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Traplet 94" Hadley Page HP42 CofG ?


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Many thanks for the link and I will see what else comes in over time (hope). I have a good idea where the CofG should be but the aerofoil wing profile used on this model is not the same as on the Traplet plans - why this was done I have no idea thinking however I am clear that when it was flying (originally electric but recently converted to IC) the take off run was "extensive" which could be down to the wing section profile. Also as this is a biplane there is currently NO downthrust or sidethrust built in which makes things worsedevil. I do not want to "suck it and see" so I am trying to see if I can take a few of the "unknowns" out of the equations. Your link will help me and I thank you for taking the time to reply as this link is one of the best I have seen thumbs upso I know it will also help others on the same quest - Regards Peter.smiley

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I found it great....I have a stampe (not from Precedent). The fus was 25mm shorter than the Prec Kit but the wings and tail are the same dimentions . I put all the info in and the C of G calculater and it was 5mm different from the Prec plans I have. Checked with the model and it was as calculated.

So it is pretty accurate thumbs upthumbs up

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Hello Peter,

This is my '42, 120 inch 4 x 46 two strokes and near 35lb. A 30 year old hanger queen which we took on, intrigued to see if it would fly.

After running out of excuses we finally took it out to commit aviation and to everyones surprise, it flies beautifully. The CG was guessed at about 25% top wing chord but TBH with so much wing area and a long tail moment, it has all of the attributes needed to fly well.

This one is adequately powered but you have to allow time to let it accellerate before 'applying to climb' and by the same token it has considerable built in drag, more so with four idling props. It needs to be flown all the way down in a powered glide, only shutting down to idle as the wheels touch. If slowed too much it has a sharp stall but it flies in a steady and stately manner as befitting the prototype.

Give it a go, you might be pleasantly surprised by how it performs.

stu k

more pics here

http://www.donvalleymfc.co.uk/page30.html

 

Edited By stu knowles on 27/03/2013 12:30:42

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Hi Stu.face 1

You are giving me something to think about and I do want to see it in the air. Currently has 2x25 two strokes but I am not confident this will be enough on a grass strip. Did notice that they all seem to need a good run of speed before lift off. I think I have the CofG sorted - thanks to all - so now its the nitty gritty to sort out but the power side is currently a worry as to have to go and buy say 4x 40s would set my pocket back a bit so I am going to give it a try at the field (when it dries out) and see how much speed I can develop down half the field - if it gets moving at all as there is a lot of weight digging in the three and a half inch wheels... Looked at your club site and seen the pictures of the old lady with the same Reg No as my beast and she looks grand. I have been working on the plane today and I am going to get everything functional and take it to the field to see if the power train fitted will work before I do anything else - if it looks like it will fly I will just fly a circuit and see what I think about the power situation because if its underpowered it makes flying so much harder... If all goes well I will then work on the cosmetic side - but it all depends on the power plants being ok.

Recon the all up weight is around 26 lbs at the moment for the 94" beast...

I wonder how many other HP42s are around flying....thinking

Regards Peter

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Not too many but it is surprising how many have thought that a four engined multi strutted biplane airliner is worth the effort. There have been a few on the LMA circuit. One beaut at around 17ft that wil be flying this year with Ian Redshaw and possibly one even bigger next year.

I also meant to say that all my engines are bolted on square, no side or down thrust.

Will 25s be enough?? hard to say. I have a 90 inch Chris Golds Lancaster on 2x 25fp and 2 x 20fp but that weighs in around 18lbs and a lot less drag. You could try 2x 40 on the lower nacelles as a halfway house.

I agree with you, I would have a few 'fast taxi' runs when the ground is hard. It will fly at slow speeds because it has a massive wing area but I have stalled mine a couple of times by attemping to climb too quickly and only got away with it by having a fair reserve under the left thumb. If yours gets airborne just give it time to get some hight under it before turning and keep the turns gentle using rudder as the main directional control.

Let us know how you get on.

cheers

stu k

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Hi Stu. Thanks again for the vote of confidence... Its only the power side I have issue with and perhaps 2 x 40 on the lower wing will make me feel better - and its always better ho have that bit in reserve.

Seen the LMA one and it looks great in the air with a good presence which is why I went for this as I am far from conventional with my planes so tend to get problems because I am unconventional but thats the fun of it. Will let you know how things progress in the future. Regards Peterthumbs up

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Hi. Perhaps this is the way to go but I will run up the 25s and see what power there is there. I have been sorting the throttle linkages as they were not even and at full throttle only one carb barrel was 100% open so now I know I can get 100% from the engines I will see that they can do. I hope to start the engines next Tuesday 2nd April (with luck) The engines are running 9x6 props which should be fine. Another factor to fitting larger engine is that of prop ground clearance as the largest prop to give grass ground clearance - but that decision will be left for another day after evaluating the model.

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After looking at the whole project I now feel to stand a good chance of this plane flying again I will have to "bite the bullet" and fit larger engines. A number of reasons for this but the first two stand out...

1) My birthdays next week so I end up getting two engines "free" - thanks to wife Jan and mate Dave.

2) My contribution will now only be half the original total cost so very good value. (linked to one above).

3) If I am going to do major work required to fit the bottom two engines (needs top wing removal) I may as well do all the four in one hit then there will never be any power issue.

4) As major work is involved I may as well renovate the whole model...

5) The drastic actions above are due to information gained here - Thanks Stu / Cymaz.

I have already done a lot to the model already and I took a few better and put them into a short video as a record.

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Hi Stu. Already started rubbing the old lady down and finding all the old wounds from "prangs" gone by - Your comment regarding the wing stall got me a bit worried - our patch is a grass strip and the grass is sometimes a bit long which will make it harder to get up ground / airspeed for take off so if she lifts off at the end of our field heading towards the sea (common wind direction here in summer) I don't have a lot of time to climb before I need to turn which is why I feel some power in reserve would be the better option. As its my birthday shortly I get 4 engines for the price of two - no husband should turn his nose up at that kind of deal from the wife.angel 2 The weight of this model but its near 10 Kgs so its not that light and perhaps on tarmac it would get off with the original engines however on longish grass it would just bog down. To fly around the sky on half throttle would be nice with the other in reserve for the gusts and tribulations of flight is ideal. Now I have started I can also tackle the landing gear which currently is not sprung. I am trying to see if I can devise a sprung leg to ease the progress over our field. I don't want to get carried away too much because she is (like yours) a very old lady but it would be nice to tidy her up and restore a bit more of her looks. I also intend to paint her in a silver grey rather than use actual silver paint which seems to show every fault / scratch / bump & anything you can think of but a silver grey with a satin fuel proofer should look better in my view.

I will keep this site updated as time goes by - I don't tend to hang about once I start - engines are ordered and I collect them next Friday so in the meantime I can keep rubbing down and making good so I have plenty to do for the old girl but with each day she grows a bit younger & prettier.

Regards Peter smile

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Good move Pete the 'Old Lady' will look a lot better after a 'nose job' with the new balsa block and I have to agree with the idea of providing additional power especially with the situation at the flying club field with ditches either end.

I was interested to note on the build of the Empire flying boat that the constructor is using aluminium 'Oracover' which if available at the time could well have suited the HP 42?

Let me know when the plane is going to fly.

Best Wishes,

Mike

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Hi Mike.smiley

I started rubbing down the model in the shed yesterday however the dust was awesome so today I went out and got an electric sander and started outside in the freezing cold when I got backface 23. Making a better job than I could have done by hand and able to flatten out the repaired (long ago) fuzz planks so they should look a bit straighter and better - recon it's taken 4 years off the old girl so far but plenty more to go yet. I am so cold working outside I am honestly blueface 9 Tomorrow I can get a coat of sanding sealer on it and leave it overnight to dry and start sanding again. Other items ordered up today engine mounts,spinners & nice cherry wood props... Course I will let you know when it will fly. Regards Peter

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Nice to see a nose job where the nose gets longer Pete!. You appear to have done some good surgery so far and made good use of my balsa block.

Snowing here today on my birthday,it's never done that before but perhaps in 1947.

Cymaz has a point but lettuce hope it flies faster than a tortoise and does not turn turtle!!

 

Mike

Edited By Mike Etheridge 1 on 04/04/2013 15:18:32

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Just came in from a friend from down under in Oz...smiley

Dear Doctor,

That is a very nice looking nose job you have performed on your ageing patient. Hope the other cosmetic surgery goes as well.

Cheers,

Darcy

My Reply - So do I... face 1 UPDATE.

The fuzz is now almost finished except for the tail area - Installed a new snake for the rudder late last night and over the past few weeks I have been playing about with different spray paints together with the dreaded fuel proofer - from what I have learned I will go ahead in the next stage and apply the spray paint and then the fuel proofer over the top and with the combinations of paint I have selected it should not react with the fuel proofer as per my test samples - I hope this is not famous last words.thinking -If all goes well with the spray finish AND the fuel proofing over the top I will show the results in some pictures and also let you know what I used as its a fraction of the cost you would normally pay but the proof will be if it don't pickle when the proofer goes on...

The main problem I will shortly have will be around the engine areassad when I start on one of the wings - it's got that old nitro fuel and oil which has eaten into the old paint face 24 it's going to be hard to get it off / out as its well pickled in - the "gunk" residue was bad on the fuzz corrugations but it's far worse around the 4 engines. .dont know . (Joy's of renovation).

Got the new engines yesterday (SC52s - gift Birthday present) so things are moving on. Also going to try and obtain some old 120mm long Oleos (in BMFA wanted add in now) I hope to be able to make a suspension system for the old girl to ease her old bones when she trundles down our bumpy grass strip and once they are camouflaged to look like the real U/C that will be great - will update - if I can get the right size of Oleos - and if I can do itthinking

Will keep the updates coming - for them that are interested.

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