Browne Monoplane

[DAVE CRUICKSHANK]

Is there anyone out there who has built a Browne Monoplane as of the free plan in August RCMand E?  I have built this exactly to the plan but when I came to check the Cof G it is horrendously tail heavy. I dont mean a few ounces, more than a pound! The CoG is shown on the main spar (as you would expect ) but is it possible the it is wrongly shown? Has anyone else come across this problem?

  Regards Dave C.

[John Bunting]

Dave, I haven't built the model, but I see from the article that Nick Browne had 30 grams, just over 3 oz, of weight on the nose of his model, so if yours needs over a pound to get the CoG right it sounds as if it's turned out considerably more tail-heavy than his. He gives the all-up weight as 4lb 10oz.  What does yours weigh?
Nick says he will answer any questions here on the forum. 

[John Bunting]

Sorry, Dave: Correction. I should have said 90 grams, not 30!

[DAVE CRUICKSHANK]

Hi John,

  Thank you for your reply. This is the first time I have built from a plan as aposed to a kit and I thinkI have just built too heavy. I have extended the engine mounting and now got her to balance OK. I amnow waiting for a suitable test day. I will post a report after I have tested but dont know when that will be as our field is waterlogged.

   Regards. Dave.

[DAVE CRUICKSHANK]

Hello John Bunting,

     Well the monoplane has flown! As I told you I had to do some serious mods but  our club test pilot flew her today in conditions the were hardly ideal. The frst flight was "interesting" but after some adjustments the second was much better. I myself am waiting for better conditions as I suspect that it will still be a bit difficult to handle. Thank you for your interest in my model

 Happy Flying

 Dave C.

[Martyn Dorrity]

Hello Dave, I've also built one and mine has the same problem very tail heavy, i've had to put loads of lead up front, i'll have to double check but i think its close to 1lb.

I've not flown it yet as the day i took it to the field i had engine problems and  my glow start battery died on me.

 

Just as well i think as i'm a novice flyer and it was pointed out to me that the wing had warped a little ,i think as a result of being left in the back of the car for too long it was quite a sunny day, i think i've sorted it though i held the wing straight and ran a heat gun over it.

Its been sat on a shelf in my shed ever since, so when the weather allows i must dig it out and maiden it, after which i'll post the outcome on here.

 

And if i can work out how to do it i'll post some pictures of it

Martyn...

[Martyn Dorrity]

Well here goes the pictures x 3 i hope...

[DAVE CRUICKSHANK]

Martyn,

    Thank you for your contibution. It sounds as if you are in the same situation as me. If you are a novice flyer I strongly advise you to get your local test pilot to do the initial test flight. Our first flight was nigh on unmanageable. After making some adjustments we ended up with a reasonably trimmed plane, bit it did require a vast amount more elevator throw than that stated. I personaly would have lost it on it's first flight. Instead of adding a vast amount of lead I elected to extend the nose/engine mounting to get the GofG under the main spar. Perhaps you should do the same.

 Best of luck

Dave C.

        PS |I will try to send a picture

[Martyn Dorrity]

Thanks for the advice Dave, i think i will do the same as you and move the engine forward.

 

Can't understand though how ours have turned out so much more tail heavy than Mr Browne's original model as i'm sure we have'nt used wood that would be a 1lb heavier than the stuff he used ? ? 

 

regards ,

Martyn.....

[Ian Jones]

Martyn, Here's a photograph to show the extended nose. I hope this is of use to you. By the way it is quite easy to use too heavy wood in the original build and then you end up with a tail heavy situation.

 

 

 

Best of luck with your mods.

 

Dace C.

 

P.S. there are more photos in the SCRCS Gallery:

http://www.modelflying.co.uk/albums/

 

Thanks Ian Jones for help with this message.

[Martyn Dorrity]

Looks good Dave ! ! 

 

Do you find  the wing warp system works ok ?
i'm a bit concerned that control responce will be slow due to the small amount of movement ?

[Paul Eason]

I too found this plane to be tail heavy. My answer to this was to use bee engine bearers to extend the nose a little, make 3 formers to fit over the bearers and used a mixture of 1/32 ply and a piece of tin to make a housing for the battery. I still had to add some weight but it was able to go over the motor so didn't need much.

I found the plane to be very responsive on the recommended throws. Needs rudder in the turns. I did find that with the wing LE moving up and down with the warping that it tended to act as an elevator at times and the flight was very up & down 'till I got used to it. I might fit some wires to the LE tips to stop it moving with the TE and see what difference that makes.

All in all a fun plane to fly.

I'm now going to try to upload a pic.

 

[nicolas browne]

Hi guys its great to see my plane beeing built i have 70 g of lead up front, i also have a vid on youtube so you can see all the control throws in action just type in nbrowne73 and that should take you to my vid's, anyother questions let me know.

             Nic Browne  

[nicolas browne]

Hi all my plane was i little livley on the first few flights but just add led to the front and reduce the elivator movment a little untill she suits your flying style!.

 

    Nic

[Graham Lee]

Hi

 

I am in the throws of getting materials to-gether to build the Brown. Can anyone advise as to where I can get the required 8 X 8 and 18 X 4 spruce (on line perhaps) as my local DIY and model shop don't have those specific sizes?

 

Thanks

 

Graham Lee

[Richard Wietfeldt]

I have seen Deperdussin 1913 at  http// richard. ferriere. free. fr/3 vues.  Richard. Wietfeldt

[Nobby159]

Nothing showing, just asking if I want another page

Nobby

[Martyn Dorrity]

Well eventually decided to pull her off the shelf and maiden her !

I did'nt extend the engine mounts in the end, just cast a great big lump of lead to fit behind the engine, must be about a pound in weight ! ! so she's very heavy ! !

Before i took her to the flying field i put her together to check the throws ect and noticed the left wing was wharped slightly up on the t.e so sorted it with a heat gun and off to the field...

well 1st attempt at take off resulted in a couple of busted wheels they were made of lamenated balsa but obviously not up to the job ! !

So next day with a new set of wheels made from "unknown" hard wood back to the field,

But conditions were not quite ideal wind was gusty and a bit strong but decided to have a go!

Well got off the ground no problem allbeit very twitchy !! But should have checked the wing for wharp again as it was back and she wanted to bank left i had to use all the trim to get straight and level, which used most of the wharp control for turning right !!

she would bank to the left ok but needed help from the rudder to make a good turn but due to the lack of throw in the right aileron input, would'nt bank right, but could be turned with rudder !

The landing approach was very hairy i ended up side on to the wind and got pushed over some rough ground, over did the rudder and nosed her into the deck !!!!!

Result = busted prop and slight damage to left wing L.E !!

Got her home and repaired straight away "but" i think i'll do the extended engine mount mod so i can lose all that lead!

And get the wharp out of the wing, and maybe mix a bit of rudder in with the ailerons to make the turns a little easier !!

When its all done and tested i'll post the results on here "good or bad" 

Edited By Martyn Dorrity on 30/06/2009 11:20:44

[john straw]

I've just completed the build.Fitted a 46 two stroke as far forward on the bearers as possible and she's definitely very tail heavy,even with the rx battery tight behind the firewall.With ballast all up weight is 5lb 8oz.

Now waiting for a window in the weather to maiden her.Could be some time!

[Martyn Dorrity]

It's been a long time but i did eventually get around to extending the engine mount, so got rid of the lead, sorted the wharp in the left wing and mixed a bit of rudder in with the ailerons. Got to the field conditions perfect took off perfect only needed a little bit of up trim on the elevator and she flew like a dream, turns lovely nice stable straight and level wing wharp work very well. made a landing approach, was coming in a bit fast so decided to go around again put her in a steep climb opened the throttle and the bloody engine died !! "dropped like a brick" luckily not much damage just a bit to the undercart which is now fixed so next fine day i'll be back at the field with her and i'm confident she'll be great !!

[Ian Jones]

Hi Martyn,

 

I'm pleased you are now having some success with your Browne Monoplane. As your last post is fairly recent and Dave Cruickshank started this thread you may be hoping for a reply. I've no doubt that Dave would have been very interested to follow your progress but sadly Dave passed away earlier this year. I flew his Browne Monoplane (AKA Monty Python) with him on many occasions so I'll try and summarise how he went on.

 

Dave did eventually have a good number of flights though he did have to add in more movement than he had in the maiden which was probably a bit on the conservative side. He kept working on the CG to get it right as we found that correctly balanced it would land very nicely. We found that the longer the nose the more sensitive it was to CG changes and more elevator movement was needed too. Rudder/aileron(warp)/elevator co-ordinated turns were the most graceful and looked fantastic in flight. Here's a few photos I've just added to the SCRCS Gallery (http://www.modelflying.co.uk/albums/member_album.asp?a=2058) that show just how much the nose was extended.

 

 

(Sorry, I don't have any good quality photos of Monty)

 

 

[Martyn Dorrity]

So sorry to hear the sad news about Dave,

I've flown the plane a couple of times since my last posting and all went very well, she tends to come in a bit fast but i think its down to me being a bit nervous about slowing her up too much on aproach !

Will have to do more with it next year when the good weather returns !

[Ian Jones]

Thanks & good luck with your wing warper.

[Scooby Do]

Hi

I was lucky to read all this before starting my 1.2 scale model . 63 inch, because I had a suitable  wing that size! Despite:

shortening rear fuselage 2cm

lengthening front fuselage the same

further lengthening the engine mounts another 2cm

moving all weight forward

reducing the size of tail controls

 

I still looked like needing 3 oz up front! I am using

 an OS .40, which is lighter than a lot of what others have put in. All up looks about 6lb 3 oz.

Thanks for tip on building box & put battery behind engine, this may bring it close to neutral. Has anyone put up a video of one flying?

cheers

 

[Koen Smits]

As a winterproject we have build 3 monoplane's, To archive the CofG we moved the wing back about 25 mm. We are using a steel block from about 80 gram as nutplate for mounting the motor. At the moment we are working the engine hood. As we converted the plane to electric. The motor we intend to use is a Roxxy 4250/06, battery 3s or 4s.