Thursday 28 March 2013

Small walnut speaker enclosure with skewed splined mitres

I needed an enclosure for a small marine loudspeaker for use with a communications receiver. It was for my Dad, who had made the receiver, and I used an old piece of walnut from his grandmother's dining table which had been in the timber stores for some considerable time!

First surprise on cleaning up was that it was American Black Walnut and not English as thought. The table dates from about 1900 so we have been using ABW for some time!



As ever the bevel up smoother
made a good job but probably
not essential in this case as
ABW is fairly easy to work.







I intended to use skewed, splined
mitres with ebony splines, more
for the fun of making them, so
needed a mitre shooting board to
use my weapon of choice, the
low angle jack.






I glued and extra block against
the back fence to make sure
it stayed put!












Next stage in the timber prep was
to rebate the sides which I did
before cutting to individual lengths


My views of the excellent
skew rebate are already well known.































The jack ran well against the fence/groove arrangement but I later glued an angled guide against the groove to give it some wear life.



















In this case I used my low angle A1 blade honed to 27 deg making an effective pitch of 39deg, excellent for end grain as you can see with smooth curly shavings and a good finish.











Glued up the mitres to make the box.
I used an aerolastic and corner blocks
to keep it pulled up tight; quite
effective. I used the back of the spline
jig as a square jig for the glue up
 - multi tasking or what :-)



That is just a small glue squeeze
out along the edge but managed
to get the grain running nicely
around the outside.






With the sides prepared I needed a jig
to cut the skew spline grooves. This
was quickly made from a few offcuts
and tested with a slotter in the tilting spindle.




Next step was a test on some scrap pine to make
sure it worked




I tried a few options but it went better than I
expected.






I think I was a bit over enthusiastic
at this point with my new found
skills and made the splines a little large.




I had an offcut of ebony which I planed up with



the BU smoother. What a strange timber to work
coming off in fragmented shavings

Safely glued in


A quick clean up with the plane was all that was
required for finishing followed by a slap of
Danish oil. I now tend to choose timbers in
advance that I know I can oil finish. Often I do
not do any sanding, finishing straight from the
plane







Speaker mounted by silicone directly into the rebate and a ply back finished the job.

Thanks for looking.

Tuesday 26 March 2013

Shiplap Front Door

Those of you who have followed my threads on the forums will be aware of my painfully slow house re-furb project. In my defence I also have a day job to do but my wife will tell you it needs to be finished. A couple of people stopped her on the street recently asked her why we handn't mended the broken window! It is a sheet of shuttering ply which has served us well for a couple of years!

Anyway time to get on with the door.

The weather where we live is really fierce on top of a ridge 1000ft up in the Peak District. Consequently the doors needs maximum weather resistnce and insulation. I decided on shiplap as this will reject any rain and also looks nice with the shadow detail. Timber is Columbian pine, again for weather resistance, to match the triple-glazed windows.





This gives you some idea of what it has to stand up to - the back door made a while ago. Note how the 25mm PU in the diagonal panels keeps the snow frozen whilst the solid rails do not!

As ever we start with a pile of timber and a pair of sawhorses






Having dimensioned and cleaned up I used the new and ridiculously expensive Felder work clamp to put bare faced tenons on the font and back boards.




 I then rebated the long edges to make the lap joints.




I used a 15mm rad knife in the spindle to form the shiplap mould




For the grooves in the stiles I tried my new (second hand) wobble saw which was great. I like the idea it has many teeth and can be sharpened like any tipped saw. This should allow much faster feeds and less cost than a normal groover.




The feared break-out didn't really occur





With the stiles grooved I chopped the mortices and tenons with an extra pair of stub tenons on each rail for extra strength, and of course to fill the groove. I used a stub tenon in the centre of each board to keep it in position during seasonal movement although it would have been simpler to utilize the domino (with the benefit of hindsight.)





With stiles 150 x 68  and 2 layers of 20mm panels it was going to be a heavy door so I decided to use an internal diagonal brace to ensure it could not sag. Also it has no middle rail. The brace was housed into stile and rail with sloping housing joints so there was a square shoulder to take the load. I chopped this out with one of Workshop Heaven's mortice chisels, which proved excellent, and pared back using guide wedges stuck on with a bit of double sided tape.







The brace was just a piece of old whitewood which previously saw service in and IKEA bed so I hope it is strong enough :-)  I used the nicker on the skew block and rebate to make the shoulders which, although narrow, do the job. Left and right hand planes were used according to the grain, leaving a clean tenon (and very quick)






 I glued up half the frame and put a couple of hefty screws into the brace.




 I selected the boards so that the heaviest and most resinous were on the outside and the lighter boards used internally - there was a huge difference.




Insualtion was supposed to be PU but I could only get Polystyrene on the day - I don't suppose we'll notice the difference.




 Final glue up was a bit fraught with 52 mortices to fit




Made it!




As it was so heavy I decided to rout the rebates and seal grooves rather than try and get the door onto the spindle table. This was not a success as I had problems with the 625 depth stop loosening and a lot of break out. I sorted it out using the skew rebate but would use the track saw in future and biscuit jointer for the grooves. Following a change of the weather strip I had to alter the door bottom and used this method which proved very easy.







I knocked up the frame from standard 80 x 68 section and double bridles on the corners. I got a bit lost and ended up placing the frame pieces on the door to check I'd done my calculations correctly.






I wanted an alloy thresh but owing to the unusual section had to fabricate it from a standard thresh and an angle section. I used the chop and bandsaw for the first time on ally and it went OK apart from machine-gunning me with swarf.









Again, owing to the weight, I decided to fit the door in the shop, including the heavyweight overlaid hinges set for a 17mm overlay. First a simple MDF drilling jig for the pins.




I used a thin spacer for setting them out so that I could get them off again without damage.




These are better that the Roto's I've used before because you can adjust the door without having to loosen the screws. There is running clearance built in.



I used 4 hinges, 1 at the bottom and 3 in the top half.




 Keeping to the same strategy of doing as much as possible in the shop I stripped it down and finished with 2 coats of Sikkens water based BL21 and two of the top coat BL31 (In Oregon Pine)




At this point I panicked as the door was incredibly heavy and decided to dowel the rails to preclude any creep under what seemed a huge potential load. I realise these should have been draw-bored but better late than never.









 Now all we need is the weather to break so we can get it fitted - a two man job. Thanks for watching and I hope it is of some use.