FT Saab Viggen 70 mm EDF.

Don't forget, Crash - Airwolf could fly at Mach 2, and reach 140,000 feet!

I would be tempted to take a 5mm chain saw file, file out the leading edge to a concave half round and glue in a 5mm dowel if it's not going to be too heavy?

That's an idea Klippy. I don't think a bit of extra weight would be a problem. The estimated all up weight is 875 grams. The Fan I have ordered produces 887 grams on 3s & 1,435 grams on 4s, static thrust. I have found a shop that has pre- shaped leading edge balsa, but I would have to order quite a few lengths to justify the postage ! I will see if I can find something local, if not weigh up the alternatives.

Just use a piece of softwood ( pine etc) .

That would be an easy solution if it would do the job. I can buy 5 mm bead locally.

5mm Pine dowel rod is readily available in most hardware stores.

A combination and refinement of Klippy and Pauls' suggestions would be to file or cut a vee in the leading edge, glue a square section of softwood on edge into that vee and sand to profile?

Good idea STF.

I have made a start on the electrics. The receiver is an Admiral 600 SP gyro & I want to make sure I have it set up properly, as this is the first time I have used Elevons. If I have interpreted the instructions correctly, the receiver dip switches are set to Delta wing & the two servos plugged into the normal elevator & aileron channels. I program the TX to a normal wing & elevator, & the mixing is done in the receiver.
Does that sound right ?

Does to me!

You don't need reminding to ensure that all the surfaces move in the correct directions following the stick AND against any airframe movements ie nose up gives down ele!

crash
A word of warning.
Taking servo reversing into account I believe there are 8 possible combinations before you get both servos moving correctly inline with the sticks and with the correct gyro correction inputs.
The worst possible outcome is you get the control surfaces moving correctly with the sticks but with the gyro working the wrong way. :woohoo:

If I am not mistaken, & the theory is the same for a normal set up, the solution is to set up everything moving the right way in the gyro/receiver & then reverse anything that's required in the TX. Whether that will work in practice is anyone's guess ! :blink:

I am still waiting for the EDF to arrive from the UK, but have made some progress with the rest of the electrics. Servos & push-rods are fitted. ESC is in position & the motor wiring extended. The receiver is set up, & the elevons are working in the right directions ! It turned out to be fairly easy to set up. Set the dip switches in the receiver for a delta wing, check the gyro corrections are the right way & reverse any that need it on the RX. Then check the direction on the DX & reverse anything going the wrong way, in this case the ailerons. I have set the throws as recommended, 9 mm aileron & 12 mm elevator with 40% expo. Just need the fan now ! I will post some pic's when there is a bit more to look at.

Made a start on the leading edges today. I went with Klippy's idea of sanding a U channel in the foam, but instead of using dowel or balsa I went with 4 mm carbon tube epoxied in. nice & strong but still light weight. I didn't quite have enough, so I will pop over my mates tomorrow & nick a length of his !