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MechSkep

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Mechanical Engineering graduate student studying robotics

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Looks good for robotics applications. The power density is comparable to the low end of brushless motors, and it can use hydro-carbon fuels which are about 25 times more energy dense than current batteries. At 3 hp, it might be a reasonable drop in for the type of weed-whacker two-stroke that drives big dog.

I have a plan for overhauling/replacing Geometric Dimensioning and Tolerancing. The way it's done now consumes way too much design time, and honestly is a bit silly considering the inputs and outputs of the system.

I'd like to talk to someone with experience interfacing with factories in China about how the current approach could be replaced. Any suggestions?

Also, if I developed this tool-chain, what is the best way to attach to the market?

So there was a DARPA initiative to do stuff like this back in the 90's/early 2000's:

http://archive.darpa.mil/darpatech99/Presentations/dsopdf/ds...

Turns out it's easy in controlled environments, and doesn't work at all outside. Once the animal sees something it wants to eat/mate with, it's just going to leave.

The claimed contribution of this work is direct ganglial stimulation as opposed to the antennal stimulation which was used previously. But I'm not seeing anything new in terms of capability/new science, and their data collection methods seem hinky:

The controllability of a roach, in terms of success rate, was subjectively rated based on user observation. If the user was able to successfully have the cockroach turn in a desired direction, then a run was deemed successful.

Ah, well here is where I could use some advice. I disagree with the way they have gone about their hardware both in the sensing electronics and the hive box itself. I don't want to go into it here; I'd feel a bit rude criticizing someone else's work in a public forum.

Should you approach someone for collaboration if you don't agree with how they're going about the project?

Weight is another good one, it drives our complexity and cost up but is hugely important. Most extant hive monitoring tools record weight. NASA uses some of these measures to track mass flow rates of nectar.

We certainly have a microphone. There is such a richness in the sounds a colony produces. Our minimal sensing package also contains temperature and humidity sensing. We're shooting for collecting a labeled data set this coming season to see what we can pull out of the information we collect.

One of my side projects is building a sensing electronics package to monitor the health and activity of beehives. The idea is to make it easier for someone just starting to maintain their hive.

Any one have feedback on the concept? Or features we haven't thought of?

This looks great! I'd like to use it to ease up the tech overhead for some mobile robotics applications. Is there anyway that the user's position in the world frame can be accessed? i.e. can this do SLAM over longish distances?

Basically I'm looking for Google's Project Tango, without the hardware constraints.

Where did you get that yield stress number? Is it from that graph with Aluminum and the plastics?

Because that graph shows modulus(stiffness), not strength. Which is pretty hinky when placed next to the statements about strength. Looks to be a bit misleading.

On top of that "stronger" has no meaning when it comes to composites. There are about 9 different failure modes, and you can't just choose one and report the "strength". I'm guessing they're talking about axial tension numbers (because I'm cynical) where their material would perform the best. Even then, their yield strength is about 200MPa (based on the "5x stronger than ABS" statement) whereas aluminum's yield strength tops out around 600MPa.

I'm skeptical too, but don't count it out because the fibers aren't woven together. The weaving is not where the strength comes from, and it's usually not omnidirectional. If this machine can set the wrap angle, and build out several layers, the fiber layout might be comparable to a filament winding process. http://en.wikipedia.org/wiki/Filament_winding

But the thing that I'm concerned about is the curing of the stuff. A composite gets its strength by having a low resin content, and I'm not sure this machine/process can pull it off. Based on the few available details, it's right to be skeptical.

This is interesting because they could potentially avoid the thermal expansion problem that would otherwise sink the hyperloop. Carbon fiber has a negative coefficient of thermal expansion in its axial direction, and you can pair it with a metal to get a net zero expansion structure.