MechSkep · HackerTrans

10 yıl öncediscuss

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.

MechSkep

10 yıl öncediscuss

You've made some good points in this thread about actuation. Can you point me to more info on SCHAFT's actuation strategy? I've been trying to turn up info, but haven't found anything great.

MechSkep

10 yıl öncediscuss

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?

MechSkep

10 yıl öncediscuss

Yep, and it makes sense for Tesla to do this. It's a new product, and the information they collect from maintenance and inspections is going to be invaluable for future revs.

MechSkep

11 yıl öncediscuss

There was no difference between the control experiment and fish exposed to parts made with FDM.

Read the article to see how FDM could become toxic/harmful, turns out it didn't.

MechSkep

11 yıl öncediscuss

Very hype heavy article. No mention of Form Labs who is already on the market with a similar product.

MechSkep

11 yıl öncediscuss

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.

MechSkep

11 yıl öncediscuss

After the single lethal attack in 1945: "Several Japanese civilians have visited ... to offer their apologies for the deaths that took place here, and several cherry trees have been planted around the monument as a symbol of peace" [1]

[1] http://en.wikipedia.org/wiki/Fire_balloon

MechSkep

12 yıl öncediscuss

I was looking for this workflow for my research, and ended up going with an ipython notebook.

MechSkep

12 yıl öncediscuss

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?

MechSkep

12 yıl öncediscuss

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.

MechSkep

12 yıl öncediscuss

It's hard to say with CCD being so large and varied. One thing we know is that beehives exposed to certain pesticides [1] are much more likely to collapse.

[1] http://www.hsph.harvard.edu/news/press-releases/study-streng...

MechSkep

12 yıl öncediscuss

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.

MechSkep

12 yıl öncediscuss

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?

MechSkep

12 yıl öncediscuss

Okay... but actual animals do way better:

http://www.ted.com/talks/robert_full_the_secrets_of_nature_s...

As a rule of thumb, any walking robot that uses servos can't approach the performance of its animal colleagues. The leg impedance is way too high.

MechSkep

12 yıl öncediscuss

Neat. Looking forward to it.

MechSkep

12 yıl öncediscuss

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.

MechSkep

12 yıl öncediscuss

So this has popped up on HN before, and again I would caution that this is snake oil. The sparse technical details they give are misleading, and they still haven't shown that their fiber reinforced parts are anything special.

MechSkep

12 yıl öncediscuss

Kinda disappointed the total emphasis is on him being a "hell of a good pilot" instead of the control engineers who allowed the plane to compensate for losing a wing. There's no way that plane would have stayed in the air without their work.

MechSkep

12 yıl öncediscuss

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.

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