switchable magnets

I have a 60's era Delta Rockwell drill press that works great, even better after I gave it a complete overhaul a year or so ago, but the one drawback is that it has a production table, flat top with a trench around the outside to catch cutting oil. The table is cast iron, and not very flat across the bottom, so sometimes it takes a little extra time to get something clamped just the way I want it. One of these days I should stop by one of the local machine shops to see what it would cost to have them cut a couple of tee slots in it, but can already imagine what that might be. Anyway, one of the thoughts I have had is outfitting a clamping fence with switchable magnets, but don't know how well that might work, so wondering if anyone has any similar experience with them. Thank you.

 

You can get tremendously strong ones now, using rare earth magnets. I have some fairly small ones I use for holding fixtures and the like, and they are very hard to move when switched on. The ones I have a magswitch brand, IIRC.

 

I use the magnetic feather boards on my table saw and they don't move till switch turned off. There are many different types but here are some.
https://www.amazon.com/Magswitch-Tab.../dp/B001DSZ7EC

 

Thank you, guys. I didn't think to mention that I knew of ones on featherboards, but don't know of anyone who uses them, so that part is great information. I'm not sure how the forces might compare, but imagine close enough that if they're working for you in that application they should be worth a shot for what I'm thinking. I will go ahead and order a couple of them this weekend.

 

Just thought that I would come back and close the loop as they say, before the thread gets too old. Got home an hour or so ago to find a package at the door, took it down to the shop, and it looks like theses magnets are going to do exactly what I want. I ordered what I think they call a "starter kit", which includes a base, two 150 lb. magnets, and a removable feather board, so similar to the one that you showed, Pugsi, but this base also has slots so that I can bolt other fixtures to is as well. Or of course can drill holes in other angle brackets or whatever to use with the magnets. Anyway, still have some playing around to do, but looks like these might be the cats pajamas for those otherwise hard to clamp applications.

 

I love my magnets just wish I had more.

 

As other forum members said, re-positioning rare earth magnets is a problem as they are too strong. The best idea is to have a magnet with a handle on it that can be grabbed and disengaged easily. For this you need a magnet with a countersunk hole through it. (so it sits flat on the metal surface) Rubber covering will prevent the magnet shattering. (neodyminum magnets are not strong and WILL shatter if they are allowed to impact a hard surface repeatedly. Also the rubber covering resists movement during the saw vibration. This magnet is at Gizmo Engineering called a pegboard magnet.