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Scram

NCFM Moth build

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Scram
3 hours ago, isoaritfirst said:

Scram need to change it perhaps..

I cannot, as far as I know.

What you said about building is explained clearly and what I said in another way earlier. 

For the fin, I did it like Dave - NCFM are a bit stingy with the lengths supplied - and saw no point/need to do otherwise, recon it is stiff/strong enough.

Nicely built Chuckie.  I fancied the NCFM colour scheme too but did not have the colours to do it, or thought I should be different  :yes:

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ChuckGlider

So that's it, she's finished and balanced, apart from the fine tuning, and ready to chuck off a big Welsh hill tomorrow :thumbsup:

20160122_161908488_iOS.jpg

20160122_170108967_iOS.jpg

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isoaritfirst

Looking good Steve. :)

All the best for the maiden.

I'm not sure about the Moth, but I do know that the bigger M60 flies best when you get it tuned to just a couple of mm of elevator throw.

Be careful to set the throws down to probably +-3 or 4mm on the elevator for the test flight.

Having too much throw will stall the wing and make it very hard to fly.

Have the other moths flown yet?

Or is tomorrow the big day for all of you?????

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isoaritfirst

Hi Steve,

Looking at your pics i see you have put the control rods on the top, I guess because you considered them safer there.

I think this will create a problem for you with poor control authority. 

I suggest that at the least you put the clevis into the very highest hole of the horn and if possible also the smallest servo arm hole.

But better still if you are able to, move them to the bottom surface, or if you really do want them on the top reverse the elevons so the bevel is uppermost.

sorry but well worth correcting...:(

 

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ChuckGlider

It's too late to move the servo control rod now. I have had some issues in the past when landing on lumpy and bumpy ground, or with coarse vegetation, so I decided to have the control rods on top of the wing, as on my Polecat. I haven't had any issues with that so I thought it would probably be the same for the Moth.

The instructions say to keep elevator throws to the minimum, so like my Polecat, I've dialled in a couple of mm only, but I'll add a high rate too of maybe 1mm more and experiment from there.

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Scram

I think what Mike is pointing to is the positions of the control rod on the horns, particularly the elevon horn.  Presently yours will give great sensitivity to stick movement and you would be better increasing the elevon horn length and if possible reducing the servo horn length.  Effective increase in the elevon horn length would also be achieved by hinging at the bottom wing surface.

Still waiting on a decent weather window to fly mine.

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evad

looking great steve , the wind is not right for the local slope this weekend and i have been a little under the weather this week , so no flying for me this weekend, I still have to make up some dowels as spacers for the ballast 

 

dave 

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isoaritfirst

You should remember that horn length is the perpendicular distance from the hinge line to the pivot hole. For top monted rods the elevons need to be bottom hinged. This adds the thickness of the elevon onto the length of the horn to give the effective length  

Currently I would guess you have an effective horn length that is around 6mm. Your servo arm length is probably 7 to 8 mm. 

This means that the servo will rotate less than the surface. On a model where you need to be able to control a surface that is moving just a few mm you need to gear the linkage as much as you can in the other direction. 

In a perfect set up i would aim for the linkage gearing, set such that the servo rotates through at least 40 degrees each way and the linkage gearing is set to allow around 20 degrees each way or even better less on the elevon.  This will then allow the servo to have some resolution as it tries to give control through2mm of elevator movement. If you simply rate it down in the transmitter you will end up with an on off switch of an elevator and also a difficult surface to accurately set to the required reflex. Reflex like elevator is very very critical any slopin the surface will make it very hard to get dialed In correctly.  Very fast roll rates are achieved by flying well rather than massive throws. 

Planks fly great but need very careful set up or they will be very disappointing. 

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ChuckGlider

Are you sure your name isn't Sheldon Cooper, Mike? :D Lol.

I will move the elevon connector to the uppermost hole on the horn, and if the connector on the servo arm will go on the bottom hole, I will move it to there too.

Southerly wind forecast tomorrow, so that means Back of Wrecker at the Bwlch. Not my favourite slope anywhere, but I'm limited for south facing slopes, so it will have to do. Sunday is forecast as showery and a SW, which would be great if it weren't for the showers.

Oh, I forgot to say, my Moth came out at 21 1/4oz.

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martynk

Very nice indeed. A great blog

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ChuckGlider

Thanks Martyn. :thumbsup:

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ChuckGlider

She flies! Yaaaaah :thumbsup: . I took it back away from the ridge line and gave it a few chucks to terst the elevon position. Satisfied with that, my f!ying buddy gave it the old heave ho.

Wind was 17mph gusting to 22mph and she went off perfectly. 

I had three flights in all and adjusted the aileron throws only as elevator seems to Ber perfect with no tendency to hyper stall. So I now must have to tweak the CofG to find the sweet spot. 

Hopefully the video will be OK, but I won't have a chance to look at it until Monday. But I'm hoping to fly tomorrow so I may get a chance to take more video then too.

 

20160123_131202100_iOS.jpg

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isoaritfirst

5 grams added on the tail of the gulp a few minor tweaks on the trim and reducing the elevator throw another few points and I think I now have it perfect.  

 

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isoaritfirst

Sounds like you had some nice conditions in Wales steve. Last to join the party but not last to get in the air:thumbsup:

It was pretty rough with the wind off the hill for most of the day on the  Mynd . Gulp coped very well with it but as the wind came square later it was going very nicely. 

So that's me done. Bring on the races 

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isoaritfirst

Bit of phone foam action here. Gulp doing its stuff

 

From yesterday at Ashes Hollow in conditions that started very crossed and very turbulent but improved to nice and smooth and lifty as the day wore on. Probably never more than 7m/s. 

Gulp was good fun in the earlier turbulence when the Shinto was ok but more uncomfortable than enjoyable..

I don't understand the facebook links, but clicking on the tag on the bottom works for me.

 

 

 

 

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ChuckGlider

So guys, check out my blog, (linked at the footer of this post by my signature) for the full story and video of the maiden flights of my Moth :D

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julianb

Tried some new stuff for the first time on a new M60 build and a Halfpipe refurb. Mixed results. A little too much heat and a few bubbles. Wish I'd read this thread first!!! Anyway here's a pic or two..

m60 and hp.JPG

$RN55LD0.jpg

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isoaritfirst

Very neat Jules, as always...

 

I normally revisit the covering a few times over the first month or so. The Gulp is now looking well stuck down and very few imperfections, as it gets more and more stuck/shrunk I find you can start adding more and more heat to get a nice tight shrink without it bubbleing through inconsistent shrinkage.

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ChuckGlider

Looks good Julian :thumbsup:

When laminating I begin with my iron at 120°c, then once it's all down, I increase the heat to 150°C and go over it completely again at this heat. I find that usually does the job nicely!

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julianb

Cheers for the kind comments chaps. I was sufficiently impressed with the stiffness of the New Stuff / X-weave combo on mine that I just went with top notch sign vinyl for colour on the wings and the aforementioned multi layer X-weave and Solartex on the fuz. I've dug out an old mini weasel to refurb, so might have a play with the New Stuff on that too!

 

 

My min-weasel.jpg

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