Part 2
It's time to add pneumatic cylinders to the bellicose prop moving machine.
I have been making my own clevis mount brackets all along. Shop made mounts can be any shape or size - completely
customized per prop, per application. The photo above shows the lift cylinder clevis mount ready for welding.
A short length of 2" pipe is used as a template for the mount.
The cylinder for the lift motion has a 3/8" mounting hole. 3/8" holes were drilled in scrap lengths of 1 inch X 3/16 inch flat bar.
The holes are centered across the 1 inch width, and 3/8" in from the end.
Measure the length of the cylinder's clevis mount protrusion. Note the distance between the mounting hole and the cylinder's
(round) casing. You need to maintain enough clearance in this area for the cylinder to pivot and not bind on your mounting bracket.
Cut the 1" flat stock to proper length. The end with the mounting hole will need to be rounded. For safety reasons, I would suggest
rounding these corners after the bracket is made.
1" angle stock is used again for mounting the flat bracket to the round spindle.
3/8" flat washers are stacked to a thickness just slightly more than the cylinder's clevis mount surface.
A 3/8" bolt is installed and finger tightened, and the whole assembly is clamped together. Take some extra time to clamp each
part a little at a time, checking for straightness and square as you go. Tighten the bolt and check everything one last time before
tacking the joints. If your alignment is still good, weld completely. Sometimes it's difficult to weld the inside
junction(s) of these brackets. Other times the weld bead would interfere with your cylinder's clearance.
In these cases, three passes with your welds will usually be sufficient. Three passes *guarantees* complete penetration
across the joint while adding more material bulk. (More material added properly equals higher strength.)
This "tee" shaped bracket will be welded to the lift arm. This is made of 1 inch square tube cut to proper length
and 1" X 1/4" flat bar drilled and cut to length. This hole will be used to attach the cylinder's rod end clevis to the lift arm.
The second photo above shows the cylinder and brackets positioned on the machine.
The shop made cylinder mounting brackets are installed on the air cylinder and clamped in position on the machine.
The cylinder's fully retracted and fully extended positions are correct. Nothing binds during rod travel. No moving parts will come
in contact with anything during travel. The total assembly is straight and square.
Cover the cylinder and tack the new brackets in place. Remove the clamps and
check for any possible shifting, twisting, etc. Once satisfied, remove the air cylinder and finish the welds.
These photos show the Bellicose machine with lift cylinder retracted, then extended.
This is a 2 inch bore, 4 inch stroke ARO cylinder. This larger bore cylinder will deliver plenty of power for the lift motion.
At 80 p.s.i. line pressure, this will deliver roughly 250 pounds of pushing force at the rod clevis. Figure in a six foot long
lever plus the weight of the lever and still up to twenty pounds of prop weight can be moved efficiently.
This is the swing cylinder clevis mount bracket clamped for welding. Same procedure, different configuration.
The swing cylinder must be elevated to clear the machine's base during travel. 1 inch square tube stock is used
to raise the bracket and provide a sturdy base for the bracket.
With the cylinders and their mounting brackets connected, it's easy to clamp the brackets to linkage
components for test fitting. Clamp each end securely and manually move the part. If needed, reposition
the mounting bracket and test again. Once satisfied with the joint's range of motion and acceptable clearance(s)
it's safe to tack the mounting brackets in place. Remove the clamps and test the motion again.
Finished and mounted swing cylinder assembly, mounting brackets, etc.
Video clip, testing the basic pneumatic and mechanical functions of the
Bellicose machine as built at this point:
Extending the Lift Arm
As previously mentioned, the lift arm for this machine will be fairly long. Any combination of substantial weight
and sudden changes in motion would cause a long, thin arm member to flex. To eliminate this flex without using a heavy walled
single tube (which would add even more weight at the end of the arm) I decided to break the arm into two segments.
The first segment, shown here, will resemble a simple truss section.
Parallel lower bars provide most of the linear strength for this arm assembly. By running them side-by-side,
chances of side flexing are greatly reduced. The dual lower arm bars are angled near midpoint to lay parallel to
the ground as much as possible. This low profile characteristic should aid in reducing the apparent size
of the whole prop when at rest.
Using this angled midsection, it's possible to add a lightweight span and gusset segment made of
1/4" round bar. Under stress, the arm would have the tendency to bend "down" beyond the cylinder rod's mount
point. By adding the span and gusset pieces, the stress is transferred across the whole arm segment.
In order for the lower bars to flex now, the 1/4" span bar would have to pull apart from either end of the arm segment.
One-inch welds secure the 1/4" bar, so chances of that joint pulling apart are minimal.
1 1/4" square tube is added to the end of this arm segment to accept the next segment.
Bolt holes are predrilled, and will match holes in the next segment.
Two angled views of the bellicose machine fully assembled (up to this point in the build) for testing.
An additional 40 inch bar has been added to the lift arm, bringing the total length to nearly seven feet.
The end of the lift arm is angled up to accept the prop torso/character. The degree of this angle must be greater than the
lift arm's fully extended arc angle so the prop body doesn't come in steady contact with the arm.
This might not be a concern depending on your design, but this character will be mounted to a limited swing
pivot point (shown above.) The spring in this joint is only used to balance the prop body. Adjusting the spring at the
rear mounting bracket will determine the prop body's static "center."
A Delusional Keybanger is used to control the programmed sequence of events.
Two mechanical relays are used to power effect lighting from the Keybanger's output signal.
A dual solenoid manifold block powers the air cylinders.
An inline air regulator sets the overall pressure for this machine.
Over the course of my haunt prop building "career," I've embraced a familiarity with the body making dilemmas.
In most animated props, it seems that two major issues present themselves every time ... the body must be
lightweight and it must be durable. To date I've yet to find the perfect material for this purpose, so I suppose the
next best thing would be experimentation. For the bulk of this particular body, I used a flexible foam product that's
typically sold as "pool noodles." This was actually sold in a flat 3/4" X 6" X 5-foot section.
After the glue cured fully, One arm was carved to the rough shape pictured above. This foam material won't take
much more detail than this stage because the cell structure of the foam is much too loose. As a result, the idea (now)
is to get the shapes correct with the foam, and achieve surface details and textures with a fabric and latex skin.
The second photo above shows a good sized Styrofoam block glued in place. After cure time,
this block should be easy enough to shape into a menacing skull.
A fabric and latex skin is applied to the foam body.
Clearly, this skeleton prop is stylized beyond the accepted realistic skeleton.
The proportions are exaggerated to my preference The skull has an expression of sorts.
The vertibrae are sized and located for appearance only. In keeping with this theme, the paint job is
different. This fellow was base coated gray, followed by washes of white and blue.
(My apologies for the over exposed photographs above.) A light blue colored surface here will show
more blue color under haunt lighting conditions.
Major "depressions" and shading areas are airbrushed black prior to dressing. Some, many, or most of these areas (?)
could be difficult to paint once the prop is dressed.
Here's a short video clip of the prop in action at this stage.
Black fabric is cut to rough shape and soaked in a reduced latex bath. The application of latex will add
a slight degree of stiffness to this fabric once set. Narrow strips of another type of black fabric are used to
tie the first layer in place while adding dangling lightweight pieces. Once in place, these strips are distressed
while the latex on the first fabric layer is allowed to dry fully.
Daylight photos of the finished Bellicose machine at rest and at full extension, slightly over eight feet tall.
2006 haunt images.
One minute video clip of the Bellicose machine as displayed in the 2006 yard haunt:
Considering the darkness of the video, monitor adjustments may be necessary ... my apologies ...
For any interested person, these are links to basic drawings of the Bellicose machine sections as built here.