Toronto Electric Model Aviation Club Forum

Toronto Electric Model Aviation Club (TEMAC) => Building / Construction => Topic started by: octagon on December 12, 2022, 06:43:12 PM

Title: Dumas DH89 build
Post by: octagon on December 12, 2022, 06:43:12 PM
I decided to take on the Dumas DH 89 Dragon kit. The Dragon was perhaps one of the prettiest planes ever built, at least in my mind. But the kit is a bit notorious for being tricky to build. The kit has great plans, and a good construction booklet, but the laser cutting is so good that the parts drop out without being touched. That would be ok if they were labelled but they are not. There is a 2 page legend that shows the parts and which sheets they are in but the parts themselves are not marked making it hard to indentify them if they fall out. Anyway, starting out is the tail feathers outer edges, which are 1/16 by 1/8th balsa, moulded around shapes that were cut out from some spare thick plastic sheets I had. I was not very happy with the balsa in the kit, to hard to make the required bends so I stripped some very light 1/16 into what I needed. I really like working with magnets and magnetic building system. Wish I had discovered them years ago.
Title: Re: Dumas DH89 build
Post by: davidk on December 12, 2022, 09:05:30 PM
Agreed... gorgeous plane.
Title: Re: Dumas DH89 build
Post by: octagon on December 15, 2022, 07:55:53 PM
So I have had time to work on the wings. The kit is intricate and the parts in the balsa sheet are not marked, but instead you need to refer to drawing of the sheets in the back of the build instructions to identify the parts. The laser cutting is excellent, in fact almost too good as pieces fall out of the sheets by themselves. The plans are adequate but not great. This is certainly not a kit for a first time builder. Still, the beauty of this plane, and the lack of other bigger kits of it, or even plans of it, make me determined to finish it. My dad actually flew in one and talked about seeing the wings actually flexing.
Title: Re: Dumas DH89 build
Post by: octagon on December 16, 2022, 06:23:55 PM
After a nice day of flying with Michael, Glenn, Peter, and Dave I came home an resumed building. I first made the landing gear struts. The plans include full size diagrams of how to bend the provided wire. For some reason I get fluxomed building mirror images of wire gear. But I got it sorted and then silver soldered it together and it looks pretty good. The gear is held to light ply supports with a course thread that I CAed in place and then epoxied just to make sure they were not going anywhere. Wings are now complete up to building the nacelles which will come after the fuse is done.
Title: Re: Dumas DH89 build
Post by: octagon on December 18, 2022, 06:32:35 PM
Built the fuse halves yesterday and joined them today. I use a magnetic building board, which makes it easy to cut and align most of the parts before gluing. The nose of the Dragon curves in toward the front, but also is tapered up from the bottom of the fuse to the top. This required that I really soak the frames before clamping them. I had to make gussets to make everything stick. I find it odd that they are not on the plans. But anyway, all good and the thing is starting to look like a plane instead of just a bunch of small sticks (the largest on the plane are 1/8 but most of it is 1/16) stuck together. Tail feathers tomorrow. I have to hold off with motor mounts and so on until I can figure out motors.
Title: Re: Dumas DH89 build
Post by: GuyOReilly on December 18, 2022, 06:41:06 PM
Great lloking plané.
I like the "naked" pictures with all the fine woodwork and stringers, et al.  Real balsa porn naked like that!! :D
Title: Re: Dumas DH89 build
Post by: octagon on December 18, 2022, 07:13:12 PM
Thanks Guy. Many for 1/16 square stringers to go.
Title: Re: Dumas DH89 build
Post by: GuyOReilly on December 19, 2022, 08:23:55 AM
For inpiration, here is a model built by Gerhard Steckling.
Do you have a colour scheme in mind?
Title: Re: Dumas DH89 build
Post by: octagon on December 19, 2022, 09:18:32 AM
Oh My. That is absolutely gorgeous. I don't know Gerhard but he is certainly a master builder. I think this is the most challenging kits I have ever built. It is so small and intricate. The plans are just so so and none of the parts are labelled. Where was that picture taken Guy?
Title: Re: Dumas DH89 build
Post by: GuyOReilly on December 19, 2022, 10:33:39 AM
@octagon the picture was taken during one of the RCFCT Club meetings, I do not recall the year.
Gerhard informs me that the plane is on the ceiling enjoying life as a display.
Let me know if you would like to contact Gerhard and I will share your coordinates with him; I know that he looked at and enjoyed your post on the TEMAC site (guest only access). He has other pictures that he sent me via email yesterday, but I hesitate to post these without his permission.
Have a great day!

BTW, I was very fortunate to be given 2 of his models that are immaculately built - a Bolkow and a Rascal.  ;D
Title: Re: Dumas DH89 build
Post by: octagon on December 19, 2022, 10:58:39 AM
Hi Guy,
Yes I would like to talk to him. It will be interesting to see what he thought of the kit and plane. My cell is 416-985-5401. or email is [email protected]  Thanks Guy.
Title: Re: Dumas DH89 build
Post by: octagon on December 20, 2022, 06:59:36 PM
So had some time this afternoon to do a bit more work. I installed the 1/16 square stringers on the top and side of the fuse and started to fit the cabin and nose. I should have cut my own stringers as the stuff they supply is for the most part just to delicate and brittle. It is nice and light though so that will work to atvantage in the end. I will start working on the nacelles and power system tomorrow. The servos are in and elevator control rod is installed. I will be using pull pull for the rudder.
Title: Re: Dumas DH89 build
Post by: octagon on December 26, 2022, 09:07:50 AM
Had a bit of time yesterday so I finished the covering of the fuse and horizontal and vertical stabilzers and their flying surfaces. Used Ultracote Parklite. Very nice material to work with. Wings will be aluminum. This is the colour scheme of aircraft used for training in WW2. The picture of the rudder shows the ply control horn I made so as to be able to use a pull-pull system to contol it,
Title: Re: Dumas DH89 build
Post by: GuyOReilly on December 26, 2022, 11:19:58 AM
She is a beauty!
Title: Re: Dumas DH89 build
Post by: octagon on December 26, 2022, 02:40:09 PM
She's also a labour of love!
Title: Re: Dumas DH89 build
Post by: Frank v B on December 27, 2022, 02:43:13 PM
How to determine the motor size/type for this DH89 model.

https://temac.ca/smf/index.php?topic=8551.msg56846#msg56846

Frank

ps: Rob asked me to publish the method of picking the motors at some point