Instruction of building simple Mechanisms with Makeblock
A linkage is one of the mechanisms, but in a linkage all the pairs that are used to connect links are turning pairs. One of the most useful and common mechanisms is the four-bar linkage which consists of four rigid link connected by four turning pairs.
Just like the animation show blow, four bar linkage can turn the rotate motion to sweep with the simplest just 4 LinkRob.
I think you should know some characteristic mention blew to help you use this mechanisms
It’s not all the 4 bar linkages can translate rotate motion through a full revolution to sweep motion, their length must obey the rule which call Grashof Criteria:
1.A linkage, in which the sum of the length of the shortest and longest links is less than the sum of the length of the other two links.
2.The crank must be the shortest link.
When the crank is rotate through a full revolution with an constant angular velocity, the rocker only oscillates through an angle blew 180 Degree. The ratio of the average speed v2 of the return stroke and v1 of the forward stroke is different, it usually produce a quick return. Obviously, the angular velocity of the oscillates is not a constant value even the angular velocity of the crank is a constant value.
Hi, every one who use makeblock as me. I was major in mechatronics in University. As many Maker and DIYer, I also play with Arduino, RaspberryPI etc…, use this tools to build Robot or Automation equipment. Many people are major in Electrical or Computer Science want to join in. Code or PCB is not a problem for them, but you may need some knowledge about mechanisms, That’s the reason I decide to write a serial passages to introduce it here.
I try to explain it simplify and easily , use animation or picture, all the concept can be find in the text book of mechanisms, but it usually evolve hard stuff - advanced mathematics, I will try to avoid that, we just seek fun from Makeblock. If anyone agree my idea about write these passages, tell me in the blew comment or send E-mail:firstname.lastname@example.org
This passage is also published on my sina blog with Bilingual Edtion(English/Chinese), if you want to read it , please proceed to http://blog.sina.com.cn/s/blog_bfb28b380101o3rh.html, Think you!