show me your nuts! (1 Viewer)

[tom_furman]

T-nuts i mean! my sub and t-nuts are due to be here any second, but i'm still not 100% sure how t-nuts work. once i have the hole for my sub in the 2 layers of mdf, i mark where the mouting holes are..but then what? How do you stick the "caps"?
i bought plain old 10x24 t-nuts from adire

 

[Jeremy Stockwell]

Tom,
I have nuts, but I'm not going to show you.
(I began building my Tempest Sonosub last weekend).
Check Pat Sun's Website. There are detailed explanations and pictures that will help answer your questions about end caps and T-Nuts.
JKS

 

[Rob Lloyd]

You need to drill a hole the size of the center section of the t-nut. Then you can hammer the t-nut in place or pull it in from the other side w/ the screw/bolt that matches it.

If it's in MDF I'd apply epoxy or glue to it (avoiding the thread hole) to get it more secure. They will spin out of mdf easily and then it's stuck - can't be removed or snugged back up.

Unless you plan on removing the components, after you've built it, more than 3-4 times, regular wood screws are your best/easiest option. Just make sure you pre-drill the mdf.

Another better option for using t-nuts is to laminate some plywood to the back of the mdf to hold the t-nuts better. I did this with my LCC more for the heck of it than removing the drivers later on.

Rob

 

[Greg_R]

Rob is correct about the T-nuts not biting into MDF. What I do is get some 1/8" ply (or other wood) and glue small squares of it onto the inside of the enclosure (where the driver holes will be). The wood will give the T-nuts something to grab...

 

[tom_furman]

Whoops! I meant to say that I have 3/4 plywood and 3/4 MDF. I'm gonna use liquid nails on them as well

OK..i just re-read pat's web page. So after I mark the placement of the holes I drill a hole the diamater of the screw straight through both layers of wood. Then I drill a slightly larger hole (for the threads of the t-nut) about 5/16" into the inside of my encap.

seems simple enough now.

 

[Bryan Michael]

i dont see y you need t nuts i just used screws for all my subs and they work great you might have a problem if you try and re install your woofer alot

 

[Anthony_Gomez]

I used to use T-nuts, now I juse use #10 screws. Liquid nails doesn't fully harden. When I used T-nuts, I used gorilla glue to hold them on....pretty much used the glue on the top and bottom and have the top over flow to the sides....those sure won't move again!

 

[Will Orth]

Well I used a damping compound over the MDF and SCREWED the T-NUTS in with a Test Bolt till the Sunk in DEEP!! the trick is to use the DRIVER and Drill straight through the mounting holes making sure they line up if not you have a mess on your hands!

do not use a hammer! they never line up.. and the mess get's BIGGER!

Will

 

[Casey H]

I second Will's comments. I think I may have difficulties with a few of mine for that very reason. I did a test fit and it seems a few of the screws are not going into the T-Nut as easily as they should, as if they are a little cockeyed or so. I like the idea of using a scrap screw/bolt to install the T-Nuts instead of a hammer.

Has anyone else experienced what I am talking about and if so how did you deal with it?

*Edit* I was actually thinking of covering up the holes I did with plugs and re-doing them with this method or not using T-Nuts all together. Input?

Thanks, Casey

 

[Rob Lloyd]

I use a drill press and get perfect fitting holes. The hammer just helps push the prongs in. Never had a problem but I see where it could if they went in crooked.

I tried the pull it in w/ the screw method. It works ok but does take a lot longer. I did have a couple that didn't thread easily and started to spin the t-nut in place - bending the prongs or digging out the mdf.

I use screws entirely now. If I HAVE to use t-nuts I either use plywood backers or a sheet of plywood laminted to the MDF.

Rob

 

[tom_furman]

Is the little bit of weather stripping around the lip of the speaker necessary? or just an extra precaution?

 

[jeff lam]

Closed cell foam should be used around the speaker to ensure that there are no air leaks. Weather it's a precaution or necessity depends if you have air leaks.

As for the t-nut thing, I decided to use threaded inserts to mount the driver so I wouldn't have to worry about the teeth grabbing the mdf.

 

[Greg.K]

Do threaded inserts stay put in the MDF better than t-nuts? It seems like it would be an easier solution all around.

 

[jeff lam]

We've had some discussion on tee-nuts and threaded inserts in some previous threads:
http://www.hometheaterforum.com/htfo...READED+INSERTS
I use some similar to these that I picked up at Home Depot. They worked great. I have not used tee-nuts so I can't compare the differences but from what I have heard from others, inserts would lock into the MDF better.
http://www.rockler.com/ecom7/showdet...ID=72&CATID=22

 

[Charles J P]

 

[Jeremy Stockwell]

 

[Jacques C]

When I do T-nuts in MDF, I glue the T-nuts in (wood glue works good enough). Before the glue dries I always flip the speaker back over and screw the screw in through the T-nut. No matter how hard you try it seems some of them are cockeyed. Before the glue dries I always use the screw to straighten the T-nut out so that when it does dry it is sitting vertical like you want it.

Since I have started doing that I have not had a problem with T-nuts.

With the 81s and 281s, though, a seperate problem of fitting those suckers in there when the holes are close to the sides becomes an issue. I typically rout a bit of a rabbet in the side MDF piece of the speaker right where the T-nut will be so that I can get the darn thing in there. Even then I still have to grind half of the T-nut flange part away so it will fit.

Take care.

Jacques

 

[tom_furman]

Well I hand rilled all the holes, and put some liquid nails all around the surface. I then put the screw through the hole and tightened it up. It pulled the t-nuts right into the plywood. a couple weren't totally flush so a whack with the hammer solved that! Almost done!!