solentlife

I am crazy about the Vulcan ... as with the EE Lightning also ....

I have gone through own design foam version Vulcans ...

Full form pusher - flew - but was a pain on the ground for prop clearance at rear !



So onto Prop in Slot version ... better but overall was weak and flex killed it ...



Back to pusher - but with double laminated form - this was a great success ...



But it lacked the shape and form .. ok in the air you could convince yourself it was ok ... but it niggled ...

Along comes Tim and Dom in Aussie - Dom - a young lad with CAD skills .. and we have a 1m 3D EDF version on Cults ... amazingly over 900gr but with 50mm EDF.
So - Vulcan EDF it is .... not one - but two. One in PLA and with camo scheme ... second in LW-PLA and anti-flash white. mmmmmm I'm thinking - maybe I can get a bit more performance out of it - so a third is produced with tractor prop .. the spinner taking the place of the iconic nose !



Moving on ... and more suppliers adding LW-PLA to their product lines and we have 3DLabPrint .... so a couple of rolls are ordered and #4 Vulcan is on the cards .... this time to use the advantage of LW-PLA to its max.



LW-PLA can expand anything from 2 - 2.5x usual PLA and this provides not only possibility to increase layer height, but also skin strength through slightly increased layer width. Example is that this Vulcan is about 650gr in PLA before gear installed ... but about 420gr in LW-PLA ..

All we need now is that 'Vulcan Howl' !

quorneng

I wouldn't hold out much hope for a true 'Vulcan howl' with an EDF (it comes from the full size inlet geometry and its volume is determined by the air density at the time) but if you go bigger and use four EDFs you will get a both an amazing sound as well as some delicious harmonics.

solentlife

Oh - I know the howl is due to inlet and the design of outlets .... and no EDF will ever get close ...........

I have to admit that my twin 50mm Concorde - I like the sound there - even though its nothing like the real one ...

I have toyed with the idea of 4x 30mm on another Concorde .... but I'm a cheap-skate and that's nigh on 180e cost just on EDF's / ESC's ...

pmullen503

A tractor Vulcan sounds like a winner and would solve the problem of the prop striking the ground (or your hand with a hand launch) with a pusher. If you could 3D print a spinner to the right shape, that would complete the look.

solentlife

The alloy spinner was actually a good match ... I measured it and removed the front part of the 3D nose print to align with it ...





Once painted - it blends in well .....

Unfortunately - the runway I tried take-off from was rough and had big lumps of weed / tough grass up through the concrete slab joints .... causing the model to bump and nose to bounce as it gained speed - such that it left ground and stalled / torqued into the ground.






Cut back and cleaned up :



New sections ..









She has new front end etc. and will be back on runway soon !! Once weather sorts itself out.

quorneng

The joys of a printed structure!
You were perhaps a bit fortunate that the damage was so relatively limited but a nice repair nevertheless.
Remember more oomph does equal more torque!

solentlife

Yep ... always a trade off ... power vs torque etc.

If I go up on prop - I get more torque and a less forgiving model when I need to throttle up ..... but if I go up on LiPo - I can still have same torque at bottom end and once speed is increasing and model level - more power range.
It crosses my mind whether a better runway allowing me to accelerate along the ground better before rotation ?

pmullen503

How about a 2 motor push/pull setup with smaller props? Counter rotating to reduce torque. More available power for take off and then you can throttle back once airborne.

My experience with my much larger (4) 70mm EDF Vulcan is that it takes much more power to get it airborne than to maintain flight. Once flying I can throttle way back. I've even flown it on one EDF. I have my fans on a switch that allows inboard, outboard, or all 4 fans to run. I had just taken off (four fans) and heard one fan let go. I switched off two fans, the noise stopped, and continued the flight to a safe landing. At that time, I discovered I had shut off the two good fans and was only flying on one fan! The bad fan had lost it's rotor and stopped making noise when the rotor left the motor!

BTW, I had set it up to fly on 2 or 4 fans hoping to increase the flight time by switching to only 2 fans after takeoff. It turned out the energy consumed was about the same whether you flew on 2 fans at higher throttle or 4 at a lower throttle setting.

solentlife

The Vulcan has a huge wing and area and is why the throttle can be pulled back after take-off. I think Avro may have understood that when they designed it.