Geom box-top 3: Penrose P3

  • Advertise with us
Project by ellgee posted 07-05-2018 10:49 PM 887 views 2 times favorited 6 comments Add to Favorites Watch

The pattern in the top of this is Penrose P3 tiling.
You can spend many (too many) hours web-browsing about tiling patterns,
if you are interested in mathematics.
The box is about 24×15 x 6.5 cm, and is mostly of spotted gum,
with some of the fat and thin rhombs of other woods.
This is the first time I’ve done a bridle-joined lid, and
I like it: not too hard to do, and seems very strong.

6 comments so far

View recycle1943's profile


5292 posts in 2676 days

#1 posted 07-06-2018 12:29 PM

nice box – I just need to get familiar with Aussi lingo

-- Dick, Malvern Ohio - my biggest fear is that when I die, my wife sells my toys for what I told her I paid for them

View helluvawreck's profile


32122 posts in 3921 days

#2 posted 07-06-2018 04:09 PM

This is a beautiful box and so creative and well done. It’s a real eye catcher.

-- helluvawreck aka Charles,

View Joe's profile


553 posts in 2141 days

#3 posted 07-06-2018 10:00 PM

I love the pattern in the box lid. Looks very complicated to the design and construct, I guess thats why you don’t see it often. Such elegance is in that fine detail, what a unique and beautiful box. Maybe you would be willing to share your knowledge of how that all comes together? Thanks for inspiring

-- CurleyJoe, "You only learn from your mistakes"

View ellgee's profile


70 posts in 2981 days

#4 posted 07-07-2018 08:56 AM

Thanks for the nice comments.
The tiling is made by
1) in Sketchup, draw an oblong an add some lines at 54deg and -54, for the fat rhombs. draw another oblong and add some lines at 72 and -72, for the thin ones. Print these, stick them on your scraps of 5mm thick wood, (or poke thru all the corners and draw lines on the wood) cut out with scrollsaw. Allow lots of extras, some will break or you’ll cut outside the lines. Keep the incomplete ones, as some can be used at edges. Hint: keep separate bowls or peanut-butter-jar-lids to contain fat-perfects, fat-partials, thin-perfects, thin-partials.
2) Roundover the 4 edges of each rhomb, on sander.
3) Starting from a printout of a valid P3 pattern (there are rules to making it, so dont just start sticking pieces any way) stick the pieces down onto thin ply. i.e. salvaged drawer-bottom. Let them exceed the boundary of the final lid-panel, and when all stuck down, set the saw to take only the pieces, leaving the thin-ply, and saw face-down to your lid-panel size. Roundover those sawn edges too, and the lid-frame edges.
4) Stick some veneer to the other side of the thin ply. Oops, that should probably be done earlier, to prevent the assembly warping from glue-on-1-side. I had enough work already invested on the top, so just pyrographed another pattern onto the lid-underside.

As for the mitered bridle-join (in case that’s what you’re unclear on, Dick)
it’s like a half-lap, but 3 layers not 2. You just cut away
the inside third of the end lid-frames, then cut miters,
and cut the miters on the front/back ones only 1/3 of the way thru
on each side, leaving the middle third whole.
Okaaaay, it is not quite that easy. Well it is, but requires precision.
Oh yeah, I recall now: the rebate for the lid-panel has to stop before
the corners.

View Ivan's profile


16721 posts in 3921 days

#5 posted 07-07-2018 12:37 PM

Pretty interesting and challenging pattern.

-- Ivan, Croatia, Wooddicted

View Joe's profile


553 posts in 2141 days

#6 posted 07-08-2018 04:13 PM

Thanks for taking the time to explain how you make the patterns. You do a beautiful job making those intricate pieces fit together to form an amazing work of art. You should be very proud of your work. Thank you for sharing your talent.

-- CurleyJoe, "You only learn from your mistakes"

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics