Magnetic table or magnetic base kind of thing?

[PekkaNF]

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

[shipto]

What about these https://www.kjmagnetics.com/blog.asp?p=magswitch its a American site but you may be able to source them closer?

[PekkaNF]

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

[ieezitin]

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.

[shipto]

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.

[PekkaNF]

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

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

Pekka

[shipto]

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.

[WeldingRod]

Buy a magnetic door lock!  Cheap, but not very fine pitch.  I was impressed with the holding power of the two I tried.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[efrench]

Here's one for you.

[PekkaNF]

Thak you

I got some industrial round solenoids and they seem to work fine.

Pekka

[efrench]

What is their holding strength and size?

[efrench]

I have a project that needs a little more holding strength than a Magswitch 150 and was curious what your solenoid was capable of.

[PekkaNF]

Sorry, I missed your mail completely. I bought 10 used industrial solenoids. Think that 3-4 should be plenty strong.

They are Isker GT-32 W, 24V, ED100% 280N
http://www.islikermagnete.ch/index.php?Page=P05

Surpricingly small for their power.