The Mini WOT 4 thread

[Darren Stephenson]

I only post when I have tried or upgraded a model I own or fly ,I tried various wing configurations before I got the model to power off glide .The wing is now on the bench to make the mod permanent ,although it now feels like triggers brush ,1 new motor ,1 new esc ,1 new prop ,4 new servos ,1 new wing ,I lost some interest as im flying a hobbyking hyperbipe that flys superb straight out of the box

[Paul Marsh]

Problem is that the Mini Wot 4 needs to fly fast, otherwise, the controls stop working. I don't think it is a very good model, very slow to respond to aileron, even with large throws, except at higher speeds, and no elevator control when landing,

The problem I think is the wing, it is too thin and loses lift easily. A redesigned wing with about 5mm more thickness would slow the model down somewhat.

[Former Member]

[This posting has been removed]

[Denis Watkins]

Spot on Percy

I persist with this model, having built my own undercarriage for it, which will at least allow its arrival without bending the legs.

Mine will just not glide at all, and comes in far too quickly to avoid bending the soft motor shaft.

In flight, it does look good and is predictable, but as the speed drops this one underperforms

[Former Member]

[This posting has been removed]

[robert feltham]

Update on mine. I am using a Hitec Aurora and have found that i need to set EPA on the throttle to 130% to get full throttle.Have flown it and now dont think i need 3s!

[andyh]

Posted by Percy Verance on 15/07/2018 12:13:19:

An unsuitable airfoil section perhaps? Thin wings don't normally take too well to slow flight.

given the wing chord & the airspeed for "slow" flight for this model, you're getting down into relatively low Reynolds numbers where, contrary to what we'd expect on a larger model, a thicker wing section definitely isn't an advantage.

[Denis Watkins]

You lads are right Andy and Percy. The model just does not fly well and drops its nose on slowing down.

It does not spiral in.

As speed is reduced, the wing just stops flying. There is no glide, just a fast arrival.

I will continue to try flying this model, reflex is my next stop

[David perry 1]

Ive just bought one of these. Not that impressed given its pedigree, but its a small thing so must be forgiven I guess. The wind blew mine over and bent the propshaft...not impressed at the cost of a spare motor!!!

Ill be changing that then.

[Ben B]

I must admit I rarely fly mine nowadays. Looks lovely on my desk but when flying its just too lairy on landing. My method now is to come in hot a long way away, almost do a low pass then chop the throttle and haul on the elevator to do a long flair. With the improved u/c its fine doing this- the stock would bend. I also think the wing just doesn't work that well. All in all you just have to fly it fast and using lots of space, kind of defeating the point of having a small (park flier) plane.

[Darren Stephenson]

bottom stacker box melted in the heat and the top one fell and crushed my fuselage .I did get it to go quite well ,plane's should crash into tree's ,spiral out of control into the ground in a blaze of glory not be taken out by a stacker box

[Paul Conlin]

I've just returned to flying after long sickness. I liked pylon turbine jets but returned to a mini wot 4 kit asI started on a balsa wot4 .and acrowot. Reading here that some experience some problems but watch Bob Harris Youtube mini wot4 flights of a little fast flyer. Any info of specs upgrades the landings looked a non event just a little nose over on rough grass.

Chris I remember was world class but this little model needs tweeks.

Thanks for the previous posts.

[Denis Watkins]

Posted by Paul Conlin on 07/05/2019 07:40:07:

I've just returned to flying after long sickness. I liked pylon turbine jets but returned to a mini wot 4 kit asI started on a balsa wot4 .and acrowot. Reading here that some experience some problems but watch Bob Harris Youtube mini wot4 flights of a little fast flyer. Any info of specs upgrades the landings looked a non event just a little nose over on rough grass.

Chris I remember was world class but this little model needs tweeks.

Thanks for the previous posts.

A homebuilt triangular style 1mm pianowire undercarriage is a big improvement Paul, over the sleek looking, none springy, metal version provided, that distorts easily.

The lads have hit the nail on the head, stating that the wing just does not fly this model, it cannot support the models weight at lower speeds.

You have observed the YouTube offering, and basically the good looking model fails as a parkfly, it is just too unstable.

There will be an answer with some wing mod, will keep you posted

[Darren Stephenson]

im back ,1m roll of solar film a bit of grandads balsa and it fly's ,il be adding some small sharklets ,small upper wing,skid plate because i bent my last prpp ,i usually stomp on them and put them in the bin but this one has grown on me

[Paul Conlin]

Hi I am trying slots on leading edge as per a 1/3 scale Turbulent with sub walking pace landings three pointers.

Question anyone tried reflex using aileronsiced to throttle? Also flaps to Down elevator on throttle back high angle landings?

Been very ill but used to fly turbines on deltas with v high drag on.bank and yank. On FAI and 20 pylon racers a flat wing was common but loaded like a 9inch brick they glided two three circuits on.dead throttle stick. I think at least one person was knocked out cold as the spinner point load was leather.

Paul

[Paul Conlin]

Oops that was "leathel" not leather

[John Bisset]

I will be interested to know how well the wing slots work out - certainly did a fine job for low speed control on the Turbulent.

I wonder, is part of the problem here that the wing loading has presumably gone up? A smaller model than the original Wot 4 will have less wing area and while total weight will be down, it may well not be in proportion. This is a common re-sizing problem. Smaller motor, battery and ESC will be lighter but maybe not so much.

That would explain the 'drops out of the sky when throttle cut' performance. It might also help explain some of the squirrely behaviour, since a higher wing loading will put more emphasis on the wingtip vortices and any slight build variations at the tips could show up, be magnifiied. If some of the pilots are also pilots of larger Wot 4s, are people subconsciously expecting the benign handling of that machine too?

(I recall a fullsize two seat sailplane we put a wingtip camera on years ago, overseas. This was long before GoPros etc. The camera was small but the rudder required to hold straight in flight surprised us. So did the stall - quite a vicious wing drop we'd never experienced before. Taping a similar sized block of wood to the other tip evened things out, but after that and a couple of other surprises we stopped doing ad-hoc mods. We realised why test pilots are required- even small changes can make a big difference! )

[Andy C]

Anyone still flying a mini wot 4 are they all in storage or bins now?  Want to revitalise mine and start flying it again maybe with upgrades so looking for any more up to date experience please.

Thanks

[Andy C]

Wow, nothing???

 

@GrumpyGnome, with reference to your Heroes post, this could be the first ever BAD Chris Foss design.  ?

[Denis Watkins]

On 14/06/2022 at 10:26, Andy C said:

Anyone still flying a mini wot 4 are they all in storage or bins now?  Want to revitalise mine and start flying it again maybe with upgrades so looking for any more up to date experience please.

Thanks

 

From my experience of the model, it is too heavy, and the wing does not support the model in flight, so has to be flown and landed like a missile.

We cannot easily reduce the overall weight as the model is quite small, and any worthwhile reduction in weight would make it flimsy.

We can thicken the leading edge with straws glued to the outer 4inches, under the leading edge, to provide lift.

We can glue on inboard flaps, about 3 inches at 20° to air lift.

In my view, the wing needs to be thinner and of an airfoil profile, with half inch to the chord for the whole span

Or about 2" span added to each wing tip.

 It appears the wing was added to the model just to look good.

[Andy C]

Thanks DW

[GrumpyGnome]

21 hours ago, Andy C said:

 

@GrumpyGnome, with reference to your Heroes post, this could be the first ever BAD Chris Foss design.  ?

 

Lol. I'm believing he had minimal input, to allow my comment to stand ?