Idigbo

Hi all,
For the past two years I have been tinkering with this third scale model of the DH Pusher, reached a milestone today coz I (we, me and my mate Chris, Hurricane 527) taxied it! The span is 114"and it is powered by a Zenoah 62 driving a belt reduction gear and a 9" extention shaft which drives a scale 30" x 10" pusher prop. It was important to get the motor in front of the C G as the unit weighs about 5lb!! Hence the shaft. I had ideas of how it might be designed and fit in but the manufacturing was done by a local engineer who builds / restores Motorcycles. (cheers Dave!) After some initial teething problems, it runs superbly, although I have another minor problem with the shaft to sort out, but it should be ready for flight soon. It is actually physically ready for flight now but it needs a final inspection from the LMA. The engine is buried in the fuselage and is cooled through the cockpit and exits through the rear former and around the dummy rotary. On the shaft inside the fuselage there is an extractor fan to draw the hot air away from the engine and out of the body. The ingoing cooling air is ducted closely to the cylinder head ( if, when the engine is running, you put your fingers infront of the head you can feel cool air rushing past, so the hot air is going somewhere.

Idigbo

Sorry those pics are a bit big, I'll reduce them in future!
Ian.

Yak18

My Feedback: (11)

Absolutly Awesome!!! Now give her the goose and put some air under those tires.

Yak

rsjr

Beautiful!!! What a fantastic looking airplane !

Jim Finn

My Feedback: (2)

Very nice! I want to do one a bit smaller electric and you have given me encouragement with these great photos!

Doug D.

Beautiful ! WOW ! How on earth do you transport this wonderful piece of craftsmanship? I'd be afraid to take it apart. Because I'd forget how it went back together. Do you plan on some scale pilots? Would love to see it in person in the air.
[&:]

Idigbo

Thanks for your kind words. Although it looks daunting, the model breaks down quite easily for transport. It breaks into 4 bits, - port wing panels, starboard panels, main fuselage and finally the booms with tailplane. It takes about 25 minutes to put together, less if there are two and all control cables ( rudder and elevator ) stay with the wing panels.
On the subect of a pilot, I am a puppet / marrionette maker so I should be able to rustle something up that looks like Capt JA Cunningham, the chap that flew the full size, although he plans to have an openable coat to let the cooling fan do its job, sucking air in through his hollow shoulders and around the seat. I haven't started the pilot yet, as I wasn't 100% sure the cooling idea would work, but work it certainly seems to do.


Ian.

ballgunner

My Feedback: (1)

Wonderful piece of work. This is one of my all time favorite WWI fighters. Not being into interplane wires and braces I go for simpler types. There's and old story about the rigging. After all was done a pigeon was thrown between the wings. If it escaped there was a wire missing. Congratulations on a beautiful model.

Bearzilla

My Feedback: (17)

GORGEOUS looking plane! how much did it wind up weighing? Whose plans/kit did you use?

VERY NICE WORK INDEED!

Idigbo

Cheers Bearzilla, the plane weighs 21kg which is just over the 20kg limit for models without inspection by the LMA, over here in Britain, but it should be a reasonable floater as there is over 26 square feet of wing area. It requires no ballast to get the balance in the right place, which I was suprised to find, bearing in mind the ironmongery is not in the ideal place! It was designed using the Windsock Datafile and a smaller RC plan as a guide. It was not designed by me although I had drawn a very similar plan to quarter scale when the third scale version came my way. It was originally designed for a direct mounted 60cc petrol, but hanging 4 / 5 lb of motor behind the balance point did not seem a good idea to me, so plans were drawn for the Speed Reducer / Extension Shaft combination, which allowed a dummy Monosoupape Rotary to spin on the shaft also. This keeps all of the powerplant in front of the balance point apart from 3/4 of the shaft. This saved the need to build in 8lb or so of weight into the nose. The dummy Rotary has cylinders cast in polyeurathane foam and the crankcase is blue foam, covered in paper for a smooth finish. Inside the dummy, holding it all together is a 1/16" paxolin 'spider' which also mounts the bearing on which the motor spins. The spinning rotary doesn't show too well on the photos, must be something to do with resolution, I guess?

Idigbo

Progress so far.

It has flown 4 times up to now, first flight was a bit of a disaster.
The 'plane took off beautifully, fully controllable but wouldn't climb above 20ft, running out of space due to big trees and not so big a gap between DH and ground, so reduced throttle to land and the thing decide not to fly anymore. I liken the approach to what would have happened if I'd have dropped it from an upstairs bedroom window!!
Those present reckon that the drag of the plane very nearly cancels out the thrust from the prop, so it needs more thrust. The motor with the 30" x 10" revs freely to full power on the ground without loading, so I have changed the prop to a 30" x 14" which has loaded the motor on the ground (down 400rpm) so the plan is that I'll get some of the lost revs back once it is in the air. I need to run it on both props and see with a spring balance just how much it is pulling.
I flew it at my club field on the original prop, it flew well but hadn't reached 50ft by the end of the first circuit. I am amazed at how slowly the thing flies, it takes approx 4mins to do an average circuit! Landings are achieved at 95% full throttle or all that drag comes into play and the game ends.
When I get around to fiddling a bit more I will post more pics.
Ian.

Lucky Dog

My Feedback: (1)

Idigbo,
Just awesome!

Regarding your "blur" on the rotating engine pics. If you can slow the shutter speed down some on your camera (by 2-3 stops), you should get more blurring (if that's what you're after). You might need a tripod though. Of course, reving up to full throttle might help too.

I look forward to the next up-date!

jasonp51d

My Feedback: (2)

Looks gorgeous - I hope you are taking her to Duxford or Cosford LMA?

VBR

Jason

Katchmarek

My Feedback: (29)

Hi Idigbo, What can I say...she is simply outstanding! I wish I had the patience to deal with all those wires...but I too limit myself to simpler types. However, I can truly appreciate the craftsmanship and the patience it took to build such a beautiful model.
Happy flying,
Rob Bailey / Pickupsticks

If you like giant scale warbirds, check out my sebsite at: www.warbirdbuilder.com

abufletcher

It's very encouraging to see such a finely detailed model actually flying!

hurricane527

hi there
just thought you all would like an update on my mate Ian,s DH2 photo's taken at our local patch on sun 4 july of its 8th flight, 5th flight to qualify for CAA exemption in our over 20kg scheme (even though it came out at 19.5- honest!!!) you will notice the lack of pilot this is due to him being overweight and putting plane over 20 kgs... actually he sits right in front of the engine and stops cool air entering ducting, is due to have surgery to allow air to pass through torso. Hope you like the pics, the slightly overweight person (the one without the beard) is me.

dottney

My Feedback: (2)

This is one impressive plane. Not only one of my favorites but also a giant. Great job.
Dave

feep

Your DH2 is magnificent! I am in the initial planning stages for a 1/4 scale to go along with my E111. Could you recomend any good plans? (I already have the Windsock datafile) and could you explain how the booms attach to the wings? Is it a problem to start inside the boom stucture? I hope you have had good luck with it.

hoonnz

Idigbo,
That is a brilliant piece of modelling, an inspiration. I fly at the Kaiapoi Model Aero Club in New Zealand and one of my flying mates specialises in large WW1 models. He is currently scratch building a DH.1A. He is not into computers (he is 84), but he asked me to help to see if I could track down the one scale detail he can't find any info on - how the U/C axle is fitted to the struts. We know there is a plate with a curved slot in it at the bottom of the V, does the axle go through that, allowing some backward and forward movement; or does it sit in the V of the struts, held by bungee cord? I'm hoping you may be able to oblige with advice or better still a drawing or photo.

I'm going to print off your photos to show him, and I'm sure you experience power-wise will be of huge benefit to him. Thanks for sharing your experiences with us.

Brian.

Idigbo

Been a while since I looked on here!

Feep, the Windsock datafile is a superb plan, go with that as it is accurate and produces a plane that works.

There is a smaller (63" span) plan by the late Peter Neate which is available and also a good source, although scaled up would be a little over engineered in my opinion. The booms have a stainless steel socket at the rear spar position, they simply push into the sockets and a 3mm bolt secures each boom. My DH2 has a spring starter on the Zenoah, so to start you pull the prop back half a turn and release. There is no problem starting like this, priming the motor is a pain though as the tank is all the way up on the top wing, with about a foot of small bore brass tubing for the fuel line! Once started once though, it generally starts very easily for the rest of the weekend.

Brian and Neil, the U/C axle on the DH2 is bungee chorded into the Vee of the U/C struts, like you thought. At the junction of the front and rear struts there is another stainless steel socket type affair that the struts bolt into. This is sort of U shaped and the axle sits into this, there is no slot and the axle is held firmly whilst being able to mve slightly front to back. I presume this is the same for the DH1 and the info I have seems to show this. I'll take some pics if it would help you both?

The DH2 has been in the air now for about 7 hours, at 10 mins a flight, so is well flight proven, and now I am used to its foibles, like having to use lots of opposite aileron in turns[:-] it is easy to fly. It has had some success to, with a bit of tinware to show over the last two years, including the Top Gun UK WW1 pot for the second year running.

Next thing to do on it is to fit a mini camera where the pilots head is, as in flight, the joystick and rudder bar move with the surfaces and it would be nice to see a video of it working! The camera will be moveable too, so 'he' can look out over the wings, and into the cockpit. Probably a bit gimmicky but who cares!!??

Here's a few more pics.

Ian.

ramcfarland

My Feedback: (44)

Send them big: the more beautiful craftsmanship to look at

Pelle Gris

Do you by any chance have a video clip of the plane flying? Would love to see it in the air.

Idigbo

I do have some video of it flying, but am not technologically advanced enough to put it on here!

A good flying mate is a wizard with things like that so I'll see if I can persuade him to put some clips together.

There is a video available in the Uk which does a feature on it with some flying and detail shots.

Ian.