MiOYOOW Soldering Practice Kit, Line Following Robot Car Kit Beginners DIY Smart Car Soldering Project Kit for School Competition STEM Education, Learning Electronic Toys for 10+ Years Old Boys Girls

Thought I'd try this little smart car kit, I built one long ago, wasn't as nice as this one though.The kit seems small at first, everything is in a little anti-static bag perhaps 3in by 5in (8cm x 13cm?). Spread the components out and it takes up a fair bit of space. Uh, don't do that though... my cat thinks red LED's are fun to bat around.Let's see... 8 resistors, two transistors, two 10K potentiometers, 4 LED's (2 kinds of red), 2 LDR's, 2 electrolytic capacitors, 2 motors, gear sets and wheels, one battery holder (2 AA) and clicky power button. An LM393 dual op-amp, a nice blue PCB, some wire and a handful of screws. Oh, and a bolt with nut and acorn nut to work as a 'caster' wheel. Plenty to do!The kit comes with a sheet of instructions, one side has an oval track on it so you can play with your smart car right away, while the other side has instructions for assembly, a parts list and a good schematic. If you download the 'Smart Car Instruction' PDF file, it expands on the assembly instructions with good quality color photos, allowing you to visually verify you've got things in the right places, right orientation (electrolytic caps, transistors, LED's and op-amp!). Very helpful.Assembly is straightforward, start with the lowest components (the resistors, usually), and solder them to the PCB as directed, paying attention to the silkscreen for LED & eCap polarity and others as needed. I suppose it took me about an hour, I've been soldering for some years (we won't discuss how MANY years!), and it wasn't difficult at all. The possible problem areas might be the 2 pair of LED/LDR's, which are soldered on the BOTTOM of the PCB, where the solder pads are... so you're kinda soldering them in 'backwards', be sure to leave the leads long on those components so you can get your iron in under them. They need to be long anyways to shine on surface and detect reflected light (or not).The gear sets, axles, wheels and motors were fiddly to assemble, you may need three hands to keep the axle and its supports aligned while you tighten the screw on the other side of the PCB. You'll get it... but you may need to try a couple of times to get it all lined up, I did. Get one screw going good, suddenly the other axle support rotates away from its position. GRRRR! Sometimes blue-tak or masking tape can be very helpful!I have a grumble, I feel the battery holder should be installed LAST, as if you're not really careful centering it and keeping it away from other solder holes/pads, you'll have difficulty placing the four wires to power the two motors. The motor power wires must be inserted into small pads which are very close to the side of the battery holder. I'd really recommend leaving the holder until last, as you'll have more room to get your fingers, pliers, tweezers, chopsticks... whatever... in the area to connect the motor wires. Then solder the two leads for the battery holder, wrap the wires around the PCB, double-sided sticky tape the battery pack in place, and voila! Examining my car, I placed the battery holder a bit off-center (only a teensy bit!), crowding the M1/M2 motor wire contacts. just FYI.Now the really fun bit! Turning it on and tweaking the two potentiometers! This is where I'd like to have a blurb in the instructions describing the potentiometer functionality. Yes, you can figure it out by playing with them, the schematic is very helpful as you can determine that they are bias voltage level controls for the dual op-amp trigger levels. And they interact with each other a little bit, so that can frustrate a less experienced kit builder.Basically, they set the threshold for the two LDR's (Light Dependent Resistors). Depending on how much light is reflected back by the surface, the resistance of the LDR changes, changing the voltage presented to the inputs to the dual op-amp (LM393). If the voltages differ, the op-amp output either goes to Vcc or Gnd, depending in which voltage is higher (wikipedia has a good article on op-amps, check it out). If the output is low (Gnd), it turns on its appropriate transistor and energizes a motor. If the output is high (Vcc), it turns OFF the transistor (PNP) and the motor is de-energized, stopping it.You'll have to tinker with the potentiometer settings to get Mr Smart Car to behave, My experience thus far is to start both pots at dead center, and with the power on, tweak them every so very very slightly CCW (counter-clockwise). My car likes to go to the right preferentially, sometimes I can get it to go left... but generally he likes going around the track in a clockwise direction. Your experience will likely vary from mine. You'll swear it has a mind of it's own though.I took mine into work and set up a huge track using electrical tape on a large table. It ran for several hours with people picking it up and looking, then putting it down to zoom around again. We all had fun!I've enjoyed the kit and will likely order more to give to my friends and their kids, perhaps I can spark their interests in electronics. Or maybe a smart car racing club!

The media could not be loaded. I did this as a father-dauther project with my 9 yo over two evenings afterschool. She had never soldered before and this was just enough of a challenge that it kept up a feeling of suspense to see if it would really work at the end or if some component might have been damaged in the soldering process.General comments:It worked in the end. It gave my 9 yo a chance to build something from a circuit board and a bag of lose parts all the way to a working toy car. The one sheet paper instructions was more of a general guide and the track is on the back so don't throw it away. There are QR codes to scan to download the instruction manual and if you search the name of the product you can find youtube videos showing you how to build it. The videos help with confidence but the actual instructions were more accurate in my opinion. I don't think only having digital instructions is a bad thing because it forces you to look at on a screen which then makes it easy to zoom in on the parts and really see what goes where. Overall, I think it's a pretty good kit. You do need 2 AA batteries (not included).Building comments:Make sure you have the right tools to start. You will need 1) a soldering iron (off Amazon or locally from a hardware store / big box retailer), 2) solder (normally comes with a soldering iron), 3) wire cutters, and 4) a small Philip's head screwdriver. Sort out all of the pieces and pay close attention to the colors on the resisters (small tubes with a wire going out of each end). Match up the colors as exact as possible with the photos and you will be fine. The lights have one positive and one negative wire coming out of it. The positive wire is slightly longer than the negative. If you look on the circuit board there will be one round (negative) and one positive (square) pads. The longer wire goes to the square pad and the shorter one goes to the round pad. The gears on the motors should not be pushed down all the way. Just push them on enough so they stay and turn, this will give you more leeway with positioning the gears for the wheels to connect. I would hold off installing the battery wires and tray until the very end. If it does not work correctly at first, check that there is enough solder to make a good connection for all of the parts. Check that the lights and sensors are allighted together so it can see the light bounce back.

Taught my daughters, 5 and 7, component identification, soldering skills, safety, and fun with these kits! Both girls had an absolute blast bending leads and placing parts, and when it came time to solder, they ran the iron while i applied the solder.Minus one star, as the Instructions are only single page with the schematic and parts list on one side and an oval track on the other. I had to refer to the product listing several times during mechanical assembly to ensure proper fitment.A great time was had by all.

Advanced Soldering Capability required. Use a fine tip, temperature controlled soldering iron to avoid destroying the solder pads. Cut component leads after soldering. Three Photo sensors are included (only two are required) but only one S8550 transistor (two are required). Potentiometers will be a challenge when attempting to align the toy to a track. Find Portland Community College's on-line instructions and avoid using the manufacturer's on-line instructions. Also consider the purchase of a set of Forceps to deal with the small parts and a Thick Pillow that you can scream into.

This got my son into beginner soldering and he enjoyed putting it together. Only rate a 3 star because it was missing some parts that allows it to stay on the black line but the motors still turn.