Keiths next scope modding plans

Its the height of the sloping roof that is the deal breaker with my car.

It's the same for me, Keith, despite my Mondeo's big boot.
What I did as a result was to put the rockerbox into the boot, and place the mirror base into the rocker box with the tailgate up, and then put the two back seats down. By opening the rear door I can pull the whole assembly onto the vacated back seat space, and the tailgate will then go down as there is sufficent clearance.
I reverse that when taking it out, and it works ok, but hauling the assembly onto and off the folded back seats takes a bit of muscle-power due to the narrow space.
I tighten up the telescope brake , so there is no movement when in motion.
That way the base unit is protected from damage when moving, and collimation is never that far out.

However, what I haven't mentioned is the most awkward thing of all.
I store my scope in the house, and getting it thru the doors is a problem, as there is so little clearance, and these things have to go thru the doors ahead of or behind me due to their size...that gets awkward in places due to the shape and weight. Storing it in a garage will be better for movement

out of curiosity, what is a good wood to make the rocker box of a dob from?

I am shocked to hear that a lightbridge rockerbox is made from chipboard. thats absolutely rediculious, considering that chipboad is not suitable for damp conditions, the exact conditions a scope would expirence on a cold night outside.

given this fact, would it not be more wallet friendly, and give you more piece of mind to build your own version of a light bridge.

i know many people build large dobs, but building a moderate sized lightbridge should be a little easier, and you should be able to obtain most of the parts online, and improve parts you dont like ( such as using a wood suitable to scope making!

fguihen wrote:

out of curiosity, what is a good wood to make the rocker box of a dob from?

The highest grade marine ply you can find.
Dont go by 'store' grade.
& Dont buy it in a chain DIY store, it will be sub standard.
Go to your local builders providers and tell them exactly
why you need it to be weather proof.
In the current economic climate you should get a very good price for the timber there.

You dont need to stain high grade marine ply either but a light
coat of transparent varnish might make it look better.

I'd agree completely with Frank.
However, the circular base is probably OK as it is solid enough, so the marine grade ply with maybe a couple of coats of white paint would be fine.

Barberskum wrote:

fguihen wrote:

out of curiosity, what is a good wood to make the rocker box of a dob from?

The highest grade marine ply you can find.
Dont go by 'store' grade.
& Dont buy it in a chain DIY store, it will be sub standard.
Go to your local builders providers and tell them exactly
why you need it to be weather proof.
In the current economic climate you should get a very good price for the timber there.

You dont need to stain high grade marine ply either but a light
coat of transparent varnish might make it look better.

Most builders providers will stock WBP plywood rather than proper marine ply. WBP stands for Water Boiled Ply and refers to the test used to characterise the glue - it has to withstand being boiled in water for a given period of time before the glue between the layers of wood turns into monkey snot and fails! For telescope building purposes, WBP is fine... unless you plan to leave the scope outside *and wet* all year round, in which case go for marine ply. D.Kantor in Arbour Hill (near the Phoenix Park in Dublin) are wood importers that supply hardwood marine ply. The do not deliver, and you will need to bring your own saw or jig-saw to cut up your sheet of 4'x8' if you don't have a roofrack on the car. Kantor are wholesalers, but I have bought loads of marine ply from them for the observatory without any hassle.

Phil.

PS - forgot to ask - how much wood do you need. I may have an off-cut that will do you. I have 1/4", 1/2" & 3/4" in my wood-pile.

The Lightbridge seems to use 1/2", just for the record.