Let's Make Robots!

3D printer issues

Why do homing my z axis it will go up 2mm and then go do 6mm? I had to plug my z end stop in the max part on my ramps 1.4 to get it to work this far. Is there something i need to set in my marlin file?

Here is my Marlin file, sorry I don't remember how to bracket it as a code for easy viewing.

Looking for someone to print a BOB for me for a present.

I was wondering if someone could print me some BOB parts for my 4 year old birthday next month. I've been working on building him a robot by gutting an RC car I had laying around. I don't think I will be able to get it done in time since I've been working on it for over a month. Kinda tough to do much when you have a 5 month old also. My son absolutely love robots. Would love to get a video of him opening a present with a robot in it. I live in the US. If someone be willing to help me out and give me a price or something would be awesome.

Just a quick question regarding battery use on a hack RC car.

Would it be a bad idea to power my robot with one battery. I would be using 5 rechargerable batteries which will give me 6-7volts or should I just power my atmega328 and maybe ultrasonic ping sensor with a 9volt batteries and the rest with the rechargerable.

Standalone atmega328

1 dc motor with L293D

1 micro servo

1 ultrasonic ping sensor

6 leds (3 sets each)

Issue with L293D

For some reason I can't get my H-bridge to turn my motor both direction. It was working a week ago when I was working on it. When I turn Input 1 High and Input 2 low it will turn the motor forward but when I turn Input 1 Low and Input 2 High and doesn't do anything. Well actually I can feel like a buzzing sound like its trying to work. I am powering the H-Bridge with it own power supply on pin 8 (Vs). Maybe something I'm missing.  I will tried adding some capacitor in to see if that help any.

Control RC car with Arduino and L293d.

I'm back after a really long break. I have a RC car that I ripped all the electronics out. I'm only using an Arduino and a L293D. I don't have no issue controlling the back motor to make it go forward or back. My issue is trying to get it to steer. If I would just tell it to turn left if will barely move. Now if I tell it to turn left wait 1 second then turn right and wait 1 second, it will start to make full turns on the second loop. Why isn't it turning all the way without me making it go left then right twice? Also I am using guibot motor driver setup.

CNC electronics

I'm in the process of building a CNC machine right now and would like a little help from the experience ones.  Right now I have $250 saved up and counting.  I'm trying to figure out what to do about stepper motors, power supply, and motor controller.  I didn't know if it be best to just buy a package that have it all in one and what would you recommend.

Determine servo strength

Could we get a tutorial on servos?   I know I seen somewhere on here that explain how  to determine how much a servo can lift and also how much it can lift by the length to the next servo.  I'm not sure if its CTC was the one but could you please explain it all.  I would love to know this as well as other on this site and viewers also.  This would be a major issues for alot I'm sure.  thanks

74hc595 with 7 segment dispaly not working right

For some reason I can't get my 7 segment dispaly and 74hc595 shift register to work right on my arduino.  I can get the segment to turn on one at a time.  When I try to do numbers it just doesn't work right?  I have clock pin, and data pin to the the arduino. It will try to light up my numbers but will be missing some segments. It will also skip numbers completely for example try to show 1, 4, and 6 and skip the rest. I tried putting a 0.1 cap on the latch also.  I have 220 resister running from each pin of the display to the shift register.  Here my code:

How do you get your bot to choose the right direction?

I have been trying everything to figure away to get my robot to choose the direction that have the greater distance.  I can't seem to figure out whats wrong.  I tried to figure something out.  One time I wrote it different and it would wait till it got to the last case and turn right no matter what. This is my code. 

Break dancing Robot

Manoi humanoid break dancing.