This set of gears is very sturdy, and the pieces fit together as they should. They do not lock in place, but, for the most part, the gears stay put as they turn. They occasionally come loose at times when it's not part of the plan, but a locking feature would create its own issues, so I'm okay with the design.The gears can be arranged in many configurations, and extra "gizmos" are included to expand the possibilities. I had a smaller set from this same brand, so when I wanted to expand it, I looked for these again. Happy with my purchase!

Great product

As expected. Timely delivery.

Bien

My Kindies made it with the guidance of a TA. It is a bit boring once its put together. It is colourful easy to assemble and sturdy.

I bought this as an expansion to the Learning Resources Gears! Gears! Gears! Super Set (150 Pieces) for my 4 year old son. He was 3 years old when I bought the Super Set.http://www.amazon.com/gp/product/B00000JGWY/ref=oh_aui_detailpage_o01_s02?ie=UTF8&psc=1I highly recommend both products. The parts are very well built and durable.The Super Set (link above) was perfect for a three year old. It gave him a lot of gears and was easy for him to learn how to use / build new set-ups. In the Super Set all of the gears are a single standard size. Therefore, it is very easy for a 3 year old to figure out and build things that will interact by default. I would recommend starting with the Super Set if it is your child’s first set. I would also consider buying the Super Set in combination with Gizmos and Gears so you have a lot of pieces to build things with.Now that my son is a year older and has experience with the base set (he has played with it a lot off-and-on over the past year), we decided to expand it with the Gizmos and Gears set.The Gizmos and Gears introduces two new sizes of gears (medium and large) and three new sizes of base plates. It also introduces several new “gizmo” pieces. For example, it comes with two connection springs which allows you to connect the center of two different gears on different planes or different orientations (e.g. orthogonal to eachother). As the driving gear turns, it builds up torque in the spring, and the second spring turns with a slight delay. Other gizmos include a propeller and several new creative structural pieces as well.The Gizmos and Gears set provides kids with good hands-on experience with machines. They will develop a natural intuition on the impact of Gear Ratios (small gear driving a large gear, or visa versa), begin understanding the concept of Gear Backlash (how much you can turn the driving gear before the tolerance stack-up results in movement / force throughout the gear chain), learn how to be creative and invent their own “machines”, etc.. all while having fun.It is fun to watch my son focus while he is building and experimenting with the various gears. With the different sized gears in the set he has to figure out which structural pieces he needs to use to ensure the teeth will adequately interact. When he wants to add a new gear, sometimes he has to remove existing ones so he can physically fit the new one in. Then he has to put the originals back in place. These are great experiences that will help him figure out how things work and build / repair things in the future. Nothing beats hands on learning. There are things you learn playing with physical objects that you will never learn on a tablet or smart phone app. This is also a great opportunity for parents to play with their kids. My son often wants us to play with him and help him build new “machines”, or to proudly show us his new machine and ask us to operate it.In summary, I highly recommend the Gizmos and Gears set, especially if it is an expansion to the Super Set I mentioned earlier in the review. The Gizmo’s and Gears set is also good as a standalone set. The first night my son used it was stand alone and not yet combined with his other gears. The number of parts in the set is a little limited, so if your child does enjoy playing with them, you may look to expand the set with a second Gizmo’s and Gears, the Super Set, or one of the other expansion sets you can find on Amazon. I can see this set being fun for kids of multiple ages. My son is 4, but I can see him playing with these , much like legos, for years to come.