Nuts Nuts Nuts ... and Tools!

[surfsup]

I have an amp with no nuts on it. It has flanges and I want to secure this to a head (wood). The flanges point inward, not outward.

It seems I have two choices looking at McMasterCarr's website: rivet nuts and/or clip on nuts.

The rivet nuts need a tool for installation:

http://www.mcmaster.com/#rivet-nut-inst ... ls/=g6x9p9

Anyone know which style to use? The concern is the chassis flange bend inward, so to rivet something to the flange, I have just less than 2" of clearance on one end. And, the amp is already built as well which further complicates things since there are caps and stuff in the way.

Am I missing an easier alternative? Suggestions welcome thanks.

[surfsup]

Hmm, I just found this on line. A self made rivet nut installation tool for a few bucks and I probably already have all this stuff...

http://www.ridgelineownersclub.com/foru ... hp?t=15647

I think I'll just get some rivet nuts...

[John_P_WI]

Before you move forward with the rivnuts, notice the diameter of the hole required for them to fit through. On some styles as you install them the back side will mushroom too. Is your flange wide enough to accommodate the appropriate sized hole for the rivnut and not pull through an edge?

I used to use them all of the time in plastics and aluminum, but the surrounding area was large. In general, they worked well.

The clip on nuts work well, but some styles will not allow the bottom plate or chassis sit tight against the cab due to the "U" that clips over the flange.

I know I did not answer your question, but these are just a couple of things to consider.

[Luthierwnc]

If this isn't a presentation piece with a glass front, just bore holes through the inward flange and out the top/bottom. Use a drill press if you can to get the two holes plumb. Run a long bolt through both holes and fasten it with a washer, lock washer and nut. I use a locking nut since I don't want to tighten it to the point of deflecting the chassis. Shrink tube the bolt if it is too close to hot wires. Be sure to give yourself enough room to get a wrench at the nut (i.e. not right next to the power transformer) or under a baffle cleat.

If the material is thick enough, use captive nuts and squeeze them in with a "C" clamp. Worst case, braze some nuts to the flange after you bore it. Ream it with a fresh bolt or tap in case some brass got in the threads.

My luck with clip on bolts isn't great. Unless the chassis was designed for it, there is always a gap where the open side doesn't quite meet the cab.

http://www.mcmaster.com/#captive-nuts/=g6xndw

[surfsup]

thanks for the tips guys, yes the flange is 3/4" on the outside, minus the thickness of material. Its the same size as another amp that I have that has what appears to be 10-32 rivet nuts on it. The flange, everything is the same. the rivet nut is about 7/16" wide on the one with them installed. McMaster shows 0.415" - pretty close - for their 10-24/20-32 rivet nuts. I'm probably just going to do that. They seem more secure and sliding the chassis in/out won't move them or anything. I just have to be precise with the drilling of the holes!

[Tillydog]

You can set riv-nuts OK with a home made tool like the one in your 2nd link - it's just a bit slow.

Get a few spares to practice with. I wasn't sure how tight they needed to be pulled until I'd pulled one too far, then it was obvious

Makes a neat job, IMHO.

Andy

[surfsup]

I don't wanna pay shipping for just rivet nuts. And I can't find them online at homedepot ace or true value. Anyone know if either of those stores, or somewhere else, might carry these nuts? I guess if I have to I will justify it with buying some more garolite, but then I'll wind up spending hundreds more on more amps!

[M Fowler]

Home Depot, Menards, Lowe's, Hardware Hank and True Value stores carry these riv-nut kits.

I think Harbor Freight and Northern Hydraulic does too.

Mark

[Tillydog]

Ebay for small quantities.....

[Phil_S]

I've used clip on speed nuts (Ace, True Value, Home Depot) with good results. It takes careful and clever [1] measurement technique. Use a small diameter spade bit or large ordinary bit to remove some wood from the bottom of the cab where you make the hole so you can countersink the screw head.

[1] Drill holes for the speed clips so the screw can go through the threaded section into the flange. This stabilizes it when the screws are in place. Then, take heavy [brown] paper (like a paper grocery bag), lay/stretch it flat on the chassis and punch the hole locations with a center punch. You want a centered hole that is as small as possible. Use the brown paper as a drilling template. Drill up through the bottom of the cab. As long as you are careful with it, you can get a very nice result. Take extra care to locate your drilling template correctly with respect to the cabinet floor, as you'll be on the wrong side. Some people may get confused by the mirror aspect of this. This is the poor man's solution to the problem and I promise, only you will know. It doesn't show.

If you are compulsive about the details, you can use a wood chisel to make a bit of relief where the speed clips will be, so the chassis has no gap between it and the cabinet. Also, no one will see this either and perfection isn't necessary.

[collinsamps]

Just clamp some pem nuts to the chassis side of the flange with a large vice grip or small vice at a fraction of the cost. I use them on almost all builds and have never had one come out.

http://www.mcmaster.com/?orderview=new# ... ts/=g7jeoj

[telentubes]

I use exactly what collinsamps uses. I've been using the 1/4" / 20s in stainless and have had no issues. They cost about $1 a piece, which seems like a lot for a nut, but not much of an added expense for an amp.

I pull then into place by tightening a bolt with a washer large enough to span the hole you made in your chassis to accept the captive nut. The nut is obviously on the underside of the chassis.
The sandwich you're making stacks in this order... bolt , washer, the hole in the chassis, nut on the underside of the chassis. When you tighten the bolt it draws the captive nut up into place in it's hole in the chassis. It seems to pull in evenly with this method and seat squarely.

Sorry about the funky and confusing description which would be easy to show in a drawing. I hope you get the idea.

[telentubes]

Here's a pic of the captive nuts from McMaster Carr