Break through!

[Omnibus]

Always good to see ideas materialize into reality even if they are basic. It's really sad that the creativity and ingenuity of man is limited by the invention of money. I hope the day comes everyone will have a 3d printer at home, one that can even print out metal parts  , do a youtube search on this . At least this revolution is slowly but surely happening already. They think the Internet is scary, but what happens if billions of people have the power to create anything they want very cheaply and fast.

What more than 5-axis CNC machine can 3D printer bring? Such CNC machines exist but the problem is only very few can afford them.

[broli]

What more than 5-axis CNC machine can 3D printer bring? Such CNC machines exist but the problem is only very few can afford them.

I would say versatility, effeciency, size and as you mention cost. When you are depositing material layer by layer there's technically nothing going to waste. You can also create very intricate shapes with inner cavities that would be near impossible to achieve with a CNC router/mill/lathe. You could create bearings, tools, nuts/bolts, complex and organic structures like schaubergers machines, objects in objects. Basically one machine would do it all.

I really don't know what made inkjets cheaper than their cartridges but I hope something similar would happen with 3d printers and Direct Metal Laser Sintering.

Open source projects like makerbot, reprap or lasersaur are certainly a good boost in the right direction.

Anyway that's enough day dreaming for me.

Again good job team lafonte.

[mscoffman]

Butch,

Money generally is not of primary importance when doing things.

Instrumentation is of prime importance because subsystem efficiency is
of prime concern. How the heck do you design something mechanically
complex and expect it to work efficiently the first time? Correct
instrumentation doesn't have to be expensive either.

From what I am seeing MIBS are always trying to bury important
projects too soon, and without proper analytical justification.

---

This is how I would do this.
I would link the center shaft to a flywheel mechanism. I would find one
that works ok in a toy vehicle first. I would then instrument the flywheel
with a white mark and an opto to read out flywheel RPMs.

1. Qenergy ~= flywheel RPM2-RPM1.

2. The speed of a demo motor during an OU demo can be arbitrarily slow.

3. The ability to store flywheel energy efficiently during the center magnet
    "flip" is of fundamental importance to the project. The connection has to
     be stiff.

I would use solenoid valve controlled compressed air to speed up the flywheel
when necessary.

a. Measure Qenergy decrease for 1/2 rotation with endcaps asserted.

b. Now deassert the endcaps use compressed air to keep flywheel RPM
    constant during the charge up flip and stop applying air during the back side flip
    where the magnet overruns the flywheel and charges it itself. This is what has
    to happen efficiently.

c. Use the results from A and subtract during B the flywheel speed should
    now be increasing. Qenergy = available for asserting and deasserting the
    endcap.

d. Build a lego endcap asserter/deasserter. This would work on-the-fly of a
    slowly rotating central magnet. It may need to store energy in hanging
    weights so they can act instantly, input energy constantly.

e. Power it from the central axle.

f. Remove compressed air. Flywheel RPM continually increasing = success.

:S:MarkSCoffman

[gravityblock]

Ferrofluids have friction-reducing capabilities. If a thin coating is applied to the surface of a strong enough magnet, it can cause the magnet to glide across smooth surfaces with minimal resistance and can reduce wear in moving parts.

( http://en.wikipedia.org/wiki/Ferrofluid#Mechanical_engineering )

GB

[Low-Q]

Ferrofluids have friction-reducing capabilities. If a thin coating is applied to the surface of a strong enough magnet, it can cause the magnet to glide across smooth surfaces with minimal resistance and can reduce wear in moving parts.

( http://en.wikipedia.org/wiki/Ferrofluid#Mechanical_engineering )

GB

Good idea! There is magnetic oils in different qualities. I bought a dl on ebay once. This oil dries out after quite short time and get sticky, but there is oils which can maintain its liquid form for very long time - specially those oils which is used to cool the voicecoils in tweeters - by applying magnetic oil in the magnet gap. These oils cost more, but are worth the money. At work, we apply such oils into tweeters which is repairable.

Also copper-paste/grease are very good for reducing friction.

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