This
article gives some of the history behind,
and then illustrates some of the recent development work I have done, on the wheeled version of my “Kactus Kicker”
cactus control tool. Before offering
this option again routinely, I have to
simplify and revise it into something a little more producible.
It
was originally a separate design worked out mostly by my friend Dave
Gross, who was doing cactus eradication
as a commercial service, before he
recently retired. We called it the
“commercial grade tool”, as distinct
from the then-much lighter-built, no-wheels “homeowner grade tool”. That distinction between the two designs is
no more.
As
my development work proceeds, I will add
updates to the end of this article.
History
My
original write-ups about cactus control are on a sub-page at the http://www.txideafarm.com
site, which has not been recently
updated. The descriptions and photos of
how it works that are posted there are nevertheless still very good, since nothing about that process has
changed. The older hardware photos posted there show quite a difference
between the "homeowner-grade" and "commercial-grade"
tools, something that has since changed
very substantially since then.
As Dave originally built
them (mostly at my shop), the
"commercial grade" tool was bigger,
heavier, and tougher, and had transport wheels which were
hydraulically, electrically, or mechanically (manually) actuated. Today, I use exactly the same tough
chassis for both versions, so there
is no longer a “commercial tool” distinct from the “homeowner tool”, there is only the “Kactus Kicker” and a suite
of options. The transport wheel assembly and the tow-bar hitch assembly
are simply two among many options that can now be added at extra cost.
The wheels allow
easier load onto a trailer, with a
trailer-mounted electric winch, if you
lack a lift bucket on your tractor. The wheels also allow you to easily
and quickly "step over" a bale of debris, if such a thing accumulates
underneath your tool in the field. That second advantage is really the more
important one. Wheeled tools today are pretty near 1000 pounds
each, and a whole lot more
expensive. Today, I only offer the wheeled option as
hydraulically-operated, since that is
the most practical option with most recent-vintage farm tractors. (Electrical is slow, and mechanical saves no labor at all.)
The tool rigged with
wheels is something I am currently still improving and experimenting with,
before I offer it for sale again. (Illustrating progress toward
that goal is the point of this article.)
I need to finish re-working and re-testing my revised experimental hydraulic
prototype, before I finalize its design and its price. But, I
believe it will price-out in the neighborhood of $5000 each at my shop (update 4-15-14: $7000).
There is a lot more steel, a whole lot more hand-work labor, and a
whole lot of really-expensive hydraulic parts, that all go into a wheeled
tool. Those I only offer to specific customer order, half the money
up-front. Update 3-21-16: for actual prices, see the new website http://www.killyourcactusnow.com, these numbers are inaccurate.
Update 3-1-18: the killyourcactusnow site has been shut down in favor of a new and improved site http://howtokillcactus.com, with even better information, photos, and videos.
The plain tool is 8 feet wide, and weighs pretty near 720
pounds, as I build them today. For both versions, the basic deck is 2 feet by 8 feet. It
has a “barge front” on the front edge to help it wedge its way over rock
outcrops and other obstructions, up to
about 6 inches relief above surface. There is a stabilizing snout
projecting forward from the middle of the front edge. Stable tow is from
the corners of the main deck,
however.
Today I build this stabilizing snout very stout, even on the plain tool, because so many customers have such rough, rocky ground to take care of. The wheeled tool needs a slightly-longer
snout with an extra skid plate,
otherwise, both versions now use
the same basic snout design.
You can see how the plain tool is built in “Construction of the Plain Cactus
Tool”, posted 10-12-2013, right here on “exrocketman”. I have changed the details of the snout
tie-down brackets and the chain towers since then, but today those components are exactly the
same as what I used on the experimental wheeled tool shown in this
article.
Availability
Plain tools I build
speculatively in pairs every so often. Once I have steel available, there's about a week's worth of piecepart
fabrication, before I am ready to call my professional welder and have
him "stitch" them together. His work schedule is the real
driving factor, which is not under my control. Once he is done,
I paint them and rig them, and they are ready to sell. This
next batch is priced at $2000 each, here at my shop on the farm near
McGregor, Texas. Update 3-21-16: for actual prices, see the new website http://www.killyourcactusnow.com, these numbers are inaccurate.
The new, revised wheeled
tools are not yet available for sale,
but soon will be. These will be
built only to specific customer order,
half the money up-front. Update 3-21-16: both the plain tool and the hydraulic tool are available. For options and prices, see http://www.killyourcactusnopw.com.
Update 3-1-18: the killyourcactusnow site has been shut down in favor of a new and improved site http://howtokillcactus.com, with even better information, photos, and videos.
How Employed
The cactus tool (wheeled
or plain) is a drag implement that you pull at walking speed on a chain bridle
behind a tractor. It breaks off the above ground cactus foliage,
runs over it instead of just pushing it around, and thereby crushes
it with the weight of the tool. Cactus foliage damaged like this will
bleed out dry, and die, before it can successfully put down new roots
from the thorn sites on the pads.
If you just push the
pads around (as in “blading” and “chaining”), much of the stuff you tore
loose will just re-root and create more cactus plants. You end up just
spreading the cactus and making your problem worse, if you don't do this
right and crush thoroughly what you tear loose. The same thing applies to
shredding: the shredder or mower blade
cuts are just not enough damage.
Either
version is stout enough to last a very long time. The big tough snout and
large barge front are there precisely to wedge themselves over fixed rocky
outcrops up to about 6 inches relief. You can pretty well run over trash
trees and brush, up to about an inch and a half diameter, one (or
at most two) at a time. Loose rocks that move when you hit them can be
run over up to about 10 inches size, although stuff like that can hang up
under the tool. If it does hang up, and you have a plain tool, stop, slack the tow chain, pry up
the tool, and remove the offending object. If you have a wheeled
tool, just lower the wheels and “step
over” it. The same processes apply to
clearing debris bales.
These
tools in either form can handle moderately rocky ground, but you should
definitely go around the bigger obstacles, stuff that would cause you to
hang up completely. You are towing on a chain, which has
no "give", meaning a piece of steel somewhere is going to
break, if you do hang up. I deliberately build these with
smaller chain, so as to try to ensure the chain breaks first. Chain
is a whole lot easier to repair or replace than any of the rest of the steel in
the tools, or the hitches on the tractors towing them.
Typical
tow loads on level ground would average around a half a ton per tool,
maybe up to a ton, which can act almost dead sideways in a tight
turn. That’s around 8-16 drawbar horsepower per tool, at 3 mph tow speed. In really rocky country, or on steeper slopes, or in really dense cactus, tow loads (and power required) are even higher. If you are towing from a 3-point rig instead
of a plain drawbar, be sure it is braced for side loads of that magnitude, or you will break it.
One
thing to remember about wedging your way with the barge front over multiple
smaller outcrops at once, is that the
tool is the "hammer" and the Earth is the "anvil". A
tool wedged up in the air is not down upon the ground crushing cactus. If you instead drag right alongside such
obstructions from multiple directions,
it will take more time, but this is far more effective at
tearing loose and crushing the cactus.
These tools are no
panacea: there is serious work involved. But, the advantage of all-mechanical eradication is
twofold: (1) I converted this to nothing but mostly “driving-a-tractor”
work, and (2) there really is an end to it, unlike herbicide
spraying. And, you can combine it
with herbicide spraying if you want to. (You’ll
reach that final eradication point sooner,
if you do. You’ll just spend more
money for herbicide to save the additional time.) With herbicide alone, there is only control, and there is no end to it. You will be buying herbicide and spraying
about every 2-3 years, “forever”.
Typically, with
either version of the tool, what you do
is select a small area like 5 acres, and you drag the tool as many times
as is needed through the cactus to tear loose and crush everything you can
reach, knowing full well that you will not kill everything (“first
treatment”). You do this again (“second treatment”) about 3 to 6 months
later, but there will be a whole lot less cactus to kill.
You do it a third time (“third treatment”) about 3 to 6 months later
again, and this may well be motoring from plant-to-plant in very sparse
growth, instead of area coverage. Every place is different, however.
After the three
treatment sequence, you kill the “ones-and-twos” regrowth from the roots
(only the big roots will re-sprout) by motoring from plant-to-plant. Do
that every 6 months to a year, for about 2-3 years, and the roots will
finally starve to death in the ground,
for lack of green photosynthetic pads above. Then, it is all
gone. That’s “follow-up”, and it
is required, or the cactus will
eventually re-grow from the buried roots.
You
can clear cactus out of fencelines with a hoe, and drag it out from the
fence a bit. Then run over the hoeings with the cactus tool to crush and
kill them, so that they do not re-root.
This works whether you have wheels or not. Same thing applies to clumps of cactus hidden
in among dense brush or trees.
Reworking the Wheeled Tool Design
When
Dave retired, he sold off his 5 cactus
tools and other associated equipment. All
of that is now gone. So, I built a dedicated experimental prototype for
myself, based on the best of his
tools, but also incorporating some ideas
of my own aimed at better producibility.
This doesn’t always work as intended,
so my prototype is a work-in-progress.
Again, watch below for updates
appended at this article’s end.
I
initially incorporated three changes:
(1) a substantially-revised hydraulic wheel assembly, (2) revised chain towers, and (3) a new snout adapted from the current
plain tool. Not long after building
it, I added a possible tow-bar hitch rig
as a fourth change. The revised wheel
assembly was simpler and much lighter than the approach Dave had used, which let me go to fixed ballast weight on
the tool deck, in common with the plain
design.
The
revised snout design was also simpler and much lighter (yet far stiffer in
twisting), which moved more of the
tool’s weight aft onto the crush rail at the rear. This unloaded a great portion of the weight
from the snout slider plate, which let
me use a smaller slider plate than Dave had to use. Although,
I am thinking of offering larger slider plates as an option for those
who have soft, sandy land. Those would need prototype testing, too.
So, the common chassis became the deck and crush
rail, plus skids, plus fixed ballast, and the same barge front and brace
system. The wheel assembly and the
slightly-longer snout weld to that common chassis. There’s not much need for a tow bar hitch if
you have the plain tool, so it is only
offered for wheel-equipped version. (The
other options can be added to either version.)
The real
differences thus became only the wheel assembly and hydraulics as an option
added to the same common chassis, and a
slightly-longer snout with the extra skid plate, for smooth sliding when the wheels are
down. The other difference is the tow
bar hitch assembly, which is still currently
far from being market ready, but which
will be an add-on option that not everybody will need, even if they do want the wheel assembly. Update 4-15-14: towbar hitch has been revised to something practical, durable, and producible, on the experimental prototype. Update 3-21-16: Towbar hitch is a standard option available on the hydraulic tool only (plain tool does not need it), see http://www.killyourcactusnow.com.
Update 3-1-18: the killyourcactusnow site has been shut down in favor of a new and improved site http://howtokillcactus.com, with even better information, photos, and videos.
Other
options will include trailer hitch points that can be added to the aft
deck, heavier-grade chains, and fences for retaining equipment left
stored on the tool’s deck, against its
rattling-off while underway. Other than
the heavier chains, I haven’t prototyped
these yet. Not everybody will need
them, either.
So, the basic common chassis assembly is
identical to that of the plain tool. The
difference shows up when the snout is constructed. There is a 15 degree fabrication shim needed
for jigging-up and welding the second slider plate. See figures 1 (4073), 2 (4075) and 3 (4076). The basic common chassis also includes the
barge front braces, as shown in figure 4
(4079). Once the snout is welded in
place, you add the barge front
pieces, resting them upon the projecting
skids while you weld them in place butted against the braces and snout, as shown in figures 5 (4080) and 6
(4081).
Figure 1
(photo 4073) – Common Chassis Being Built
Figure 2
(photo 4075) – Longer Snout Being Built
Figure 3
(photo 4076) – Shim Under Snout During Fabrication
Figure 4
(photo 4079) – Adding Barge Front Braces
Figure 5
(photo 4080) – Barge Front Rests on Skids
Figure 6
(photo 4081) – Barge Front Welds to Braces and to Snout
For the
wheeled version, the longer snout needs
shear tabs added at both ends, as shown
in figures 7 (4084) and 8 (4085). The
plain version only needs shear tabs at the aft end, where it mounts to the tool deck. The new triangular plate snout brackets are
clearly shown in these photos. These new
brackets replace the older-style brackets made of angle stock. They are at least as strong as the older
design, and cut a lot of labor from both
the piecepart fabrication and the welding.
Figure 7
(photo 4084) – Aft Shear Tabs (one each side,
both versions)
Figure 8
(photo 4085) – Forward Shear Tabs (one each side, wheeled only)
The
prototypes for the new chain towers are shown in figure 9 (4088). These are made of channel stock, and calculate as far stronger than the older
gusseted-tube design. These are good
enough to break the heaviest chain I plan to offer. For production, I replaced the flat-plate tops with
channel, which controlled the weld
distortion evident in the prototype photo.
This new chain tower design has been standard in production since serial
number 055.
Figure 9
(photo 4088) – New Chain Tower Design
I rigged
this prototype tool with the same chain bridle as is used on production plain
tools, just a slightly-longer piece to
accommodate the slightly-longer snout.
It has the same kind of cross chain,
as shown in figure 10 (4092).
This serves to limit pitching and yawing motions on very rough
ground. More importantly, the cross chain allows you to convert the tow
bridle to a lift sling, with nothing
more than one single bolt, which is
included with all production tools sold.
Figure
10 (photo 4092) – Chain Tow Bridle Installation
Figure
11 (4096) shows my initial hydraulic wheel installation. Unlike Dave,
I mounted two struts with a clevis hinge, on the deck atop the ballast bar aft and atop
spacers forward. I used his original 24
inch spacing for this. The same kind of
struts also formed the wheel assembly itself.
My first version used lighter-duty solid wheelbarrow wheels on a
narrow-gage spacing, but with the same
diameter as the heavy solid shredder wheels that go on a production
design.
Figure
11 (photo 4096) – Narrow-Stance Hydraulic Wheel Strut Assembly
The main
difference from Dave’s version is that I moved the hinge line off-board aft of
the tool deck. This allowed me to use
lighter, simpler, easier-to-build, and less vulnerable straight legs. By carefully arranging the actuating arm
geometry, I was also able to maintain a
far lower equipment profile over the deck with the wheels retracted. This allows better clearance when working
around dense brush and trees.
The only
problem with this narrow-stance design proved to be too much “wobbling
instability” wheels-down rolling over rough terrain. (The next version is a re-work of the same
basic design, just to a wider stance.) I had a clever axle-and-spacer design that
allowed me to use a single key to retain the wheels, as depicted in figure 12 (4097). But,
this kind of narrow design proved unsuitable for rough-terrain work. Plus,
an axle across like that is vulnerable.
(The wider-stance version will trap each separate wheel with two
struts, and eliminate the long
vulnerable axle between them.)
Figure
12 (photo 4097) – Narrow-Stance Wheels and Axle Assembly
I
arranged the hydraulic cylinder mechanism to achieve 100 degrees of wheel strut
travel in the 16-inch stroke of the cylinder.
The diameter is such that hydraulic systems operating anywhere from 300
psi to 2500 psi are all accommodated with no hardware changes. The cylinder stroke travel limits are the
actual stroke limits of the cylinder itself,
so no super-strong travel-limiting features are required of the wheel
assembly design; it only “sees”
tool-raising loads.
Figure
13 (4098) shows the fully-extended wheels-down position., and figure 14 (4100) shows the
fully-retracted wheels-up position, with
the struts slightly-upswept at 10 degrees above the deck plane. This allows greater ground clearance for the
retracted wheels, with the tool sliding
on the ground in use.
Figure
13 (photo 4098) – Wheels Fully Extended Down
Figure
14 (photo 4100) – Wheels Fully Retracted Up
There is
a cross-connection valve needed in the plumbing assembly for the hydraulic cylinder. This allows you to bleed off line pressures
for coupling and uncoupling hydraulic hoses.
My prototype plumbing assembly,
shown in figure 15 (4101), is
built of hardware-store components rated “WOG” (water-oil-gas, 600 psig working pressure). The hydraulic pump on my old antique tractor
only produces around 300-400 psi, so
this was acceptable for my experimentation.
I still need to re-work this into real steel fittings and a hydraulic-rated
valve, for modern hydraulic systems now
pushing 2500 psig.
Figure
15 (photo 4101) – Cross-Connection Valve on Hose Manifold
In my
very first tests, I had not added the
tow bar hitch assembly. The tool came
out of the shop as shown in figure 16 (4104).
At this point, the chain bridle
is still rigged as a lift sling. The
following video clip (4108) shows the very first tests of the wheel
assembly, under the awning at my
shop. My son did the filming. You can see why the snout has two slider
plates: wheels-down it slides on the
forward one, wheels-up it slides on the
aft one. These need to slide flat, so the snout doesn’t dig into the dirt.
I had to
modify my antique tractor into a modern two-way hydraulic system. My hose connections are low near the left
main wheel. My hoses are about 16 feet
long, although for this setup, I didn’t need that much. For production, I will use the same 20-foot length that Dave
used. You just coil up the excess on the
tool deck and lash it there with a light,
breakaway cord. Update 3-21-16: you don't even need to lash it there. They won't move far out of position. If the coils move a bit too far, you can always re-coil them next time you stop for something else. What you watch for is fouling on the hydraulic wheel assembly, or against your tractor tires in a turn. You meed to do that anyway.
My long
feed hoses are half-inch, with half-inch
pipe-size fittings, and quick-disconnect
couplings that trap the hydraulic oil on both sides of the joint when
disconnected. The ports on the cylinder
are “typical” at 3/8 pipe size. Because
of the short run, I used 3/8 hoses from
the cylinder to the manifold, and transitioned
to half-inch size at the manifold for a low-friction long run to the
tractor. The long feed hoses need to be
of very tough construction, because they
will be seriously abused by dragging through the rough ground.
Figure
16 (photo 4104) – Tool As Initially Tested
Video
Clip 4108 – First Hydraulic Actuation Tests at Shop:
xxx unable to upload yet
Out in
the pasture, the first field tests were
in an area where I had not followed-up properly, so the few widely-separated cactus plants
represented about 6 years’ regrowth. This
pasture was full of dead grass,
weeds, and a ground-hugging
invasive vine. These items combined to
cause debris to “bale-up” under the tool every so often. As shown in the following video clip
(4111), this stuff eventually raises the
tool up a little. By the end of the
clip, we “step off” the bale, a process far easier than slacking the chain
and prying the tool up to manually remove the debris.
It is
also easy to see why I recommend doing more than one pass, since the cactus pads are too often not torn free
from their roots if you only drag across them once. The other thing obvious from the video is
that flexible stuff (live grass, live
weeds, etc) just bends over as the tool
passes; it is the brittle stuff
(cactus, dead stuff) that breaks
off. That’s how and why the tool
works.
Video
Clip 4111 – Initial Field Tests Out in the Pasture:
xxx haven't been able to load yet
After
these tests, I added a concept for a
lighter-duty tow bar hitch to the snout.
This would not be suitable for actual dragging operations, or even transport across rough ground. This one is just for light-duty movement
across relatively level, smooth
spaces. As it turned out, while useful for this purpose, I don’t think a rig like this would be
suitable for the market. It allowed me
to transport the tool slowly (solid wheels!) in my front yard without leaving
even any snout drag marks in the grass. Not
everybody will need or want this, so
it’ll be an option, when I do get it all
worked out the way it needs to be.
While
rigging the tow bar, I also addressed
the problem of how to protect the hydraulic hose assemblies from damage should
the tow bridle chain break. There were
two possibilities to pursue: (1)
breakaway fittings, and (2) a safety
chain like that used with trailers on the highway. The breakaway fittings are available although
more expensive, and require a secure, strong line rigged to pull the clamps you
attach to the sleeves on the fittings.
After
thinking about it, since you have to add
the line anyway for breakaway fittings,
it was just about as easy to “add that line” as a simple safety
chain. So that’s what I did. I attached it to the snout, so that if the bridle broke, you would be towing the tool by its
snout. The tool does not tow very stably
that way, it tends to wander around
badly, which should attract the tractor
driver’s attention. That way, he can stop and repair the tow bridle chain, but not have any hose damage to repair, or any loss of hydraulic oil.
Figure
17 (4122) shows the tool rigged for transport with the light duty tow bar. This takes the form of a trailer hitch on a
two-inch bar, pinned at the length
needed, and pivoted at the rear for
vertical swing, to assist hitch-up. It is strained from lateral motion by the
forward “tower” trapping structure. You
back up under the hitch, and then
restrain the tow bar vertically with a chain looped around it. When you put the wheels down, it lifts the entire tool, including the snout, like a wheelbarrow. The clearance is low, but adequate for slow transport on relatively
smooth ground. Update 4-15-14: this is not the practical, producible towbar design that I finally ended up with.
Figure
17 (photo 4122) Tool Hitched for Transport
To
unhitch, first raise the wheels, as in figure 18 (4123). Undo the safety chain, and slack the tow bar restraint chain, as in figure 19 (4124). Then release and stow the tow bar, as in figure 20 (4125). Hook up the tow bridle as in figure 21
(4126), and take out its slack, as in figure 22 (4127). Hitch up the safety chain as in figure 23
(4128). I like to duct tape chain hooks
to prevent them from rattling loose, as
in figure 24 (4129). Wheels-down / tool
raised is the same as before, see figure
25 (4130). Wheels-up tool lowered is
also the same, as in figure 26
(4132). Hitching back up for transport
is the reverse.
Figure 18 (photo 4123) – Unhitch: First Raise the Wheels
Figure
19 (photo 4124) – Unhitch: Undo Safety
and Slack Restraint
Figure
20 (photo 4125) – Unhitch: Release and
Stow Tow Bar
Figure
21 (photo 4126) – Unhitch: Hook Up the
Tow Bridle
Figure
22 (photo 4127) – Unhitch: Take Out
Bridle Slack
Figure
23 (photo 4128) – Unhitch: Re-Hook
Safety Chain
Figure
24 (photo 4129) – Unhitch: Securing
Chain Hook with Duct Tape
Figure
25 (photo 4130) – Unhitch: Ready to
Step-Over, Wheels-Down
Figure
26 (photo 4132) – Unhitch: Ready to Drag,
Wheels-Up
Conclusions So Far:
Transport
wheels greatly ease the labor to clear debris or objects trapped beneath the
tool. This saves considerable time and
effort in the field, for those
situations where the risks of trapped debris or objects are high. This would include debris like barbed
wire, ground hugging vines, dead weeds and grasses.
The
wheel assembly as tested has too narrow a stance, as there is a lot of wobbling instability as
it rolls over debris bales or rough ground.
The axle between the wheels is vulnerable to impact against rocks or
other obstructions. A wider stance with
each wheel trapped between two struts is indicated.
The
light duty tow bar hitch assembly is too limited in strength, and too limited in snout ground
clearance, to be a marketable
product. A fixed receiver and a
hand-cranked jack on the tow bar are indicated,
more like what Dave used on his tools.
This is true in spite of the short life problems Dave had with those
jacks in the field. Update 4-15-14: I finally solved this problem with a fixed towbar, and a jackpoint on the snout tube for a small hydraulic bottle jack. You just raise up the snout, and back your trailer ball under the hitch on the towbar. The bottle jack solves the crank-jack wearout problem for just about the same price.
The
safety chain method of protecting hydraulic hoses from damage if the tow bridle
breaks seems to be very practical. This
part is ready to market.
Near-Term Plans:
Rework
the wheel strut assembly to a wide stance with two struts at each wheel. There is no need to procure real shredder
wheels for this.
Redesign, rework,
and retest the tow bar hitch assembly in a suitable alternate form, based around a fixed receiver and a
jack.
Add
installations of equipment fences and tow points.
Related Articles Posted on
“Exrocketman”:
(date highlighted on this one)
Date.....…
title/
content
2-9-17....Time Lapse Proof It Works
............watch cactus being crushed and composted
7-30-15......New Cactus Tool Website
...................turnkey site for info, photos, videos, purchases
1-8-15……Kactus Kicker Development
………………production
prototype & 1st production article
1-8-14……Kactus Kicker: Recent Progress
…………..….testing
a revised wheeled design (experimental)
10-12-13..Construction of the Tool
………………building
a “Kactus Kicker” (plain tool)
5-19-13…….Loading Steel Safely
……………….transport
and storage of materials
12-19-12…Using the Cactus Tool or Tools
……………...how
the tool is employed (applies to any model)
11-1-12….About the Kactus Kicker
..…………….painting
and rigging finished tools (plain tool)
12-28-11..Latest Production Version
………………new bigger snout and barge front (plain tool)
Update 1-18-2014:
The next effort was to widen the stance or track of the
wheels to improve stability. I picked a
nominal 5 foot track to match the wheel track of most smaller tractors. This makes possible loading a tool onto the
trailer without having to move the ramps to load the tractor. The only requirement is a center ramp.
As a caution: do not simply
drive the tractor onto the trailer with the tool hitched up behind. Your trailer tongue load will be far too
high. You need the lighter item forward
(the tool), and the heavier item (the
tractor) aft over the trailer axles.
Winch the tool up, wheels-down, dragging on its snout. Then drive the tractor up afterward.
I removed (1) the wheels,
then (2) the wheel strut assembly,
and then (3) the hydraulic hoses, cylinder, and manifold as a unit. I used an angle grinder and an oxyacetylene
torch to cut away the deck struts and hydraulic manifold mounting. Then I cleaned up the tool deck smooth where
they were mounted.
I then cut my wheel strut assembly on both sides of the
center near the actuation arm, leaving
plenty of room for a second strut inboard of each existing wheel strut. I cut extension pieces and splice rings to
splice-out my wheel strut assembly to the wider stance, as shown in Figure 1.
Figure 1 – (photo 4340) Cut-and-Splice Wheel Strut to Wider Stance with
Jig
I used my fabrication jig so as to position the actuation arm
and hinge line correctly to match the cylinder stroke and retract-arc geometry
I had before, and tacked it together. My cut-and-spliced prototype is ugly; production units will use one long piece of
square tube all the way across. Once
tacked, I hoisted the strut assembly
onto sawhorses for complete splice welding as in Figure 2.
Figure 2 – (photo 4344) On Sawhorses for Splice Welding
I then welded-on the inboard wheel struts as shown in Figure
3. These are spaced 6.25 inches to
provide room for my prototype’s light-duty 15-inch diameter wheelbarrow
wheels, with a washer or two between the
hub faces and the struts. The production
units use a real shredder “tailwheel”,
which is solid, 15-inch
diameter, 1 inch axle bar size, and a hub face-to-face dimension of 5.25
inches. Production units will space the
struts 5.75 inches
(update 4-15-14: 6 inches worked much better, and gave me a very practical way to secure wheel and axle to the legs with one single spring clip) apart to accommodate these wheels with washers.
Figure 3 – (photo 4346) Adding Inboard Struts
I matched locations with the on-deck struts and welded them
in place at the wider stance. This is
shown in Figure 4. Figure 5 shows the
wheel strut assembly attached to the tool complete with wheels. My wheelbarrow wheels use a 5/8-inch diameter
axle bar, production units will use a
1-inch axle bar, but the basic assembly
is the same, you just drill bigger holes
in the strut tube.
Figure 4 – (photo 4348) Wheel Strut Assembly Welded to Tool Deck
Figure 5 – (photo 4350) Wheel Strut Assembly Complete with Wheels
I used a spacer block at the original location of the portside
on-deck strut to re-mount (by welding) the bracket that holds the hydraulic
hose manifold. This is shown in Figure
6. Then I re-mounted (by bolt-up) the entire
hose, manifold, and cylinder assembly as shown in Figure 7.
Figure 6 – (photo 4352) Re-Mounting of Hydraulic Manifold Bracket
Figure 7 – (photo 4355) Re-Mounting the Hydraulics
In the field, I
revised the rigging of the hydraulic hoses to pass over the chain bridle and
the cross chain. You can see this in
Figure 8. You can also see the safety
chain rigged from the snout barge front plate to the tractor drawbar
assembly. If the tow bridle breaks, you are towing the tool by its snout, which is not stable. But,
you have not broken your hydraulic hoses and lost oil. The misbehaving tool provides a warning to
stop and fix the chain tow bridle.
Figure 9 is another view of the same features.
Figure 8 – (photo 4362) Hoses Re-Rigged over Chain Bridle Assembly
Figure 9 – (photo 4363) Another View of Rigged Tool
This thing worked exactly as expected: very stable stepping off of debris bales or rocks
(or other debris) hung-up underneath the tool.
Otherwise it did exactly the same job the narrow stance design did. I will add a video clip as soon as one
becomes available.
Next on the list is reworking the tow bar transport hitch
assembly into something market-ready.
That will be difficult.
Prototyping the other contemplated options should be pretty easy.
Watch this space for further updates.
Update 4-15-14: The towbar hitch was revised to a fixed rig with a jackpoint and bottle jack, on this experimental prototype. It worked very much better, with greatly simplified and reduced-effort hitch-up. I got the towbar just about right, but not the jackpoint. Reworking that item on this experimental prototype has gotten rather impractical, but the revised jackpoint design turned out to be very simple, simple enough to just build it on the next tool.
I still need to test out a trailer ball hitchpoint on this tool, but that design is quite simple. The tool retention fences are also very simple and need a trial on this tool, as well. Plus, I will try out rainwater drain holes, and if they work right, I will make them standard on all production tools, plain or hydraulic.
These outcomes being so favorable, I decided to build a real production pathfinder prototype, to identify the last minor changes needed, and to work out all the best production procedures and handling tooling. And I built it! This was a hydraulic tool with the towbar option installed, complete with "proper" shredder solid wheels, and a fully-qualified 2500 psi hydraulic system. Except for some very minor changes, it is the production design. I will keep that one on hand for the rental business. Watch this space for another article that documents the production prototype rollout.
Update 7-30-15: The new website is fully operational. It has all the information, photos, and videos anyone could ever need. It is a turnkey site for selecting, customizing, and purchasing a production tool. Shipping is available, so sales of plans have been discontinued. Some additional parts and labor have been farmed out to appropriate vendors, to adjust to higher production rates, so prices posted previously are now obsolete. Go to http://www.killyourcactusnow.com
