avengers63 Posted February 14, 2008 Report Share Posted February 14, 2008 For those of you who have used these before: I've seen in the build threads some folks using Rare Earth magnets to secure their control cavity & truss rod covers. Which magnets did you use? What type of glue did you use? I'm guessing that the 1/4"/6.4mm disk would be a safe diameter, but the thickness is up in the air. Any input? Quote Link to comment Share on other sites More sharing options...
Xanthus Posted February 15, 2008 Report Share Posted February 15, 2008 http://www.radioshack.com/product/index.js...rentPage=search Something like that, you'd be looking for. I don't even think I glued them in, honestly, just drilled a hole and pressed them in. You can just use them for direct replacements for screws. They're strong, but they're no problem to get the covers off too. Just make sure that there's something for them to magnet to. I was impatient and broke off the heads off of some nails I had lying around, and hammered them into the body. It wasn't pretty, but it got the job done. Quote Link to comment Share on other sites More sharing options...
jmrentis Posted February 15, 2008 Report Share Posted February 15, 2008 (edited) I had almost finished my response with links and all a few hours ago and as I was finishing up the power died, ugh I hate that. I'm extremely happy that I finished my homework before it went out though. Anyhow, I got mine at Rockler because I saw them there first. I grabbed the smallest ones they had and they are probably the biggest you'd ever want to use. I'd probably go smaller if I could. Here they are Rare Earth Magnets (Rockler). The worked just fine, though I didn't quite realized how strong they would be at that size, so I way over did my cavity cover. I used the 3/8" diameter X1/10"thick magnets. I believe you get 10 in a pack for less than $5. I installed my magnets with epoxy, I found a 3/8" forstner drilled it to the proper depth so it was about flush, then just used a dab of epoxy, which worked well because the forstner left that little extra deep hole where the epoxy could sit. It really worked out great. I think in some applications and for the really small magnets you could just use a tight fit, but honestly with the ones I used, I don't think they would stay in place. I've seen those magnets jump so far, they are amazingly strong, I can barely get my cavity cover off. I'd probably use epoxy or CA, either should be plenty enough to hold it in. Magnets in cavity & cover Cover in place Cavity from a distance I really dig the magnets idea, this was my first attempt so it's not perfect, but it looks and work fine. I'll probably try for the next one to find a bit smaller magnets, diameter wise or just use 3 sets instead of 5. There is no real issue with how many I used, there is just no need for that many. The thinner you can get them, probably the better otherwise you'll need to be very alert on the thickness of the cavity cover or truss cover. Well, best of luck. J Edited February 15, 2008 by jmrentis Quote Link to comment Share on other sites More sharing options...
Hydrogeoman Posted February 15, 2008 Report Share Posted February 15, 2008 They work great. I use 1/8" diameter ones. On this LP Jr I epoxied in a total of 4 - two in the body and two in the control cover. Just make sure the poles of the magnets are oriented correctly (like I didn't the first time ) otherwise your cover will be trying to pop out. I will probably never use screws again. Quote Link to comment Share on other sites More sharing options...
jmrentis Posted February 15, 2008 Report Share Posted February 15, 2008 Good point, I kept worrying myself about the polarity also, after rechecking the third time before glue up I decided to mark the backsides with black magic marker, so I could easily see how to place them. However with 1/8" I'd bet it'd still be tough see, where you marked them. I never thought to try magnets for truss covers as avenger63 suggested and with those 1/8" it would be easy and cool. I'm with Hydrogeoman on the never using screws again, too many cool things to do with magnets. Where did you find the 1/8" magnets Hydrogeoman? Are they thinner than 1/10" also? Good idea, like I said I way underestimated the strength on those little things. Quote Link to comment Share on other sites More sharing options...
erikbojerik Posted February 15, 2008 Report Share Posted February 15, 2008 Search for rare earth magnets on Amazon....and prepared to become dizzy from the array of choices. Quote Link to comment Share on other sites More sharing options...
Jon Posted February 15, 2008 Report Share Posted February 15, 2008 http://www.amazon.com/MAGCRAFT%C2%AE-Magne...0118&sr=8-9 Cool, I'll be ordering some soon. Quote Link to comment Share on other sites More sharing options...
al heeley Posted February 15, 2008 Report Share Posted February 15, 2008 I bought a load of tiny ones off ebay - Neodynium, they're amazingly powerful. really neat to recess in the wood for holding on a TRC or ctrl plate. Just don't swallow them, they cause really serious havoc int he guts of any toddlers you may have around the house. Quote Link to comment Share on other sites More sharing options...
Xanthus Posted February 16, 2008 Report Share Posted February 16, 2008 I wonder if you could search and locate a swallowed neodymium with another magnet on the outside... Talk about an awkward sensation. I never tried this when I was building my first guitar, but do the neos stick to the copper shielding well? I'd go home and try it out myself, but I've got work all this weekend. Quote Link to comment Share on other sites More sharing options...
black_labb Posted February 16, 2008 Report Share Posted February 16, 2008 i got some small ones when i got some mags for pickups from a localish place (happens to be about 1 minute from a luthiers supply place that i get fretwire and a few other things from). seem like a great way. small screws can strip, magnets will last for longer if youre always going in and out of the cavity. Quote Link to comment Share on other sites More sharing options...
Hey Posted March 1, 2008 Report Share Posted March 1, 2008 I love this idea. Has anyone tried this: How about using magnets in the cover, and just iron in the guitar itself? If the grip is still strong enough, it seems like it might have some improvements. No worry about the polarities matching. And if you have trouble getting the covers off, you could use maybe lift it them off by using magnets on the outside. Quote Link to comment Share on other sites More sharing options...
Rick500 Posted March 1, 2008 Report Share Posted March 1, 2008 (edited) I use 3/16" diameter, 1/16" thick neodymium magnets. Five or six is enough for a control cavity. I drill recesses for zinc screws into the ledge of the cavity, and screw them down so that they're recessed a little less than 1/16". Then I center a magnet on each screw, put a drop of CA glue on top of each magnet, and put the cavity cover in place. [Edit: Careful not to glue the magnets to the screws...] When the glue is dry, all that's left is to remove the cover and tighten the screws down so the cover lies flush to the back. If the magnets are holding the cover down too tight, you can also use the depth of the screws to adjust the strength of the hold. Edited March 1, 2008 by Rick500 Quote Link to comment Share on other sites More sharing options...
anderekel Posted March 1, 2008 Report Share Posted March 1, 2008 That's an awesome idea rick, I may have to try that on my build Quote Link to comment Share on other sites More sharing options...
Xanthus Posted March 1, 2008 Report Share Posted March 1, 2008 +1, thanks for the tip! I went over to my radio shack when I was buying my momentary switch, and the lady there said they were ALL OUT of rare earths. Damn kids and their second-semester science projects... Quote Link to comment Share on other sites More sharing options...
al heeley Posted March 2, 2008 Report Share Posted March 2, 2008 +1 for Rick - I redid my Warmoth truss rod cover recently exactly like this, with a couple of tiny neo magnets holding it down. Now you can just pop it off with your thumbnail if you need to tweak the truss rod, and it holds really strong with no rattle. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.