VellemanMK129 Crawling Microbug

This was a fun little build that I did as a Christmas present for my goddaughter. The LEDs flash as it walks and it kinda looks like a crab. Photoresistors are designed to make it seek out light, so you can get it to chase around a flashlight beam in a darkened room. You do need a very flat floor on which to run it -- kitchen linoleum is best -- it won't work at all on carpet and catches in any groove on the floor.The exposed-but-low-voltage wiring and motors make it look cool and high-tech, although it doesn't actually use any technology that hasn't been around for 50 years.You will have to fiddle with the trimpots and the "aim" of the photoresistors to get the thing to behave right, and for some reason the kit I built didn't seem to have much stability in this department. It seems the combination of components was such that one side wanted to run away while the other tended to remain stationary -- so it tended to go in circles a lot. For whatever reason this other "bug" kit (https://www.amazon.com/dp/B000TA7AHM/ ) made by the same company and put together by the same person, performed a lot more reliably. I'm not saying Velleman kit MK129 is intrinsically bad, but that's why I rated it four stars instead of a five.

This awesome little kit was a present for my honey. He really had fun putting it together. He said instructions were clear, and to the point, as long as you read them!All you need is your soldering supplies and some AAA batteries.He had some issues with installing the motors after (he says) 'not reading well enough' the motor install portion of the directions, thus ending up with the motors too low to the ground, but it was an easy enough fix. One issue was the supplied tubing for the motor shaft being too loose and he ended up using some small bits of sheath from stripping some wires from his junk box; this then allowed the tubing to stay on the motor shafts.There are controls for the speed and the light sensitivity for both left and right. One note is that the light sensor actually causes the opposite motor to run, so the bug moves towards the light.There are two walks, a side stepping one and a straight one. These are switch selectable. There is also an on/off switch - a plus in his book.He loved the look of the open chassis motors - being able to see how they work was quite unique for him.All in all a really neat little kit!

This is the most complex and difficult of the little kits I have put together and the first soldering I'd done in a while. There is some mechanical work - the mounting of the two motors by soldering to board patches - that I found tricky. It doesn't work and the PCB layout makes it difficult to troubleshoot. Afraid I probably damaged the board in a spot or two. Then again, this is "practice" and at the price I could buy another one for my grandson.Might mention I tried a couple no-lead solders to start with and was not pleased at all. The good old 63/37 resin core was far superior.

This 'mothbot' really works! Fun to play with.A preventative measure:I put snubber diodes across the motors to protect the transistors from motor spikes.Little common 1nxx signal diodes. The line on the diode goes toward the fangs in front. (Plus on the left side, minus on right, because the polarity is actually the same despite the markings)He he.The larger black diode that makes up the rear wheel would be overkill, and you'd need a second one.

Great gift! 14 year old enjoys tinkering and putting things together to get a visual result! Once together, it's made to follow light. It follows a flashlight. As long as you can saulder, you can put this together. Just follow the simple steps Will continue to purchase more of these items.

Watching it crawl across the table now. Very satisfying knowing saying, "Hey, I built that." Built several Velleman kits now and all have worked first time. I made one modification in that I soldered the two Led eyes close to the circuit board to avoid accidentally damaging them.

This was a fun project to build and fun to watch it crawl around following a light source.All parts were there and it took less then 1 hour to build for me.

I turned it on three times and one of the motors quit working already

Ich bin mittlerweile sehr verärgert. Seit Stunden versuche ich dieses kleine etwas zum laufen zu bewegen.Dieser Bausatz ist normal nicht sehr anspruchsvoll. Aber es gab von anfang an Probleme.Ein grosses problem war die Platine. Sie war an einer Stelle sehr schlecht geätzte. Ich habe daraufhin den Schaltplan zur Hand genommen und die Stelle genau begutachtet. Ja da war eine Brücke (Schlechte Verarbeitung) die da nicht hingehörte. Also habe ich sie kurzer Hand getrennt.Nach dem Zusammenbau der natürlich recht einfach und schnell von statten ging war es dann so weit. Batterien rein und was passierte? Eine Seite (Motor) dreht schneller.Ich habe somit alle Teile durchgemessen, konnte aber nichts auffäliges findenAuch die Potis für die Empfindlichkeit habe ich exakt gleich eingestellt (gemessen mit Multimeter) doch es brachte keine Verbesserung. Ich Tauschte auch die Transistoren und Motoren um auszuschliessen das es dort einen defekt gäbe. Aber immer das selbe. Eine Seite (immer Links) funktionierte normal und die nicht korrekt. Meiner meinung nach Funktion unplausibelMittlerweile nach ca. 3 Stunden bin ich mit meinem Latein am Ende. Ich bin darüber hinaus auch sehr enttäuscht.Meine vermutung ist das es irgenwas mit der Platine zu tun hat. Bruch einer Leiterbahn oder sonstiges.Morgen erhalte ich noch einen Bausatz von Velleman. (Etwas anderes) Mal sehen was sich dort für Überraschungen ergeben.Für diesen Artikel gebe ich auf keinen Fall eine Kaufempfehlung!!!!! Finger Weg!!!!