RMH design program

Dear rocket scientists,
I'm planning my first RMH build at a friends house and would love the ability to play around with different designs etc. Unfortunately despite working with architects for over 5 years my handwriting and more importantly sketching is pretty indecipherable I call it my own code language.
I learned a CAD-program in university (Solid Edge) and I still know my way around that program a bit (I hope). But we mainly used it for industrial designs with a very high level of detail.
I recently tried SketchUp and Tinkercad but in both cases it was really hard for me to give the individual elements the exact size I required and to orient them towards each other.
I wanted to tap into this unending well of knowledge and ask which product you are using (and also maybe why)?

Thanks in advance

Hi Benjamin;
Peter Berg uses Sketchup and he is a pro at it!
He attempted to explain it to me but, alas I am a computer dinosaur and I can not get the hang of it. (Even though Peter is my senior and he gets it!)
Other friends picked it up right away... so you could too.
I have another friend who builds aircraft parts as well as RMHs he uses a CAD program to design his stoves.

What exactly are you trying to design?
The core units are already proven designs so I am guessing, that you are looking at bells or bench arrangements?
Are you trying to give your friends options on what you are building in their home?

Hi Thomas,
thanks for the quick reply.
That's good news. If Peter is using SketchUp I'll give it another try.
I would like to be able to put together cores (from individual stones), play with bell and bench arrangements, etc. See what fits into the room and how...
Also yes, I would use the plans to show my friend (and in the future costumers) what the options are.

There are Sketchup files of many different builds available from threads here, and you could probably extract core elements from those to use in a new project, without having to build new core elements. Ask the experts how to do that...

Thanks Glenn.
For the moment I'm fine, tinkering around and getting used to Sketchup. It is powerful, no idea what threw me off last time.