Another Greenacres contender - The Whizzza

[Chris Bott - Moderator]

There we were just starting to come up with contenders for the Mass build 2013 and I found myself with some spare building time.

But it was not in my usual workshop and not even at home.
So something was needed that could be built with the absolute bare minimum of tools and space.

It also had to be easy but great fun to fly, easy to launch and go in the car in one piece.
I had to hand a Whizzza plan and a few planks of balsa, so in the car they went and here's the result.

The model has been slightly altered to take 4S A123 batteries ('cos I have them) and a rear mounted brushless motor but otherwise sticks to the plan.

I've had about an hours air time now and can only say how much it has surpassed my expectations.

A gentle lob at less than half power has it nicely away straight and level, opening up will allow an impressive vertical climb as far as eyesight will allow. Huge jet style loops only need corrections if it's blustery and it seems to handle quite windy conditions well. I can't make it stall, it seems to just sink with the wings level if I hold full up. Quite tight loops and bunts are just as easy, rolls are pretty axial and inverted flight just needs a little down.

So all in all I'm a very happy bunny, with a good looking, robust, chuck it in the car model which I think I'll have with me whatever else I take to fly.

If there's any interest, I have photos from most stages of the build, and I can show just how few tools I used.

[Radge]

Good looking Chris!Well done chap (radgeclap on back). Most interested in the build pictures also.

[Biggles' Elder Brother - Moderator]

Chris is being very modest here - I happen to know that he basically built this model in a hotel bedroom during the evenings whilst away with work! Remarkable mate.

BEB

[Dale Gibson]

That's amazing Chris and I'd love to see the pics

Dale.

[WolstonFlyer]

The Wizzza looks great

I am very interested in the build pictures.

[GrahamC]

That looks great, I bet the cleaners in the hotel loved you!

I'd be interested to see the pictures. I've been thinking about building one of these, and would prefer to rear mount the motor myself.

I have a Tucano, so won't be joining the mass build as I don't want another. I might lurk on the fringe and build one of these!

I'm begining to realise that I get more Fun per £ with stuff like this. I have a week off work and the weather is horrid. Thick fog. So I finished this...

Not a Whizza, or a Fizza, more of a homage to Nigel Hawes! It's only little - but I think I'll put the real thing on my build list! Total cost..... £0! Just left overs and scraps!

[Chris Bott - Moderator]

Here are the majority of the construction tools.
A piece of scrap plasterboard to cut on and pin to, although I don't think there was actually any pinning. The black and yellow stripes are from a roll of anti slip strip intended for step treads, but it happens to be a nice bonded grit surface that sands balsa very well indeed.
A scalpel and roll of masking tape. These got me a good way through the build.

Moving on, here are all the flying surfaces. Wing is 3/8" sheet with a full span 3/8" x 1/8" hardwood spar. Leading edge is also hardwood. 1/4" x 1/4 I think.
Tail is all 3/16" sheet. It turned out later that it may have helped had this been lighter.

[Chris Bott - Moderator]

Graham that Fizza lokes great

[Chris Bott - Moderator]

Yep I had to be pretty careful in the hotel, no sanding was done there at all.

Next tool was a razor plane to shape the wing profile, this was done straight into plastic shopping bags

[GrahamC]

Ta... its a rounded off copy of Nigel's little pylon racer. [Pylon Racing Advanced Trainer] I didn't have a plan just a few measurements - and an idea about how the Tucano fits together.

I'm in the process of learning to design my own stuff at the moment and its surprising what you learn reverse engineering the experts designs!

The grey circles are cut from scrap printer's vinyl with a compass cutter from 'The Works'

However.... I think I might see if anyone has a Whizza Plan on the wanted section.... of I go.....

[I'll be watching the pictures]

[Steve Jeffery]

Chris - This is brilliant

I am relatively new to this hobby and spend all my working week in hotel rooms and had thought that I only had weekends to play - at weekends swmbo finds other things " more important" than modelling. Is it worth a thread "what can be built in a hotel room" as inspiration for people like me and others limited to the kitchen table?

[Chris Bott - Moderator]

Last post tonight I think.

Here the rear motor mount can be seen with the motor's cross mount attached. It is offset from centre to allow for both side thrust and downthrust. I increased this because I would have far more power on tap than the brushed motor on the plan.

Thoughts on this mount were to allow removal of the motor by unscrewing it from the cross mount and removing from the front. What I didn't properly allow for was a good ESC location in some airflow.

[Chris Bott - Moderator]

aha just thought - tools for that ply mount included a drill and some of that black and yellow "sandpaper" stuck to a pen.

[Steve Jeffery]

My subscrition to the mag is just about up and I hope I will get the free tool kit for the next one.

This could be a good starting point for a travelling kit (plus a piece of plaster board small enough to fit in a suitcase, plans, glue and balsa to builld a complete model away from home.

[IanR]

Great model, Chris. You can even see "whoosh" lines in the flying photo.

Ian

[WolstonFlyer]

So much would it cost to build this sort of plane starting from zero meratials (no "bits" box or balsa, covering etc)

[GrahamC]

That's a good question Wolston Flyer.... I build to a budget , so here is what I would probably do..... [All guesstimates....]

I would order the wood, a snake, and threaded rods from SLEC. I don't have a wood list so I would guess at somthing like £30 maybe a litle more. I think I might get away with one snake cut in half on this build. (I've not checked!) I would need sufficient 'ends' for two linkages and a torque rod set up.

[Also remeber that SLEC is cheaper if you spend more than £50 on balsa, so if you want to get into building it might be worth stocking up on useful sizes. You can never have too much triangle stock I find! - and get yourself a decent balsa stripper if you don't have one. It will pay for itself any times over. Also take the opportunity to grab a razor plane if you don't have one of those.]

I would then order a motor (maybe something like a 3545 at less than £15) 3 reasonable mini servos [£15] maybe a spinner [£3], horns, [10 for less than £2} a roll of covering, [£11] cyano hinges, [35p] captive nuts [Less than £2 for lots] and bolts [proabably m3 again less than £2 for lots] and they do torque rod hinges that are quite clever for a quid or so.... all from GiantShark - something like £50in total...

[Its the little stuff that really build up if you have to buy it from an LMS, so its worth thinking through the build before you place the order.]

And then I would buy an ESC from HobbyKing and maybe a UBEC and anything that Giant Shark didn't have in stock. [GS seem a bit pricey on 50/60A ish ESC's and the Turnigy SS ones are cheap and work well. Hopefully less than £15 delivered which keeps you safe from customs charges. Remember that Hobby King sell stuff like heat shrink which comes in handy for making up weight on orders as it costs very little.

I might buy batteries from the LMS and on common sizes they are quite competitive, and much more helpful in the even of a problem. Depending on your set up, you could certainly fly this with 2200 3 cells {That's what I do with my Tucano] but it would certainly carry a larger battery for longer flight times.

I would then go and speak nicely to a printer and blag some offcuts of sticky back vinyl for the purposes of decoration.

So... in the air for something like £90 plus batteries. [I shudder to think what it would cost if you go down the LMS route -probably heading on for double] So... it will cost you more than an ARTF... this time. But you will have bits left over which will make your next build much cheaper.

I know there are some who are keen to support the LMS. I'm just saying that this is what I would do!

EDIT: Chris.... I don't know if its too late to ask, but it might be interesting to know what wood a prospective builder might need. Do you happen to know roughly what you got through in the build?

Edited By GrahamC on 24/10/2012 13:03:37

[WolstonFlyer]

Thanks Graham that is a really detailed answer, so I am looking at about £150 perhaps a bit more really including getting plans, glue, the tools you mention and the postage costs and some extra "spare" balsa for mistakes etc.

I am mainly thinking about the mass build, it looks like the Tucano might win but both planes are similar and I am just trying to work out if I can afford to take part !

Edited By WolstonFlyer on 24/10/2012 14:34:02

[Chris Bott - Moderator]

Wood - I THINK it was something like this:-

3off 36"x4"x3/8" balsa. (For wing, 1 either side of the spar and one for ailerons and wingtips. Offcuts used for fus tops and nose bottom)
4off 36"x4"x3/16" balsa (Fus sides, fus bottom, tailplane, fin elevators and rudder)
1off 1/4" x1/4" spruce (wing L/E)
1off 3/8"x1/8" spruce (wing spar)

On the SLEC website that comes to £15.80 + postage.

There is also a bit of ply needed for the motor mount, and I added some triangle reinforcement around said mount, but this could be made from scraps of the above.

[Chris Bott - Moderator]

WF You're probably right to add it all up beforehand, as building a model can add up to more than an ARTF. But many of us actually don't like to think about it. One of the advantages of building from a plan is that you can buy bits as you go along, spreading the cost over many months if you need to.

IanR - Swoosh lines? That's just er... how fast she flies Just a bit of fun

Edited By Chris Bott - Moderator on 24/10/2012 14:43:17

[WolstonFlyer]

Thanks Chris, it does feel like a lot of money when you put it all in writing!

I will be spreading the cost out but don't want to repeat order from the same company so end up paying multiple times for postage.

I will wait for the build to start and see if anybody puts together a materials list etc. Sorry this is not really in the right thread, should be over in the mass build discussion.

Edited By WolstonFlyer on 24/10/2012 14:54:29

[Chris Bott - Moderator]

No that's fine WF, it counts no matter what ends up the winner. (We all know what will !)

Of course this is actually just a slightly customised Tucano. With a mid wing and an altered planform

How much interest do you think there would be in a plan + woodpack?

[WolstonFlyer]

I think for new balsa builders (like me) a Plan + Wood Pack (perhaps also canopy) is a great idea, it would certaily get me started without needing to figure out what wood to buy. Especially if a wood pack contained a bit extra to allow for mistakes!

For other more experienced builders I am not sure, it sounds like many people might build their model from off-cuts and wood that they already have in stock?

 

 

Edited By WolstonFlyer on 24/10/2012 15:35:33

[Steve Hargreaves - Moderator]

Might the Whizzas little brother fit the bill WF.....

Nigels Fizza is a great flyer on anything over 150watts or so with a cheapish outrunner & a 1500 to 2200 3S battery.

This is mine.....flies great on 230watts or so & very easy to launch with the midwing layout.....

[Chris Bott - Moderator]

The build pics must be a bit out of sequence. It seems I must have shaped the wing before starting the fuselage.

No sanding was done in the hotel by the way, it either happened outdoors at work at lunchtime, or at home at weekends.

The wing was profiled more conventionally than the plan shows, which both added to the effort and possible made the wing less strong. No idea if it was a good idea or not.

Fuselage sides were drawn on the balsa and the depth increased to allow room for the A123 packs that I already have.

No fus build photos it seems, but it only consists of cutting the sides, adding doublers to the inside and sticking both sides to the one and only former. Then with the bottom hatch and a dummy former taped in place, the rear ends are stuck together, the rear bottom surface added and then the two rear upper side pieces. Finally the nose floor was stuck on.

 

Edited By Chris Bott - Moderator on 24/10/2012 20:07:18