Hurja

Let's Make Robots Robots
1

Designed the frame with inkscape, got a friend to print it out with his self-made cnc out of polycarbonate. Very small, less than 10cm * 10cm, low enough to fit under most furniture.

  • Width: 90mm, Length: 72mm, Height: 62mm
  • 4WD (no proper clutch though) with 4 x micro gear motors
  • LiPo 1400mah
  • L9110 motor driver + breakout board
  • Raspberry pi zero w Raspberry pi camera
  • Suspension (pen springs), a bit too hard for the weight and speed of the robot.
  • Axles for suspension are very thin bolts cut by hand.
  • Polycarbonate frame.

Suspension isn't the best, but it kinda works. Fried one raspberry pi zero w and motor driver, but after replacement, finally now all tests are running well, no explosions at all yet.

Update 1: Cut the springs from pen shorter and re-attached them, still a bit too hard, but I can live with that. It's more or less a working suspension anyway.)

Basic Motor Test https://youtu.be/6X6F4jfGn7M

Obstacle Test https://youtu.be/GMInshyt5rs

Bulldozer and flashlight test (accessories) https://www.youtube.com/watch?v=BRKY-MWfe8w

Real work! Getting water bottles and rubbish from impossible-to-reach -places. https://youtu.be/abEBS6xGwZI

Update 2: Taped the camera on better position, and stuffed the battery inside the case to make robot even smaller. I'm gonna say the robot is now more of less finished. I'll have to leave one wall open as I didn't leave enough space for camera wire and sd card, and as L9110 is slightly bigger than the TB6612FNG I had planned to use. In addition, with current configuration it's a bit too much to integrate a battery charger in the circuit, therefore I need to be able to access the JST power connector to recharge the battery.

Update 3: Added a diagram of suspension design (not to scale!). Ballpoint pen spring is fastened by hot glue, bolt is just taped on place.

Update 3: Accessories - a blade and a flashlight. Blade is handmade, glued together from pieces of polycarbonate, I tried to maximize mechanical contact with the body of the robot. The actual attachement of accessories is just with transparent tape. Flashlight makes it now possible to delve deep under furniture, and in addition, under gymnastics plyo floor. At our circus gym there's a problem that students leave water bottles next to plyo floor, and the bottles end up below the 8cm floor. I designed this drone so small that it can fit under the plyo and be used as a surveillance tool and also water bottle bulldozer.

Update 4: Real life test success! Hurja was actually useful in getting some rubbish out of places that were impossible to reach by other means. Video link above.

 

 

Update 5: Just had to make a trailer :). It does work, though Hurja is still quite light for pulling it.

 

Update 6: Made an attachable wrench tool that can take nuts to hard-to-reach places.

https://youtu.be/_7BrMKCBxYw

Drives around wifi controlled

This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/hurja
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Micro Robots

Love the concept of making hte robot as small as it can be - nicely done to integrate a Pi. If you’re able to design parts - based on your abilities you might love a 3D printer to use to create your next robots. Any idea how you fried the Zero so others won’t do the same?

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Thank you

I’m really happy with the end result, although I had some failures with the original design. I’m sure I could use a 3d printer for some special parts, but so far, I’m more than happy to just abuse my friend’s superb cnc router. Zero might have shorted with a tiny drop of solder at a wrong place, or more likely a motor wire got into wrong zappy places as it was pulled out while I was testing the motor controller.

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3D printer

You should definitely get a 3D printer, it will allow you to evolve your designs. You can get one really cheap nowadays and it is worth it, trust me.

Nice work :slight_smile:

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Transparant 3D printing?

A far as I know clear transparant 3d prints are still not possible,I could be wrong though. (I like the see-through look of robot.)

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suspension

Can you provide some more info on the suspension. From the video it looks quite agile.

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Fairly agile…

I added a diagram of the suspension to the post. It’s somewhat mimicing some basic car technology. The springs are from old ballpoint pens, I cut them to length I wanted, bent them a bit and glued on place. Yeah, the robot is fairly agile after all, 4wd and suspension do help. Softer springs would make it a lot better though, and with a robot this small, the gauge of wires also matters. The best suspension is on those wheels with soft bendy motor wires, and when the axles have just a tad of looseness - not too much, but not too tight either. For agility, stuffing the battery inside the case also made a change, as it lowered the center of mass, so it doesn’t fall to it’s back so easily.

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Suspension

I’m assuming that the gray rectangle is the motor and that there are 4 of these fixtures.

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Diagram

Grey rectangle is actually the side of a polycarbonate plate that acts as one wall of a box for the motor. There’s a hole in the polycarbonate plate for the axle. There are four of these fixtures.