Made correction … had put Valwood not Monetary. Senior moment … somehow that phrase isn’t as funny anymore.
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FWIW I have almost nothing besides a handful of odds and ends that are unlikely to be useful except my roll of carbon fabric and epoxy. I might be willing to bankroll some stuff in the event I get really involved and have the motivation, but I am not willing to commit to that at this point.
$200 for balloon sounds about right. Most would go to He, the rest to antennas if we find we need them.
My brief googling of aero-mapping suggests the limiting factor would be the mapping software we get our hands on. What’s the sort of software we would require to have it work out? Also, how good and/or heavy will the mapping camera need to be?
its about ~$150 for He and tank rental, ~$50 for delivery, Harold says we already have the balloon (two, in fact)
I have used Microsoft I.C.E. in the past for stitching photos together to make a simple map. It’s not the best, but it’s free and has good results. Camera options are plentiful. A camera that I have seen used in the past for this application is a Sony rx100 (about .5lb). You could really use anything, though. I’ve stitched together stuff taken with my cell, even. But to answer your question, not much. I’ve flown larger payloads on flite test models.
If we want to use photogrammetry software for a topo map, we still have some free options, though they will not produce commercial-quality maps, and trees tend to throw it off. or we can do a cloud-based service for a per-map fee and get professional quality results.
Ok, just wanted to be clear whether reasonable / desired results didn’t require anything ridiculous.
So before the next meeting lets see what materials we can come up with. I think the cheapest options are likely to be either 3D printer filament (I’ve never printed a plane, but from what I hear it takes about a roll – so ~$20), DTFB (a good place to start, but these air frames wear out fast), Insulation foam (This would probably make the best choice for something cheap and durable, but will likely require us to source some form of a hot wire cutter – CNC would be awesome, but I’m sure a few plywood templates and some practice will work fine as well)
To get this project off the ground I think we should do it in a few bite-sized steps:
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Build a DTFB plane and put an autopilot on it – no cameras, no mapping, no expensive equipment. We take it up and have it fly a mission, come back and land safely under autonomy.
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Redesign the air frame to be made from a better material (I imagine it will come to a decision based on price – foam if we can afford to tool up for it, or printed if we can only afford some filament)
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Move the electronics to the new air frame and repeat the mission from the first step – analyze differences to determine improvements/drawbacks over DTFB model (and hopefully address the drawbacks).
Step 2 and 3 can be repeated to improve design further. (with more emphasis on aerodynamics/balance than materials)
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Install camera and fly a mapping mission – The goal here is just to test flight times with payload, while collecting some test data
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Take the photos and make a test map using Microsoft ICE
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Party!
What do you guys think?
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I’m wondering if you can use something like “Great Stuff” - the spray-in foam that seals around pipes, etc, to make some custom foam fill-ins. You can easily shape that stuff once it dries.
It also sticks to stuff so you can let it act like a glue.
I’ve seen great stuff used as infill for FT wings (namely the versa) to make them a little more crash tolerant. While it works beautifully for just that, in my experience seen that will also add a considerable amount of weight to the air frame making it handle a little sluggishly. As far as a pure great stuff casting, I’ve never attempted it, but it definitely seems plausible, and you’re right, the dried product feels fairly similar to EPP. A really important piece if kit for that process would be finding something to act as a mold release – that stuff sticks like shit to a blanket.
Change #6 to profit! and I am in. Kidding, about everything but being in. I keep planning to make the meetings and keep getting busy with errands etc.
Awesome, it seems that everyone who is active seems interested in doing a drone. A few designs have come up in meetings, one being a design similar to an RQ-7 and one that @CKraniak came up with. Between the two designs, I’d say that the RQ-7 style build would be much more doable (having to invert for landing is a bit of code I’m unsure of how to get done, and as we have determined, our custom software capabilities are limited) unless someone else knows how to program that feature into ardupilot.
That being said, I’d like to plan a meeting for APR 29th to start designing whatever air frame we settle on.
I would also like an organized way to see what everyone is able to loan/donate to the project. I’ll also add a checklist of required stuff to the roster (which will likely be updated as the plan develops and as we move through the phases of the project) – this can also be used as a log of who has loaned what to the project.
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How big can we make it? 
I suppose that depends on what motors/esc’s/batteries we can come up with. I have motors that can suit most planes of this style (long range flight) from anywhere between about a 30" wing span up to about a 60" wing span. To give an idea of the capabilities of a 60" wing span plane: I have built an all DTFB plane with a 60" wing span capable of carrying a 10,200mAh 3-cell lipo. I never actually timed to see how long I could have it in the air for, but just flying it around I could easily manage about 45 minutes of continuous flight (that’s with me fun-flying and doing mild acrobatics, not playing the efficiency game)
What I’m getting at is that unless we see some donations of motors/esc’s/batteries ~60" will be the most we could do
After our meeting last week we were able to nail down a design (RQ-7), list the desired functions for the final build (A-Tail, ailerons, throttle, flaps, retracts [optional], flight mode), and got all the parts for the DTFB airframe built.
Our goal for the next session will be to assemble the plane and get all the electronics into the airframe, make all the servo linkages, and center all the control surfaces.
Not directly connected to our upcoming meetings, but something I’d really like to start thinking about is construction methods/materials for the final design. A few ideas have been kicked around, insulation foam, balsa, carbon fiber or maybe even a combination of them.
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Oooh oooh ~ when you get it assembled, please post pix here and in the current #public-relations:show-and-tell thread!
Good build meeting, I am looking forward to seeing this bird fly 
@Millioncorn I am super interested in that class you mentioned re: DTFB aircraft
In like with the idea of building several for fly-ins etc, I’d really love to build this:
Suggestions/etc. very welcome.
Source: https://www.flitetest.com/articles/all-flying-penguin-plans-free
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Are we meeting this Saturday?
Yes, my apologies for not submitting a class to the calendar this week. We are meeting at 10:00am. Let’s try for a spot in the workshop, but as I failed to schedule an event, we don’t have any space reserved. We may just have to find an empty table.
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No worries, I will be there. I bought some servo pushrods I’ll donate if we need them
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This weekend, and the following two weekends as well, I will be unable to host build events. I apologize for any inconvenience. I will be sure to update you guys as soon as I get back into town. I can work with y’all to make sure you have the hardware you need to continue working on the plane before I leave town (Thursday next week).
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If others are still interested in showing up I was still planning on being there from 10 to 12 or so.
What do we need? A radio and RX, a battery (which I can obtain if need be) … what else?
Edit: pushrods
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