Improving RoboRaptors bite and fixing neck bind???

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BronzeGoodIronBad
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Improving RoboRaptors bite and fixing neck bind???

Just wondering if anyone's gotten Roboraptor to open his mouth during the bite animation??? My raptor opens his mouth when he rotates his head to the left and thats about the only time he opens it...I'm guessing this is the norm, as most videos i've seen of the raptor are the same way.... but i'd like him to open his mouth during the actual bite, to allow him to pick up small objects off the ground and such.

Looking at Mr Scotts post on his cure for lockjaw it seems he was able to improve the bite on one of his roboraptors by simply bending a mounting clip that is attached to the lower jaw cable to increase the tension on the cable, but my raptor seems to be constructed a bit diferently, there is no mounting clip, the cable is simply wrapped around a screw and then crimped off, so it seems like my only option would be to cut the cable and then recrimp it around the screw.... thus shortening it and applying more tension, but I think doing this would make the cable a little too short.... which might cause the mouth to stay open even in the neck up position..... any ideas????

 Also, I'm wondering if there is a cure for the neck rings binding up... and if anyone else has noticed this.... the neck ring at the base of my raptors neck seems to turn alot and sometimes causes the neck to *bind* which causes a scary "clicking" sound on a full neck rotation... the neck still fully rotates, and it doesnt seem to be a big problem, but "clicking" sounds just always cause an alarm to go off in my head for some reason.... it seems like this could be solved by slightly tightening the fit of the base neck ring to the base neck segment, anyone else experiencing this problem? Any attempts to fix it yet???

hehehe btw I spent a little time yesterday in photoshop creating a "battle" scene that I'm now using as my avatar.... looks alot better at full size then it does in that tiny avatar area, dont ya think???

Roboraptor VS Berserk Fury

SealedSealedSealedSealed

Peter Redmer
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It's cool! Reminds me of the old 2-d fighting games...

"Ready... FIGHT"

or some variation on that theme, usually in poor 16-bit digitized sound :)

BronzeGoodIronBad
BronzeGoodIronBad's picture

hehehe, I loved those..... standing there minding my own business and all the sudden this big blond guy in a karate suit comes along and starts launching fireballs at my face while shouting "I BROKE IT!", or the guy with plasticman arms that could reach over and punch you all the way from the other side of the screen!Laughing

Peter Redmer
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Ah, the good old days of Street Fighter 2...

MrScott
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Regarding the mouth motion and when it happens, when I was fixing my Raptor's lockjaw, I confirmed that there is a mechanical interlock between the twist of the head to the left and the mouth cable opening the jaws.

The lockjaw fix thread that you referenced shows some pictures of the cam connected to the head twist motor. That cam pulls the mouth cable taught at only one position in the head motion.

To have the mouth open at different times would require a different mechanism to pull that cable taught. Not impossible, but not built into the current beast.
It's a not a control or electrical issue. It is a mechanical interlock issue.

BronzeGoodIronBad
BronzeGoodIronBad's picture

Hi MrScott, I think i see what you mean, I was sorta leary of powering him up with the left body panel removed to find out for myself, out of fear that the neck would jump out of the housing and cause me to lose or damage some parts.

Now I'm kinda tempted to install a servo in there to control that cam for mouth opening on demand.

MrScott
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A separately controllable mouth motion would be an operationally simple mechanical addition. All you need to do is mount the actuator, and attach the mouth cable to it. No changes to the mouth or neck would be needed. Just relocate the existing cable to the new actuator.

You could use a servo, a DC motor with a cam, or a solenoid to tug on the cable.

The trickier bit would be to get that actuator activated at the right point in the preprogrammed behaviors. Most of the logic is in a single chip, so you don't have access to signals for "roar" or "bite". The chip logic controls the various motors to accomplish the tasks.

BronzeGoodIronBad
BronzeGoodIronBad's picture

Well, i was thinking of hooking the servo up to the cam instead of the cable, this way, the neck mechanism could still open the mouth, and you could additionally open the mouth using the servo.... since i'm not that good at figuring out logic circuitry I would probably have to hook the servo up to a seperate reciever, and hack up an old TX to create an extension for the remote for controlling the mouth, i would probably use the trigger from a pistol grip transmitter for opening and closing the mouth.... this way I'd have full analog control, i could open the mouth a little... or alot.

MrScott
MrScott's picture

The cam is part of the existing neck turning motor assembly.
It pushes on a lever that the mouth cable is attached to.

You can't really use the existing cam with a new actuator, as it's integrated in the neck turn gearbox. What you can do is attach the new actuator to the existing lever. That way either the normal head turn actuator, or your new RC actuator will cause the mouth to open.

BronzeGoodIronBad
BronzeGoodIronBad's picture

Just took another look inside my raptor, doesn't look like it's gonna be easy to fit a servo and a reciever inside.... the best mounting point seems to be directly behind the leg box, the only problem is that when roboraptor shifts his body forwards or backwards, the space behind the leg box is affected...... I'm almost sure I could get away with using a micro servo and a micro reciever, but a micro servo wont have enough torque unless I replace the jaw spring with a much lighter spring(which would make it harder for roboraptor to hold onto his prey), and unless I can find a place on the main board where I can pull 4.8 to 6 volts, I'd have to wire the reciever directly between the battery box and the power switch... which would feed the reciever with anywhere from 7.2 to 9 volts(depending on if I'm using NiCds or alkalines).... either way, micro recievers don't tend to like that much voltage, so I would be forced to use a larger reciever with a built in BEC to regulate the voltage flow......... So basically it all boils down to the best option being a standard sized servo and a full sized reciever, and it just doesn't seem that there's enough room.

MrScott
MrScott's picture

Make him a hunchback?
Perhaps some Godzilla-esque dorsal plates?

As for regulating the voltage, that's a wee small amount of silicon or discrete components to step it down.

http://www.radioshack.com/sm-5v-fixed-voltage-regulator-7805--pi-2062599...

BronzeGoodIronBad
BronzeGoodIronBad's picture

Well I'm trying to avoid altering the outer appearence at all, I don't even want to make any holes for the reciever antenna to protrude if it's not necessary.... as to that regulator, if i wired my reciever between the power switch and the motherboard with the regulator on the reciever.... wouldn't it also step down the voltage to the mother board to 5 volts????

MrScott
MrScott's picture

You don't break the wire feeding the main board, you just tap into it, and route the output of the regulator to your receiver.

+9__________________________________Board
|
|____________Regulator__+5____RX