60" Build Step #11

This step is a purely self-congratulatory photograph now we've completed the first module of three (viz. airframe, flight-deck and undercarriage). A benefit of the modular means of construction is that you can pay as you go. Another is that it can be stored surreptitiously among the other detritus lodged in the garage: "What helicopter, dear?".

60" Build Step #10

You can see that nicely from the first of those pictures, where we've turned one of the edges through ninety degrees with the tube-connectors secured, and slid it into place. Note that the other side awaits the same treatment.

The only reason for attaching lengths in opposing pairs in this way is that the central section is bolted in position. Releasing these bolts allows for sufficient flex to apply the tube-connectors one by one, if this alternative method makes you any happier.

This done however we can park the airframe upright and bang in those extra rivets with the assistance of G-clamps. I have put a perimeter squeeze of silicone along the edges of the foam insert prior to capping the centre-section off and this final pressure will likely squeeze some out from around the edges.

All that remains to do now is to draw-file its rough edges and finish with a little emery   cloth and the assembly is ready for a white undercoat and a shiny finish in Post Office red prior to an appearance on Instagram.

60" Build Step #9

With the centre-section assembly complete, lay out the parts on the workshop floor again so as to size up the assembly mentally. The component parts of even the Titanic were once chalked-out on the workshop floor; and look what happened to that. I have called on a set of weights to secure the arrangement in position during this process. Knew I'd have a use for them eventually.

With this done, mark up where the bolt-holes will have to be drilled again in order to attach the centre-section to the perimeter frame. An advantage of square tubes over any other is that you cannot make a mistake doing this as they can always be turned through ninety degrees.

Entering stage right now are our the four-way tube-connectors, and there is only one way these will lie flat on the floor (which is technically the wrong way, reason being that we're going to want to terminate each corner with upward- and downward-facing stubs).

What we do here then is to secure a pair of connectors into only the lengths of tubing that are going to form opposite sides of the 'square' so we can slide them into place at a later stage. Make sure when you do that therefore with the previously-drilled hole where you want it to be when you've turned each length through ninety degrees to fit.

Finally beside the inevitable squeeze of silicone, rivet each connector in place during.

60" Build Step #8

This is a cheeky little phase in construction because it calls upon a material which is strong in compression and also in shear, in the form of a low-density insulation foam. The benefit of this is that it is available off-the-shelf, albeit rarely intended at your local DIY store for flying machines.

One way of cutting this to suit is simply to place it about where it's going to be and just knick the edges with a Stanley knife before using the same tool and a yard-stick to eventually cut the panel to size.

Then flip the frame over (note the right-pronged appearance) and apply a silicone seal around the edges before squeezing the foam into place. When you do this, spread the weight gently and evenly so as not to crack the foam within its foil-backing.

You can see that we are good to go from the last picture, whereupon we rivet the next sheet-alloy square to form a cap on the underside.

60" Build Step #7

With the arms teed up on that back-plate, use a 10mm (confusingly that drives a 6mm shank... it's all about the head-size) box-spanner to hand-tighten the joints. Normally I save the final twist until the assembly is complete, as it provides for a little leeway for the inevitable jiggery-pokery involved.

I just realised too (or else I'd forgotten from previous, which is one benefit of sharing knowledge among the matrix) that rather than slip out that template from underneath we could just have used the second of the pair of sheet-alloy squares to place on top.

What I did again here tho' was to slip that square out from beneath and set it up on top with the benefit of the set-squares to keep things true. When I say true, we're not working to microns here because ultimately it doesn't matter: unique amongst the designs of flying machines drones are simply self-levelling devices that don't care as to how and where the various motors and propellers are mounted.

With things broadly looking just-so, therefore, we hammer four more rivets around the perimeter to hold the top-plate in place. With this done we can all relax, maybe over a cup of tea. Then add a rivet in each corner, being careful to avoid the internal bolt else removing each one temporarily to allow. I generally then add a fourth and fifth rivet at each side, though this can be done at a later stage once the general outline is secure.

60" Build Step #6

Around the side of those stickers we've used an arrow so as not to mark up the wrong side of the tape. With that done I've taken an off-cut of 1" tube and marked out the width of the joint, using the same straight-edge to mark an 'X' for the centre-punch.

I may be teaching granny to suck eggs here, but of you want to be super-accurate you can drill from both sides in the absence of a power-pillar drill, which I've given away. I trust to my own judgement and go in from the top with 4mm pilot-hole. This usually results in an off-centre hole on the other side of the tube, but then I go in from the backside with the 6mm drill-bit (that matches our hex bolts) so that I can lean on in the hand-drill in the required direction to centre things up.

60" Build Step #5

With that centre-section flying free as a bird now on the garage floor, we've raised the sheet alloy and using the pencil-marked margins lined it us as-good-as with the four arms. At this stage we apply a length of masking tape to mark where these cantilevers will need to be drilled, and at the same time numbered them viz. a viz. where they are going to end up on the 'drone. Handily, the film backing on the sheet metal includes an arrow that we can use here to remind us of which way we will be headed.

It does not really matter whether the airframe is going to be flying 'left foot forward' or whether you're what the snowboarders call a 'goofy rider'. At the end of the day it is down to whatever floats your boat... or drone. Note that both the cantilever arms and the sheet-alloy are numbered up.