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Who Else Wants a 63" Lavochkin La7 kit?


jrman
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Did you say on the video that you thought it was a bit nose heavy? I'll be interested to hear where it ends up balancing as mine is coming out 1-1.5cm back from your 7cm suggested fuselage only point depending on whether I put a 5000 or 4500mAh pack in. I'd guess that it will be pretty tolerant of the exact balance point in view of the wide chord and decent size tail.

Has anyone else played with the CofG?

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It felt slightly nose heavy Bob but it also wanted to pitch over on take off and landing (rake on U/C ?). So I've replaced my 3000mAh LiFe with a 2100mAh one and moved it back by about 20mm. Hopefully going to get out again one evening this week (I'm working every day this week crying) and try it out.

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Just checked back a page and it was 75mm from F2 without wings that Ron posted so I'm .5-1cm back after all. I'd call that good enough for now. In the past my trimming has been to move the balance point back until spin recovery becomes difficult then move it forward a shade on the rebuild face 1

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Picture time! How to paint a spinner evenly:

painting the spinner.jpg

The ESC is a neat fit, cable tied with a pice of non-slip matting underneath:

esc fitting.jpg

Battery tray fitted:

battery tray.jpg

underside - battery tray.jpg

Radio bay - one aerial goes up the middle of the pilotsurprise

radio bay, not short of space.jpg

And with the front end together (less the hatch)

fuselage side view.jpg

Apologies to the cats for stealing their blankets!

Edited By Bob Cotsford on 12/07/2020 17:27:22

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Bob , I like your colour scheme , for someone who says they dont like finishing , you make bloody good job of it .wink

 

Ron , great flight and video . The La7 looks so relaxed and on rails and BTW . if British Airways start recruiting again they could do a lot worse than hire you for a smooth landing course .

Cabin Pressure anyone ?

Edited By RICHARD WILLS on 16/07/2020 12:06:08

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OK so I promise that this is the last of the photos, I just can't help it as the 'plane is just so good! These are some shots from yesterday's session. So no more photos but I will get a better vid as a new camcorder is on it's way!

ma1_0361.jpg

Caught the sun on the canopy

ma1_0370.jpg

Love the exhaust on this one!

ma1_0371.jpg

ma1_0377.jpg

You can even see the gunsight on this one.

ma1_0379.jpg

ma1_0380.jpg

ma1_0384.jpg

Could even believe it was a full size coming in for landing!

ma1_0388.jpg

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The Curse of the Eflite Retracts strikes again. I'd got them installed with 1/8" shims to rake the legs forwards and 1/16 tapered to nothing to tip them outwards so that they would lock up with 3 1/2" wheels fitted. Tested several times, all ok so I extended the left leg to look at the cover mountings and the leg lowered an inch and stopped. Dead as the proverbial. Eflite don't do repairs or spare boards, been there before! Luckily I had a pair of Lado units handy which just needed the mount area extending by 3mm, they are now in and working but the 10mm Robart oleos don't fit the Lado units so I have some 12/13mm or so oleos on them. Of course the Eflites weren't going without a fight, one mounting screw rounded so I had to drill off the head and extract it with pliers. Not breaking my glasses last week would have helped my general mood at this point!

With the thicker oleos the 3 1/2" wheels were a tight fit on depth but 3 1/4" fit without the need to cant the legs outward. They only look a couple of mm thinner than the 3 1/2" ones but it makes quite a difference.

In conclusion, don't buy Eflite retracts, not even if they are offered at a bargain price. Not unless you like screaming at the world in general angry 2. Also Specsavers are doing two for one at the moment.cool

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Posted by Ron Gray on 22/07/2020 17:55:43:

I agree with you Bob, the eFlite retracts on my H9 Hellcat are a nightmare, last night one 5mm connecting wire snapped off on landing, no other damage fortunately.

Didn't realise that Specsavers are doing 2 for 1 on eFlite retracts now.

I have a stock of assorted Eflite retract units with dead boards or broken leads and I could probably cobble together another 'strut ready' one to make up the pair but do i want the hassle?

Maybe I misread the sign in Specsavers. I think I was in Specsavers...thinking

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  • 1 month later...

Just to let you know I've not abandoned this project yet! This afternoon (after the WSBK second practice thumbs up) I finally assembled the complete model - in the kitchen - for a weigh-in and power test. With a 4500mAh 6S pack weighing 740ish gms it came in at 10 1/2lb and balanced exactly on the plan recommended spot with zero lead. That seems a lot but I know Tim said his was the same weight and with the battery aboard it's the equivalent of having a full tank, ie an additional 10-12ozs. So that equates to about 9 3/4lb dry weight IC equivalent.

With a battery still in storage mode I got a max 830W which was a little disappointing, I guess I need to step up from a 15*8 to a 15*10 to get above 100W/lb.

When will it fly? That's a good question as I have yet to get out flying this year. I'm hoping for a classic Indian summer in late September/October. Then again I'm also hoping for my lottery numbers to come up smiley

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If it flies anything like my LA-7 you won't be disappointed, 20+ flights on it now and it still brings a big grin to my face. The only problem I've had was when one leg failed to drop so I had to belly land it. The only damage was a a broken oil rad but a new one was 3D printed the same evening. I'm finding it hard not to take it to the field!

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  • 2 months later...

An update. Nearly 60 flights now but I’m afraid to say that I broke it last week! It was quite windy with gusts round the 20mph mark and cross winds at that. I was on finals approaching the threshold where I know that it can be quite turbulent and that was the case on this flight, I was caught by a sudden shift in wind direction and this coupled to slow landing speed allowed the LA-7 to be picked up and tossed into the ground! The result was an airframe in 4 parts, nose broken off, tail broken off and wing broken off. Now this is testament to Richard’s design and to the form of construction i.e. veneered foam, if it had been ‘trad’ balsa stick and formers covered in film then I would have been looking at a pile of matchwood, instead I was able to ‘easily’ repair the damage and it was back out flying last Wednesday just before Lockdown2. I do also think that the laminating film covering helped in reducing the amount of damage.

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  • 11 months later...

Thank you @Ron Gray and @Bob Cotsford - I have the little 57" kit and your posts have made for an interesting read. I am going to be installing a Laser 70 into the 57" LA7 so lots of this stuff is going to be handy to refer back to.

 

Did anyone get to the bottom of what is a half decent fuel proofer but which doesn't fry your lungs?

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  • 1 month later...
On 04/08/2017 at 16:31, peter harvey 1 said:

/sites/3/images/member_albums/46334/757699.jpgif anybody is interested here are 2 scale drawing of the la5 and la7, if anybody wants copies let me know and I will email to you

/sites/3/images/member_albums/46334/757698.jpg

Do you still have these? I'd love one for when I embark on my 57" La7!  

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  • 2 months later...

I've been building my 63" La7 over the winter and found this thread really helpful, so thanks to those who contributed . Most of the construction is complete so I'm at the covering stage. I intend to use the brown paper method as I've used this before.

Ron is there any chance you could post the stl files for the oil cooler/ wing retaining parts you printed.

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