Ambitious cabinet design for Nat P!

[Johnnz]

Hi all,
I have finally ordered parts to make the Nat P's (floor standing versions ala "Yet another Nat P thread"). This coincides with setting up my own workshop so it will be one of my first projects that will include veneering as part of the finishing.
So, below is my planned cabinet form for these speakers. I already have cherry wood veneers to use to cover the MDF construction but obviously wont be able to use a flush trim bit on my router for many of the edges! It will be my first veneering project (besides test runs of course). Originally I planned a curved cabinet that is posted in this forum somewhere but decided against it as it really required a vacuum press for veneering that is a bit too speciallised.
The design should go nicely with my music library I made a year ago that I documented the construction of in this thread.
However, I would also like feedback and opinions on this design. The sketchup file can be downloaded here.



I intend to cover the baffle and base in leather where coloured in brown in the sketchup file.

Wish me luck!

[wkhanna]

I like it !

[fbov]

Well, between the odd angles, skewed panels and desire to veneer, I think you have enough challenge built into the design to keep you busy. If the juke box had been veneered, I'd be concerned this was too easy for you, but you've already done the odd shapes.... I don't see any reason not to!

Have fun!
Frank

[baniels]

I really dig that jukebox. Thanks for sharing.

[Hdale85]

Looks awesome.

[Johnnz]

Thanks all for the feedback! Checked out your WIP Baniels, very interesting and impressive build you have on there, and what a workshop to do it in! Will keep up with your progress. Looked at your work website and very interested at what you guys design and produce. Haven't seen anything quite like here. I take it that the water jet is for cutting vinyl and the ultrasonic machine somehow cuts through the granite etc?

[baniels]

Actually the waterjet cuts it all. Water-only cuts vinyl, VCT, sheet goods, and for stone, metal and pretty much anything else. It is water + garnet dust added to the stream to give it more abrasion.

We also have an ultrasonic cutter, but that is only used for large sheet goods that are too big to lay out on the waterjet machine.

[---k---]

I like it. I look forward to seeing your completed project.

[JonMarsh]

Very interesting concept, as in the old Chinese proverb, may you live in interesting times! Please do keep us posted how it goes- it's an intriguing concept!

~Jon

[BeerParty]

I am looking forward to watching this build, it will be a awesome speaker when finished.

Quick question for you; in the jukebox build you mentioned in the last post that you were going to build a stereo rack for the jukebox. That was a joke, right? 8O You wouldn't really hide that beautiful piece of equipment in a rack?

[Johnnz]

I am looking forward to watching this build, it will be a awesome speaker when finished.

Quick question for you; in the jukebox build you mentioned in the last post that you were going to build a stereo rack for the jukebox. That was a joke, right? 8O You wouldn't really hide that beautiful piece of equipment in a rack?

Actually, what I had in mind was a nice open glass shelved Hifi rack so I could put my jukebox/music library on top to display the unusual wooden cabinet it is in. Unfortunatly I have yet to get around to building or buying such a rack and the jukebox is still tucked away in the only shelf that can accomodate it's height - underneath the TV :cry:

[Hdale85]

Where is this "jukebox" build?

Edit: Gah nevermind haha

[Johnnz]

Most of the drivers and crossover parts arrived for building these speakers (after considerable delays) a couple of days ago, which inspired me to get back to work on my sketchup file extracting all the compound angles from the drawing, and working out my construction method. I will use butt joints top and bottom, as well as front and rear, and use mitred joins only on the two diagonal edges both sides of each cabinet. Using a biscuit/plate joiner tool to align joins. I will probably screw and bog over screw heads where possible for extra strength (can't imagine that veneer would have a problem with that?)
All up given the symetrical nature of this design, I only had to work out the shape of 4 pieces, though some are mirror imaged, and will add the extended front and rear baffles later.

Made some measurements and am happy that the 3" precision port flared mouth will fit nicely underneath and will have plenty of space for the internal pipe.

I managed to work out the internal cabinet measurements (based on 18mm MDF material to be used) and got a gross volume of 48.7 litres. This will decrease after I put in some internal bracing, xo's, internal tweeter box, etc, etc,. What other information/data do I need to work out how long to cut the port pipe?


Also, I redesigned the base plate as I wasn't really happy with the style of the original idea. The new one will give the speaker better stability too.

[fbov]

The best part is you don't have to deal with the heat, because it's not hot on your side of the equator....

We will want to see pictures, you know.

Have fun,
Frank

[Owen Bartley]

Very cool design, John. Definitely ambitious, but I think in the end when you have a pair of these sitting in your room you will be a very happy guy.

[Johnnz]

A begining

Rough cut each individual panel out of one and a half MDF sheets and cut out all pieces that have parallel square edges to final width. Hoping that a digital angle finder that I ordered a few days ago will be in the post box tomorrow so I can confirm I am cutting accurate angles on my table saw.

[---k---]

Progress is good. :T

[Johnnz]

Cutting shapes

Been busy making sawdust today, and most of the shapes I need for cabinet walls. Except for a few (and a complete re-cut of a top), most came out accurate to within half a mill by inching closer to the blade on each pass. Certain angles required more inventive thinking than others.

[Silver1omo]

looking good!!

[baniels]

You're right about inventive. Nice jig :T

[JonMarsh]

Been busy making sawdust today, and most of the shapes I need for cabinet walls. Except for a few (and a complete recut of a top), most came out accurate to within half a mill by inching closer to the blade on each pass. Certain angles required more inventive thinking than others.

Looks like you're getting there- more inventive indeed!

[Johnnz]

The best part is you don't have to deal with the heat, because it's not hot on your side of the equator....

We will want to see pictures, you know.

Have fun,
Frank

Heard about the "pressure cooker" heatwave conditions over in the states. Opposite here of course, snowing at the moment outside looking out the window and lots of frosty mornings of late which slows me down in the mornings (slow fingers) - will have to get a diesel burner for for my workshop next winter but they are quite pricey.

[Johnnz]

Have now done a dry fit on one speaker and done the necessary triming to panels for it. Quite happy with the fit. Have made alignment marks on all panels and numbered all joint pieces. Due to butting most pieces together biscuiting will be done to alignment marks on exterior of cabinet, but the mitred joins on cabinet sides will be biscuited to internal marks as fence will need to be angled to align to the surfaces of panels.

Trying to plan now for veneering. It is quite difficult to source tools and glues for veneers in New Zealand, but I am thinking that I will probably use Titebond II and a clothes iron to apply the veneer. At the moment the most difficult veneer join looks to be the two subtle angles on cabinet sides. I will possibly just sand them curved slightly and veneer a full sheet right over all three surfaces - though I hope this wont detract from the 'angled look' I was hoping to acheive with this design.

A couple photos:

[---k---]

Looks great. :T

[john trials]

You must have done really well in geometry class!

[Johnnz]

Thanks, things are moving along. Have dry fitted both cabinets now. Waiting on a new second hand workbench with vice to arrive before I will biscuit the panels held in the vice to help ensure accuracy. Have been working out hole placement for router cut-outs today.

Wondering though, is it really necessary to enclose the tweeters? It appears they are already fully encased from back wave pressure of woofers. Or is it recommended nonetheless?

[Johnnz]

Been making circles today with the help of a very nifty jasper jig. Have tested fitting the tweeter into the taut leather. Seems to work pretty well. Hope that it will work just as well with three drivers together, though I think the loose flaps will need to be pulled tight into the baffle too.

[fbov]

... is it really necessary to enclose the tweeters? ...

No, but...

My thought process was that the baffle needed reinforcement on the line between tweeter and woofs. A ring would do the job, but a panel that also tied to the side panels would be easier and stiffer. From there, it was easy to cut two panels and only hole one.

Plus Jon did it, and he's smarter than me.

https://www.htguide.com/forum/showthread.php?t=13969

Have fun,
Frank

[Johnnz]

Base colomn supports

Finally found some 38mm pipe (took my angle grinder to an old exercise machine at the recycling centre) that will work with the 38mm spade bit I have that will allow the pipe to recess into the angled bases. Once cut to length I had to file down while in the lathe to get the fit a bit looser so after painting they wont be too hard to get in place. Was a bit cold for spray painting but have quite a nice black finish on them now (not that they will be seen much at all when in position).

Here's a few pics showing a test run of how I will use the columns to mount the speaker cabinets to their bases:

[JonP]

Looks like a sturdy platform... should do the job!

That's got to be the world's largest T-Nut!! :E (unless I'm getting tricked by perspective) How big is that bolt holding the top and bottom panels to the pipe?

To your earlier veneering questions... something you might try would be to make some mock up angles of those edges you're wondering about, and get some cheap veneer for testing, (unless you have a lot of what you will use) and try different techniques.

It would give you a good idea of how well it will make the corner, how it will look if you sand it down a bit, can you make a joint with two pieces there and have it look good... etc. Also get you up to speed on the ironing technique in general.

Another thing to look into would be veneer softeners, to see if that might help in getting a tight coverage over an edge.

Looking forward to the results!

[Johnnz]

Although it is the largest I could find, it is actually only threaded for 10mm. The bolt is 160mm long. Will put some pictures up tomorrow of the actual arrangement for the column support.
Good advice for veneer testing thanks.

[Johnnz]

Here's a pic of the bases routed out for 3" ports. Unfortunately I realized only after drilling the recesses that I had altered the location of the front column which meant the already cut (and Painted) pieces of pipe were no longer correct length. Rather than re-cut those, I deepened the front holes to embed the pipe deeper into the base of the cabinet by 3mm.

to help center the bolts I ran an octagonal shaped piece of wood the length of each pipe piece and drilled out the center for the bolt to go through.

[baniels]

Excellent build quality and great documentation. Keep it coming. That leather is going to be great.

[Johnnz]

Did some more test runs yesterday to work out what method I'll use to upholster the corners with the leather. I also decided to change to a black leather to try avoid ending up with a 'busy' look. This hide is a little thinner than the brown hide sample I was working off so I wanted to make sure the tweeter still looked tidy in its recess. It is a little looser so I will just have to make sure the drivers are centered properly well before fixing in position.

As for the method to upholster, the best way I found so far is to hollow out an angle for where the leather overlaps (since these need to sit flat against the sub-baffle of the tower cabinet to which they will be internally screwed to). I will try to reinforce the thin tapered corners somehow (CA glue should soak in and make the mdf rock hard I suspect) to prevent the truncation shown in the front view photo (bottom picture). Am wondering now if I should apply fabric glue to the back of the hide before I stretch and staple the baffles. Not sure if it would be helpful or not.

[Johnnz]

Picture of the rear of a baffle checked out for fold/crease of leather to keep flush.

[JonMarsh]

That's coming along very nicely! Keep us posted.

~Jon

[evilskillit]

Everything I've ever built is fiercely jealous of these cabinets already; and they're not even finished.

[Johnnz]

Have done a bit of tweaking to my design, and have decided (as I mentioned earlier) to use black leather rather than brown, and also now to round the edges of leather clad surfaces with a 10mm radius router bit. In addition the leather base and leather access panel on rear of cabinet will protrude from wooden surfaces by 10mm. This should help make the join between veneer and leather a lot tidier too as they will be perpendicular to each other.

[Johnnz]

Have just got around to applying the leather to the outer baffles. They turned out pretty well, but I may have to gouge some small hollows in the cabinet where they are pressed against in final position at outer corners. I used spray adhesive on the MDF and leather which should help prevent deformation of the hides later on when I cut through the leather for insertion of drivers into their holes and they are pressed and fastened into position.





When finished, I also clamped them both flat to help make sure the hides settle smoothly on the glued mdf:

[bbcmp1979]

That looks really good. U sure knows how to make me want to re-do my NatP cabinets... :-)

[Johnnz]

Thanks bb.

Got the internal braces made today. Grooved the edges so they will slot in on biscuits each side when I glue up the cabinets.

[JonMarsh]

Nice work. Glad to see someone else using biscuit joiners! Please keep the pictures coming...

[Johnnz]

Have been working on the bases today. One is now drilled, test fitted and ready for covering the center piece in leather. Waiting for the other's glue to dry before doing the same. Will run the outside edges lightly over the buzzer to get nice straight sides before veneering.

[Johnnz]

Leather on bases. Mock-up with steel spacers in place:

[Johnnz]

Some photos from today - lots of work on the router doing cut-outs, rebates and roundovers! What a versatile tool. I've only got a little Makita 3620 but so far have not found need for a larger router in this project. I did have to get a templet guide collar but with that now and the jasper jig I am pretty happy with what can be achieved with this great little tool.

I would probably have prefered to have the speaker terminals lower down, but I need all the space I can lower down for the crossover to fit in between the back wall and the gap in behind the port pipe. Will use little 4mm countersunk bolts and T-nuts to secure the Xover board to the back wall, directly behind the access panel that will be fastened in with 5mm bolts and T nuts. The two rounded over panels will be covered in leather again. The smaller top one will be permanently glued in position and the larger bottom one (the access panel) will be clipped onto the inside panel that is bolted on with the M5 bolts and T-nuts. I will leave a strap of leather sticking out in the middle so the lower panel can be pulled off the Snap-Dome fasteners (which will be screwed into the MDF). I plan to source these from a second hand clothes shop tomorrow...