Maybe OT: Tumbling wood

I have a couple of medium sized wet vibratory tumblers at work and use some
douglas fir 2x4s to keep small parts circulating. They don't seem to wear
down much, too soft for the abrasives. YMMV.
--
Stupendous Man,
Defender of Freedom, Advocate of Liberty

Gautham, this sounds like a job for a wood shaper.
http://www.rockler.com/product.cfm?page=18208

--Winston

On Wed, 05 Aug 2009 06:09:48 -0700, the infamous Winston


Delta?  NAH!  Go with Griz!
http://www.grizzly.com/catalog/2009/SummerFlyer/8

--
"It was difficult for the three of us to write a book titled _The End
of Prosperity_."

"We're not doom and gloom people; we're natural optimists. And we're not
part of the trendy set of intellectuals who like to trash our nation,
blame America first for all the world's problems, or worst of all,
predict with glee America's downfall as some kind of punishment for our
alleged past environmental crimes, racism, financial mismanagement, greed,
overconsumption, imperialism, or whatever the latest chic attack on the
United States is."
         --page one, by Arthur B. Laffer, Stephen Moore, & Peter Tanous

Larry Jaques wrote:

Yup, I included the link to give Gautham a quick idea
of what I was referring to.  There are many suitable
tools available to do that job at many different
price points, both new and used.

I think a hand held router with a round over bit
would be way cheaper and faster than using a belt
sander.  A wood shaper would probably be better yet,
WRT speed and finish, particularly if you could
use a custom knife to cut opposite sides at the same time.

--Winston

You don't say how big, or how many blocks, but it might be just as quick to
clamp a router to your work table, or buy/make a cheap router table.

Routing with something like a 1/16" or 1/8" corner round is quick, easy and
does a very good job.

    --What he said; been there done that and it works very well. Just be
certain that you have fences really tight and that you have a minimal
clearance ring around the toolbit so you don't have a bad day with small
parts..



--
        "Steamboat Ed" Haas         :  Imagine what I could do if
        Hacking the Trailing Edge!  :  I knew what I was doing...
                          www.nmpproducts.com
                   ---Decks a-wash in a sea of words---

I am looking at blocks an 1"square and perhaps some a little bigger.
Except for a few of them, I would be wary (read WOULD NOT) of using a
router/shaper. Think building blocks and blocks for puzzles (like the
soma cube, pentominoes etc.)
Is there a jig which might make this safer?

TIA, gautham

Jangle wrote:

http://images.rockler.com/rockler/images/20725-lg.jpg
http://www.rockler.com/product.cfm?page=11177

--Winston

Winston wrote:

http://www.dremel.com/en-us/AttachmentsAndAccessories/Pages/attachmentvideo.aspx?vid=231
http://www.dremel.com/en-us/AttachmentsAndAccessories/Pages/AttachmentsDetail.aspx?pid=231

--Winston

On Fri, 07 Aug 2009 22:17:26 -0700, the infamous Winston


Cha-CHING!  Hold on there.  Try these:

http://www.rockler.com/product.cfm?page=18917&filter=wood%20clamp
I use the HF 12" wood clamps to hold objects or other clamps, and you
can drill into them, making them complete jigs. Used along with a
handheld router, they should do the trick.

http://www.rockler.com/product.cfm?page=976&filter=router $49 PC!


Or hold the router in the clamp and the block with a pair of vise
grips.


--
Content thyself to be obscurely good. When vice prevails, and
impious men bear sway, the post of honor is a private station.
                                   -- Joseph Addison, 'Cato'

Larry Jaques wrote:

I like that handheld router!

Hokay, building on your idea, how about
stacking & clamping nine 1" cube blocks 1 deep
sideways in a vise using a 1/8" neoprene jaw cover
on the bench side, resting the blocks on a bottom
lip milled into the movable jaw (Think 'Parallels'):
http://www.rockler.com/product.cfm?page=21523&filter=vise%20jaw

Use your handheld router to round
over all the exposed edges.
(The three edges on the two end blocks and two
edges on the seven 'constrained' middle blocks.)

Unclamp and rotate each of the blocks 90° and pick
up two more edges on the 7 constrained blocks
and the remaining edge on each of the two end blocks.

You are half done!  Spin all nine blocks upside down
to expose the unmachined edges and finish up with six
more passes. Should cost less than 30 seconds per block
on average, (not including latency).
You should be able to bang out all 100 pieces in less
than an hour.

Protect yourself from inhaling hazardous dust
produced from machining some exotic woods.

Vacuum and clean the workpieces.
Stain and seal as appropriate.

My apologies if this is not clear.
Sometimes I forget that I am completely incapable
of abstract thought.

--Winston <--(Hi Harley and Gary!)

On Sat, 08 Aug 2009 11:08:25 -0700, Winston wrote:

[snip links to routers/shapers/clamps]

Treating the end blocks differently than the others (ie, cutting
across their ends) apparently makes no difference in the total
number of router passes or the number of clampings, so it should
not be done.  Treating some parts differently than others slows
things down and can lead to errors.  Anyway, snipe is a problem
for short planer/jointer/router/shaper cuts.

For high volumes of blocks (thousands?) I think that tumbling
the blocks is a better approach than using any method that entails
handling blocks individually.  But if you don't mind one
"rotate each of the blocks 90°" step per block, make a tube-like
jig with a cross-section like a square with a corner cut off.  
When this magazine is loaded with blocks and the ends closed
tight, the line of blocks can be treated like an uncut stick, and
run across a joiner (or perhaps a sander, router, or shaper) to
chamfer one edge of each block in the jig.  Then push the line of
blocks out of that jig into an empty jig rotated 90°, exposing a
new line of edges for cutting.  (Or push them out of the jig into
an open v-channel, rotate the jig 90°, and push them back in.)  
After 4 passes, unload the jig into a v channel, rotate each
block 90° to expose 4 new edges, and push the line of blocks
back into a jig.  


--
jiw

James Waldby wrote:

(...)


Good point.  Rounding only the +Y and -Y edges would limit chipping
and you could do the job in only 8 passes instead of 12. By extension,
one could make a clamp that held say 52 pieces instead of only 9.
All 100 cubes could be done in only 16 passes.


Perhaps.  I've never tumbled wood but it strikes me that you could
get more predictable edges very quickly by using a router or shaper.
I can't quite squash the image of unintended dings caused by corners
hitting planar surfaces.


That's one cut per block per setup.  Previous way is two cuts
per block per setup. Which would be faster?

Your square tube jig is sure adaptable to automation!

I can see a vertical square tube that contains two contoured
planer knives.  Press a stack of cubes in from the top and you
get four edges rounded at once.  Press these workpieces into
a horizontal square tube. Four more edges and we are done.
It would take many, many cubes for such a machine to pay for
itself, however.


http://www.gvwg.ca/docs/Articles/WoodToxicity.htm


--Winston

On Sat, 08 Aug 2009 16:07:47 -0500, the infamous James Waldby


Yes, tumbling is probably the best bet all around.

--
Content thyself to be obscurely good. When vice prevails, and
impious men bear sway, the post of honor is a private station.
                                   -- Joseph Addison, 'Cato'

On Sat, 08 Aug 2009 11:08:25 -0700, the infamous Winston


Yes, Porter Cable tools are nice. I got a free handheld router when I
bought my Griz dust collector and bandsaw. They're definitely handy!



See my other post this morning. Great minds think alike, but we're
backwards on this one: you preferring to move the cutter, me
preferring to move the blocks for mass processing.



Yes, use a dust collector, _always_!



I always wipe with lacquer thinner or paint thinner prior to
finishing.



You misspelled "clearcoat", dummkopf.  When you use the proper wood in
the first place, you don't have to _stain_ the poor stuff. Stain ends
up giving you a mottled, ugly POS.



Are you sure?

--
I'm still waiting for another sublime, transcendent flash of adequacy.
                                                    --Winnie of RCM

Larry Jaques insisted:

(...)


The OP stated that he needed enough pieces for one classroom
but we don't know how many pieces he could envision making.
There are a whole range of tools and techniques useful
from 1 piece to fractional millions.

(...)


We are in violent agreement.


That'll be the thing I learnt today.


Only when I'm wrong, Larry.


It's gonna happen too.  I have faith.

--Winnie

Jangle wrote:

I agree - that's putting your fingers much too close to the bit.


I would make one like this: take a piece of 1 x 2 pine, maybe 6" long.
Cut a 1 x 1 notch in the end:

   _____________
                |
           _____|
           |
  _________|

Take 2 pieces of 2 x 4" 1/4 plywood/Masonite & fasten to the sides of
the 1st piece, making a 1 x 1 x 1 pocket.  Your block goes in the pocket
& is held firmly against the router table & fence.

Make a pass, flip the block & repeat 11 more times!  Repeat 199 times!

You can reduce the repeat's as follows:  route the long sides and the
ends of your 1 x 1 stock before cutting off 1" pieces.  Then you have a
block with 8 sides already rounded.  Route the cut end after each cut.

Bob

On Fri, 07 Aug 2009 21:42:40 -0700, Jangle wrote:

Your router should already have a fence; all you need is a featherboard
and a push stick, and maybe another push stick or another featherboard.

Admittedly, it'd be a bit time-consuming, but tumbling square pieces
really doesn't sound like that hot of an idea, as has been noted.

In any case, remember to wear your eye protection, and maybe hearing
protection.

Good Luck!
Rich