Hi Nori,
I decided on a 5' 265 gallon tank. The 4' tank will certainly be
easier to fill and manage, but obviously will require more
batches. I'd recommend making your frame large enough to accommodate
a 5' tank should you decide you want a bigger tank later, after
you've got a sense of volume and mixing issues -- sounds like you'll
be making quite a few batches, so tank size might make a big difference...
Over this past weekend I finally attached a 4" Valterra gate valve to
the bottom of my tank. I did some pursue the tire "elephant trunk"
approach of
http://www.makepapercrete.com/The-Papercrete-Tow-Mixer.html, but I
wasn't happy with how it was coming together, and decided I really
wanted more control of the output, which a gate valve gives me. I
purchased the 4" gate valve over eBay for about $80. See "Eric's PTO
Mixer Part 2" for a photo of the valve and the valve mounted. The
2x6 between the valve and the tank serves as a mounting flange. Note
that I actually have a short section (~3") of 4" PVC sticking through
the 2x6 -- it helped line up the valve to the tank, and just makes a
better flange assembly. A PVC flange might have been nicer, but I
couldn't find one, and this seemed like a very doable solution.
As you can see from the photo, it dumps nicely into a
wheelbarrow. My plan is to drill 3 or four 1/4" holes on the
downside flange of the valve, allowing me to quickly bolt on
different PVC elboes and lengths, for a de-watering process. With a
4" to 3" reducer, this type of setup could be ideal for connecting to
a trash pump input. Just tilt the tank a bit so it all flows to the
valve -- no need to pump up and over the edge, and easy to get
everything out of the tank.
After getting my valve installed, I noticed a gate valve setup on
http://www.livinginpaper.com/mixers.htm -- a "slide ditch gate valve"
-- essentially a gate valve but perhaps one more appropriate for
papercrete. I encourage you to check this out. The challenge for me
with my Valterra gate valve is that it is essentially a stainless
plate that slides between two rubber gaskets. I'll have to make sure
to clean it well after each use to keep it functioning properly. The
"slide ditch gate valve" shown on Living In Paper looks like it would
be more forgiving -- it also looks like you can get it in larger
openings, possibly at more reasonable prices. I haven't checked out
prices, but here is a starting link:
http://www.allmetalssupply.com/waterman_gates.htm.
I went to mix my first batch over the weekend and discovered I needed
to do some more work. Essentially the paper would stall the
blade. So today I had my 12-spline carrier hub welded to a 1/4"
4"x4" plate with two 5/16" holes for bolting on the lawnmower
blade. This is similar to what a rotary cutter does-- they have a
"dishpan" assembly, which is essentially a 12-spline carrier hub
welded to some bar stock and a circular dish, to which the blades are
attached. My welded carrier hub how has a positive connection to the
lawnmower blade -- if the blade can't turn, either it will stall my
tractor, or sheer the 5/16" bolts that hold the blade -- I'll let you
know how this goes! I'll post some photos later...
While sorting through the solutions to the problem, I considered
using the whole rotary cutting assembly, just mounted upside
down. The benefit of the rotary cutter blades, is that they are
designed to "jump stumps," or get smaller, if they can't cut through
something. Essentially there are two independent blades, each
mounted on only one bolt -- as the blade gets "to speed" the
centrifugal force pushes the blade out. I could see how this design
parameter could be useful when mixing papercrete, say the mixer
"hits" a phone book, or large, un-pulped mass-- rather than stalling,
or breaking the blade, the blade would simply retract and slide
around the obstacle. Also, the rotary cutter blades are generally
3/8" - 1/2" thick, so definitely less likely to break than a
lawnmower blade. If anyone has experience using a traditional rotary
cutter blade assembly in a papercrete application, I'd be interested
in your experience.
Nori, since you're using a rotary cutter gear box, just make sure
you've got a positive connection to the gear box output shaft splines
-- tightening down the bolt just doesn't do the trick...
warmest regards,
Eric
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/papercreters/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/papercreters/join
(Yahoo! ID required)
<*> To change settings via email:
mailto:papercreters-digest@yahoogroups.com
mailto:papercreters-fullfeatured@yahoogroups.com
<*> To unsubscribe from this group, send an email to:
papercreters-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
