Tuesday, 31 May 2016

Old dog and new tricks?

As a result of a conversation with Peter Gunning I offered to retrofit Peter’s recently acquired Freestyler 3 with the Servorahmen drive system and fit the model out with KST High Voltage servos. These servo mounts and control mechanisms are very robust and slop-free when installed.

Getting the existing RDS out was straightforward and just needed careful pulling out with pliers taking care not to overdo it! Getting the large horns and pushrods installed required a deal of cogitation but the end result is superb. The scariest operation was Dremelling the control surfaces to fit the substantial horns without damaging the wing skins. A steady hand and eye are required. The pictures show various stages of the installation.

This picture shows the whole servorahmen assembly from one of Peter's previous installations.

Test fit of servo in mount. This allows access to the servo retaining screws but not to the pushrod/servo arm.

Control surface horn in place. Getting the horn/pushrod assembly in place was a bit of a faff because the whole assembly is quite big and there isn't a lot of space. Glass tape to try to protect wing from any wayward Dremel cutting disc!

Servo mount epoxied in place. Note the two 3mm holes for access to servo release screws. Masking tape to protect wing skins. Servo connected to aluminium pushrod but not epoxied yet.

High Voltage KST servos in fuselage and time to hand back to Peter for final installation. The KST servos are smaller than the ones they replaced so a ply adaptor plate was made up and epoxied in place. Note the 1mm glass board raising the servo height and reinforcing the servo plate.

Monday, 1 February 2016

Winter blues Dodd Hill 31 Jan

A break in the incessant rain and storm force winds tempted me to go out flying for the first time in ages. After the snow on Saturday and looking over at the Fife and Sidlaw hills I could see they were quite white and past experience has seen me struggle to drive up the access roads so I charged up my Weasel Evo and Reaper and headed for Carrot/Dodd Hill. I still had trouble getting along the snow covered access roads. My house is around 50m and Carrot Hill is about 250 and the difference that 200m metres made to the amount of snow on the ground was dramatic. Nothing at home but around 2 inches of snow cover at Carrot Hill.
Winter wonderland
The lift was very light and I should have taken my DLG but my Weasel Evo went well. The lift on this hill is never great but at least I got a couple of hours flying in before the wind died to almost nothing. Nice to get out for a fly even if it was only a foamie. 
Weasel Evo scoots along the slope
Early on I thought there might be enough lift to fly my heavy Reaper. There wasn’t! Retrieving the model from the middle of a thick patch of gorse on the quarry face was a painful and unpleasant experience! I lost my footing at one point and ended up sitting on my bottom on the steep slope under the gorse (and held down by it) and unable to get up again. Tx in one hand and Reaper in the other!! 

Tuesday, 5 January 2016

Splash Down!!

The blog has been very quiet lately because I haven't been flying and I had nothing to add! The weather for at least the last 5 weeks has been awful apart from the very occational day when it was flyable and I couldn't make it. Typical! We have had winter storm followed by winter storm cycling through constantly. Rubbish!!

28 Dec 2016

I had been getting more and more stir crazy over the Festive Break and when I spotted a good south east wind was blowing I took my Reaper foamie along to East Haven aka McTurbulator. 

Reaper ready for launch
It was blowing about 30mph straight onto the low slope but being a proper foamie racer it went much better than my lightweight Weasel Evo which I flew there last time. You do have to keep in the narrow lift band but the speed builds very nicely if an EM pattern is followed.

I amused a skeptical couple walking their dogs when I first tried to launch and flew the model straight into the ground several times before I twigged the elevator trim was reversed. Muppet!

I then discovered that flying wings won't fly when a servo fails. I didn’t know what was wrong at first and struggled to keep the model level but with only aileron and elevator on one wing the result is inevitable. I should have tried letting it hit the beach but instinct had me fighting it until it splashed down in the North Sea about 10 metres from the shore. However it bobbed back up and proved that foamies float quite nicely! By the time I clambered down to the beach the strong wind and waves had driven my poor Reaper onto the shore and it was fairly easily retrieved. Glad I had SealSkinz socks on thought! 

I glanced up at my dog walker audience but they were walking off and I'm sure I heard the sound of satisfied chortling!

Burnt-out circuit board and melted case. The gears in this servo were VERY stiff compared to the one in the other wing and I suspect this was the problem.

After a couple of days drying the model out the offending servo together with its matching pal in the other wing were replaced with a pair of HS85MGs. Ready to fly again if this weather ever improves.