Tony Nijhuis' new Vulcan

Now here's a pic of the new Vulcan.....one of two sizes,,, the smaller being 48" and the larger being 78". The larger is sorted and will have a couple of 90mm fans or a single 44 size turbine (yes only a single!!!!)

The 48" is proving a problem due mainly to it's size. The pic shows the 48" with a couple of 68mm fans, but the weight is creeping up to 6lbs plus due to the complexity of the design and hand launching will become an issues. I have added some micro retracts but the wheels will be too small to prove useful either landing or take off (unless on tarmac) so I'm thinking of ditching the fans on this smaller version and going for a electric tractor and keeping it all very simple

just need to gauge the responce from the masses out there so all sensible comments welcome

maybe an electric pusher would look better.

Hi ,

I reckon a 50 50 split here as there will be plenty wanting the fan and settling for a bungee launch .

And at that weight the safest way will be the bungee

I agree with Tony Bennet, EP pusher

For C/G  would it balnce better with the motor on the Ft or Rear ?? saving adding weight         

Barry

Edited By A.A. Barry on 07/06/2012 00:22:19

Presumably the weight increase includes the impact of a spar incorparating the ducts to maintain strength in the airframe. Moving to a pusher format would surely be a retro step for this effort and would be further compromised by increased drag of none functional ducts. I can't help feeling that as Tony suggests a tractor set up is the best compromise for a good performance, that is unless you go pss and chuck it off a cliff - problem solved

My own view is that to have any sort of prop on this beauty would be sacrilege!

If it is simply a choice of having a prop driven Vulcan versus needing to use a bungee or dolly, then the latter wins for me. Once it is in the air then there are no props to spoil those long low flypasts.

I would go for two small pushers on the trailing edge of the wing but give a few hints on the plan to anyone who wants to go EDF?

I have had a Wren 44 sitting on my bench for the last three years; sacrilege I know! I purchased a plan of Graham Dorschell's 68in Vulcan with a view to heavily modifying it (redesign) to accomodate the Wren. However this would be a big job and I have little time for a project like this. I wasn't particularly bothered by the prospect of a single jet exhaust as I am not a purist, I just wanted to capture the character (wing shape) and turbine sound of this legendary aeroplane.

It is exciting that TN has produced a 78in span Vulcan for EDF or Turbine, I have no doubt that it will build well and fly superbly. Can't wait to order the plan and start cutting balsa- I will just have to MAKE the time!

As far as the 48" span Vulcan is concerned I would prefer a pusher prop configuration but care would be required for hand launching if inadvertent digit removal is to be avoided!

I would also opt for twin pushers.. I have a atand off scale Vulcan made in depron with a single pusher prop, and have no difficulty hand launching that.

Perhaps a single pusher and ditch the retracts for the smaller Vulcan. Have the ducting open from front to rear to reduce drag. Can have twin brushless on the outer engine exhausts.

I will go for the larger model and have EDF. Can't wait ...

Make the 48" a PSS  Maybe the 78" version should be for 2 x Jet Cat P20's or Kolibri's.

Keith - keeping the ducting open will increase drag by the way.

Edited By Frank Skilbeck on 07/06/2012 14:04:27

Some good ideas.......I do like the twin pushers idea......keep them coming

Frank you are spot on....if you dont need the ducts....block them up

For the smaller 48" one, a twin 70mm EDF for catapult ramp launch. I fear twin pusher props might get a bit finger hungry for hand launching.

Very interested in the twin 90mm EDF, assuming it doesn't get too heavy which then means more expensive higher powered fans/lipos etc in that vicious power/weight/duration cyclone. Using cheaper and less efficient HK type lower powered fans would be better, but i guess the AUW would have to be sub 8-9Lbs to get any performance without massive A draw.

My 6S Jepe fan is great and kicks out 6.5 lbs (1250W) of thrust for 54A, but that costs a fair bit and two would only give 13lbs of thrust max so I guess at 200 watts/lb the AUW would have to be about 12Lbs. Still I suppose cheaper than a WREN 44!

Stick with the EDF and bungee lauch, props would be sacrilge

A couple of HK 64 mm 2nd generation fans will pull 1500 watts with the right batteries, do away with the retracts, stay light, and bungee/catapult launch. May not be what the masses would understand, but it would work. Offer several options in the design. I would be happy to cobble one together with the twin fan set up to prove that option. Have done that with the NH Tornado.

Regards

Graham

For what it's worth, I think I'd be tempted to adapt the design for twin pusher configuration anyway.

Cheers, Pete

I too think pushers are far less obtrusive than props at the front.

As for the 48" fan version it's all but finished so the plan is to give it a go anyway, It will work as it has a couple of 68mm Lander fan but that is where the weight has come from i think!

I'm thinking I will build another version for prop drive and get the model flying first so i'm comfortable with flight characteristics before bungeeing something untested.....

any more comments?

PS... The 78" version will have a couple of 90mm Lander fans on 8s lipo so hoping for an AUW of 12lbs should see much better set up

How about using props inplace of the fans, have a slot in the wing for them to turn in, once they where spinning, one would hardly even see them

Barry