Making a magnetic knife strip

[bennyprofane]

I recently visited an old friend who's a carpenter and we decided to make a magnetic knife strip. We used walnut wood and made a board of 1200x100x20mm and we used 37 Neodym N42 disc magnets 20x10mm. The magnets should be at least twice as thick as the wood which separates them from the knives. There is a 3cm distance between the centres of the magnets. This enables me to put the knife at every point on the strip.

These are the magnets: https://www.supermagnete.de/scheibe...mm-hoehe-10mm-neodym-n42-vernickelt_S-20-10-N


Here are some pictures.

Choosing the wood

Milling the holes for the magnets

We glued them in with wood glue, one had to cover the previous hole with the thumb as they would jump out.

For drying we stuck the strip to the side of the table, the magnets stuck so hard to that thin steel that it took a lot of force to remove it.

The mounting for hanging it up.

All done.

 

[ThEoRy]

Pretty dope.

 

[Castalia]

That is a good looking strip (and knife collection and woodshop)! It helps to have great tools. :doublethumbsup:

 

[Lazarus]

Sharp looking knife strip sir.

 

[Matus]

Nice work!

 

[Factotum]

Very nice.

 

[bkultra]

Festool, the other expensive collection I see

 

[DanHumphrey]

LORDY that is a long strip and a lotta knives.

Have to see how long of one I can fit in the new house.

 

[malexthekid]

Would love to make one of these but the wife won't let me/isn't really anywhere easy to out it in mu current house

 

[JBroida]

i would recommend using a metal backing for the magnet to manage magnetic flux... you will get a stronger pull on the front, and almost none on the back.

 

[aboynamedsuita]

i would recommend using a metal backing for the magnet to manage magnetic flux... you will get a stronger pull on the front, and almost none on the back.

+1

I used a piece of sheet metal cut 2"x23" and placed 1"dia x 1/8" magnets in a checkerboard pattern (sides attract when you do this, and the metal backing keeps them together) so there is continuous magnetism (although thin parers can feel the pull 1" on centre). I had a local woodworker do the actual wood stuff but I did the research and testing.

 

[bennyprofane]

The magnetic pull is plenty strong, even if I attach the knife slanting it sticks perfectly in that position, it's really the perfect amount of pull and no comparison to the small magnetic strip which I had earlier. And the magnetism is continuous, makes no difference at which position I attach the knife, it just sticks the same everywhere.

But thanks for the tip!

Edit: I just made a test with a very thin parer, for that kind of knife magnetism is not continuous for the big ones is, so I might attach a metal sheet if feel that I need it.

 

[Marek07]

+1

I used a piece of sheet metal cut 2"x23" and placed 1"dia x 1/8" magnets in a checkerboard pattern (sides attract when you do this, and the metal backing keeps them together) so there is continuous magnetism (although thin parers can feel the pull 1" on centre). I had a local woodworker do the actual wood stuff but I did the research and testing.

TJ - Intriguing. Would you be able to post any photos of the back of your strip? Or a sketch of the design?

 

[aboynamedsuita]

TJ - Intriguing. Would you be able to post any photos of the back of your strip? Or a sketch of the design?

I'll email you so I don't hijack the thread

 

[bennyprofane]

No, please, I would be interested to see it as well and it fits perfectly in this thread.

 

[aboynamedsuita]

Okay fair enough, I just didn't want to steal your thread. There's nothing wrong with not using metal backing on the magnets, it just allows you to make do with less magnetism

Here was the (free standing) rack awhile ago:

Here's from the back, The back is seamless because it is made of two pieces so the holes are covered.

 

[bennyprofane]

Nice! But we can't see your magnet set up, right?

I just posted this to inspire / help others so the more other solutions are presented, the better...

I understand now, using a metal backing could have enabled me to use less magnets. We actually considered it but the magnet dealer had advised me not to do it.
Probably wanted to sell more magnets. :laugh:

It's fine the way it is now but happy to learn more.

 

[JayGee]

Very nice strip. Regarding using metal backing - where in these pieces would the magnetic backing go?

Say you have milled holes for the magnets. Would you still glue the magnets in (as close to the front of the strip as the holes allow), and then cover the open holes at the back with a piece of thin sheet metal?

 

[laxdad]

Several years ago, I added rare earth magnets to the inside of some fishing reels as a way of controlling freespool and backlashes. It was recommended to install the magnets inside metal cups to increase the magnetic strength. Steel sheet metal backing would serve the same purpose as the cups. Lee Valley tools sells the magnets and cups.

http://www.leevalley.com/US/hardware/page.aspx?p=32065&cat=3,42363,42348&ap=1


BTW, both knife racks are beautiful.

 

[DanHumphrey]

I keep thinking about what the perfect knife rack would be. Still haven't decided. For countertop, I think it might be Tanner's. By "metal backing" you really just mean sticking the magnets on stainless steel prior to putting the wood over them?

The correct answer, of course, is something like Tanner's for the big ones, and a long strip for shorter ones, and maybe to have knives on each side of the kitchen.

 

[JayGee]

By "metal backing" you really just mean sticking the magnets on stainless steel prior to putting the wood over them?

To me that means you need the thickness of the rail to be just larger than the thickness of the magnets... As well as some difficulty in terms of getting the magnets precisely in the correct position.

I wonder how close the 'backing' needs to be to the actual magnet to function in the way the other's have described (control flux, increase strength...)?