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Birgir

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Posts posted by Birgir

    Bleriot XI

    in Vintage Kits, Semi-Kits and Plan Projects

    Posted

    Dear friends

    Browsing the net about Bleriot XI rc model, I came across a text on Mick Reeves webpage that describes a 1/3 scale Bleriot XI model.

    The main facts from that text is:

    • Wingspan: 115”
    • Weight of nose ballast: 4 kg
    • Total weight of model: 14 kg
    • The model flew.

    My question is:
    Can I downsize this information to my 60” wingspan model using the rate 60/115 assuming that my model could take 52% of the weight i.e. 7,3 kg (incl. 2 kg of ballast)?

    dsc_0008b.jpg

    At present it looks like my model will be 2.6 kg incl. 0.55 kg of ballast, a lot less than the calculation above.

    Birgir

    Bleriot XI

    in Vintage Kits, Semi-Kits and Plan Projects

    Posted

    Hi

    This is a very interesting discussion and there are many good advice here.

    John, if your model, without engine and battery, is 3.63 kilos it could be about 4 kilos dry weight with engine and battery.

    My model is 1.55 kilos without wings and covering. If I use the ratio between wingspan.e. 60” to 90” I must keep mine below 2.66 kilos. Hopefully that gives me some margin for lead.

    Is this way of thinking logical?

    B

    Bleriot XI

    in Vintage Kits, Semi-Kits and Plan Projects

    Posted

    Hi John

    What an exciting project. I agree that a project like that should be enjoyed slowly, like eating a good dinner.

    A lot of questions come into my mind. Do you know the weight of the airframe? Do you know if it was flown a lot with the 61 engine? Was it powerful enough?

    And last but not least; have you tested where the CoG is?

    B

    PS. To Donald Fry - I agree

    Bleriot XI

    in Vintage Kits, Semi-Kits and Plan Projects

    Posted

    Hi everyone

    I‘ve been building a Bleriot XI for the last few months. I’m using a plan by David Boddington of a 60” Bleriot. (**LINK**)

    I’ve done some modifications to get closer to the plane Luis Bleriot flew over the Channel in 1909. For example split stabilizer and roof-like strut. Now, when the building is well on way, I’m having some doubts.

    Firstly, I decided to use the SC30FS engine. The plan recommended a PAW 29 which is a diesel engine. The SC30FS is probably not a very powerful for a 60” model, but the original ANZANI was probably not that powerful either.

    Secondly, it looks like I will have to put quite a lot of lead in the front, to get the CoG right. According to the plan CoG is about 10 cm from the LE of the wing which is 34 cm from LE to TE.

    I would welcome any thoughts, ideas or suggestions that could help me along solving these problems.

    Here is a video of the landing gear that I think is working quite well smiley

    More pictures can be found at my web: http://flugmodel.weebly.com

    Regards,
    Birgir

    Edited By Birgir on 11/10/2015 20:53:02

    Mini Jazz builders hangout.

    in The 2014 Mass Build

    Posted

    img_20150710_083200.jpg

    Before and after the rebuild. I also found a new location for the switch so it does not weaken the fuselages side. (Not that it would have changed anything in the last crash J )

    During the crash investigation it was discovered that two of the nylon geared servos were stripped. One aileron and the elevator. Of course it could have happened in the crash but it is better for my self-esteem to believe that one of it stripped just before the crash. I have now replaced all my nylon geared servos with metal geared one.

    B.

    Help needed

    in IC Engines

    Posted

    Problem solved!

    tankoperation.jpg
    I decided to do a "keyhole surgery" and replace the clunk tube. When I got the clunk tube out for inspection there was nothing wrong with it BUT in the clunk itself there was a wire filter the was partially clogged. I replaced the clunk and the tube.

    clunk.jpg
    After the operation, I tested the engine and now everything seem to be alright.


    So after all, it was Kenking that was right – at least partially – the problem was due to disturbed fuel flow thru the clunk tube.

    Thanks for everyone’s help, it’s been a pleasure working on this problem. wink 2

    B.

    Help needed

    in IC Engines

    Posted

    fueltank.jpg

    Yes, the red thing is a cap. smiley

    The setup is similar to this picture but the fuel pipes go through the bottom of the tank/flask instead of through the cap and there is also a fill pipe. The fuel pipe is a bit above the center.

    This picture was taken during the last rebuild.

    ms_tank.jpg

    So now I must make a tool I can use to change clunk hose through the opening.

    B.

    Edited By Birgir on 27/02/2015 15:16:38

    Help needed

    in IC Engines

    Posted

    Hi and thanks to everyone for sharing their thoughts.


    I finally made the Baker-test this morning and 12 points goes to Bert Baker

    burger.jpg
    The clunk-pipe nipple is at the top of the tank so with a half tank of fuel I ran the motor full speed to be certain that the problem was still there. Then I turned the model upside down so the clunk-pipe was fully submerged in fuel and Vola! No problem. I did this several times to be absolutely sure.

    Of course there is a small chance that there is something wrong with something else that disappears when the model is turned over, but I think that the clunk pipe is a reasonable suspect.

    dsc03047.jpg

    So now I only have to figure out a way to change clunk-pipe through the tank cap. Doctors do heart surgery thru smaller holes so it must be possible.

    Until then my Bleriot is coming along nicely.

    dsc03043.jpg

    Thanks,

    B.

    Edited By Birgir on 27/02/2015 12:12:22

    Help needed

    in IC Engines

    Posted

    Thanks kenking

    I like your theory. If we take this line of thought a bit further it could also explain the forming of bubbles in the fuel line from tank to carb. As you probably know, when the pressure drops in a fluid, a vapour bubbles can form, just like boiling.

    The boiling point of fuel must be rather low so this is probably not as far-fetched as it sounds. The boiling point of methanol is around 65 deg. so the fuel could have even lower boiling point than that. (I’m not going to test it.)

    I wonder if it is possible to test this theory by putting an adjustable clamp on the fuel line from tank to carb. If that part is made a little narrower a cyclical phenomenon in the clunk hose should stop even though the engine might not reach top rev.

    B.

    Help needed

    in IC Engines

    Posted

    Well, we actually do have Iceland in Iceland too – you know – so I got the pun, but thanks for the concern.
    Maybe I will send some burgers over when I've done the test devil

    B.

    Edited By Birgir on 22/02/2015 19:01:41

    Help needed

    in IC Engines

    Posted

    Hi

    I‘m still waiting for an opportunity to perform the Baker-test, i.e. checking if the problem still exist if the clunk pipe is fully submerged in fuel. Because the test needs to be performed outside I must wait for suitable weather, and it can be a long wait around here.

    While waiting I’m forced to spend time on my next building project.

    B.

    Maths and English

    in Chit-chat

    Posted

    “Our youth now love luxury. They have bad manners, contempt for authority; they show disrespect for their elders and love chatter in place of exercise; they no longer rise when elders enter the room; they contradict their parents, chatter before company; gobble up their food and tyrannize their teachers.”

    Socrates, 469–399 B.C.E

    B.

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