5" Newtonian

This may fall into the category of, "An idle mind is the Devil's workshop" but...

I have a Meade 4.5" f8 reflector. It's accessories aren't worthy of the name. It's on a GEM2 aluminum tripod that wiggles 'n waggles in my gentle hands. But in spite of these short comings I use it often because it's light and available. Now here's my thought: A 5", 750mm mirror will fit in the same tube and probably the same cell. I have better accessories at hand. I have a lathe and vertical mill to refit the GEM2 with larger shafts and some bearings...

But am I trying to make a silk purse out of a sow's ear? I have an 8" f5 reflector so I don't want to clone that. Are there any sane minds on this Forum that might counsel this madman? What say you?

Some thoughts here:

1. The short comings of that mount are more related to the tripod and the over all design than to the shafts and bearings.

2. One needs to provide adequate ventillation, stuffing a mirror into a tube that is too small is asking for thermal issues.

3. The OTA that probably suits your needs is the Orion SpaceProbe 130ST. 130mm F5, the one I have has very good optics and has provided me with some impressive views. Fit it with a 2 inch focuser and it will do a 3.5 degree FOV at 20X . Those widefield views with the max useable exit pupil will basically blow your mind when point the scope at the summer Milky Way from a dark site. But it also does a nice job at higher magnifications, splitting some pretty tight doubles with relative ease.

4. I like to think in terms of how scopes can compliment each other. Your Meade has a focal length of about 900mm, nearly the same as your 8 inch F5 scope. Not much the 4.5 inch will do that the 8 incher won't do better.

On the otherhand, taking an 130mm F5 OTA and using your fabrication skills to build a DOB mount similar to the Orion Starblast would give you a very capable widefield scope on a stable mount that was easy to setup and use.

So to answer you question, I think you would be trying to make a silk purse out of a sow's ear. Let the Meade be what it is, a beginners scope. If you want to make it more useable, build a nice little DOB mount for it.

Jon