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Discussion Starter #1
Ok folks, I guess I need to get off my hind end and post a thread on one of my builds this year. I'm going to attempt to make as close to park accurate Ezra as possible. I got a jump start but so far nothing has been done that can't be seen by the current photos I'll post in a bit.

This first post is my long winded background on the idea and goals for the project so bear with me.

In short I am going to try and create as close to an exact replica as possible of Ezra. Now, you will see later that the other 2 ghosts are going to be departures from Phineas and Gus. As our yard is a college town and I'm an OS Alum we like to tie into the sports aspect. Thus the Pac-12 stones, Grim Beaver mascot etc. Ezra will be exact, the other 2 will be departures to bridge the HM with the other theme.

Phineas is kind of big and hulking so he is going to be a football player. Gus is short-thus he is going to be a baseball catcher in a squat position and instead of the ball/chain he will have a catchers mitt with the ball in his hand. This will tie in the HM and sports team concepts. On paper it sounds muddled but I think it will work and be a bit different.

Now, there are some excellent renditions of the HH prop that folks have already done using wiper and dear motors. www.phantasmechanics.com/harryhitch/Phantasmechanics "Harry the Hitcher" has been a great inspiration on this project and was going to be my model. Let me be clear this is a great prop, I'm not trying to relieve myself on it or other similar builds. However, after a trip to DW recently I decided I want to try and improve the design.

Most hitchhiking or swaying ghosts use a parallel link system run by a rotating motor. Almost all builds use this solution and honestly it is a great one. It's strong, reliable and inexpensive. With proper lighting and staging the frame and links can be made to go away visually. However, the bar and external frame still bugs me and since this is an outdoor prop I can't control the light 100% of the time. Secondly, the movement is not quite right. Now this is an EXTREME nitpick on my part as 99.9% of people will never be able to tell. However, "I" know its there and half the fun of a home haunt is building a better mousetrap.

Time to reverse engineer the prop and see if I can figure out how they made this guy 40 years ago.

Research:

Step one was finding some video of the prop and watch it for hours. The following is a 15 sec.video that captures the current animation as of 2014. www.youtube.com/watch?v=yW_1Th2SV5Q(I find this makes a really cool screen saver.)

I noticed a few things.

1. There are only 3 basic movements to the prop. Ezra has a body lean/tilt, rotating head and moving arm. DL saved a few bucks as Phineas does not move his head, and Gus does not move his arm! Only Ezra has all 3. I never picked this up until I studied the video.


2. The arm does not go back and forth but has a jerky back, back, forward, forward movement so its NOT a continuous rotational motor. The humerus is static and at an ~ 45 degree angle. The lower arm moves in a 180 degree movement. SERVO!!

3. The heads are also a single axis back/forth motion that also screams Servo. Ezra is standard X axis back/forth. Gus is a Z angle. Phineas' head does not move.

So. That leaves the lean. How in the heck did they animate the lean with a very skinny body and no external framework? Especially, how did they do this 40 years ago???

That's where 10K of the budget from this prop kicks in. I took a vaca...uh-hem, "Research" trip to Florida and noticed something. THE GHOSTS ARE ON ELEVATED BOXES!!

4 more trips through back to back and I think I know how they did this.

-It appears the body is a rigid frame from the ghost's left foot through the body. It's on a pivot at the base of the left foot and can be animated below the ghost. The ghost's right leg is just hinged and will move by gravity.

So fast forward to a couple of weeks ago and I have welded up my frame.

CONT...
 

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Discussion Starter #3
OK, so let me point out a few things about these pics. The "floor" of the prop will be where the bolt/pivot is, I'm going to add another layer of ply on 4 corner posts once the mechanics are dialed in so his feet are standing on something. The ghosts right leg is hinged on the hip and knee and will be hinged to the floor, it will just bend as the entire body sways. The motor to move the entire contraption will be at the bottom and will only need about 6" of travel. I am going to try and use a wiper motor with springs to assist the weight. However, if this fails the fall back position will be a Pnu cylinder.

The ghost's right arm will have a servo mounted on the tab I welded in place and will have the foam arm attached to it. Oh, here is a pic of that work in progress... Its a 2" thick piece of foam I am carving. It's got a ways to go but should work. I'm going to inlay a 1/8" piece of AL to the back for strength and mount point for the servo. Should work just fine.



Oh, and of course the head was made by another member of the forum.
 

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I'm so excited about this build! I've seen only one youtube video with animated HHG. You are building my dream Halloween right here!
 

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Discussion Starter #8
Progress:

Took a couple of hours this weekend and got some more mechanical features fabricated.

1. Servo and arm mount were fabricated and welded into place for the moving arm. The servo is a Hitec metal gear high torque unit. I cut the servo mount into a 1/8" piece of flat stock and tacked it to the end of the upper arm. This required the use of my drill press, dremmel with about 3 cut off wheels and a lot of file work. To attach the foam arm to the servo I used a piece of aluminum angle and riveted that onto the sort servo arm that came with the servo. The aluminum piece is inset into the foam arm and will be glued in later during the "make pretty" stage.



2. Head swivel/mount. The problem is the local big box store does not sell smaller lazy susan style swivels and I was in project mode and had no desire to wait for a mail order piece. So, I channeled McGyver and modified a 1.99 swivel caster instead. Using a cut off tool I removed one side of the wheel support arm and ground off the head of the axle pin on the other side. I then chucked the remaining side into my vice to flatten it and bent to a 90 degree angle. This gives me a swivel with an attached motor connector that reminds me of a 3 axis skull. I then welded a 1/2" black pipe coupling to the top of the swivel and tacked the assembly to the ghost's frame. A longer nipple is then was used to give the head support. The crusty foam and hair in the image is from the ghost head after a test fit.

(FYI: I am not a welder! I'm using a 110 wire feed Lincoln with flux core and no shielding gas. My welds are not pretty just functional)





Here is a shot of the head and arm. The pool noodle was just something I was playing with and won't be part of the finished prop. Also, the arm and hand are going to be refined, I'm in the mechanical rough in phase.



Next up: swaying motor. I am going to try and get away with a standard wiper motor. However, per Fright Props they only have ~4.4 ft pounds of force. The stronger high torque motor they sell has 25 ft lbs which should get the job done. However, since that's another $75 bucks with the power supply and shipping I'll try and cheat with springs to get the lower power motor to work.

I am going to try and avoid a pnu cylinder as this thing is going to run all month long and 30 days of a compressor going off all the time will be annoying.
 

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Discussion Starter #10
Adding another $95 to the build. Ordered the high torque motor from Fright Props as the basic wiper I can see having issues when fully dressed with his body and clothing. Motor, power supply, shaft and shipping. I also picked up the head servo and will mount that up tonight. Looks like the actual full operational test will be bumped back a couple of weeks.

http://www.frightprops.com/electric-motors/motors/high-torque-prop-motor-6-rpm.html
 

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Lookin' good! Just a suggestion on that servo, you may want to use a piece of mono fishing line fastened between the hand and the shoulder to take the weight off the servo arm. I know it's just foam and a piece of aluminum but once he's clothed (and possibly rained on) it could be too much for the servo arm. ;)
 

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Discussion Starter #12
I have actually thought about the weight issue on the servo and it is a concern.

One idea was putting a swivel joint on the elbow similar to the head to reduce the stress on the servo. However, the guy at the local RC plane store I purchased my servo from thought I could attach directly when I showed him my plans. The one I have is the HiTec645 MG Ultra Torque. At 6.0V it produces .69 foot pounds of torque or about 133 oz inches. This unit is used to move large parts of the big model aircraft which was explained requires a lot of stress and force. I know that 2/3 of a foot pound does not sound like much but a 12v wiper motor has about 4.4 ft pounds.

The arm weighs 1.52 ounces as it sits per my tournament fishing scale and I have a bit of foam left to carve away. I figure about 1/2 oz for paint for 2 ounces total on game day. The clothing is going to be clear plastic so that also should only add ~1 oz to that system.

My real concern is not the stress but the exposure to weather. I was going to buy the marine grade servo but was advised to use silicone in a couple of spots and given the rain jacket he will be wearing it should be OK.
 

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I have no doubt the servo torque is not a problem, it's the stress on that plastic servo arm due to the angle of the Hitcher's arm. An aluminum servo arm might be the way to go.
 

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If they don't ServoCity.com will have an aluminum servo horn that will suit your needs perfectly. BTW absolutely love the build, can't wait to see it moving.
 

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Awesome work! If you're looking to do park-accurate props, have you checked out the HM blueprints page at Haunted Portraits? He has a number of blueprints for the animatronics; I don't believe the standing Ezra's in there, but he does have the one of Ezra from the mirror effect, so you may find some valuable info. Looking forward to seeing how it turns out!
 

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I so need to learn how to weld. A steel frame armature would be awesome for upcoming projects. Looking forward to more details of your build.
 

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Discussion Starter #18
I did NOT have that website!! I have seen lots of the blueprints/plans and patent drawings over the years but not all in one place.

UPS just dropped off the package from Fright Props. High torque motor is VERY powerful. It's a bit loud, but for an outdoor prop that will be over 20' from the fence line this won't be an issue. However, if this was indoors you would need a soundtrack to mask it. I have been playing with it a bit this evening and I may not have to do any counter balance springs which will make the build much easier.

Looks like I have to go to the hardware store as the bolts are an ultra fine and/or possibly metric thread that I don't have a match for. Typical! I have tons of various nuts/bolts but never have the exact one I need.

Hopefully I will get the engineering done this weekend.
 

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Discussion Starter #19
Yep, bolts were metric T-5. And, the mount holes are about 1/8" too wide to use a standard mount plate I like to use so its going to require a custom fabricated piece. Arc welding in 90 degree heat = fun.
 

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Discussion Starter #20
Progress:

Last night I welded up a mount for the motor and fabricated the linkage. I may reduce the throw of the crank another 1/2" but we at least have proof of concept. The gear motor as expected is POWERFUL. There is no need for any counterweight/spring assist on this baby.

I also mounted the servo bracket for the head. I made the bracket out of aluminum scrap I had lying around and pop-riveted it to the neck. I'm going to get ball and socket rods from the hobby shop for the linkage.

I'm debating where to install the control board. I want to but it in the base but I'm going to have to run approx 6-8' of servo extension cable to get it down there. I'm not sure how much current drain this will cause and if it will present a technical issue. As the physical force is pretty light on both motors I'm hoping this will work. Otherwise, I'm going to have to mount the box about mid back.

I'll post pics during lunch.
 
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