I have no experience with log splitters but what I would do is look at how lots of different ones are made and how they work, then find the design features they have in common and the things that are different. Generally you want to reverse engineer them and just look at the basic principles of how they function. I think they just drive a splitting edge through the wood right? Figure out what forces are needed and where and what objects (like a blade) are needed. This is pretty much what I do when I want to make something. Once you have the basic workings just figure out how it can all fit together and you can ask for help on that
Generally I just find this cuts out any features that you dont really need to have and it helps me to come up with my own design that suits me (part of that is normally cost and materials). Anything can be done any way and you dont need to copy the exact way something is normally done for it to work! The only problems I run into with my ideas is then safety with things. With some things you cant just look at how it works because there are hidden features etc. But if I had my way then I would be figuring out everything before I made it which is what design is all about! So you minimized possible problems in the future by looking at what could be problems before you put time and money into it.
I hope that helps you in some way. What I'm trying to say is to get what you need to do don't think you have to copy everybody else to get the same outcome. But most of the time what everyone else is doing is the best way anyway. In the past though my ideas have been limited by that, not understanding fully how something works so I can't reverse engineer it and make my own I ended up just trying to replicate or copy other things which wasnt what I should have done!
Anyway goodluck with your project. I wanted to offer help but thats all I could do to help