Who doesn’t love robotic spiders? Today’s biomimetic robot comes in the form of Miles, the quadruped spider robot from [_Robox].
Miles uses twelve servos to control its motion, three on each of its legs, and also includes a standard HC-SR04 ultrasonic distance sensor for some obstacle avoidance capabilities. Twelve servos can use quite a bit of power, so [_Robox_] had to power Miles with six LM7805 ICs to get sufficient current. [_Robox_] laser cut acrylic sheets for Miles’s body but mentions that 3D printing would work as well.
Miles uses inverse kinematics to get around, which we’ve seen in a previous project and is a pretty popular technique for controlling robotic motion. The Instructable is a little light on the details, but the source code is something to take a look at. In addition to simply moving around [_Robox_] developed code to make Miles dance, wave, and take a bow. That’s sure to be a hit at your next virtual show-and-tell.
By now you’re saying “wait, spiders have eight legs”, and of course you’re right. But that’s an awful lot of servos. Anyway, if you’d rather 3D print your four-legged spider, we have a suggestion.
Wieviel Erwerbsminderungsrente bekommt eine Spinne, die die Hälfte ihrer Beine verlor?
What?
He said: How much disability pension does a spider get that has lost half of its legs?
There are eight servos, two for each leg, not twelve.
waiting for the two-legged spider red-blue marketing thing to rescue this amputated article.
I would think that putting six LM7805s in parallel could lead to trouble because the regulators will be in contention with each other, possibly leading to oscillation, unbalanced loading, etc. The applications section of the TI datasheet shows a high current implementation using a 2N6132 rated at seven amps. This would seem to be a better approach.
Robox Didnt read LM7805datasheet apparently. No heatsinks either. 1 Amp is not max current on 7805. Five 7805 in parallel but not six. One is clearly set apart for stepping down 12V supply to Logic and peripheral. Guessing Insufficient filter caps. Dualing Banjo quintet.
If the intent was to take advantage of 7805s over thermal and short circuit protection then this is the wrong configuration.
Not a bad Alpha. Needs work. Missed the vid of operational unit. Hidden somewhere or shows up later I guess.
Other points not directed at anyone in particular:
What is a “Pheonix”? Assume it’s a battery of some kind or this is a tether bot.
Sg/mg90 can easily consume more than 1Amp EACH. Some of the cheaper brands can exceed 1.5A. Bad maths and no experimentation. Cheap DMM Amp meter and a little servo stall experimentation needed. 6VDC is optimum for many SG90. Other brands may allow higher voltages like 7.2VDC. Spec sheets on SG90 tend to vary. Torture one and find out limits.
Designer hasnt heard of PCA9685. A daughterboard and 16 channels saves MCU for doing other more interesting things like sensory input and actions in response. Like current monitoring or contact switches on feet. Could put 9685 on motherboard. Plenty of room.
I appreciate over sized blades in anime but in reality not effective and waste power. Swiss cheese them blades and lose some weight. Reduce wear and lateral axial loading. Those aint ball bearing (BB) servos. Spend a little more plastic on linkage.
Thread locker and washers. Looks like bottom screw axles gonna loose some Nut just sitting there. A little brass tube screw axle sleeve might be nice.
I missed seeing sonar in pictures. Must be cloaked SRF-04.