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[Matt Hoyland]

Latest F3P model from the Ernst Disse stable.  Cut by Andy Whitehead and painted by Gaz Holland.  The build may take a while as I won't be flying indoors again till October but will see how we go.  Certainly won't be like Steves SENSATION build that appeared to be finished in a few days  .

Heres how I received it from Gaz.

[Matt Hoyland]

One more...

[Matt Hoyland]

First job is to bevel all the hinge lines.  A metal ruler and scapel is all that is required.  Depron blunts blades like nothing else so to get clean edges I only make around 5 cuts per blade.

I am also going to try and take the award off Steve for most blatant product placement...

[Matt Hoyland]

The hinge is created using 3M blenderm tape.  If you are struggling to get it to stick to some of the printed surfaces then a thin smear on UHU Por helps keep the tape in place but not required here.

[Matt Hoyland]

A few small pieces of blenderm tape are also added to the underside of the wing and tailplane to keep everything secure.

[Matt Hoyland]

Next 80mm of 3x0.7mm carbon strip is in layed into the tip of the ailerons and elevator secured in place with a smear on UHU Por.  Making sure to insert from the underside to get a neat finish on top.

[Matt Hoyland]

Thats about as far as I have got, need to order some carbon tube next to stiffen the elevator and ailerons.  Heres what the underside looks like layed out on the bench.

[Matt Hoyland]

Also need to decide which motor to use, options are (if they'll sell me one)

Glavak Contra
Kimmo Kaukoranta Contra
Nicola Pietu Feather (available from www.flying-dog.co.uk)
or a standard Glavak.

Any ideas anybody?

[d.k]

I'm wondering how powerful the Nicolas Pietu motor may be on a model that will be as heavy as the piggy. Nicholas used it on a 74g lightweight but piggy will be over 100g even if built light. Mark probably has the better idea of this. I got one from Rob; nicely made and cheap to buy.


Glavak meant to be redoing the contra so lighter and less power as a little much apparently. Seemed to perform awesome and any advantage it gives you has to be good.


Kimmo is nice but noisy. I actually think this may be a benefit as some feedback is good. I found it so noisy at EIM I couldn't hear my radio never mind the airplane.

[BrianH2]

actually, I spoke to Derk about the contra at EIM and he said it offered no advantage on the rebound torque roll and did nothing for braking on the down lines.  According to Mr Van der Vecht, the only thing it give is slightly better straight lines when flying level.

Seems an awful lot of pennies for so little advantage   

[d.k]

They never were meant to be the advantages of a contra though.


Torque, P-factor, Gyroscopic procession & spiral slipstream all a result of the spinning thing.


Torque & spiral slipstream affect trim and vary with RPM. The other two affect the aircraft when pitching or at high angles of attack.


Contra should improve the track of the aircraft when pitching most especially in the A schedule.

[angelwing]

As I've flown the only Glavak regularly on UK shores it fair to give some input.


The Yofiel did fly better with the contra than other motors I had tried.


Its also an interesting model to give a fair statement on some of the advantages / disadvantages of the Contra system.


Firstly you have to remember the Yofiel flew initially at 105g with the regular Glavak motor but tail heavy.
Next up was the Axi 2203-52 and 7g of lead!
Finally the Contra


So comparing the performance with the Axi and the CR is fair as the flying weight would be within a gram or two.


Downline breaking is very noticeable with the CR over the AXI
Inverted and upright flight is unchanged by the P factor and trimming
Torque rolls are no easier, in fact possibly more difficult with the CR. With a conventional system a blip of throttle straightens things up nicely in the TR. All that happens with the Contra when you do this is it climbs. There is also a delayed throttle response similar to a Petrol model over a snappy throttling two stroke glow, The props tend to need that extra moment to wind up and bite.


Derk would be correct in saying that the CR offers no advantage on the Disney or Piggy. These models have long noses for small lightweight motors. Adding an extra 12g is not going to help in the downlines on what is already a slow downline model.


CR needs 180 packs, Regular Glavak only needs 120's




Kimmo system , if anyone decides to fly a Kimmi system I withdraw my judging duties as the pilots already complain they can hear me giving zero's. I dont want to shout it so all of Wakefield can hear me.


For me Standard Glavak on a Piggy is the way I would go and with 120 packs
The Pietu motor does not seem to give the flight times and efficiencies of the Glavak

[angelwing]

I agree with Dave the Contra does make for cleaner entry and exits in up and downlines

[d.k]

Spiral slipstream why we have side thrust so contra not noticeable on a well setup model.


Every pilot I've judged in C & B would pick up points. No rolling motion on a badly done stall turn (or even a good one). Straight entry into torque roll rather than having almost 30 degrees of turn done as the model hits the vertical.


P-Factor and gyroscopic procession are opposites to each other but one will dominate. A has a lot of 90 degree pitching manoeuvres which is where you want the effort.


Ernst was explaining that the Disney CG was correct (he did say he has gone back a little). Not interested in no input axial rolls and hands off inverted. It is all about pitching nicely and minimising corrections on the hard stuff.

[d.k]

I wonder whether the Glavak contra is slower winding up on the downlines than the Axi thus increasing braking. I've noticed my Axi in the Helix winds up quite quick as it freewheels past the idle setting.


Next advancement will be in ESC's. F3A style braking for the smaller ESC's and then the ultimate: constant RPM like the new big sensored Hackers.