Thread: Side by Side Skull Comparison, Skulltronix & GYS rack and pinion VIDEO

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This year we busted the family budget and picked up a Skulltronix 3 axis skull from Skulltronix.com and a GYS R&P Lindberg skull from Graveyardskulls.com. I was curious how close I could get the GYS skull to the Skulltronix.

The GYS skull came assembled which included the 3 axis servos, the jaw servo and 2 servos that operated the eyes. The eyes came with tri-color LEDs in them. I decided to run the servos and LED's using a Medusa DMX controller board. You could also run this skull with a number of other controllers such as the Parallax USB or the Lynxmotion SSC-32. While the Medusa DMX controller board is small, it still will not really fit inside of the skull, so I made my own wiring harness to connect it to the Medusa DMX board. After connecting everything and performing some initial tests it turned out that the LEDs that came with the skull were common cathode and the Medusa must have common anode LEDs. Since I wanted to be able to have the ability for the eyes change and blend colors like the Skulltronix did, I replaced the LEDs with common anode tri-color. Building the wire harness took me about 3 hours and changing the LEDs took me about 90 minutes. Graveyardskulls.com does sell a quick connect kit for a very reasonable price if you're not into doing a lot of soldering and connector construction.

We have several different GYS diy skulls including Lindberg and Buckys we have used for several years, including Buckaneerbabe's very first 3 axis build she did following along with HalloweenBob. The construction of the GYS rack and pinion skull is pretty impressive. The parts all fit well and seem well designed. Like all of our GYS skulls, the angle of the primary rod positions the head with the chin tilted down but this one seem to do so more than the others we have. We built a simple bracket for the rod that enabled us to position the head more in the center of its nod range. The skull also arrived with the eyes positioned pretty far out of the skull and positioning them a little further back was a matter of loosening a couple of hex bolts and sliding them back.

The Skulltronix skull itself is a custom design. It is somewhat larger and much heavier than the Lindberg skull. The top of the skull has screws holding the top on and since it appears to be glued on as well, I have not taken a peek inside to see how it is constructed. The Skulltronix skull comes with a Board of Chuckee DMX controller board installed inside of the skull. The Board of Chuckee DMX board must be setup with special software that controlls servo position limits and sets the DMX address for the board. I had some trouble getting it to work but a quick phone call to Jerry Jewel helped me through that process. The Board of Chuckee works well with an Enttec Open or Enttec Pro. However, the setup/configuration program will not work with an Enttec Pro. As we had an Enttec Pro, we had to spring for an Enttec Open to have access to the skull with the configuration program. The Board of Chuckee also uses 2 DMX channels for each servo. In total, it takes up 17 DMX channels. The first channel the Board of Chuckee uses is for a relay that gives you the ability to cut power to the servos after a certain period of time of non-use. This is touted as a servo saver, because it can be used to cut power to the servos during periods of non-use.

The Skulltronix comes with a power supply and DMX cables already connected to the skull. It also comes with a neck that can easily be set upon the rod in the spine of a typical skeleton. The angle of the neck and head is very good and with the range that exists in the nod motion, there's plenty of room to accomodate even some odd angles.

The Skulltronix skull I think at this moment sells for $999. The GYS rack and pinion Lindberg goes for $399. That does not include a power supply, wiring harness or controller board. These items could easily put the total cost over $500. For us, we spent $90 on the Medusa DMX, $0 on the wiring harness since we alread had that stuff laying around, $30 for the two power supplies (servo power and logic power are separate) and the LEDs were $3.

The video shows the two heads side by side and as much as I could, had them moving in sync. You will easily see that the range of the rotate/pan motion and the range of the nod motion on the Skulltronix is much greater than the GYS. The tilt motion on both is very similar except that their good sides and limited sides are opposite of each other. The eye movement in the Skulltronix also has much greater range than the GYS.

I like the GYS skull and for the money, it's a great alternative to the much more expensive Skulltronix. It just has a much more limited range of motion. In fact, the GYS rack and pinion Lindberg has more limited range than our old Lindbergs with GYS diy kits in them.

Great comparison video, it's nice to see a side by side. It maybe interesting to add a DIY skull to the mix as well. I've dealt with both Skulltronix and Graveyard Skulls. I believe people will be happy with which ever they get.

Would be nice to get one more side-by-side comparison 3 axis skull added, the new "TSL Twisty" design of Triaxiale skull Labs, interested in these.
Thank you, nice post on Skulltronix & GYS's rack'n pinion skulls.

Great video and love the music even more. Joe Satriani rocks!

I agree that people will be pleased with whatever skull they get. The expressions that you are able to create with each skull are subject to personal preferences for sure. I think the Skulltronix skull has a more mysterious or sinister basic expression and the GYS Lindberg has a more friendly almost cheerful expression. The eyes in the Skulltronix really complement and maybe enhance the basic facial expression while the eyes in the GYS do a good job of making it seem more alive.

After finishing the video I thought it might be interesting to add the 3 axis Lindberg Buckaneerbabe made with a GYS kit. He is our hearse driver we call Grimsley. Since I already put everything away, I'll just have to say that Grimsley's range of motion is closer to the Skulltronix skull than it is to the GYS rack and pinion skull. I think the original idea for the R&P design was to provide more independent movement on each axis over the original design. While I can say they accomplished the independent movement, you can see in the rotation comparison in the video, that the GYS skull does not move entirely horizontally. It moves in something of a diagonal path from upper right to lower left on the screen. That's not that big of a deal for the same reason it's not such a big deal with the original design. When programming the original design, all of the movement leverages off of essentially the same point. When any of the three servos are moving, it affects the other two. This is particularly true with the rotate and tilt motion. This was a big problem when programming movement on each axis individually in VSA. Now though, VSA offers a feature that allows you to use a joystick to program on all 3 axes at the same time. This feature in VSA is pretty new. I've played with it some and can say that I much prefer MonkeyBasic's "TrackSkull" program. Anyway, when using a joystick to program the motion you really don't notice so much the way the servos act against each other. They seem to move in concert when using the joystick.

The diy kit from GYS is great for anyone wishing to save some money and willing to tackle the assembly process. The R&P skull is a great value for those willing to spend a bit more cash and skip the assembly process. The Skulltronix is a substantial investment but one that pays off in ways the GYS skulls can't at this time. I'm guessing that GYS will continue to develop their R&P skull. I wouldn't be surprised at all if they introduce a R&P skull down the road that has significantly improved range of motion and I bet they are working on the eye movement as well.

Heh, yeah about Joe Satriani, I got a note from youtube about using copyrighted material. Apparently they won't be able to view the video in Germany?

I really like the brow of the skulltronix. I definitely makes it a better looking skull. The DIY skull looks cheesy IMO. I'd like to see some skins or maybe even some plaster to make the DIY skull a bit more respectable.

I'd love to build a skull with DMX for next year as well.. I thought all this time that some of you guys bought the servos, leds and such and put them together yourself. I didn't realize they come assembled. Is it just the skull, or does it come with a complete body? How do you stand it up in a yard haunt?

I want to eventually add two or three like this and use some DMX controller motion lights where I can sort of have a talking and/or singing show put on where I put the spot light on one skull and it lights up and starts talking, then another one turns on and starts talking too, and so forth. Is something like this very difficult to program with dmx? I assume there is no software that provides talking jaw movement to DMX commands.. you'd probably have to manually put in each jaw movement, eye movement, etc in a sequence?

I am thinking with VSA and DMXorcist, something like this should be possible?

Bunch of questions... I'll take a swing...

Skulls
You can get these in a few different degrees of completion. Both Skulltronix and GYS sell complete skulls. As I understand, Skulltronix is built from the ground up, whereas GYS adapts off-the-shelf skulls to their mechanisms. GYS also has two different varieties. Their newer version uses a rack-and-pinion mechanism that has very little backlash, so there's very little flopping around after a move. The other version uses push rods on the servos.

Other people prefer to make their own, and save some dough. In this case, they'll usually do some variant of the push rod design. Some make all the parts themselves, whereas others will buy some of the components from GYS.

Body
Many here use "buckys", which are reject medical reference skeletons. Skulltronix also sells skeletons with animated torsos.

Animation
There's 4 basic ways you can get animation cues into the software. (that I can think of, anyway)

Joystick: You make live moves with a joystick, while the software records your movements.

Head Tracking (for skull only): You put on a hat with reflectors, while a high speed camera tracks your head movements.

Keyframe: Very slow going, but very accurate - allows for a lot of fine tuning. You can always come back to this, after importing moves from one of the other methods.

WaveMotion (for jaw only): VSA can analyze a sound file, and make moves based on the volume - great for running a jaw with minimal work. I also like to do a little pre-processing of the audio (companding) to help make the jaw move the right amount, even when the speech is quiet. The drawback is that you need to have the vocal track alone (no sound effects). So if you're dealing with a premade song, you're outta luck. [On my talking pirate, I used this method exclusively. You can see a drawback of this method at 0:44, with the word "everything", where it missed the 2nd and 3rd syllables. Normally, I'd go in and keyframe to improve, but I ran out of time.]

Hope this helps,
- Hook

Originally Posted by Hooked_on_Scares

Bunch of questions... I'll take a swing...
...

Animation
There's 4 basic ways you can get animation cues into the software. (that I can think of, anyway)

Joystick: You make live moves with a joystick, while the software records your movements.

Head Tracking (for skull only): You put on a hat with reflectors, while a high speed camera tracks your head movements.

...

Hope this helps,
- Hook

Check out TrackSkull for these two items.

holy crap. sorry.. but these are $500-$1000 EACH?

I understand there's a lot of technology there but yikes!

I really had no idea what these cost so the pricetag took me by suprise.