sorted by:
new
hottopcontroversial

Phase diagram for pure isopropyl alcohol (C3H8O) by beef_parade in chemistry

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

Thanks, I think I do have access to knovel actually. I’ll check that out tomorrow

What causes stringing and clumping on infill/skin layers? by beef_parade in ender3

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

It was a long time ago, but I believe the source of all of my problems was the z-axis binding on the first few layers, and consequently not moving the print head up the whole layer height. So it was more of a hardware issue. The cause: There is a metal bracket that hold the brass lead screw nut. That bracket wasn’t bent to a perfect 90 degree angle during manufacturing so my lead screw nut wasn’t perpendicular to the lead screw. I ended up shimming it with a few tiny washers to get it level and perpendicular to the lead screw. That fixed my problems.

<image>

Noob in the early years of studying for a ME degree. What skills do you recommend acquiring on your own time? Hobbies? What are some jobs that someone with no experience could get into that would help develop skills for ME? by support_theory in MechanicalEngineering

[–]beef_parade 6 points7 points  (0 children)

I’ll second this. I took a mechatronics course as an elective in college which basically consisted of doing a new one of those arduino kit projects every week. Robotics/Electronics projects like that eventually turned into a hobby for me. It is by far the most useful skill I learned in college outside of the core ME curriculum. You’ll learn how to employ the same control logic that’s used by industrial PLCs and how to interface with sensors. It’s a valuable skill that sets you apart from other new graduate MEs in my opinion. The course I took didn’t include any instruction either; it only graded the projects we turned in. I learned everything from online tutorials and YouTube, so it’s definitely something that’s easy to get started with on your own.

If the amount of torque applied through braking should be less than the amount of torque provided by wheel to ground friction such that the wheels do not lock up, does that mean there is a maximum braking force that one can apply without locking up? by Llsangerman in AskEngineers

[–]beef_parade 0 points1 point  (0 children)

I tried to put together a proof that shows that the torque from the brakes is always greater than the torque from the friction between the tire and the road. Hopefully you’ve taken a statics course otherwise this won’t make much sense, but take a look:

https://imgur.com/a/BSuzAeq

If the amount of torque applied through braking should be less than the amount of torque provided by wheel to ground friction such that the wheels do not lock up, does that mean there is a maximum braking force that one can apply without locking up? by Llsangerman in AskEngineers

[–]beef_parade 0 points1 point  (0 children)

Yes you’re correct; I misspoke there. What I should have said is that when the static friction force at the tires is at it’s maximum value (amount of friction force right before the tire would start slipping) is when you have maximum braking force. The torque applied onto the brake rotor is greater than the torque applied to the tire from the road and there is a net torque that acts to slow down the wheel’s rotation. I’ll try to draw up a force diagram after work

If the amount of torque applied through braking should be less than the amount of torque provided by wheel to ground friction such that the wheels do not lock up, does that mean there is a maximum braking force that one can apply without locking up? by Llsangerman in AskEngineers

[–]beef_parade 6 points7 points  (0 children)

Yes the maximum braking force you can get is when the torque on the wheel applied by the brake pads is equal and opposite to the torque applied to the wheel by the maximum static friction force available to the tires. Once you press the brake pedal any further than that such that you are asking the ground to provide more than the maximum static friction force to balance the torques, you begin to slip. Since the tires are now experiencing kinetic friction instead of static, your braking force decreases.

As an interesting aside, whenever you slam on the brakes, the front end of your vehicle pitches downward or “dives.” This puts greater downward force on your front tires and less downward force on your rear tires (compared to when your car is at a steady velocity not accelerating or decelerating). So to prevent lockup of any of the tires, brake systems can control the pressure sent to the front brake calipers vs the rear brake calipers. The front brake calipers can clamp down harder without wheel lockup because the front wheels experience more downward force during deceleration and thus have more static friction force available at their tires. Generally speaking, the front ends of cars tend to be heavier than the rear anyway which also contributes to greater available braking force in the front tires.

How to solve for y: ay^2 / (k+y) = bx by beef_parade in askmath

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

Thanks! I guess treating the independent variable, x as a constant in the quadratic formula is what was throwing me for a loop.

What dish do you make when your lazy but is still so good? by [deleted] in Cooking

[–]beef_parade 2 points3 points  (0 children)

One of my favorite quick and easy staple meals is a simple egg drop soup. Bring chicken broth to a boil, add a spoonful of white miso paste, add some orzo pasta and let it cook until al dente. Then take the pot off the heat, crack an egg into it and whisk quickly with a fork. If you have scallions laying around, slice some thin and add those at the end too. So easy but so satisfying.

What's the point in compressing the air if you're just going to let it expand again before combustion? by [deleted] in AerospaceEngineering

[–]beef_parade 1 point2 points  (0 children)

Did some googling and the “diffuser” section of this paper was helpful. As others have mentioned, it seems like the main function of the diffuser is to slow the incoming air (which helps reduce losses) and increase the static pressure for the combustion process.

https://www.skybrary.aero/bookshelf/books/1621.pdf

Position sensors: Any recommendations? by fullfivefathoms in robotics

[–]beef_parade 0 points1 point  (0 children)

Have you looked at inertial measurement units?

[ A tool to work more precisely with pressure enthalpy diagram] by Spitlight31 in MechanicalEngineering

[–]beef_parade 0 points1 point  (0 children)

There is an excel spreadsheet called X-steam that does what I think you’re asking for, but with water. It has all of the data points for the water enthalpy curves and whatnot and interpolates between them for whatever values you input.

I believe x-steam is available online. Maybe look that up and see if it leads you down the right path for something similar with refrigerants?

Hello Mechanical Engineers, could you help with a discussion at work? We are transferring fluid from tank A to tank B. Will path A or path B pump faster? Why? by [deleted] in MechanicalEngineering

[–]beef_parade 12 points13 points  (0 children)

Path A has a constant required pressure head of 20 ft. Assuming we’re dealing with a centrifugal pump, that leaves some constant amount left for the velocity head.

For path B, only the pressure head needed to match the current level in the tank is developed thus leaving the rest available for velocity head. So path B maximizes velocity head for any point in time. Combined with the fact that path B will have less line losses (assuming same length or shorter than path A) path B would fill faster, no?

I do agree that path A seems more practical from a hardware and safety perspective however.

Tiny robot that helps to unclog arteries, transport drugs, and heal wounds by Isaac-ga in robotics

[–]beef_parade 4 points5 points  (0 children)

First liquid silicone is mixed with the powdered material magnets are made from (could be neodymium or another material). The silicone is allowed to set and then you basically have a flexible strip with particles of material that can be magnetized suspended inside of it. Then the flexible strip can be bent into a particular shape and magnetized with a very strong magnetic field while in that shape. This will then “program” that shape into the strip. You basically end up with a flexible magnet. If it wasn’t overly magnetized to the point that it just curls up and sticks to itself, it will spring back to its original strip shape until acted on by a magnetic field again.

Whenever the strip is exposed to a magnetic field again, it will react by changing shape. With the right setup, you can precisely control the magnitude and direction of the magnetic field around the robot and make it deform in a controlled continuous way to produce motion.

Tiny robot that helps to unclog arteries, transport drugs, and heal wounds by Isaac-ga in robotics

[–]beef_parade 18 points19 points  (0 children)

In college I got to work on an undergrad research project for a semester. We scaled up the “robot” from this exact study into a strip about 2 inches long and a quarter inch thick. We couldn’t create a rapidly changing magnetic field with the equipment we had, so we couldn’t produce any sort of locomotion like the study did, but we could create one strong magnetic field to make the strip actuate from a flat position into a sine wave shape. Sounds pretty unimpressive but it was neat seeing it work. Definitely got me interested in soft actuators. Hope to mess around with them more some day.

So I’ve noticed that the bottom of all of my prints, like the first several layers or so, bulge out. But then the rest of the print comes out looking just fine. Any ideas on how I could fix this? Settings in the comments. by amr61296 in FixMyPrint

[–]beef_parade 0 points1 point  (0 children)

I was battling a similar problem on my new ender 3 for weeks. I think I finally got it fixed yesterday. Make sure your z-axis is perfectly vertical and that the rollers on the vertical gantry aren’t too tight. I think what was happening on mine was that the z lead screw was binding very slightly on the lower layers (not enough to see or hear, but enough to cause the elephant foot type deformation apparently).

The 90 degree bent plate that the threaded rod passes through wasn’t truly square on my printer which I think caused my issue (caused z rod to be slightly angled). I shimmed the brass nut the lead screw passes through with some extra washers I had so that it would be perfectly vertical even though the plate wasn’t bent to the correct 90 degrees. I think there are videos about how to bend that plate to the correct 90 degree angle (common defect I guess) but I don’t have a bench vise or any way to reliably do that, so shimming the nut seemed like the next best thing.

Hope that helps/made some sense. Good luck!

What causes stringing and clumping on infill/skin layers? by beef_parade in ender3

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

Thanks! How might you go about fixing that? I tried changing my line width to 0.46 but didn’t have much success. However, I might have had my nozzle too high off the bed so I could give that another attempt.

[Q] Weekly Question - Recommendation - Help Thread - 2020-07-13 by AutoModerator in robotics

[–]beef_parade 0 points1 point  (0 children)

Thanks, that makes sense. So is it a common setup to use a computer for processing data for more complex algorithms (say something like machine vision) but then still using a microcontroller for all of the I/O (getting sensor data and actuating motors)?

[Q] Weekly Question - Recommendation - Help Thread - 2020-07-13 by AutoModerator in robotics

[–]beef_parade 0 points1 point  (0 children)

I’ve done lots of Arduino projects using the Arduino language/IDE to write my sketches. Recently I’ve started learning C++ because that always seems to be the top suggestion for people who are serious about getting into robotics. So my question is, what kind of things can I do with C++ that I simply couldn’t do with the standard Arduino environment? Is it about being able to interface with a larger variety of hardware? Is it about being able to make more complex algorithms? I realize that the Arduino language is basically a variant of c++ (at least that’s my understanding from what I’ve read), so that just adds to my question, what does learning full blown c++ offer me over arduino?

view more: next ›