Davids for Tom

[publicIdaho]

Would have been nice to have the boy here to hold the end of the panel while drilling the top holes.

Marked the end of each magnet as I pulled it off so I could keep track of the magnets polarity.

These are strong little buggers! Had to get a thin putty knife to get the last two apart.

[publicIdaho]

With the magnets in the holes in the front panel, I set the grill in place on the front panel.

Then I tossed a magnet toward each corner - literally, and the magnet zipped right over the magnet inserted in the front panel. They move around a bit, tap them untill you are pretty certain they are right over the other magnets.

I like this method, especially in this case where the sides are angled. Unless you have a good center line down the panel and the grill and measure out from there to mark centers for the holes, measuring from angled sides is asking for trouble.

This way, the magnets go where they want (it is pretty cool, you can move the grill around and the magnets stay right where they want to be.) Mark carefully around the magnets and drill.

I set the depth just a little deeper for these holes. It was set so that the point of the bit was just coming through.

[publicIdaho]

Worked like a charm.

[publicIdaho]

Put some PL Premium in the holes on the back of the front panels to hold in the magnets.

On a different note, when I was routing out the rabbits on the back panels on the cut out holes, I had some issues keeping the router flat and having the dull bit grab. I ended up with a few spots where the back side of the router base came up which resulted in the bit coming in too far.

I am going to try a technique we use to fill voids in rustic hickory cabinets.

First thing is to get some melamine scraps. Almost nothing sticks to melamine. Cut these to fit on the rough edges. Clamp them in.

[publicIdaho]

We use fiberglass resin to fill the voids. It sets up pretty hard and it can be sanded. It also is good because it will flow down into cracks.

When sanding, do not sand on the same spot for a long time. The resin will get hot and start to get soft. We belt sand the high spots then pad sand it flat.

[publicIdaho]

Put tape where you don't want the resin to go and use a flat stick to dab the resin on. It will flow down into the cracks so you will have to go back and add more resin to the spots were it is getting low.

Hope this will work for this! At least it is the back of the speaker, and one more trick to show you all.

I did find dad's soldering kit at the shop so it looks like the crossovers might get assembled tonight.

[publicIdaho]

The resin set up pretty nice, had a little seep under one of the pieces of melamine which stuck to the particle board underneath and it did not come out clean, but a chisel cleaned it right up.

[publicIdaho]

Here it is after a bit of sanding.

Should work out pretty well for the finished product.

[publicIdaho]

Cut out a hole to mount the speaker terminal cup. Used a hole saw.

Tips on cutting a hole with a big hole saw bit:

Cut with low RPM.
Hang on to that drill! It is very easy to get the RPM up getting the guide bit hole started and push harder on the drill, then boom, you are through the 1/2" with the pilot bit and the bit surges forward and the hole cutter hits the wood, grabs, and then that drill has a huge amount of torque and can easily spin right out of your hands.
Do not drill all the way through with the hole saw. The pilot hole is through and you can go to the other side and finish up the hole. If you push the bit all the way through, it will tear up the back side of the board.

[publicIdaho]

Hate the chuck on that Dewalt drill, but it is the only 1/2" chuck hand drill we have. Of course, with a little forethought, I could have cut the hole on the drill press before the panel was glued up.

This shows the pilot hole coming through the other side. Drill the main hole 1/2 way through the go to the other side. This way your hole is clean on both sides.

[publicIdaho]

The hole was pretty tight on the terminal cup. Opened it up a little with a drum sander bit.

These are pretty handy for getting your size right on speaker holes, especially when mounted in a drill press and you can use both hands to manipulate the piece you are sanding.

[publicIdaho]

Mounted the crossovers.

Each section has its own board - 1/4" vinyl we use for cabinet backs (i.e. scraps)
Since the heavy iron core coils are screwed into the 1/4" and the screws come through, and the zip ties are also on the back, the crossover boards are screwed to a small piece of 1/2" that fits inside the stuff on the back of the board. The 1/2" was glued and pinned to the cabinet, then the crossover board was screwed into the riser board. Used 1" screws so they went through the riser and halfway into the side panel - more meat for the screws to bite into.

[publicIdaho]

Getting ready to cut out the holes for the speakers in the front panel.

Got lucky on the tweeter, had a hole saw that was about right. Did this hole on the drill press - remember to crank that speed down! Also, hole saws have no good way to get rid of the wood shavings as they cut, so work the bit up and down often to help clear out the chips. Not much of an issue in 1/2" though.

The mids measured 4 3/4", which is in between my hole saws. Don't really want to cut a 4 1/2" hole and sand out the rest, and a 5" hole is too big.

I was getting ready to just jig saw the hole out when visitors came to the shop and somehow co-opted the rest of the day.

The photo shows a little jig dad made half a million years ago - it is simple and a great way to get accurate measurements on those hard to measure diameters.

Hopefully the gods will let us finally get the front and back panels glued on.

[publicIdaho]

Another short day working on speakers.

Cut the holes for the mid drivers in the front panels and the grills. Dicey job on the grill - it gets awfully thin on the edges; had to go slow and keep things supported as best as possible.

[publicIdaho]

The front panel holes are not visible, so as long as the drivers fit, it is good enough, but the holes on the grill might show a bit through the speaker cloth, so I wanted to true up my not so perfect jig saw cuts.

We have an oscillating spindle sander, but it has a very important function of holding all our door making bits. But the drill press was set to slow from the hole saw, so I decided to clean off the sander.

Got it all cleaned up, then set the grill on the sander and realized DOUGH! the magnets in the grill stuck that sucker right to the cast iron table on the sander. One of those moments, where you are going along just fine and then pow something is bonkers and then you have to laugh when you figure it out.

So it was off to the drill press. Notice the board with a hole on the base so that the sanding drum can be lowered a little lower than the level of the base board.

Again, the thin edges on this thing meant the sanding was done carefully.