Thread: My 3 axis skull...in progress

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The bucky kit will have the pully system. Pretty easy to fabricate, just a &#^@*( to get it all aligned... but again, that is why you will assemble it!!! (No we will include step by step instructions on how to assembly it together. In fact, that is what I doing as we speak. Getting the manual in rough draft and then sending it over to an illustrator house to make it look pretty and to make sure the grammer is correct (engineer's can't smell... ah, spell.)

Joel

Will the 425 servos be a problem in lindberg skulls Joel?

On a side note, you totally rock and it's not because it's April fools day neither.

Yeappers - they will work fine, 425, with the Lindberg. Almost all the folks building the Lindberg are using them - with great results.

Myself, I just like the Bucky and plan to stay with it. We built a few using the 425 and they had some problems. When we want to the 625, it was a major improvement.

Good Luck,
Joel

I will need to purchase 6 of your kits. Just wanted to let you know I am calling "dibs" on 6 of em. For the lindbergs of course.


I've been meaning to ask, how did the haunt go last year. I remember you were doing a dead man's party theme. What do you have planned for this year?

Thank you.

Originally Posted by gym_ghost

Yeappers - they will work fine, 425, with the Lindberg. Almost all the folks building the Lindberg are using them - with great results.

Myself, I just like the Bucky and plan to stay with it. We built a few using the 425 and they had some problems. When we want to the 625, it was a major improvement.

Good Luck,
Joel

What sorts of problem did you have using the 425BB's and the Bucky skulls???

Another member said using the combination would be fine!

This makes me worry starting the project now with the buckies and or if i should get the lindbergs or what!??!

ah the confusion

Just a note, I'm uploading my Lindberg builds to YouTube so I should have the links to it here in a little while...

I finished my first skull tonight, and actually learned VSA! YIPPPEEEEE!!!! uh.. um.. I mean...

I've single-handedly tamed that timerous beastie wot known as the elusive tri-axis scallywagged skull! Did learn of the secrets of yon VSA giant, and fought the dragons, swash-swash-buckle-buckle.. a sequence in said program did I make, and lay waste to the disarray on my bench...

This is the day that you shall remember VSA almost bested Capt Jack Sparrow!!

I used 425's in my 3 axis bucky, but I didn't use the plate design...just for that reason, I knew it would be too heavy for the 425s. My mech is gangly and difficult to fit but it uses the bucky's center of gravity to keep things balanced. The weight of it is supported nearer to the to the front. Seems to me that that the key to balance is keeping the weight off of the servos as much as possible in relation to the center of gravity, meaning if you're going to do a plate design using a bucky, mounting the tilt/nod servos closer to the front would work if you modify the gimble to work forward of the neck hole. I'll draw up a pic and post it to get advice from all you engineer types to see if it is feasable. You shouldn't need pullys if this works.

With the 425s we tried several different configurations. The Bucky skull center of axis needs to be at the center of the hole at the base of the skull and it needs to be inline with the axis rod - if not, problems. The weight ratio to front of skull to the back of the skull is 65% to center of skull base hole. Basically, the center of gravity on the skull is about 1.5" from the center of the skull base hole toward the front of the skull. Here lays the problem - how to center the skull with out machining out new holes and it interferring with the jaw?

Now, as I said before, we used 425 on the bucky with the lindberg setup and had one run for about 30 hours before one of the servo's failed. We did not have rapid movements nor did we have any X, Y, or Z plane movement extend beyond 20 degrees in one direction. The bucky is a heavy skull and the servos were working about 135% of torque to move it back to 0 plane.

If someone got it to work without a pulley or counterweight system, KUDOS to the them.

Now with all the being said, we're looking at a whole new approach to using the 425 servos with the Bucky. We will not be using the servo plate, but working off the skeleton rod itself and attaching the skull to U Yoke Joint that attaches to the skeleton rod. We're in the preliminary stages of development and if we can get this to work, it will be a much easier to build and control. The dynamics of movement will be flow like - that is to say, human like. Weight will not be problem for this setup. In fact, with some preliminary model build up using 4 lbs weights, we use a HS-322 with very favorable results. At 6 lbs, we encounter the first limitations of no movement. At 5 lbs, it was okay, but movement slowed down about 15%. But again, were in the R/D phase and wont be building a skull until May.

As I remind myself every now and then, the mouse trap has been around since the building of the pyramids in Egypt. The first Patent was in 1894. Since then, about every five years or so, a new idea comes about.

Joel

Dionicia,
I responded under, General, title "Halloween 2008 - graveyardmadness", regarding last years and this years halloween plans.

Thanks
Joel

Thanks for the clarification on the problems.

Looks like i need some lindenberg skulls to make my life easier