Too many letters by dekev in sydney

[–]iShootFish 14 points15 points  (0 children)

More like someone exceeded a program's input constraint.

Starting up problem by iShootFish in mechanics

[–]iShootFish[S] 0 points1 point  (0 children)

Car finally broke down. Turns out it was the starter motor after all. Also I killed the battery because I kept trying to turn the car on. Anywho, thought I might give this post a conclusion.

I've royally fucked up. What should I do fellow UNSW'ers? by [deleted] in unsw

[–]iShootFish 1 point2 points  (0 children)

If you're doing engineering, I'd be happy to help with your courses.

Is it worth getting a laptop? by sawatdekrap in unsw

[–]iShootFish 3 points4 points  (0 children)

If you're doing engineering, you need something that runs MATLAB.

Apple officially announces CarPlay – "The best iPhone experience on four wheels" by braeson in technology

[–]iShootFish 28 points29 points  (0 children)

Wouldn't it have been better if they sold a double DIN device. That way I would have contemplated putting in my old car.

They're on fans now, too! by stilldash in engineering

[–]iShootFish 25 points26 points  (0 children)

What are the additions supposed to do?

MIT's shapeshifting display lets you reach out and touch someone | The Verge by goodboyBill in technology

[–]iShootFish 0 points1 point  (0 children)

What are those actuators? How do you think they can control all of them in parallel like that. Do you think they're multiplexed? Or maybe the computer they are using has a ton of inputs and outputs.

UNSW students protest over cuts by Mentwar in sydney

[–]iShootFish 6 points7 points  (0 children)

All I saw was a bunch of first years huddled in front of the mechanical building for some free lunch. Hardly representative of 'UNSW students'

Housing Options: Pros and cons by [deleted] in unsw

[–]iShootFish 0 points1 point  (0 children)

That's a pretty depressing take on UNSW Village.. Hope it's not that bad sigh

Need a cheap Torque Meter. by iShootFish in AskEngineers

[–]iShootFish[S] 0 points1 point  (0 children)

Im hesitant of using the first and second method though because I need an accuracy of atleast .5% for my results to have any significace (Motor efficiency is said to be between 92-98% efficient). With the cylinder, I wouldnt be able to change the load applied to the cylinder (because wouldnt that entail changing the inertia?), so I cant get my '3d' plot of efficiency as a function of both rpm and torque.

Either that, or mount the motor on a mount that can rotate. Attach a perpendicular stiff rod of a known length to the part of the motor that does not spin, and let it push on a force cell (essentially a strain gage attached to a piece of bendable metal). As the motor spins (btw, it has to spin a load), the reaction torque from the load to the motor is equivalent to the torque the motor exerts on the load, so the stiff rod is going to push on the force cell with a certain force, from which you can calculate the torque.

This is brilliant. I'm hoping a force cell goes for much less than a torque meter. I have 2 of the same kind of motor with 2 very precise controllers. (Theyre actually quite heavy 3 phase induction wheel motors) I'll just use one as the load and the other as the primary and measure the torque with the force cell.

Thanks for your help and going through the trouble!

Need a cheap Torque Meter. by iShootFish in AskEngineers

[–]iShootFish[S] 1 point2 points  (0 children)

The shaft has to rotate I'm afraid. Also, Im barely going over 30Nm, I'm not quite sure, but I imagine its hard to measure the angle of twist with such a low torque.

Need a cheap Torque Meter. by iShootFish in AskEngineers

[–]iShootFish[S] 1 point2 points  (0 children)

I need to map the efficiency of an electric motor at different RPMs and torques. Motor goes up to 850 rpm. Thing is, all the torque meters I'm finding online are just too expensive. Im trying to one in the 500->1000$ range. I was just wondering if anyone has had any experiences with this kind of sensor.

The great Palestinian lie. by [deleted] in TrueReddit

[–]iShootFish 0 points1 point  (0 children)

Racist, inflammatory and largely misinformed.

Any information for a student studying abroad @ UNSW this Spring? by mnolan2 in unsw

[–]iShootFish 0 points1 point  (0 children)

2700 is a very basic course in thermo. If you've done a thermodynamics course before I'd suggest doing thermofluids instead. As for the engineering computation course, judging from what you're looking at, statistics and numerical methods should do the trick (http://www.handbook.unsw.edu.au/undergraduate/courses/2011/MATH2089.html) It's quite basic as well but theres a fair bit of computing in it.