Engineering

I'm trying to design a cup holder that can stick to metals, looking around at magnets I thought I could get away with a string of neodymium magnets down the side and they would be strong enough. After trying a 20 count string of 3mm squares it's not at all strong enough. I've learned the hard way not to brute force things when material cost is involved. ie. I don't want to buy 20 different types of magnets lol.

If anyone can offer some insight that would be awesome. I've tried searching for some information on different magnet types and possible uses but it seems like there isn't a lot about strength to size, application, etc.

Any information would be greatly appreciated!

1a. Are there any resources for this kind of information that I haven't found yet, I'm sure there are I think I probably just don't know how to interpret the science.

1. Does size matter?
2. Are neodymium the best for size to strength ratio?
3. Cost isn't a huge deal, these won't be a production run, just for fun.
4. Are there certain magnets that are better pulling through different materials? ( if the magnet is behind a few layers of print )
5. Do certain material types effect the strength of a magnet? ( thinking about filament types specifically )
6. Have you had success with magnets before? If so do you know a reputable source?

7. Are there any "Fake" magnets out there? Like different grades that could be mislabeled nefariously? If so how could you tell other than trying multiple versions of the same magnets?

8. Thanks for reading this far, you're awesome.

So i logged onto thingiverse earlier today and this is what happened:
https://www.thingiverse.com/ajax/things/paginate
Can anyone explain this?

*this doesnt have anything to do with engineering.

I'm looking for gear profile that would drive 8mm lead screw like this one:

https://www.amazon.co.uk/Zomiee-L300mm-Diameter-Printer-Length/dp/B074W3KHN4/ref=sr_1_2?s=officeproduct&ie=UTF8&qid=1548078428&sr=8-2&keywords=T8+L300mm+8mm+Lead+screw

Does anyone know gear that can drive this rod directly?

Its possible to go to the beach with a magnet and pull metal powders from the sand. These vary from place to place so it might be useful to know about how to mix them into pellets and get a metallic filament.

Hi everybody !

I'm building a little CNC router (and laser) for fun and learning more about CNC. Im currently using GRBL, arduino, TMC2100 and nema 17 for the hardware. To run all this, I bought a 12V 30 amps 360 watt PSU out of amazon, and I have a question about it ! My PSU has a potentiometer to set the desire voltage value, if my system draw about 10 amps, can I take the voltage up to about 20 volts ?

To recap my question: is the output rating voltage important to respect, or the wattage is more important ?