fuselage.

Electrics next and sorting that pesky ESC to factory settings.

 

My booster shot yesterday has made me feel a bit under the weather with a few muscle aches, so have some steady time today.

 

I think the membership is at the end of the season, next week looks evil so I might not fly again this year

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Bit of a final message on this (I hope).

Plane all back together and working. Side strengthening strips on and damaged area painted to try to hide the mess.

 

all looks square and true, flying and trimming will tell.

Tried to reset the ESC to factory default, and tbh not sure if I have.

 

The sequence of beeps do not tally to those in the FMS manual. The sequence starts with 5 loud beeps, manual shows 4, and it goes on from there.

 

Hard to spot the sequence from the ESC to the manual.

The normal start-up sequence 'says' the motor brake is ON, the factory default should set it to OFF...

 

Throttle response is just as it was before the crunch.

 

My aerial re-solder seems to have worked, needed to do it to sort the signals out, but will test it and the ebay unit when it arrives, and will go with the ebay unit if range test is good.

 

Ran the plane up to WOT many times to test the glue on the nose, all ok, but a flight is needed (by my buddy link guy).

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Just to vent my spleen...

 

There seems to be no rhyme or reason to programming this ESC using the instructions that came with the plane.

 

The key to high pitch, low pitch etc are not obvious, and I cannot find a sequence of them that tally with a particular  function, ie I cannot hear any sequence to get to the factory reset so I can drop the throttle stick to OFF and that setting be established as the norm.

 

Have tried that move several times guesstimating I was there, and nothing has changed,  a soft start is still present.

Everything else functions for the flying surfaces. Motor beeps are 3  for the battery cell number, followed by a pause and one beep which shows motor brake. 

 

I think I can only leave it alone now and fly with fingers crossed. What a mad system, obviously written by the engineer who did the design assuming the reader knows what he is doing!!

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2 hours ago, 911hillclimber said:

Just to vent my spleen...

 

There seems to be no rhyme or reason to programming this ESC using the instructions that came with the plane.

 

The key to high pitch, low pitch etc are not obvious, and I cannot find a sequence of them that tally with a particular  function, ie I cannot hear any sequence to get to the factory reset so I can drop the throttle stick to OFF and that setting be established as the norm.

 

Have tried that move several times guesstimating I was there, and nothing has changed,  a soft start is still present.

Everything else functions for the flying surfaces. Motor beeps are 3  for the battery cell number, followed by a pause and one beep which shows motor brake. 

 

I think I can only leave it alone now and fly with fingers crossed. What a mad system, obviously written by the engineer who did the design assuming the reader knows what he is doing!!

Using a programming card is easier and they're not expensive 

 

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Finally!

Cracked it. There is a whole instruction missing from the method.

 

I now have no brake and full linear throttle, no delay and rest is factory setting.

I won't go through it all but the fog has gone and all done.

Happy now the plane is set up to fly.

As ever, many thanks for everyone's help and patience!

Phew!

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Well done on getting there in the end. I think it's your patience that has been tested!!

 

But do tell us what step is missing from the instructions, just out of interest. I have a copy of instruction sheet (downloaded from the CMLwebsite) and I'm interested to know.

 

Thanks.

 

Brian.

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I'll try here Brian, but my command of words is not the best!

Here is what I discovered:

Switch Tx on, then stick to max then connect plane battery.

Ignore all the beeps until you hear 4 loud BEEPS, the 4 large black dots on the top of the instructions.

The system is now about to start going through the Programming sequence.

You hear one beep, that is telling you Brake (of the motor) is now ready to be set, ie on or off.

Ignore that and you hear 2 beeps, Battery Type, ignore that, you hear 3 beeps, ignore that and you hear 4 beeps, Factory restore.

After the 4 beeps drop the stick to xero.

You then heara beep, raise the stick to max and wait a few secs for 2 beeps and then drop the stick

 

The plane is not at Factory settings, but i wanted to have no throttle delay, so pull the battery lead apart, switch the Tx off.

Wait 5+ secs, switch Tx back on, stick up and connect battery.

 

Wait for the 4 x BEEPS, and follow the beeps thereafter, ignore the 1.2.3.4.5 (5 is a higher pitch beeeep)

When 6 arrives (one high pitch beeeep and 1 normal beep) you drop the stick.

NOW! you have 3 choices, v soft, soft, hard motor response to choose from, I wanted Hard shown/voiced as 1/2/3 gap 1/2/3 gap1/2/3 gap1/2/3

You wait as the programming paces itself, quite slowly, until you hear what you want.

THEN you raise the stick and wait for 2 close beeps and then drop the stick.

 

You have programmed now: factory reset and modified it to hard motor response.

 

The missing bits are

1

the programming beep work like roman numbers, 1/2/3/4 are beeps, 5 is a higher beep, 6 is a V1, higher beep + 1 beep

7 = V11, 8 = V111

2

The stick acts like a switch and is used to select all you need, THAT was the bit I could not find, how to select the range of functions each characteristic has.

 

So, disconnect the battery, kill the Tx.

Pause for 5+ secs, switch the Tx on, stick at Zero, connect battery (as if you are doing pre flight check).

The plane does it's set-up dance and goes silent.

 

Test all Tx functions, rudder, ailerons, elevator and finally motor (NO prop fitted)

The mototest tells it all 9for me)

The motor response to stick movement is instant from Off to WOT and snapping the stick down shows the spindle gently coming to a halt, not abruptly (like it does when braked).

I replaced the prop, put the plane on the floor and stood with ankles ahead of the tail plane as iif pre-flight testing.

The motor would rev instantly and snapping the throttle to zero showed the prop coasting down and free-wheeling to a gentle halt.

 

I did the floor check 3 times from Tx off and al was good.

 

There, I will stay awake now all night after writing that essay!

 

Local weather just might be ok for Tuesday and I hope my buddy link will also get to the field and link with me for resumption of Pre-Solo flying.

I know he will not buddy unless we do this way for a few more days at the field.

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Hi Graham,

 

Thank you for that description, I can see why you initially couldn't work out one beep from another... your 'missing bits' - the number of beeps indicating which function to select and using the stick to select that required function.

 

Oddly, I have found two very different versions of the programming instructions online for the FMS Predator ESC so perhaps they have been updated at some time. One version does say that the number of beeps indicates the function, and that one long beep equals 5 short beeps, but there are other differences, for example one has 10 settable functions the other only 8. It's likely that over the years of production the ESC has changed even though it still has the same name. Strangely, both of these different instructions are on the same page of CML's website (either on the page itself or as a pdf download).

 

https://www.cmldistribution.co.uk/product/PRESC002/fms-predator-30a-esc

 

I know this states 30A but the instructions cover all current ratings.

 

Anyway, I'm glad that you have got to the bottom of the problem... and hope you get to fly again this week.

 

Brian.

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Yes, the instructions say 10 functions but only 8 are enabled.

when I worked, all our instructions were written by my engineers, re written by the marketing girls and then sent to The Plain English Society for final vetting and changes, then tested by our Test Dept!

 

In the end we blended minimal words with hand drawn pictures, worked a treat.

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11 minutes ago, 911hillclimber said:

when I worked, all our instructions were written by my engineers, re written by the marketing girls and then sent to The Plain English Society for final vetting and changes, then tested by our Test Dept!

 

In the end we blended minimal words with hand drawn pictures, worked a treat.

Same here, Engineers method statements ran to pages and pages of details. One day everything changed on asking it was explained that when sent to the guys in the field all the pages put them off reading it so to address the issue an instruction was sent to the Engineers that method statements sent to the field had to be in bullet point format with each point preferably being less than one line in length. Pictures would also have helped, good idea.

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Indeed, we designed our instructions for  the over 60's!

I was the 'artist' who drew the instructions, far better than a CAD as I could 'cheat' and remove a lot of un-needed detail.

The instructions were also given to the Police to check, i did domestic door locks, surprisingly easy to confuse people.

 

'New' Rx arrived this morning, and have just fitted. Bound easy and all functions ok

My soldered aerial connect was not very assured, so used the new one.

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Flew this morning at 5 degs but zero breeze.

Buddies-up and all went well, 3 take offs and 3 landings and some good circuits in between.

 

Motor control is nice and you notice the lack of motor braking on landing, there is no prop drag to slow you down!

Buddie took the plane up at first to check the trimming after the Big Repair and needed to trim 6 clicks to stop it from climbing hands off, then over to me.

Gulp.

Felt quite tense as the memories of the crash still in my head. Got to fix that.

 

So, back on an even keel. Buddie only cut in once when it looked like I was going to land into the field fence....

 

Plane in one piece, just need to warm up now.

Doubt we will fly much again in 2021, might be some special days yet.

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911hillclimber

With no motor brake on there should be more prop drag once the throttle is fully closed. A free spinning prop creates more drag than even slow spinning one.  Indeed if you dive fast with the throttle shut and no brake there is a possibility that the prop will spin the motor faster than it ever can on the battery.

 

Glad your flight went well. 

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Congratulations on the flight and the repairs 911.

 

As long as your master is willing and you have sufficient experience, I would suggest that you fly whenever the opportunity presents itself.

Hopefully that would prevent you becoming a fair weather flyer only.

As you get more experience, the more you can challenge the limits you set on your flying conditions which can be fun in its own way.

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