[mlundy57]

Jay,

Good idea thanks. I hooked them up and got sound not smoke so I guess I did it right 




Mike

[Oscillate]

"I hooked them up and got sound not smoke so I guess I did it right"

...no, you certainly don't want them to lose any of their magic smoke 

[Captainhemo]

yup,  no smoke = good

Glad they work  , bet that little sound test has you  even more anxious   now    LOL

-jay

Also,  have you decided how you're finishing the cabinets yet  Mike ?

[mlundy57]

You better believe it. I was doing a happy dance. The smoke comment goes wayyyy back to my time in the Army Field Artillery Officer Basic Course at Ft. Sill. The Sargent in charge of the communications class commented that when you put a bunch of Lieutenants in a room with radios one of two things happened, maximum communications or maximum smoke. His money was on the smoke.

Now I gotta finish the cabinets. I prototyped a grill frame out of 1/4" hardboard. Got the basic design down. Nothing special at all really just rounded edges but I think it will look good if I can execute the actual grills better than I did the prototype. I need to get the grills done so I can determine where the magnets will go on the baffles before I glue them to the rest of the cabinet.

As for finish I'm going to do a 4 step process (1) apply a pre-stain conditioner so the wood, including the rounded over corners, will take up the stain evenly, (2) apply an oil based stain, (3) multiple coats of shellack, and (4) wax and buff.

I haven't decided on stain color yet. It is down to 4 candidates: red mahogany, Danish teak, pecan, and black cherry. I have used the 7" diameter circle cutouts from the CS's braces and from the LS's woofer holes as test blanks. At this point I have them stained and one round of shellack applied. I'm going to wait until I have at least 3 rounds of shellack applied before I choose. This may seem a little extreme for test pieces but there can be a lot of difference in appearance in a stained piece of wood before and after the finish coats are applied.

Unfortunately I won't get much done for a couple of days. My wife believes weekends are for honey-dos and I have some stone I have to finish mortaring and laying around the edge of a flower bed. I only have about 65' left to go. 

Mike

[lacro]

You better believe it. I was doing a happy dance. The smoke comment goes wayyyy back to my time in the Army Field Artillery Officer Basic Course at Ft. Sill. The Sargent in charge of the communications class commented that when you put a bunch of Lieutenants in a room with radios one of two things happened, maximum communications or maximum smoke. His money was on the smoke.

Now I gotta finish the cabinets. I prototyped a grill frame out of 1/4" hardboard. Got the basic design down. Nothing special at all really just rounded edges but I think it will look good if I can execute the actual grills better than I did the prototype. I need to get the grills done so I can determine where the magnets will go on the baffles before I glue them to the rest of the cabinet.

As for finish I'm going to do a 4 step process (1) apply a pre-stain conditioner so the wood, including the rounded over corners, will take up the stain evenly, (2) apply an oil based stain, (3) multiple coats of shellack, and (4) wax and buff.

I haven't decided on stain color yet. It is down to 4 candidates: red mahogany, Danish teak, pecan, and black cherry. I have used the 7" diameter circle cutouts from the CS's braces and from the LS's woofer holes as test blanks. At this point I have them stained and one round of shellack applied. I'm going to wait until I have at least 3 rounds of shellack applied before I choose. This may seem a little extreme for test pieces but there can be a lot of difference in appearance in a stained piece of wood before and after the finish coats are applied.

Unfortunately I won't get much done for a couple of days. My wife believes weekends are for honey-dos and I have some stone I have to finish mortaring and laying around the edge of a flower bed. I only have about 65' left to go. 

Mike

 Mike, Your crossovers look great! Did you use any components from the original crossovers? Also, is the cabinet plywood Maple? I used Maple Apple ply to make a boombox, and found it difficult to get a stain to look good and ended up only lightly tinting it. Maple is not the easiest wood to stain. If your going to round over the edges I found the fact that plywood has the grain alternating with each layer, I got minor tearout of some plys on the roundovers. Maybe experimenting with different router speeds on scrap pieces would be prudent.

Keep the pictures coming...

Larry

[mlundy57]

Larry,

No I did not use anything from the crossover circuit boards that normally come with the kit. Since I wanted to upgrade everything on the board and do a complete point to point crossover the circuit boards would have been redundant so I didn't get them to begin with, just the parts and schematics like you would get with any of the A/V, N, or OB kits Danny sells.

I'm using Baltic Birch plywood for the cabinets. It takes a roundover very well with no tearout, especially when using a brand new, higher end carbide roundover bit. The bit was pricy but the performance has been worth it. The pieces I am using for color samples have taken the stain well and are looking really nice even with just one round of shellack. 

Mike

[Ron]

Mike,

  Your crossovers look great. Good job! 

Ron

[mlundy57]

Thanks all. If it wasn't for the sticky tutorials and all the build threads y'all have posted I'd still be scratching my head trying to figure out how all those squiggly lines on that paper turned into a crossover.

Mike

[mlundy57]

Got a little more done.

Here is a sample of the color I intend to use, it is Mahogany. It has one coat of pre-stain, one coat of stain, and 2 rounds of shellack with sanding to 400 grit after coats 1 and 2. The actual finish will have 2 or 3 more rounds of shellack with progressively finer sanding. I like the darker, richer colors and warmer tones.  However, I cannot figure out how to keep the flash glare out of the pictures.



Here are the cabinets glued up and flush trimmed.





I realized that since I cut the front baffles oversize all the way around so I could flush trim I could not align the grills before gluing the baffles on without risking them being cockeyed. Therefore I decided to mount the grills afterward and live with plugs over the magnets.  How thick of a plug will a 1/4" x 3/8" neodymium magnet work through?

Here is one of the grills. I recessed the back for the woofer. 



Is there enough room around the tweeter?  The stock is 1/2" Baltic Birch. How much of a round over should I put on the inside, 1/2" or 3/8"?





Thanks,

Mike

[Danny Richie]

Mike,

The negative effects that a grill frame has on the response is from a flat inside surface that is as tall as the grill frame is thick. Put a large radius on the inside edge of the frame and you will greatly minimize its effect.

[Captainhemo]

You  could try taking  a phot  on  a bit more of an angle to reduce  some of the    flash reflection.  You're still going to see it, but  might  not be as much glare,  hard to say.

I'd try  to keep the plugs as  thin as you  can.... are you  using the N52  greade magnets , they are stronger and will let you  get away with a bit thicker plug  .   You might want to try some different thickenss's  between a couple of the magnets just to see  how much  the plugs effect   the pull

The bigger roundover would probably be better but may be a PITA to cut on the 1/2"  grill frame due to the depth of the bit.  If I remember correct,  I used  a 3/8" roundover  then  used a   foam sanding block to   try and increase the  radius slightly. 

They are looking great Mike 
-jay

[mlundy57]

Thanks Danny.

Jay,

Yes the magnets are N52 grade. 

I will probably do the roundovers on my router table. I haven't been able to figure out how to hold something that thin high enough and solid enough to use even my smaller trim router.

Mike

[mlundy57]

Lesson learned..... a 1/2" roundover won't work on a 1/2" piece of stock, there is nothing for the bearing to roll against. The router chewed that grill cover up, it's toast.    Now I have 2 to make instead of one. At least I'd already traced out the 2nd one.

Mike

[gmurray618]

yup,  no smoke = good

Glad they work  , bet that little sound test has you  even more anxious   now    LOL

-jay

Also,  have you decided how you're finishing the cabinets yet  Mike ?

A little more on the importance of smoke and possible remediation.

http://www.eetimes.com/electronics-blogs/the-engineering-life-around-the-web/4405831/Smoke-re-concentrator-refurbishes-blown-electronic-components

[gmurray618]

Lesson learned..... a 1/2" roundover won't work on a 1/2" piece of stock, there is nothing for the bearing to roll against. The router chewed that grill cover up, it's toast.    Now I have 2 to make instead of one. At least I'd already traced out the 2nd one.

Mike

On a more serious note, if you had stacked another board with a similar hole for the roller to follow would it have worked?  Would it have a desirable shape?

I ask because I will be getting back to my N3 project and will face the same issue.  The help and experience here invaluable. Thanks to all.

George

[mlundy57]

If you could get another opening to exactly match it would probably work but since the opening was cut out with a jigsaw and final shape was achieved with a sander getting an exact match would be difficult. I'll try a 3/8" roundover on 1/2" stock and see if that works better.

Mike

[NeilT]

I used a circle jig to cut out the holes in my grill frames, then you can cut out the extra by dropping them on your table saw blade.








Your project looks great
Neil

[gmurray618]

Thanks Mike and Niel.  I was just wondering about using a jig with my router. I'm still pretty green with the router.  But my table saw?  Wow I must have misplaced it.    I'll be using my circular saw.   Oh yeah, I should pit my boxes together first!   

Ya know I'll be watching your build. 

[Captainhemo]

Lesson learned..... a 1/2" roundover won't work on a 1/2" piece of stock, there is nothing for the bearing to roll against. The router chewed that grill cover up, it's toast.    Now I have 2 to make instead of one. At least I'd already traced out the 2nd one.

Mike

DOH   

That's why  I  was  saying the  depth of the 1/2" bit might be  a PITA  .  Thought   if you  were trying it yo  might have   clamped the  2 frames back to back   on a table, routed the top one,  then flipped it  to  route the bottom one. 
Sorry Mike,  I should have explained   rather  than  just  saying  PITA

George, will have a look at the link

-jay

[mlundy57]

Oh well doubt I'll ever forget that lesson.  But it is also a reminder as to why routers can be so dangerous. I was routing out the inside with the stock upside down on a router table. If I had tried to save the piece when the router grabbed it I could have lost fingers instead of just a piece of wood. I can always remake the piece, but not fingers. Luckily I have spent enough years setting up and operating industrial machines that I never attempt to argue with a machine when it grabs the product. I get out of the way, shut the machine down, then go back in and fix whatever got broke. In this case the only thing broke was the grill frame which was $10 worth of wood and a couple hours of my time.