ROKR Building Toy Set Marble Run Model Kit for Adults 130 Pieces Brain Teaser Puzzle STEM Kit for Kids DIY Hobby Unisex Boys Girls (Parallel World MR01S)

I am thoroughly impressed with the ROKR precision engineering of this kit. I am a semi-experienced model builder, and it took me about 3-4 hours to put this together. I proceeded more slowly than usual because I knew, with moving parts, things had to fit perfectly. But it is hard to goof up this kit, since the parts fit so well together. The art design with all of the lights and spinners is really fantastic. You can watch this run for a long time without getting bored. Most of the parts come on traditional plastic breakout frames. Each frame comes in a clear plastic bag with a frame letter printed on the bag and clearly etched on the frame. Each part on the frame has a number etched nearby, and the frame-number combination is identified clearly for each part in the instructions. The instructions are only pictures (few words), so language should not be an issue for any kit builder. There were a few loose parts, but all of these had distictive shapes easily identified from the instructions. A major value that sets this kit ahead of most plastic models, the plastic parts are all well manufactured. No trimming of excess plastic was required. I only found ambiguity in selecting required screws. Although there were several screw bags, I found different screws mixed together in a few bags. On the instructions, only a length (e.g. 4mm) is given. Note to ROKR: Maybe include one size screw in each bag. The kit includes three tools, a magnetic rod handy for extracting marbles and tiny screws, a screwdriver (all the screws have the same tiny head), and a slanted nipper to extract parts from frames. The nipper was very good for clipping the plastic close to each part, but they are small and I much preferred to use a larger pair of modeller's nippers easily found on Amazon. The ramps and other parts of the labyrinth fit tightly into position, and I found the ramps to be perfectly aligned and connected at the end. The instructions were so clear, it was hard to go wrong. With the labyrinth frame assembled, the instructions suggest testing a few marbles through to make sure all paths are good. I would also suggest, after attaching the small connectors to the circuit board on the back, apply the power and see that all the lights are working (they were). It is quite difficult to see the slight variations in the connectors and know you have put them in the right way. Note to ROKR: It would be great to mark an edge of each connector to see the correct direction. The elevator assembly came together fairly easily, but as I read on-line, was problematic for me as it was for others. It worked fine at first, but after several on-off cycles, jammed up and stopped. On-line, I learned that I should limit the marbles to ten or fewer, instead of all 15. This was a good lesson, but the jamming still occurred for me. I removed the back from the elevator, and watched the marbles correctly line up at the door. After stucying this some more, I realized that one of the two lifting bars had somehow dropped out of its correct position on the drive gears. The tiny servo motor is good enough to stop dead on resistance. After fiddling with the bars to reposition them correctly, I realized I would never be able to realign them properly without disassembling the drive mechanism and putting it back together again. When putting the kit together initially, these lifting bars were carefully aligned with the drive gears using two alignment pins. The instructions said to save in case they are needed again. (Great advice). Because it is well engineered, there is a great temptation to treat this like it is solid as a rock. But in reality the elevator assembly is somewhat fragile. In my case, I removed the clear plastic cover in the front of the elevator to be able to see the action better. This cover seems to protect the moving elevator arms from rising off of and skipping a gear tooth. Once this happens, there is no reasonable way to recover without disassemly/reassembly of the elevator drive. Moral: If you open the elevator front cover, be sure the elevator is not running, and tip the unit back a little to make sure the elevator arms do not pop out of position. Note to ROKR: Is there a better way to secure these elevator arms, to allow a better view by opening the clear plastic door? So treat this completed model with due care. If you have to move it, first make sure all of the marbles have cleared the labyrinth. Then remove the back elevator panel and remove the marbles queued for the elevator. Then lay it flat, open the front clear elevator door, and use the magnet tool to carefully extract the marbels from the elevator lifting bars, being sure not to deposition those bars. Then close both doors. Funny story: I could not, at first, figure out how to turn it on (by touching the gold bar at the bottom of the front). Videos online showed me how, but I could not find this information in the instructions. The switch has three positions. The first touch starts everything, the lights and the elevator. The second touch turns off the elevator, and leaves the lights on. The last touch is fully off, turning off the lights. I have a very experienced modeller friend who has put together many ROKR models, and he marvels at how well engineered each one is. Now, I marvel at this one.

same issue with the lift like the other commented, the kit came with 15 metal balls, if you put all of them in it, the lift can't handle the weight for non stop lifting and would stop randomly, it's fine running 6 of them or less, you can tell the motor is struggling but overall, love it. Also, I used glue on some of the small parts because they were very loose. Not sure if I will get the other 3 because of the lift unfortunately update: the lift was having difficulty even running 1 ball so I did more testing, then realized it was the friction between the balls and the lift while going up. I ended up putting a very small amount of oil based lube evenly (petroleum based would probably melt the plastic) onto the metal balls, now it working fine with all 15. Maybe I should get the other 3 sets after all, 5 stars again

I've put together a lot of different kits, metal, plastic, wood. This was a very fun one to do. The pieces look really nice, not just molded platic. A lot of the pieces fit into the base almost like lego, with a grid of holes that are all the same size. Really nice design. This is not meant to be a negative feedback, just info for those looking to build this kit: The setup is made to be configured in multiple ways, either 1, 2 or 4 different sets, in one big marble run. Depending on the configuration you are doing, you will need to follow different steps and use different parts. Kind of makes me wish I would have just bought all 4, and I could have set it up for a large marble run. I put it together as a stand-alone kit (Type A) and I think if I wanted to chain multiple sets together, I would have to re-do some of the setup. Definitely possible, and if you plan to do that, make sure to save the extra parts, there's a lot of them. Once you understand that there are different configurations, the instructions make a lot more sense. This is probably obvious, but always make sure you don't skip pages. I went from page 2 to page 4 and didn't notice it till the end. Luckily, it was easy to fix, as the parts just snap together. I wish they had you test the marble "elevator" before putting the whole thing together. Those steps are very particular about the gear alignment, and it would be nice to test it before you snap it all in. There are only 2 tools included, and that is all you need. All screws work with the one included screwdriver, which is really decent quality. And the "nail clipper" sprue cutter is a welcome add, it's always nice to be able to properly cut out the pieces to make sure you don't break anything. But be careful to check where you cut so you don't cut off some pins that are needed for assembly. The box says "90 minutes", and that is probably possible, but it doesn't count the time you should spend opening the bags and laying out the parts. The big "sprue" pieces can be removed from the bags, each piece has the bag letter molded into it. I would personally leave the small bags with the screws and other metal parts and wiring in their bags till needed. The parts count page is VERY useful in case you get lost on part of the instructions, they are all clearly marked as to what bag/piece you should be using. Overall, it was a ton of fun, and I'll probably get another set or 2.

It look amazing and it is fun for kids to run it

Great product easy instructions wonder build time!