NEXT STEP, Photos of all the frames.
This step : design
When designing anything, you need a rough idea of how you want it to turn out, I usually have an idea in my mind but for some i recommend sketching and possibly taking measurements to figure out how you want the final model to look.
In this case, i took inspiration from the basic design of quadcopters, a simple x, but i felt that was too bland and so took parts from various frame designs and fashioned it into my frame.
I wanted something unique, that stood out not simply because of the material it was made from, but because of its design
In this case i wanted a dome to house the electronics and i wanted a unique looking set of arms that werent simply to hold the motors apart.
So i came up with this design.
(image 1)
I had made it to be relatively lightweight by removing large amounts of material (the helix design which is lots of squares cut out), but still needed it to be strong so i made a honeycomb design that was the many little squares cut out.
This halved the weight of the model, but it also hugely increase the cutting time, which i has to pay for , the longer the time to cut, the higher the price tag.
Which meant i had to compromise, so for larger parts i cut large pieces out.
so i had a few things that needed to be factored into the design to make it a viable frame.
Airflow (the props had some of their thrust lost when blowing onto the arms, so i had to make them thin or i ha to allow air flow)
Length (the props lose efficiency when close to other props, so i needed the arms to be long but not ridiculous)
weight (the copter loses flight time with weight, so i had to make it as light as possible)
Time Cost (because i pay for time used on the cutter, i had to make the design relatively simple)
Material strength (i could not design outside of the materials strengths, it could not be ultra thin as it could snap, or oscilate causing bad flight performance)
With the above factored in, The design can go ahead.
the trick is to design part by part, rather than design it all in one go, in this case, i designed the sides of the arms before i designed the top/bottom or plates, the arm was designed to be two x the length of the propellor i would use, this ensures the props would not be too close to each other or the board.
I tried to make the design as unified as possible which meant as few joints as possible thus as few weaknesses as possible.
so now i had to make it 3d, which meant in between the two side plates i had to put somthing that spaced them.
I could have printed out lots of side plates and stuck them together, but it would have used huge amounts of material and would have been heavy, instead i used spacer plates that slotter in with finger joints.
There were just slightly wider than the motor mounts and were 3mm thick, one thing to note when designing how they fit together is make sure you know the thickness of the material you are using.
In this case i used 3mm MDF so the finger joints were 10mm long and 3mm wide.
I tried to make the spacers as long as possible to make assembly easier and reduce cutting time .
I also had to make the plate the motor would mount onto.
I used dedicated spacers for this and used two samwidged together for extra strength.
at the time i did not know where the motor mount holes would be, so i cut generic equally spaced holes.
I now had to make the holes in the side plate that the spacers would fit into, so i made a line of boxes 100mm ling, 3mm tll and spaced 5mm apart like the fingers on the spacer plates, i then took the template and placed it on top of the side plate in the position needed..
It was very simple to do and the end result was a clean design.
i did make sure that the holes where the spacer plate slid into, would not compromise other parts of the frame making it weaker.
, i now had he arm designed, but i need to think how i would fit 4 of them together, so i h to make two plates that would clamp to the bottom and top of the arms, to hold them in place securely, this was ver simple, i measured the space i had available on the top arm and make a square that was double the size.
I then put two "fingers" that poked out of the arm that would slot into the top plate.
, i then had to put holes in the top plate that would allow those fingers to slot in, as you can see in the photo i did just that but i forgot the arm was actually in 3d and at the time only put in one set of holes for each arm.
So i had to correct this which was simple. i just copied the holes and spaced them the correct distance apart..
Now that i had a top plate, i decided i would simply cut out two and stick one to the bottom in the same manner.
I now had to design the holes for fitting the flight controller, this was difficult as again i did not have the measurements of controller at the time, so i made a generic design that would supports lots of mounting points.
I also put in lots of holes for any extra wiring that would need to be slotted through.
I now had to think about the dome, it would be too weak on its own, so i made a simple spacer that all the arms slotted into and make it far stronger.
the frame was now finished.
when i later cut it out and tried it, i found i had not completely thought out all the design, it was still a bit too heavy, the motor mount plate was a bit too weak and the dome needed strengthening.
So i took these ideas and proceeded to design many different frames, somewhere for fun and some were for practicality, you will see them all in the photos.
As you can see i have had a lot of fun designing the different frames, i have tried all sorts of designs, some for strength, some for practicality some for looks, some for nostalgia.
I have also included the image where i designed the frame and the image where i space it for the laser cutter bed.
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