Here is a list of all the postings Birgir has made in our forums. Click on a thread name to jump to the thread.
|Thread: Sig Somethin' Extra build|
In a very easy and slow manner I‘ve started my next build. It is a Sig Somethin Extra kit I bought a few years ago. When living on an island in the middle of the Atlantic Ocean it takes some time to gather everything you need. So when I bought the kit I also bought the servos, engine, wheels and most other things I remembered.
Now when the build is well under way I remember that I havn’t bought a suitable propeller.
In the instruction manual the recommended engine is a 40 – 46 (even 50) two stroke but I decided to be on the save side and bought an ASP52A engine. Also, in the instruction manual, it is recommended to avoid heavily pitched props.
The recommended prop for the engine is in the range from 11*7 to 12*5
So now to the question at hand: Would a 12*4 be a suitable choice in this model/engine setup?
Thanks in advance
|Thread: A new caption competition - winner declared!|
And then a grizzly bear came out of nowhere and graped the rudder...
|Thread: Bleriot XI|
I’m sorry for your not so soft landing, but bear in mind that Luis also had a tough landing in England on the 25th of July 1909 and also broke his landing gear.
By the way, I also learned the hard way that the Bleriot is no glider, so just look at this as an opportunity to redesign the engine room.
My Bleriot has been hanging from the sealing of my garage since last year so it is still in a pretty good condition.
To answer your question, my Bleriot has 425 gr of lead up front so I think that it would be good to put in a larger engine and use some of that weight to create power. My SC30FS needs full power almost all the time to cope with the heavy model.
Usually when you come home with a broken model it looks a bit better after some inspection and rebuild planning, hope that this is also the case this time.
Please post some pictures of the rebuilding procedure.
|Thread: Aileron differential|
At last I had the opportunity to test my new aileron differential setup. As suggested, I put in 1:2 differential i.e. twice as much up as down.
This helps a lot and now I must practice using the rudder for coordinated turns.
I also need to practice my landings, nothing serious though.
Thanks again for the advice.
Thanks for this enlightening discussion, it has helped me to get a better understanding of the task at hand.
I ‘ve already put in 2 to 1 aileron difference as John suggested and now I ‘m waiting an opportunity to test that configuration.
I also agree with Jon that I would like to managed the rudder to practice the coordinated turn by hand rather than mixing it with the ailerons.
I had to read Jon exercise suggestion a few times, but when I got it I look forward to trying that in the air. I also wonder if I can put the aileron difference on a switch and use the same method to test the effect of that.
Regarding CoG, that had crossed my mind. I felt that the model was a bit livelier than my old Mini Super trainer and thought that perhaps it could be because of rewarded CoG. When I checked it, it is as per plan so I thought that the reason for a livelier model is just a different and a sportier model. 😊
A few years ago I built me a Sig Hog Bipe, which is a 60” biplane. There are four ailerons, top and bottom connected by a rod and 2 separate servos in the lower wing.
Recently I have built up a courage to fly the model after some practice with my Mini Super trainer.
Of course there are some differences between the flying of those two models. I’ve already flown it 5 times and I’m getting a better understanding of the model’s behaviour.
One thing that troubles me is that when turning, using ailerons and elevator as I’m used to from my trainer, something unexpected happened. When applying the ailerons the model banks to the correct side but when applying a small amount of up elevator it tends to climb out of the turn and raise the nose. I’ve managed to work around this by either applying rudder in the correct direction and/or rolling the model almost 90 deg and use a considerable up elevator.
A friend at the field pointed out to me that possibly this has something to do with the down aileron on the outer wing creating a drag working against the turn.
So my question is: Does anyone have a similar experience form a similar model?
If I put in an aileron differential, how much should I use?
As is the aileron movement is about 1 inch from top to bottom, half an inch in each direction.
Any comments appreciated
|Thread: Ben Buckle Mini Super - Build|
I admire your build and it is very inspiring, hopefully I can find some time to start my next build soon.
Have you made a decision about the three or four channel, aileron or not?
I have a 45 year old Kiel Kraft Mini Super. A few years ago I gave it some rebuild (not the first one) and put in two wing servos, decreased the dihedral and put in ailerons. Of course it lost some of its originality but I find it much more fun to fly.
|Thread: Forum members' new models: Let's see them.|
This morning a managed the maiden flight of my first biplane, - at last.
It was built in 2013 and was supposed to be my comeback to the sport of RC flying. Four decades ago I had build a Mini Super but never did manged to fly it successfully. So now I intended to do everything right and listen to every advice (being that older and hopefully wiser).
I joined a club, got me a sim and started to practice. When I asked my new clubmates for advice, it was simple. A biplane is not a good first plane, - not even the second or the third. Probably the fourth or the fifth.
So, I decided to do the right thing and listen to the experienced flyers. I rebuild my Mini Super, I build a foamboard Nighthawk FF-117, a FoamFighters Old Fogy and a Spitfire, and a Mini Jazz, all of them, except the Mini Super, now a history that can by read at **flugmodel.weebly.com**.
Then I built a Bleriot XI by David’s Boddingtons plan and that has been a success and is still in a top condition.
So, the Sig Hog Bipe is the seventh model maidened over the last five years and has now had two successful flights – the advice of my clubmate has proven to be right.
Edited By Birgir on 06/07/2018 12:28:39
Edited By Birgir on 06/07/2018 12:28:58
|Thread: Bleriot XI|
Yes, it has crossed my mind to put in a bigger engine but the front of the fuselage is more or less designed around the 30 so it would call for more changes than I would want to do.
I’ve also got hooked on the challenge of flying with the marginal power, it is more demanding 😊
Yesterday I put in a new plug and now it is running almost 9000 rev. spinning a 10x5 and that helped a lot on take-off.
Maybe it is time for me to carry on with the next project, the Bleriot has been THE project for almost three years now.
Thanks for all the help along the way.
Yes, it looks a bit tail heavy, but the reason probably is that I'm holding the tail down trying to gain some hight.
The engine is a little SC 30 FS so the power is marginal.
At last I managed to do two proper flights with my Bleriot XI.
This morning the conditions in Eyrarbakki where perfect, calm weather and the field at its absolutely best.
I took my Bleriot to the field and manged two proper take-offs, trimmed the plane for level flight with about 60 – 75% throttle and managed a very acceptable landing,- twice!
Here is a very short video of the accomplishment 😊
When reading my explanations again I now see that I might have switched the phrases “up” and “down” . What I ment to say is that the elevator trim needs to push the tail down, but that is an up trim, isn’t it?
So that is what is baffling me. The tail needs to be pushed down even though the CoG is 4.5 cm behind the marking on the plan.
But to answer Donald’s questions:
Yes, it got better and better when loosing the lead and at 425 gr. I thought it was quite manageable although it was a bit twitchy. After reducing the throw of the elevator that also got better and I decided to practice with that setup. I also checked the incidence yesterday and it is according to plan.
I ‘m still practicing flying and trimming my Bleriot. Now when new season is coming I’m re-reading the suggestions made on this thread preparing for the first flight this summer. Before last year’s season was over I managed to trim the elevator, and CoG for a levelled flight at a little less than full throttle.
The CoG is about 14 cm from the LE edge which is about 4.5 cm behind the spot suggested by Boddo. I now have 425 gr. of lead up front. Bearing this in mind I would think that the problem would be a tail-heavy model rather than nose heavy. BUT the trim needed for the elevator is a down trim of about 12 – 15 deg. (Remember the split stabilizer has a big elevator area)
I’m not sure what I can read into this. Is the stabilizer creating lift which needs to be corrected by down-trim elevator?
This trim must be creating unwanted drag. I wonder if it would be wise to alter the incidence of the stab a little by putting a 1 or 2 mm shims of plywood between the fuselage and the LE of the stab and reducing the down trim of the elevator.
All comments and suggestions are appreciated.
|Thread: Mini Super|
Thanks DeeBee - this is a fascinating story
I’m a proud owner of a Keil Kraft Mini Super. It was built by me and my dad in the early seventies, ‘72 I think. It was a Keil Kraft kit and I still have the original box and plans.
It has had several rebuilds and some modifications over the years but I’ve been flying it every summer since 2013 when I did the last rebuild. I also did some modifications, ailerons, less dihedral, steerable front wheel and so on.
It has gained some weight over the years, just like some of us and today it is 1.835 gr (64.7 oz). The last modification, a bigger fuel tank welded together to fit available space, added about 40 gr. The original kit had a tiny tin tank.
The wing area is 2.267 sq. ft. not counting the middle section so the wing loading is up to 28.5 oz per sq ft. in my model. That is a bit heavy and the landing speed is also a bit fast but a heavier model suits the windy weather in Iceland very well.
The original plans in the kit came on two sheets, clearly marked 48” wingspan and are signed by Ernie Webster if I’m reading it right. I didn’t know that David Boddington had a hand in the design. Can anyone explain to me how that came about and who is the original designer of the Mini Super?
|Thread: LED-lights DIY|
Even though I had much fun implementing the navigation lights into my Mini Super they came out a bit dim.
Next time I would follow John Stones suggestion earlier in this thread and buy a ribbon to pull the leds out of. It can be bought in any length
The link is: LINK
|Thread: Ask..Peter Miller|
|Thanks kc 😂|
I look forward to reading the missing parts.
I’ve already ordered your book Designing Model Aircraft. It can be bought from Amazon.co.uk, there are still a few copies left:
Good evening Peter
I hope your health is coming back.
I find this middle article part very interesting and would very much appreciate if I could see the other two.
Best wishes from Iceland,
Edited By Birgir on 03/01/2018 16:05:23
|Thread: Bleriot XI|
Thanks for this
I think I’m beginning to understand the task at hand and getting a better understand of the problem.
I’m used to land my trainer using the throttle to control the decent, (i.e. elevator – speed, throttle – height) but the trainer is trimmed for level flight at ca. 60% throttle. And a proper decent at about 40 - 50% throttle.
The Bleriot isn’t trimmed properly at all. I fly it at full throttle using the elevator to maintain height. This is the first thing I must change.
My limited experience with the Bleriot tells me though that I have a very narrow band of throttle change to play with, much narrower than in the case of my trainer.
So, next flight the task is to trim for levelled flight at something less than full throttle. Full throttle should then increase height and something less should cause levelled decrease in height.
Because of the narrow band in throttle change, it is possibly wise to install throttle curve in my TX. For example, setting 50 – 75 – 90 at 25%, 50% and 75% stick position resulting in the last 10% of throttle change spreads over the top 25% of stick movement.
When this trimming is accomplished I should be able to practice a few low passes hopefully resulting in a smooth landing in the end.
I would welcome any views and warnings about this approach.
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