One Scope for two different sized mirrors

I'm grinding my first mirror, an 8 in Pyrex blank, hopefully to f7. I recently purchased a 14 in blank which I will probably grind to f5.

I was wondering if it's possible to make a truss dob that can be altered to use both mirrors.

I was thinking that I could make an interchangeable tailgate and have 2 sets of tubing, one for the longer focal length and one for the shorter focal length, and I'm all set.

Is there a lot of issues with using a large secondary mirror with a smaller primary mirror. I would obviously have to use a larger sec mirror for the 14 in.

I am hoping to save on some costs by making one scope that can accommodate both mirrors. Is it feasible? How about worth while? Any suggestions or comments from experienced people would be appreciated.

One scope for both those mirrors will be optimal for neither. And it will likely be more complex and expensive too.

I would recommend making a simple sonotube dob with the 8" scope. Use cheap plywood and make it simple and cheap. An 8" is small enough that you don't need heroic measures to make it light, rigid and usable. Look at the inexpensive Chinese/Taiwanese small dobs for inspiration.

I bet when all is said and done, two scopes will be as cheap as one "superscope". And you will be observing quicker too. And you will end up with two scopes for different purposes.

All IMHO, of course.

Joe Larkin