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Scram

Strega 2 Build

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satinet

I saw a clevis that was a metal version of an mpjet clevis today on Facebook

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RGPuk

I saw a clevis that was a metal version of an mpjet clevis today on Facebook

Interesting ....... with a removable pin too, a la MPJet, or just the basic form?

Do you have a link Tom?

Ro.

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Austin

thanks for taking a close look at those MPX clevises

you've solved a mystery for me - as to why I've often had problems getting them into and out of the metal horns !

I standardised on MPX 2.5mm clevises a couple of years ago after having various problems with cheap-n-nasty ones

I've just looked at an aileron linkage that happens to be on my desk - same "burrs" as you've got

I'll still use them, but now I know to do a bit of filing to make them nice before fitting them

 

Phil.

 

Phil.

 

Here is a real close up of a clevis pin, most clevises are probably originating from poor chinese production and are a real pain to get through brass horns. I have tried all makes and they all seem to have similar problems.

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Scram

Thanks.

 

I will arrange my Rx whiskers internally, as best I can on different axes.

 

On the clevises, I just had another look at the ones came with the plane which I rejected.  They have nice smooth pins.  It's just that the pins are loose and only 1.49mm diameter so loose in the holes of all my horns.

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Gromit

When i finally got round to switching to 2.4 about a yr ago, i too was concerned about aerial positioning. With long slender fuz's on most F3f ships, getting the aerials anything like 90 degrees to one another can be difficult to achieve. I know that having them at 90 degree's is 'the ideal', but is it as important as the 'blurb' says' ? 

 

       Stu.

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mtreble

When i finally got round to switching to 2.4 about a yr ago, i too was concerned about aerial positioning. With long slender fuz's on most F3f ships, getting the aerials anything like 90 degrees to one another can be difficult to achieve. I know that having them at 90 degree's is 'the ideal', but is it as important as the 'blurb' says' ? 

 

       Stu.

I think the important thing is that you never have both aerials pointing directly at the transmitter, as this is the point when they will (may) fail. Any angle between 45 and 135 should ensure that there is always one sideways on to the transmitter no matter what orientation.

I normally wrap one around the receiver, and route the other along the servo tray using off cuts from snakes or lengths of heat shrink as guides to hold them in place.

The only time I have had any issue is with my wizard compact which has carbon in the inner nose. It was fine after routing one of the aerials through the top of the fus where I had the old 35mhz aerial

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Gromit

Is there a need to keep the ends of the whiskers away from the fuz servo's, or away from the reciever itself, to avoid any possible interference issues etc ?

 

  Stu.

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satinet

Interesting ....... with a removable pin too, a la MPJet, or just the basic form?

Do you have a link Tom?

Ro.

 

 

http://www.hoelleinshop.com/Zubehoer/weiteres-Zubehoer/Ruderanlenkung/Gabelkoepfe/Alu-Gabelkopf-23mm-mit-Pin-1-6mm-und-Sicherungsring-M2-Anschluss-VE6.htm?shop=hoellein&SessionId=&a=article&ProdNr=MJ2151&t=49303&c=15663&p=15663

 

Looks the same as MPjet but made of metal.

 

I find mpjet the only ones you can really get on in tight situations.  7.90euros for 6. I was going to make an order from Hoellein soon anyway, so I will try them.

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Pete Burgess

Is there a need to keep the ends of the whiskers away from the fuz servo's, or away from the reciever itself, to avoid any possible interference issues etc ?

 

  Stu.

We are told (by the electrical experts) that 2.4ghz is way outside the frequencies that any servo motors might generate and any metal to metal interference. From a user point of view after over 5 years of 2.4 usage (FASST) I have NEVER experienced any such issues (touch wood :o ) 

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satinet

I've experienced it plenty of times .

It happens when you have an rx that is two way. A lot of servos suffer interference.

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Gromit

Hmmm, anybody else had interference probs like Tom has experienced from placing the whiskers on the fuz, alongside fuz servo's ?

 

Scram, hope you don't mind me asking these questions regarding 2.4 whisker placement in your build thread. I just thought as the matter had arisen it was the perfect time to ask.

 

Keep it up Scram :thumbsup:

 

  Stu,

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Gromit

'?do=embed' frameborder='0' data-embedContent>>

 

I'm not in the habit of making stuff up Stu! :P

 

lol, Thanks for the link Tom, very helpful indeed :thumbsup: . I was sure it had been discussed on here before but couldn't find it.

 

  Stu.

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satinet

It's a right pain in the posterior, believe me. 

 

It doesn't matter in this instance as I think he (Scram) is an FRSKY rx that is a receiver - not a transceiver (VF8 something), so there shouldn't be a problem whatever servos are used - looks like mks6100. 

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Scram

It's a right pain in the posterior, believe me. 

 

It doesn't matter in this instance as I think he (Scram) is an FRSKY rx that is a receiver - not a transceiver (VF8 something), so there shouldn't be a problem whatever servos are used - looks like mks6100. 

 

That's right Tom - FrSky Rx which is not a telemetry one.  But I will check the fuz servos for any problem.

 

 

Scram, hope you don't mind me asking these questions regarding 2.4 whisker placement in your build thread. I just thought as the matter had arisen it was the perfect time to ask.

 

Keep it up Scram :thumbsup:

 

  Stu,

 

That's alright Stu.  I started the whiskers question anyway.

 

Jerry

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Scram

On with the wings.

 

I made up new wiring harnesses for both wings.

 

I made up the flap pushrods to the same lengths and ground the clevis ends so they would be good not to interfere with the horn centres and set up the flap servo for the first wing and found my horn was over rotating at full flap which meant I had to rotate the horn on the servo round one notch and now my pushrod seemed short so I had to heat up the soldered thread and unscrew the clevises about 5 turns  :huh:

 

Got that right and then applied vinyl tape to the bottom of the servo with some furniture polish to ensure I did not glue it in when fixing the servo mount.  I applied 15 min epoxy to the mount with the servo fixed in place, and slotted it into its place in the wing whilst connected to the Rx powered up.  Connected the pushrod and let it set.  The support bearing was not in place at this time.

 

When that was set, I removed the servo and put the bearing in its mount onto the brass shaft.  I mixed 30 min epoxy with micro-fibres and applied this all round the servo frame to strengthen its attachment to the wing skin and plopped some in the place the bearing support was going, then worked the assembly into position and screwed down the servo;

 

IMG_3007_zps81bb88f8.jpg

 

Sorting this all out was a real PITA.

 

I don't think I will do it again  :(   Just wrapping the servo in vinyl tape and gluing it straight in is much easier and so far, I have not had any difficulty removing one.

 

Sorting the second wing this afternoon has proved even more problematic. I do not know why but with the same length pushrod, the flap servo ended up too far under the lower wing skin to be able to get at one of the securing screws.  All other dimensions seemed to be the same - unless it is the flap horn position is different.  Anyway, I had to shorten the pushrod to make it go in.

 

We will see what the effect is.........................  :blink:

 

Just need to sort me whiskers and cut some steel bar for ballast, checking the CoG both empty and full, then set up the final surface throws.

 

Maiden on Saturday at LM, I hope.

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isoaritfirst

best way I have found is to power up one flap servo with the transmitter and drive to full forward rotation and switch off.

Now  refit the servo arm so that it sits as far forward as the arm/clevis will allow before fouling the servos centre shaft when the push rod is running upwards at the angle needed to match the flap surface horn.

 

Mirror for the opposite flap servo. 

Check them side by side on the bench.

 

Then power them up and drive to full deflection (up flap) fit in place with the flap raised by the amount you want as up flap (7mm ish works for me)

 

Alternatively fit one with the flap level then tyake a reading from a digital servo tester and set the other servo at the mirror reading on the tester before fitting.

Servo centres are at 150 so if first sits at 170 second should be at 130 etc etc.

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Scram

Thanks again Mike.  I don't have a digital servo tester and the T9 Tx gives no servo position info except on the small graph which ain't much use for that I think.

 

Setting up the servo linkage and position seems to be a function of several things including Tx programming with several screens affecting how the servo behaves and of course this latter is Tx make dependent.

 

My aim was to have the servo horn essentially horizontal (in line with the rod) at full flap deflection and then get as much rotation as possible. Then grind the clevis so that it did not interfere at full up flap position - and how much up that achieved is then dependent on how long the horns are and the Tx programming.  All gets a bit complex for me  :huh:

 

After setting up for this and then gluing the servo in, I found the servo was over-rotating at full deflection, thus effectively robbing some of the rotation.  The only cure for this then (aside from grinding out the mount :(  and starting again) was to re-position the horn on the servo and then adjust the rod length.  Obviously I done it wrong in the first place - do it right first time! - is the motto I try to achieve!!

 

I've not yet checked how my flaps move but I'm hoping/trusting I can get even travel by adjusting programming, if necessary.

 

Onwards .......................

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Big Bear

Does anyone know where to get the rear elevator cover from as I trashed mine on landing?

Adam

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Scram

Flap movement proved to be OK.  Some slight difference can be seen in relative rates of movement but they both end up with same total deflection.

 

The maiden went off OK.  Slight difficulty with elevator movement amount in crow, like it was going up instead of down so had to be landed without, but as the wind was quite strong landing speed was not excessive.  However, there was an ominous crack as it slewed on coming to rest and the vee-tail (I'm used to a cross tail) made me think the fus was broken  :o   but in fact it was just the diamond wing tape coming away.  Maybe I should not have polished it!!  :rolleyes:

 

CoG seemed to be about right but I have had to trim in a couple of mm up to get it to fly level.  Is this a CoG or incidence matter??

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