Dornier 335

Well as I am new to this site, I might as well start with a new scale model construction, I fell in love with this plane many yrs ago, but then we only had I.C. engines, the ft engined would protrude from the cowling, and the rear one looked like a real handful + weight,, so time marchs on and I revisted the craft a couple of months ago, and with some consultation with an E.P. fanatic, I decided to act.
Al marshall's plan at 81" was a little to big for me, so I contacted one of our Laser guys and asked him to reduce the plan down to 73" and supply me a short kit for it.
It is now on the bench being constructed,
I will try to download a pic

This looks iteresting ill pull my chair up and watch

that looks like a good build.

got me coffee and biscuits and will enjoy watching this one develope.

tony.

Make a bit of room please lads, got my coffee and chair, very interested in this one .

Garry

when i worked with YT, several of ours were sold, not many fitted the rear motor, one guy even slope soared his as a PSS model, i havnt got a chair, ive rigged up a live vid feed

The main issue with this project is of course the rear prop, SO, after much thought and studing the situation, ( sometimes though the bottom of a glass), I will be mounting the rear motor as close to the C.G. as possible, with aid of high speed bearings ( 5 of them, 1 at motor 2 in the middle, 2 at the rear to take the prop load) secured to the fuz formers. The shaft will be an 8mm ali rod, it will be cut around 1/2 way and a flex coupling will be added, the same will apply at each end, I might have to cut the shaft into 3 pieces, to stop the whip but I will know after a test is done before fitment. I will laser beam align the whole fitment to keep the shaft as straight as possible, the wing, at centre, may have to be opened out to accomadate the motor
Motors , at this stage I am going with Turnigy G46's but allowance will be made at the ft for a G60 if required, the batteries will be 4s 4000hr x 2m and they will be slotted into where the ft fuel tank should be, but they can be moved if necessary, these are just idea's at the mo .
The web brings up the build of Al Marshalls model in good detail, instructional build actually,, but it relates to the 60" one and of course I got his 81" plan reduced, didn't I, so altho there are slight differences in the structure, the download is very helpfu l
The colour scheme of the full size is of a splinter nature, but there was a night fighter produced with a snow effect scheme ,underside is RLM 65 at the fuz side view it starts to blend into white ( RLM 21 ) with what looks like splashes of RLM 75, much the same pattern as the desert camo
added a few bits last night, but not a great deal
Cheers all
Thanks for the kind words
Barry

I'm watching with interest too.....I've always hankered after the West Wings FF rubber powered version which is slightly (well a lot really) smaller than yours.....

www.samsmodels.com/site/dornier.html

Quick question - why go to all the trouble of fitting an extension shaft for the rear motor. It looks like a lot of engineering for very little weight reduction and there'll be a lot more to go wrong?

.....Best of luck with the build!

That was exactly my thought as well.
Surely with heavy batteries required countering a rear mounted motor should not be an issue.

Yep, I can understand your thoughts, but with 400 gms of engine/motor in the rear and 900mm from the C/G point, one will need a lot of weight on the ft, with the batteries, I can adj the overall model weight......that's the theory anyway.
Do ya know that 12ozs of fuel weights close to 375gms, add that to the engine weight an more weight is needed in the ft
Cheers all
Barry

chookman wrote: Do ya know that 12ozs of fuel weights close to 375gms,
Barry

I thought it weighed 12oz.

But surely there is another 300g nearly as far at the front anyway.
The batteries (how much are they likely to weigh?) only have to make up the difference in moments.

Guys, correct me if I am wrong, all of this is to lower the overall model weight :- with 1000mm from tail to C/G and 500mm to the nose, to get the balance, I will need twice the amount of weight in the ft as compared to the rear, OK, if I was to fit the motor to the rear, say 400gms, disregarding batteries, because fuel + tank = batteries, it will mean I need 800gms to balance, ok I hear ya say, "what about the other motor in the ft," , well that is correct , but with the motor shifted to the centre, I only have 400gms on the C/G point, so I have saved 400gms to the total model weight so far, but with shaft and bearings I have to reduce that figure 50/70gms ......I hope
Cheers
Barry

Barry
Not sure why you discounting the effect of the weight of the batteries.
They will weigh at least as much as the pair of motors and possibly quite a bit more. (eg 5000mAh 6s = 980g)
They are free to be placed in any particular part of the airframe and as they don't get lighter as they are used up there is no requirement for them to be placed on the CofG.
The only problem I could see would be if the batteries cannot be physically installed in the required location.

I avoid using ballast like the plague on any electric plane and always use the batteries to achieve the required balance.