Desktop/PC speakers...

Dedicated to those large boxes at one end of the room
simon
Thermionic Monk Status
Posts: 5600
Joined: Thu May 24, 2007 11:22 am
Location: People's Republic of South Yorkshire

#31

Post by simon »

Nice saw Nick. No substitute for good tools, I want one!

You're a funny boy Davey :-D
User avatar
shane
Social outcast
Posts: 3403
Joined: Sun Sep 16, 2007 12:09 pm
Location: Kept in a cool dry place.

#32

Post by shane »

If it's as good as you say, it doesn't look that pricey. I'd have said you'd have a job finding a pair of speakers as good as what you'll end up with for the price of the saw and materials.
The world looks so different after learning science. For example, trees are made of air, primarily. When they are burned, they go back to air, and in their flaming heat is released the flaming heat of the Sun which was bound in to convert air into tree.
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#33

Post by jack »

Oh, its good alright. Just was a big single payment.

Its perfect for speakers and anything that requires accurate one-off or repeat panels - e.g. speakers, kitchen doors and so on.

Its also really nice being able to get an 8'x4' sheet and easily and very accurately reduce it to panels.

First thing you do is cut a "true edge" - a perfectly straight edge, then everything else references from that. No more frigging around with large sheets on table saws or hand-held power tools. Doing repeat cuts doesn't even require marking up - the saw and guides move over the wood precisely in seconds. When cutting the uFonken stuff above, I didn't use a pencil or a ruler once - I did use a digital vernier to confirm sizes, but that was all...
Vivitur ingenio, caetera mortis erunt
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#34

Post by jack »

Managed to get a very dirty full sheet of Decoflex 8x4 black walnut for 30 quid.

Funny stuff - its more like a plastic backing. I only wanted a small piece to practice on but they didn't have any samples so offered me this dirty sheet. Quick wipe over with white spirit and its fine.

The backing seems quite britle - how do you get it round a radius or 45deg corner? The timber merchant hadn't a clue...
Vivitur ingenio, caetera mortis erunt
User avatar
Toppsy
Shed dweller
Posts: 2400
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country

#35

Post by Toppsy »

The backing seems quite britle - how do you get it round a radius or 45deg corner?
You can persuade it to bend around large radius bendsin both grain directions, but if the radius is small and bending around 45 deg chamfers only with the grain not against the grain. Should wrap around those speakers in a single cut panel with the grain vertical so the grain is in the direction of the speakers in the vertical position.

Cut a single panel to size to wrap around the whole speaker. Round over the 90 deg vertical edges but only slightly. Apply Aliphatic resin wood glue (yellow glue) to the backing of the decoflex veneer and a coat of glue to all 4 vertical sides of the speaker. Allow to dry. No take a standard domestic iron set to cotton heat setting and iron on the veneer. Use light pressure and the sole plate of the iron to go around the corners. Easier than it sounds. Try a practice pice of wood first. Wrap around so the end verical joint occurs on the rear edge of the speaker. Cut excess with a sharp scalpel and sand round the cut egde flush. Simples. Works for me everytime. Check out my NORGE speaker thread using DecoFlex Oak veneer. You can do the same with the top and bottom panels of the speakers but the edges to these panels are best left a sharp 90 deg edge. Thats how they were covered.

Go for it.
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#36

Post by jack »

Thanks for that - they had the oak but the grain pattern was quite big and would have looked odd on a small speaker. The walnut has a closer grain and whilst quite dark I feel it'll look better in the end.

If not, I'll just make some more.

Grex P635 pinner arrived today. Brilliant for assembly and glueing up...

I'm sneaking into the cupboard under the stairs to nick the iron ;)

The aliphatic glue I was going to use is Titebond II...
Vivitur ingenio, caetera mortis erunt
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#37

Post by jack »

Few more boring photos - made some templates to make the machining a bit easier in future (and for the second baffle) - one for the rebate and a matching one for the actual cutout - rebate is used first, then main cutout - then have to put in some vents (45 degree cutouts) as the driver is so dinky that it can't breathe properly when mounted in 12mm ply...

Small speakers seem harder than large ones 'cos they're so fiddly... I do believe that I'd be happier with 0402 SMD parts ...

Used SS hex-headed M4 bolts and brass captive nuts (!). Looks OK-ish.

All that's left is glueing up...

...then veneer...
20150614_175237.jpg
20150614_175142.jpg
20150614_174705.jpg
Last edited by jack on Wed Jun 17, 2015 9:33 pm, edited 1 time in total.
Vivitur ingenio, caetera mortis erunt
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#38

Post by jack »

Rebate template has been used (2mm) so next is the cutout - the templates lock the baffle in place so they align perfectly (in theory...).

The FF85WK is so small that you have to have a cut-out for the tags. Bleugh.
20150614_150926.jpg
20150614_145857.jpg
20150614_174711.jpg
Last edited by jack on Thu Jun 18, 2015 10:19 am, edited 1 time in total.
Vivitur ingenio, caetera mortis erunt
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12273
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#39

Post by Dave the bass »

Shoddy!

DTB.

P.S. Nice!
"The fat bourgeois and his doppelganger"
simon
Thermionic Monk Status
Posts: 5600
Joined: Thu May 24, 2007 11:22 am
Location: People's Republic of South Yorkshire

#40

Post by simon »

jack wrote:The FF85WK is so small that you have to have a cut-out for the tags. Bleugh.
Impressive Nick, looks perfect. How did you make the template?
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#41

Post by jack »

simon wrote:How did you make the template?
There are two templates - initially two blank templates were made with a small locating hole in the centre of the speaker position so that they aligned perfectly. Note each template has a single "true edge" (indicated by a "V" - see photo) from which all measurements are taken.

Both had 45-degree lines drawn so that the speakers could be aligned correctly.

One template had a 76mm hole cut using a pillar drill and a Bosch hole saw http://www.screwfix.com/p/bosch-progres ... 76mm/26065

The hole ended up at about 78mm - the speaker needs 73mm, so I used a 5.6mm router bit in a 1/4" router with a suitable guide to give me a cutout that would be almost exactly 73mm, i.e. the difference between the edge of the cutter and the edge of the guide was about 2.5mm.

For the rebate template, I centred up the speaker face down and ran a line round it using a space so that the line was about 3.5mm outside the speaker - this would give a final rebate with a 1mm clearance round the speaker.

The rough cutout was done with a fine fretsaw, then I used a vertically-mounted Dremel (actually a MiniCraft drill in a press) and a small drum sanding attachment so that I could gently sand the template in smooth arcs to the correct size - see attached - sanding in long arcs minimises bumps. The drill is fixed in position (locked down) - its the template that is gently moved around by hand.

This method also gives vertical edges to the template which are needed for accuracy. Finish was by a soft piece of balsa wrapped in wet-n-dry to ensure no lumpy bits !

Making the templates was a bit of a pain (couple of hours), but now they're done I can knock out these front panels with no bother in a few minutes.
20150613_170459.jpg
Last edited by jack on Thu Jun 18, 2015 10:29 am, edited 1 time in total.
Vivitur ingenio, caetera mortis erunt
simon
Thermionic Monk Status
Posts: 5600
Joined: Thu May 24, 2007 11:22 am
Location: People's Republic of South Yorkshire

#42

Post by simon »

Thanks for explaining Nick, that's rather impressive really, and quite a labour of love. I'm not familiar with the Dremel type mini drills - do they have a separate stand type thing or can they mount in an average drill press?
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#43

Post by jack »

I've had a brief discussion with the designer of the uFonken as there is no guide as to the depth of rebate required.

However, the perforated baffle is supposed to press against the rear of the driver and its well off, so my rebate is obviously too shallow.

This is where having a template is great. I just drop the front panel back in the template and I can deepen the rebate with complete accuracy...
Simon wrote:...do they have a separate stand type thing or can they mount in an average drill press?
Dremel/MiniCraft/Whatever are pretty common smaller "craft" drills - have a look on eBay - the drill press is pretty small - there are several on eBay. One thing these are good for is drilling PCBs etc.
Vivitur ingenio, caetera mortis erunt
User avatar
jack
Thermionic Monk Status
Posts: 5493
Joined: Wed Dec 29, 2010 8:58 pm
Location: ɐılɐɹʇsnɐ oʇ ƃuıʌoɯ ƃuıɹǝpısuoɔ
Contact:

#44

Post by jack »

Toppsy wrote:
Go for it.
Any ideas on what to finish the black walnut with? I have an HVLP gun for small jobs but I was wondering how to bring the grain out?

Edit: just tried ironing on the veneer using Titebond II with our new iron :) Brilliant ! So easy... as you say, it goes round corners pretty well so long as the grain is in-line...

Thanks
Last edited by jack on Sat Jul 04, 2015 11:05 pm, edited 1 time in total.
Vivitur ingenio, caetera mortis erunt
User avatar
Dave the bass
Amstrad Tower of Power
Posts: 12273
Joined: Tue May 22, 2007 4:36 pm
Location: NW Kent, Darn Sarf innit.

#45 Re: Re:

Post by Dave the bass »

jack wrote: Any ideas on what to finish the black walnut with?
Arrrgggghhhhh! The 80's, stoppit!
Image

Hehehehehehehehheh (etc).
"The fat bourgeois and his doppelganger"
Post Reply