Modelling > Drone/UAV/unmanned whatever GB
Battlefield Unmanned Delivery Drone (BUDD) - Delivered on Time
Robomog:
Hi All
Fresh from the Jings! build and fully recovered from my model related brain implosion I'm going to throw my hat into the ring for my first ever group build, and looking at the entries so far I'm up against some stiff opposition. Apologies in advance if this is a bit less detailed than my previous build.
The Battlefield Unmanned Delivery Drone (BUDD) is a concept to deliver materiel to the battle field especially in remote situations and live areas where any emergency supplies/munitions need to be delivered under fire. I was going to Call it Forward Air Resupply Transporter System but that didn't scan for some reason.
It will feature turbofan lifting and a hydraulic grab system so that the payload can be unattached very quickly in emergency situations. It will be modelled with the cargo pod and if time permits I will add other load outs using the universal grab system, a search and rescue or gunship attachment come to mind.
Here is the start position with parts
20171115_195345 by Robomog, on Flickr
I have already started the cargo container at this point and the base frame of the drone, everything will hang off this. I was going to have a single prop but this is a fairly heavy lifter so I have opted for turbofans either side Avatar style, the photo shows two types of props but since it was taken I have opted for two two-blade contra-rotating props to give it some Umff. Some bubble packaging will become the twin engines and the command pod. The small tubes are empty biro tubes which accept 2mm plastic rod and will form the hinge on the turbofans. The large plastic tube came with some brushes I brought and will probably be used as air intakes/exhaust. Small wings for a balancing tail and wheels, the wheels may be ditched in favour of skids for ruggedness.
Let the construction begin ........
Mog
GTX_Admin:
Liking where this is going...
Dr. YoKai:
Looks like a good batch of raw material - and the design sounds pretty plausible. Looking forward to seeing it come together.
Robomog:
Thanks for your comments guys.
Next thing is to prepare the bubble packaging, you can get some great shapes with bubble packaging but it is not the easiest medium to work with, the plastic is hard and does not sand well, you have to fix it with CA or the like and often once cut becomes quite flimsy. I find the best way to cut it is with a good pair of scissors rather than a knife. Probably the best way to approach it I to treat it like a troublesome vacform.
20171123_194618 by Robomog, on Flickr
You can see here I have trimmed the packaging back and reinforced it with styrene sheet. I was originally going to have tubed air intakes but the hobby drill had an eppy and melted the plastic, it now refuses to run at anything other than full speed. I managed to tidy it up with a knife and a battery powered drill intended for buffing and grinding fingernails. I fixed the tubes (from the brush container) on the inside to give it a more realistic appearance. More of the tube forms the engine exhaust.
Another piece of bubble packaging that will be the command module has been reinforced in a similar way.
20171125_171312 by Robomog, on Flickr
Above is a sort of exploded view/story so far of the project. the engines have been stuck on the baseplate and the assembly is placed in position, as is the proposed tail boom. The holes for the driveshaft/hinge have been drilled and part of the biro tube installed.
I have settled on contra-rotating props and have constructed the Turbofan body. The cones for the turbofan are aircraft spinners from the spares box (two Kittyhawk and two typhoon I think).
The cargo pod is almost finished I have added reinforcement and the door detail, all that remains is to devise a method of attaching the pod to the aircraft.
Seeing the layout here I have just realised how much work I have set myself, with Jings! about 50% of the build was spare parts and premade stuff. This build is going to be mostly scratch built with barely 10% of other components. Slight panic has set in as there is a deadline on this one but then again, whatever, I am really enjoying the challenge.
Coming next the attachment system………
Mog
Robomog:
So, how to attach a bulky container to a drone. Its probably going to be thrown around the sky in certain situations so it will have to be a strong connection, it will also have to be a quick release so that the turnaround time on the loading can be short and the drone can whizz into the war zone drop the load and scarper in double quick time. I am intending BUDD to be multi role so it will have to be universal to all the proposed loadouts. To complicate matters for me, I want it to actually work in some way because if I have time at the end of the build I want to construct some said loadouts.
For real world inspiration, I looked toward the CH54 Skycrane but came up with a blank, magnificent aircraft, but it is really a big skyhook and its payloads are mainly carried by hook, wire winches or bolted to the structure, so no quick release here. Most other helicopter lifting operations revolve around a hook, the Chinook offered a quick release solution but it was still a hook and the payload swings about under the aircraft like a huge pendulum.
Inspiration finally came from the cranes that pick up the shipping containers at container ports, they have a hydraulic grab that attaches at the four corner posts of the container. On the drone, this morphed into two clamps made of a continuous length of angle that attach to a reinforced edge along the top of the container.
The opening mechanism was the next hurdle, I devised all sorts of systems in my head some impractical, others would work but would be difficult to model in 1/72 scale. In the end, I opted for brute force and simplicity, three hydraulic rams that would hold the container tight in flight and release it very quickly when on the ground.
So, to the construction, quite simple in the end. Empty biro tubes became the Hydraulic Rams with plastic rod forming the push/pull rods, the clamp is constructed of plastic angle with connecting plates glued on. This construction was then glued to the end of the rod leaving the rod to slide in an out of the biro tube. I will be first to admit it’s a bit stiff in operation and a tad over scale, But It Works !!!
20171201_201904 by Robomog, on Flickr
Here we see the biro rams in place these are stuck with gel superglue, this is my CA of choice it doesn’t run everywhere and has a little bit of grip that aids positioning parts also if you put down a generous blob it rides up the sides of the part and improves the quality of the fixing. It does need to be left 24 hours to fully cure however. The rams are covered by a protective plate which also strengthens the assembly.
20171201_201921 by Robomog, on Flickr
The top of the cargo pod has received its reinforcement and the clamps constructed. It was at this point I realised that I had made a boo-boo in the construction. With 20-20 hindsight, I should have assembled the clamps and rams on the cargo pod first then attached them to the drone. But I had already glued down the rams. Doh! A frustrating night entailed carefully attaching the clamp to the rods.
20171203_200743 by Robomog, on Flickr
20171203_200806 by Robomog, on Flickr
Got there in the end.
………Clamp closed
20171203_201013 by Robomog, on Flickr
……..Clamp open
20171203_201030 by Robomog, on Flickr
And a picture of the finished assembly YAY!
Coming next the Turbofans or the landing gear or the tail assembly or the Command module assembly. Who knows? I'm working on all four in relays.
Update soon……….
Mog
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