Silver Maple STUMP..."stability questions"

[Bob G.]

Need a little bit of knopwledge from wood "savey" guys and gals!

I am planning to build a Dome in which to house my telescope and I need to remove a 60-70 foot tall Silver Maple tree in the back yard anyway...

So this morning I went out and measured the trunk at a point about 3 foot off the ground and it measured 141 inches in daimeter... !!! Big Tree !

Normally with a Dome you would dig a hole 3 to 4 foot deep and 2-3 foot square and pour in a concrete base ..A pier would then be bolted to the concrete base and a telescope bolted to the pier... This gives enough stability to the scope that when takling 2-3 hour exposures or longer of a Planet/ Galazey etc is possible using a good motorized scope mount....

Ok to the point..... Silver Maple tree trunk !

IF i cut this tree and leave the trunk about 3 foot off the ground and then build an observatory around it...with the floor of the obsevatory being a few inches above the tree trunk (say 4 oot off the ground)... What would you woodworkers think the stability be of the trunk as a base on which to bolt a metal telescope pier...

Shrinkage rate? etc... the metal pier has adjustments etc to keep it level.. but the tree/pier bolts have to stay tight

I am in my 60's and lets face it I do not think the trunk would Rot away before I die... and the trunk would be enclosed and out of the weather (think of it like being in the basement of your house..)

Grinding the trunk even with the ground, or having the entire root system removed is expensive...? and if I could use it as my base for the telescope it would also save me from digging a big hole and pouring in a concrete base...?

What do you woodworkers think ?

Thanks Bob

[Morris Dovey]

| Need a little bit of knopwledge from wood "savey" guys and gals! | | | I am planning to build a Dome in which to house my telescope and I | need to remove a 60-70 foot tall Silver Maple tree in the back yard | anyway... | | So this morning I went out and measured the trunk at a point about 3 | foot off the ground and it measured 141 inches in daimeter... !!! | Big Tree !

| What do you woodworkers think ?

This woodworker thinks that you should consider a different location for your observatory.

-- Morris Dovey DeSoto Solar DeSoto, Iowa USA

[Michael Latcha]

Wow... a maple that is 11-3/4 feet in diameter has to qualify as some sort of record, not to mention that it is pretty wide for its height. Maples are usually more than 6-7 times taller than wide. And you'll have to explain to us all exactly how you were able to measure the diameter.

Now if the tree actually measured 141 inches *around*, it would be 3-3/4 feet in diameter. Big enough to look around before dropping it, but not nearly record-breaking, and a whole lot more attractive as a tree.

As for your question of stability, the cut trunk will move and check a lot as it dries, and the base that you left in the ground will move a lot as it rots away. How fast the trunk dries and the roots rot depend a lot on the ground moisture and air humidity levels around the stump. In addition, to mount your telescope you'd probably be sinking screws, or more probably lag bolts, into the stump's end grain - the weakest and worst way to put screws into wood. You'd eventually have to remount your telescope mount many times as the stump slowly falls apart.

Michael Latcha - at home in Redford, MI

[James Lerwellen]

I agreee, the stump over time will start to decompose, not a pretty situation, if your telescope is mounted to it.

Jim

[Pat]

Renting a stump grinder and removing a stump generally costs $100 here.

[cselby]

Years ago, my dad wanted to cut a 6" dia. tree in the back yard that was in the way of his patio. I suggested we cut it at about 30 " and mount an old oak table top on it. "I' cut the tree. "I" drilled the tree for the bolts with a brace and bit. "I" mounted the table top. "I" painted the top to match the chairs. It lasted quite a few years. Did it shift? Probably. Did it rot? Eventually. Did "I" have to take it down after 8/9 years? Yes. Did "I" learn to keep my mouth shut? Apparently not.

Pete

[fredfighter]

That is almost 12 FEET in diameter. Are you sure it isn'tt 141 inches in circumfrence?

I think the answer depends on the telescope.

I know some people who mounted a long focus Newtonian, (I don't rememebr the size but it was bigger than an 8 inch, maybe even a 12 1/2") on a red oak stump that was about 18 inches in DIAMETER four feet above grade.

It worked fine.

Do you have a lot of problems with ambient lights? If not, I suggest you consider a rolling roof observatory. It's a real bummer to be trapped in a dome when a fireball comes by opposite the slit.

Here is one I designed:

[Connor Aston]

SAVE the Tree - I agree!

[Phisherman]

Not a good idea. The silver maple will begin to rot quickly, shrink, draw termites, and fungus will grow. Have the tree and stump professionally removed and pour a concrete foundation. You may live

20 years or more!

[lwasserm]

70 feet high and 141 inches= ~12 feet in diameter? That sure is an unusual maple tree.

[Mark & Juanita]

If that was circumference, then the tree is only about 45" in diameter. Still a big tree, but is it big enough for an astronomy dome?

+--------------------------------------------------------------------------------+ If you're gonna be dumb, you better be tough +--------------------------------------------------------------------------------+

[Bob G.]

================== Slight "little" Boo Boo on my part or big Oops....Your pick ! it is 141 inches in Circumference NOT Diameter...

Thanks Guys ...I got the information that I needed...back to the drawing board I guess.. due to the location the floor of the observatory has to be about 8 or 9 foot above ground level (like a deck off the back of a house).. otherwise I would have very restricted views ..

Bob