Thread: 3 Axis Bucky Skull Project Tribute

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Hi all,
I am about to start yet another thread on creating a 3 axis talking skull. I am doing this to pay tribute to Halloween bob and his singing quartet. I have always loved Disney World (especially the animatronics) but never could get started on a project. I saw Bob’s work on You Tube and was hooked. Without his help (and evilbobs work as well on YouTube) this would likely have never happened. So I wanted to pay back this forum and although I will be doing about the same things over again , Maybe I can help someone else the way I was helped. Now let’s get started.

All about Bucky,
I purchased 2 Bucky skulls from Boneyard Bargans in Toronto (see web site) for $15 Cdn each
as well as a prototype scull plate. Paul was very helpful and told me his CNC machine would be producing more of these when he had time. Everyone was saying the Bucky quality was degrading and they are right. Let me say this right off the bat…..DO NOT USE A BUCKY SCULL FOR THIS PROJECT , I’ll tell you why.
- They are mis-formed (a it took half an hour with a heat gun to get the plate to fit and the jaw to work straight).
- They are too heavy (Too thick, too mush nasal detail and heavy mould material). Servo’s will take a beating.
- They are terrible to cut (plastic melts behind the cut and takes forever to work through).

These are for medial purposes and display but horrible to animate. Having said that I had two of them and the principals are the same for any skull so I pressed forward.

I used a dermal with a wand attachment and a 1 ½ abrasive disk (used to cut off bolts) . I thought this would make quick work it. Boy was I wrong. 45 mins and a huge mess and smell later I was done. The problem was the material has such a low melting point that it seals up right behind the cut. The trick was to cut a little then goes to another area while that one cooled and start again. In same places the skull was ALMOST AN INCH THICK! I wanted to widen the hole in the base for two reasons.
1- To give the rod end more play (rotate nod and tilt)
2- To reduce weight

I copied the information for the rod ends directly from the Halloween bob forum. I didn’t look too close enough at the size. It was too small. Halloween Bob’s design is for a milled rod but I wanted to use evil bobs threaded rod idea. The problem was that inside diameter was too small and the rod was only 3-16. This was far too flimsy for my 4 lb Bucky. The answer was to buy some ½ inch aluminum rod and tap it so the 2-24 (3-16) rod fit inside.
I used compression fittings (Thanks Evil Bob) but they are for ¼ rod so they are sloppy. I will have to change them later. The aluminum strip I wanted for the bracket was $15.99 but an aluminum ruler was only $6.99. That’s why my bracket has numbers on it. So long story short, USE A BIGGER ROD END IF YOU WANT TO USE THREADED ROD
I won’t know till the end if it all works but onwards and upwards.

I called around to the local hobby stores to see if anyone had the 425 servo. I found a place and talked to an RC airplane guy. He set me up with some parts (see picture).
I also needed a tap for 4-40 screws and other things I already had.

I made and mounted my new bracket. This is the part I know nothing about I sort of eyeballed both bob’s design and made my own. Halloween Bob’s is at the back were mine is at the front like evil bob. I don’t know if this is right or wrong but I know the bucky is front heavy so I put it at the front. Same with the Jaw servo bracket I put my servo on the side. Will it work? I’ll find out soon.

Great project, If you send your complete mailing address, I will send you a free sample of the new design 3 pc skull from MrSkeleton.com. It is half the weight of the old bucl y skull, which means less jerk action when the servos recover from the max movement range.

It also has all the original internal landmarks for plate mounting.

Thanks,

Jeff Nix
Mr Skeleton - Your resource for Bucky's best props and accessories (soon to be retail)
678-776-8861
jeff@mrskeleton.com

Originally Posted by Snap

Hi all,
I am about to start yet another thread on creating a 3 axis talking skull. I am doing this to pay tribute to Halloween bob and his singing quartet. I have always loved Disney World (especially the animatronics) but never could get started on a project. I saw Bob’s work on You Tube and was hooked. Without his help (and evilbobs work as well on YouTube) this would likely have never happened. So I wanted to pay back this forum and although I will be doing about the same things over again , Maybe I can help someone else the way I was helped. Now let’s get started.

YouTube - Classic 3 Piece Skull IMPROVED DESIGN INFO

Very cool project...and Jeff your new skulls look wonderful!

Wow, thank you for the offer Jeff. I plan to build a few of these and would love to see how your product compares. I sent my address. And thanks Dr Morbius for the comment. As far as the current project it going I am setting up the servo’s and will be posting the results tomorrow.

I started positioning the servo linkages keeping in mind to make them as perpendicular as possible (thanks HB) and really was happy with the tilt and nod. When it came time for the rotate I wanted to keep the rod as horizontal as possible so I put a ¼ pvc spacer in between the plate and the servo.
* valuable machining tip – always drill holes first in the large material then cut it into little tiny pieces with the holes already in place. I didn’t and had a great deal of problems trying to hold the small buts of pvc in my vice to drill it.
I cut and tapped the travel arm for the rotate from my trusty ruler and this time I followed my machining tip and drilled the holes before I cut it into a tiny little piece.
It this point I was feeling pretty good about myself. Here I was almost done the mechanical and no major problems. You see I do a lot of embedded electronics and that never ever works the first time. Any way I should have known it was too good to be true because when I tried the nod servo it slammed right into my turn linkage. It can look down but not up. You can see by the pictures it is directly under the servo DUH! I haven’t had time to work out a solution but my two factors are how deep the skull it to lower the servo even more and I will probably have to cut a new mounting plate and make a longer threaded rod. I hesitate to post the pictures but at least everyone can see HOW NOT TO DO IT.

Picture 1 is from the top Leaving the rods long makes it easier to position them perpendicular.