Scale Soaring UK

The 3548-900 electric motor mount has been made up from some 9mm ply I happened to have to hand & M3 Tee nuts fitted to take the motor back mount fixings. I used the original 4 firewall holes to screw the mount to the firewall whilst 24hr epoxy provides the primary long term attachment. Note that the motor is fitted with the shaft on the same centreline as for an IC engine.
The photo below also shows the sloping battery shelf fitted in the original tank bay. I plan to fit a divider to separate the flight battery from the radio battery.
With all the primary components now available, I hope to be able to try a dry assembly of everything tomorrow prior to sorting out the fuselage/wing fairings.

First overall dry assembly today with tail surfaces temporarily pinned in place to check squareness to wings. All ok.

Although no posts for a couple of months since the aerotow season started, I have been making slow progress on this model.
With the retract servo and the wing mounting bolts in place the moulded plastic wing root fillets have been fitted and the forward fuselage underside faired into the wing area. The fuselage floor has also been fitted, together with a rudder/elevator servo tray at the rear of the wing mounting area. Plastic exit tubes have been fitted for closed loop rudder and the elevator pushrod made from a hardwood strip.

I have also had a rethink about the electric power system and decided to play safe by making provision to fit a larger motor/battery combination (5055 motor & 5S Lipo) to provide up to 1500W on tap rather than up to about 700W from the 3548 motor on 4S as recommended. This may be overkill, but I would rather have a little too much power available than too little, especially for a first flight!!
As a result of this, I have modified the motor mount to reduce its length by 6mm, with provision to also mount the cowl 6mm further forward to get the propellor backplate in the correct position with the longer motor. The other modification in this area is to fret out the original firewall between the motor mount in order to allow the longer 5S battery to fit in the original tank area sliding down through the firewall.
Photos to follow when I get home from a short break in Kent.

Hi Peter
750 watts on a 14 x 7 prop is about right.
Mine ia a TMRC part kit and came out at about 10lbs. It does nice slow aerobatic, but I have found it hard to land without bouncing. The model has got better as I move te cg foreward.
I think you will like your RF4
Col

Bouncy landings on RF4 and the Milan are Scale behaviour !
Our Milan syndicate insisted that all landings by non-members were conducted engine-off to avoid prop strikes and great expense. A 'wheeler' landing after the initial flare, fuz level & tailwheel up, was more successful in avoiding the kangaroo effect.

Use Rudder (a lot) and enjoy your RF4.

Many thanks for the comments chaps.
They have reminded me that I had forgotten to take some photos of the current state of play.
Apologies, but other projects have got in the way

A couple of photos below of the fuselage in its current state, with motor and tail control servos fitted, plus wing root fairings etc.

Not much progress on this project until the last few days when I decided to have a go at making arrangements for the fin & tailplane to be removeable.
Progress so far is to insert a balsa/ply/balsa sandwich block in the centre of the tailplane which has then been drilled through to enable the tailplane to be bolted to a ply plate in the top of the fuselage (front peg to stop any twisting).
The fin can also now be plugged onto the fuselage and retained by a 3mm cross dowel through the fuselage sides and a tab projecting downward from the fin - much like the method Cliff Charlesworth uses on his Olympia design, except that the downwards projecting fin post (trapped between the projecting fuselage side sheets when in position) takes the place of the rear wire dowel pin.
The final part of the 'mod' will be to arrange for the upper tailplane fairing to be attached to the fin so that with the front of the fairing pegged into the fuselage, the rear is held in place by the fin - hopefully neatly covering the tailplane fixing bolt recess

I know that this will add a little weight at the back end, but it will make covering and subsequent access to the elevator horn connection and tailwheel attachment so much easier.

Fin and tailplane attachment now complete, with upper tailplane moulding cut ready to secure to fin at rear and pegged block at front.

Well off thread. Do you know that Totnes is twinned with Area 51.

I apologise but couldn't resist it.

Ian