Can two hydraulic cylinders of two different sizes, be plumbed together?

[CCWKen]

Like most backyard engineers that throw parts together and hope for the best, it sounds like you don't have your stress/design limits in mind. And nobody else here knows either. The suggestions are offered as a solution to a common problem. You can make your own links but the premade links above are for mounting two 3500 pound axles under a trailer. They make them bigger. A 17" stroke cylinder rod will need to be pretty "robust" too for full extension. The link can cut your cylinder length in half and perhaps allow for a slightly larger cylinder for the same or lower price.

But, you can do whatever you want. You seem convinced you need to build a carnival ride. :confused3:

 

[Bigshooter81]

Like most backyard engineers that throw parts together and hope for the best, it sounds like you don't have your stress/design limits in mind. And nobody else here knows either. The suggestions are offered as a solution to a common problem. You can make your own links but the premade links above are for mounting two 3500 pound axles under a trailer. They make them bigger. A 17" stroke cylinder rod will need to be pretty "robust" too for full extension. The link can cut your cylinder length in half and perhaps allow for a slightly larger cylinder for the same or lower price.

But, you can do whatever you want. You seem convinced you need to build a carnival ride. :confused3:

I've been in fabrication for 23 years, a Machinist for 5, all of my loads and leverages are calculated and accounted for. The question was about cylinder function, not design input. The design side was brought in as inquiries by other members. Your opinion is based upon assumptions, and while I thank you for taking interest in my posting, please reserve your judgement for someone else. As far as my research has shown, there has never been a design/ function like what I am trying to build, and am intentionally trying to be discreet with specifics. Additionally I stated that I need 17" of total stroke, not necessarily from the same cylinder, but in total to achieve the necessary arc at the given fulcrum and load points.

 

[bcp]

You appear to be doing what I often do, combined with what I should do.. I design what I want or need, they try to buy parts to build it or fit it, usually unsuccessfully. I need to find the most likely parts first, then design around them. The parts on hand to start with should be the most important part, or the most difficult to make.

It sounds like you are designing around a link you want to use, but maybe you should have found the cylinder most suited, then design around it, even if you have to make a link or change your design slightly. Hard to give more constructive ideas without knowing more.

I find lots of ideas in patents and don't mind copying them for personal use.

Google Patents

Search for anything related to your use, or anything that may have a use for a similar linkage. Just a quick glance at the drawing should lead to more investigation, or skipping past it. You may be designing a post-pulling crane, but find your answer in a lobster trap retriever.

Bruce

 

[Bigshooter81]

You appear to be doing what I often do, combined with what I should do.. I design what I want or need, they try to buy parts to build it or fit it, usually unsuccessfully. I need to find the most likely parts first, then design around them. The parts on hand to start with should be the most important part, or the most difficult to make.

It sounds like you are designing around a link you want to use, but maybe you should have found the cylinder most suited, then design around it, even if you have to make a link or change your design slightly. Hard to give more constructive ideas without knowing more.

I find lots of ideas in patents and don't mind copying them for personal use.

Google Patents

Search for anything related to your use, or anything that may have a use for a similar linkage. Just a quick glance at the drawing should lead to more investigation, or skipping past it. You may be designing a post-pulling crane, but find your answer in a lobster trap retriever.

Bruce

Excellent advice.

The design only has one constraint and that is space. It absolutely must be as compact as possible, while still meeting the minimum performance requirements.

 

[bcp]

Another thing about cylinders is the mounting and attaching. For example, a trunion-mounted cylinder with cross tube or an attachment hole in the rod end will be much shorter retracted than a same stroke cylinder with 2 clevis ends.

Bruce

 

[aircommuter]

Perhaps you could use a scissor linkage arrangement and have the cylinder pushing instead of pulling. Then a smaller cylinder would give you as much power as the bigger one. Plus that would allow you to be more selective on total motion in a limited space.

 

[BukitCase]

Good point; a 4" cylinder with 2" rod will have 1/3 more push than it has pull, at any given pressure...Steve