Electric avenue

Flying a canard aircraft is an amazing experience, fast and handles great. Hand winding the gear up on a bumpy climb out is not great.

The existing offerings for the retract system are great units, no doubt about it. Though they are pretty expensive at $2500. Thats more than a prop, for a convenience item.

There have been a number of examples over the years where people make something automatic by adding a motor onto the bit you manually operate, tries, tested and most important to us right now - cost effective.

I set about trying a few different motors to get a feel of the kind of torque needed, initially I thought 2Nm was enough. It’s not. It will get you most of the way but wont get it up and locked. Ok time for some engineering.

Calculating the peak flight loads (120kts) on the gear is relatively easy, just assume it’s a rectangle in frontal area. A motor to meet this expected load is far larger than what we had thought might suit. So now we are going to make sure its right, lets go for a unit delivering 8Nm at stall.

Now to mount the thing. Given its heavy I wanted to ensure it was ac cocooned as possible, no attaching to a flat plate and having a 1.5kg motor unit flop around on some aluminium. This means it needs to be printed. Going through 3 iterations we went from 800g to 300g and vastly increased the achievable loads but adding material in high stress areas and around parts that where going to transmit torque to the mounting points.

After 4 months of fiddling (not full time) we have a unit that fits great, doesnt interfere with feet and is super simple to install.

For controlling it, we went through a number of options, purely on switches (simple -ish but not elegant), using an Aquino board (great but if you ONLY want to put the gear up and down, its way too overkill), a basic control board with relays and controlled by a switch plus limit switches.

I really like the idea of a complete glass cockpit, anything in front of the pilot on the main panel being a screen. So I made a control unit which is arduino based plus a capacitive screen to select what you want to do. It works great but definitely isnt for everyone.

A custom switch panel is a one size fits all approach and will fit in with most existing aircraft.

Now it’s made and installed on our aircraft, it’s pretty cool. I get why people spent a fortune on sets to make the nose wheel retract electrically.