Telescope Reviews: Am I Nuts???

Background: Newbie. I bought a celestron explorascope (80mm reflector) for my daughter for christmas. After taking it apart to fix the tripod mount, I thought to myself "Hey, it can't be that hard to build a telescope..."

Of course, I realize that this is going to be a lot more work (and expense) than I thought, but hey, that never stopped me before...

So, here I am. I've decided that for my first scope, I am going to go with a 4.5" F8 mirror. Primarily, I want something portable, since I will probably walk to a local park (maybe a block away) with it for my observing.

I've done some searching on the internet and have found lots of plans, and ideas. I will probably work on this scope a little bit at a time, so it will take me a while. I will purchase a mirror set, since I don't think I have the ability to grind my own mirror yet.

First step: Tube. It seems that Sonotube (and similar) is only availble in 8" sizes or larger, but I want a 6" tube. After doing some searching, I found that McMaster Carr sells a 6", 4.5ft length of PVC tube for $13, so I went ahead and purchased one. This is a non-schedule PVC tube, so hopefully it should be lighter than the typical schedule 40 PVC.

Next step: I think next I am going to want to design the mirror holder. Most of the plans have you cut a couple circles out of plywood, and assemble with bolts. Typically the mirror is glued to one of the circles, and the bolts allow you to adjust collumation. What I am wondering is if there are any alternatives. For instance, rather than cutting the mirror holders out of plywood, can I cast something out of plastic/epoxy? I.e., a circle maybe 1/2 inch thick made from liquid epoxy. Assuming this is strong enough, should be relatively easy to do. Is this possible, or should I just go the traditional route?

Other steps: Spider. Haven't really thought too much about this yet. I have seen several designs, and also pre-made spiders that you can buy. If possible, I would like to make one myself rather than buying, but as a last resort, I could just buy one.

Other Steps: Base. This is going to be a doozy. I want to keep this scope lightweight. I have seen one base that uses a larger size PVC tube as the base of the scope. Another interesting idea is a portaball type of mount, but that may be too complex for me at this point. Anthing else I can do to keep this lightweight? Maybe I should just mount it to a simple Alt-Az tripod?

Other Steps: Focuser. This I think I will purchase. Probably start with a 1.25" Rack and Pinion focuser. I noticed Orion sells one for $25 which isn't too bad. Would I want something more complex like a helical focuser, or a all-metal one on this size of a scope?

That's it for now. I'm sure I'll have tons more questions as I progress further into this project.

I'd appreciate any advice anybody may have, as this is the first time I am attempting something like this, and I am probably in over my head.

I've done some searching on the internet, and found the ATM archives. I also found the Newt program and think that that will help me in the design. I have several plans (one is specifically for a 4.5" scope, others are for larger scopes, but the same principles apply, I believe).

Thanks!