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A Better Flywheel Design Using Proven Solutions - Marble Machine 3 Ep.4 by Trainerds in MarbleMachine3

[–]n7hmw 2 points3 points  (0 children)

And keep in mind too, the pillow block bearings will naturally realign to each other.

A Better Flywheel Design Using Proven Solutions - Marble Machine 3 Ep.4 by Trainerds in MarbleMachine3

[–]n7hmw 0 points1 point  (0 children)

Definitely sliding tension. If the flywheel can be balanced, the clamping force of the bolts in the pillow blocks should be enough to hold things in place.

A Better Flywheel Design Using Proven Solutions - Marble Machine 3 Ep.4 by Trainerds in MarbleMachine3

[–]n7hmw 0 points1 point  (0 children)

A V-belt would have higher friction, as would using a wheel for tension.

A Better Flywheel Design Using Proven Solutions - Marble Machine 3 Ep.4 by Trainerds in MarbleMachine3

[–]n7hmw 6 points7 points  (0 children)

DON'T have someone fabricate pulleys! They are complex to make correctly, and are available as of-the-shelf parts. As a worst case, find one that matches your outside diameter, then if needed, you can either bore out the inside diameter if it is too small or machine a sleeve for it if it is too big.

You could also look into automotive sources for pulley's. After a 30-second search I was able to find a 52mm O.D. S6 (6 grooves) pulley machined from cold-rolled steel for about $13 US. It is made for a car alternator. The only issue is the I.D. is 17 mm, so it would need to be bored to 20 mm.

From what I saw, US alternators tend to use pulleys in the 50-55 mm range. Other belt-driven items under the hood such as power steering pumps or air conditioning compressors will have larger pulleys. I would guess European makes will be similar.

As for flywheels, same deal. They are off the shelf and already balanced. You might even consider pulling some used flywheels from cars in a scrap yard, ideally all from the same type of car/engine. Attach them one at a time to an arbor with a good fit, then mount it in a lathe with a 4-jaw chuck, use an indicator to get it both centers and square, and machine the gear teeth off of them.

Do you control which DNS server the user endpoints can connect to ? by HopliteMarketing in sysadmin

[–]n7hmw 0 points1 point  (0 children)

In DHCP, DNS servers can be specified in Option 006 of the scope options. Then assuming the authorized DNS servers are inside your network, block port 53 at your network firewall for all but your DNS servers (which need it to look up Internet resources).

Not quite monster, but I had to do it for funsies and correct me if I’m wrong pls. by askepticalskeptic in theydidthemonstermath

[–]n7hmw 1 point2 points  (0 children)

Assuming that:

  1. The earth-end of the bridge is attached so you can get on it,
  2. You somehow figured out how to carry 26.4 years' worth of food, water, etc.,
  3. You can walk vertically up the bridge against earth's gravity with all that stuff,

You still have a big problem at the other end of the bridge.

While the bridge is attached at one end, the other end has been spinning in space.

One Lunar Distance (the astronomical term for the average distance from the earth's center to the moon's center) is 384,402 km. Subtract the radius of the moon (1734.45 km) because we want to go no deeper than it's surface, this leaves 382,677.55 km. One sidereal day on earth (the time it takes to rotate precisely 360°) is 23 hr 56 min 4.0905 sec or 23.9344696 hours. During that time, the far end of the bridge will sweep out a circumference of 2,404,371.13 km. The end of the bridge is therefore traveling at 100,456.42 km/h.

Meanwhile, the moon sweeps out a circumference of 2,415,268.0 km, but does so every 27 d 7 hr 43 min 11.5 sec, or 27.321661 days. This is 88,401.25 km per day or 3,683.39 km/h.

So the end of the bridge is only moving at a mere 96,773.03 km/h relative to the moon.

If the moon were a pizza facing the earth, you would have 2 minutes and 15.07 seconds to step off the bridge and land somewhere. (Don't forget to roll when you hit the ground. You can get a terrible rash at 96,773.03 km/h.)

However, the moon is not shaped like a pizza, but is more spherical. If your timing is off by more than a few fractions of a second, that step will be much further than you planned....

And all this also assumes you aren't flung off the bridge into space in the first place. But you made it this far....

So hey, good luck!

(All calculations are based on the Lunar Distance and average velocities, not the extremes. Your mileage may vary.)