OK ... I have a WOT4 Mk2 .... IC / EP version.

I have two power systems on bench ...

ASP 61 Glow

4250 650kv Turnigy.

Originally I was going to fit the ASP Glow .....

Guys at my club have been discussing with me final power solution for my WOT4 .....

4:1 in favour of E-Power !!

So ...... its a 4250 650kv / 4 - 5S setup back again on the cards !!

Just need to build a 32mm extension motor box to take the motor. Laser cutter in ops !!

Nigel

OK ....

4250 650kv .... 5S 3000 ..... 50A ESC .... 13x8 prop with alloy spinner

4 standard servos

The elevator and rudder servos will be fitted to rear of fuselage to shorten control rod span and give direct control.

No added ballast as the servos in rear compensate for the bigger motor up front.

AUW ready to fly with the 5S in .... 2.22kg ...... which is less than I expected ....

Photos later once all completed.

Nigel

I also amended the tailwheel set-up to Chris Foss original where he used a rubber band as shock absorber link ... just means bend the stock wire close to the plastic mount horizontal to bottom of rudder ... bend a hook and cut of excess. Then embed a U wire into rudder to take the band ...

Nigel

Wife did the honours !



General view :



Modification to balance bigger motor / battery pack by moving servos to rear and direct link :



Chris's original tailwheel steering idea from the 80's ... instead of the wire rod into the rudder hinge line. This allows shock absorbing and reduces risk of rudder failure :



CoG spot on



Turnigy Propdrive 4250 650kv, 50A ESC, 13x8E prop
LiPo is set up for single 5S 3000mAh ... but its a very tight squeeze to get it in ... so I picked a compromise prop in the 13x8 that allows me to parallel twin 4S 1600 packs.

Just waiting for weather now !!

Nigel

She has extended servo arms - so once trimmed / sorted - I can then dial her up for extreme antics ....

Nigel

Originally Posted by solentlife

Wife did the honours !



General view :



Modification to balance bigger motor / battery pack by moving servos to rear and direct link :



Chris's original tailwheel steering idea from the 80's ... instead of the wire rod into the rudder hinge line. This allows shock absorbing and reduces risk of rudder failure :



CoG spot on



Turnigy Propdrive 4250 650kv, 50A ESC, 13x8E prop
LiPo is set up for single 5S 3000mAh ... but its a very tight squeeze to get it in ... so I picked a compromise prop in the 13x8 that allows me to parallel twin 4S 1600 packs.

Just waiting for weather now !!

Nigel

Thanks heaps for posting that tailwheel closeup.

I have one of the Sullivans that just has an inline spring along the bottom of the rudder and it's just not strong enough to keep the tailwheel aligned in a lot of crosswind.

The Chris Foss solution will let me use the same basic setup, but improve the centring tension.

Hope the maiden goes great!

I use that tail design on most of my models as it really gives you good service but stops breaking rudders !

I really hate the setups where you embed the wire rod into the leading edge of the rudder ... has no shock absorbing or damage limitation at all.

OK .......... Thrust tests :

On the 5S - ESC is about on its limits .... so may swap out for larger.

52A WOT and 900W

But static thrust is a whopping great 3.5kg .... for a 2.2kg AUW ...

Next is the twin 4S ...

38A WOT and 530W

Static thrust 2.35kg .... so still enough to be interesting !!

Nigel

just gave it a 5 min flight .... evening and wind died just enough to get her across the road for a quickie ...

PERFECT !! 5S and 4250 dragged her up there and she flew a dream !

Flew a full 5mins as calculated .... LiPo came down at 42% ..... so that gives me between 6 and 7 mins with a lot of low throttle work ... 5 mins with spirited.

Stupid me - I fired up my headcam - but forgot to start it recording !

Only niggle - Why can't any factory get cowl blocks right so screws don't pull out or blocks split ! I just have to fix the top cowl screw block ...

Nigel

Here's flight with 3S packs .... I made mistake - should have been 4S ... but in the rush to power up - picked up wrong ones !!

Chris Foss WOT4 MK2 with 3S LiPo 01 Sept 2017 (6 min 27 sec)

Then on 4S as it should have been !

Chris Foss WOT4 MK2 on 4S LiPo 01 Sept 2017 (8 min 15 sec)

But the ultimate of course was with 5S .....

Chris Foss WOT4 MK2 on 5S LiPo 01 Sept 2017 (7 min 21 sec)

Am I happy ? You bet !!

Nigel

The servo extenders I had on Rudder and Elevator arms have now been removed, standard arms with same stroke length of horn / arms now .... Tx DR full rate increased to compensate and regain resolution.

Wheels - Sullivan Skylite 3" have been fitted to replace the smaller stock wheels, that should help with the nose overs on grass.

Just waiting for weather to improve so I can go fly her again.

I had plain forgot how good the WOT4 is ... now its making me hanker after the AcroWot - to replace my Zlin Z50 I crashed.

Nigel

Electric fired smoke being added now ....

Canister to each UC leg ... the trigger is powered and controlled via the Rx ...

Flick Gear switch on Tx and #1 smoke ignites ..... flick gear switch again and #2 smoke ignites .... the trigger being sequenced.

The canisters require a short length of fuse in a small ring round the detonator, a plastic card piece taped over to hold against the solid fuel till it ignites.

Hopefully once weather clears - I shall be able to test and video ...

Nigel

What can you say ... its a WOT4 !!

WOT4 White Smoke test 7 Sept 2017 (11 min 22 sec)

Nigel

WOT4 No Smoke 11 Sept 2017 (11 min 42 sec)

WOT4 Smoke 11 Sept 2017 (5 min 39 sec)

WOT4 compilation 17 Sept 2017 Kuldiga (9 min 16 sec)

The 5S combo pulled the motor box apart during a flight ... but luckily the damage on crashing was minimal.

I decided to replace the ply box with alloy Stand-offs fixed to the firewall which is suitable for Glow motors.
I repositioned the threaded fixings and bolted up .... she lined up perfect with just enough gap spinner to cowl.

The thrust line was slightly less down than previous so I expected a slight trim adjustment ...

As usual she took off like a scalded cat ! 5S makes her 'ballistic' ! But the trim was spot on literally ... and she tracked nicely showing the prop line was good.

Here's the video ... (I think battery ran out on my Headcam and why the video cuts short ... )

WOT4 22 Oct 2017 with alloy stand offs (4 min 55 sec)

Nigel