Author Topic: Magnetic table or magnetic base kind of thing?  (Read 350 times)

Offline PekkaNF

  • Hero Member
  • *****
  • Posts: 1603
  • Country: fi
Magnetic table or magnetic base kind of thing?
« on: March 24, 2017, 03:27:55 PM »
Need an idea or inspiration on a grinding machine tool rest. Has to have a lever, switch or something to turn the magnetic flux on and off , to make placing the rest near lapping disc very easy.

Bit like this:
http://www.model-engineer.co.uk/sites/7/images/member_albums/119484/656464.jpg

1: Like above, permanent magnet. Maybe a magnetic base, but they have often only one hard point. Not great for stability.  Maybe just can drill and tap two holes? Sides should be soft steel.

2: Sort of magnetic table? Just don't want to pay over 200 //$ of sort of magnetic table.

Something like that?

Pekka

Offline shipto

  • Hero Member
  • *****
  • Posts: 600
  • Country: gb
  • Redditch, UK
Re: Magnetic table or magnetic base kind of thing?
« Reply #1 on: March 24, 2017, 06:06:28 PM »
What about these https://www.kjmagnetics.com/blog.asp?p=magswitch its a American site but you may be able to source them closer?
Turns out this life c**p is just one big distraction from death but a good one. For the love of god dont give yourself time to think.
https://myshedblog.wordpress.com/

Offline PekkaNF

  • Hero Member
  • *****
  • Posts: 1603
  • Country: fi
Re: Magnetic table or magnetic base kind of thing?
« Reply #2 on: March 25, 2017, 05:26:50 AM »
They look nice. Googled them fast, one place to get them here, but they are bundelt with featherborad and stuff - pricey, but they look right ar first glance.

Pekka

Offline ieezitin

  • Hero Member
  • *****
  • Posts: 659
Re: Magnetic table or magnetic base kind of thing?
« Reply #3 on: March 25, 2017, 08:06:16 AM »
I own a set, they were designed for a ground cable for welding, the magnet is ok but the mechanism is a little chiniezium your going to have to modify them yourself which you are more than capable of doing..


All the best

Anthony.
If you cant fix it, get another hobby.

Offline shipto

  • Hero Member
  • *****
  • Posts: 600
  • Country: gb
  • Redditch, UK
Re: Magnetic table or magnetic base kind of thing?
« Reply #4 on: March 25, 2017, 04:37:22 PM »
Just read further down at the explanation of how they work it may be you could make a more bespoke version for your project if you can source the magnets.
Turns out this life c**p is just one big distraction from death but a good one. For the love of god dont give yourself time to think.
https://myshedblog.wordpress.com/

Offline PekkaNF

  • Hero Member
  • *****
  • Posts: 1603
  • Country: fi
Re: Magnetic table or magnetic base kind of thing?
« Reply #5 on: March 25, 2017, 05:36:13 PM »
That is some inspiration. Thank you.

 I been having a flu and had time to do some internet loitering. Haven't got far.

There seems be two options: Mechanically or electrically route the flux.

Dial indicator magnetic mount seems to use very simple method.
https://www.quora.com/Is-there-any-simple-low-energy-way-to-make-a-permanent-magnet-able-to-turn-on-and-off-similar-to-an-electromagnet

Magnetic table seems to work by alligning the magnet block to soft iron poles. Not sure about the very detals. How much air cap is alloved, or does the mechanism wedges parts to very close contact?

And then there is an electrical way.
https://en.wikipedia.org/wiki/Electropermanent_magnet
https://youtu.be/w9dqq0qfbGQ

Some sort of stuff seems easy in priciple, many details to do it efficiently.

Pekka

Offline shipto

  • Hero Member
  • *****
  • Posts: 600
  • Country: gb
  • Redditch, UK
Re: Magnetic table or magnetic base kind of thing?
« Reply #6 on: March 25, 2017, 06:50:40 PM »
Your welcome nice find with the magnetic base page it looks really simple just a iron-aluminium-iron sandwich bored out to suit your magnet. Just looked on ebay and a suitable magnet was 9 ish + postage.
Turns out this life c**p is just one big distraction from death but a good one. For the love of god dont give yourself time to think.
https://myshedblog.wordpress.com/