Observatory Update

[laser_jock99]

The 'Beast' (12" F4/F2.9 Newtonian) has finally been installed in the permanent observatory. With care, it is actually possible to close the roof with the scope in place (by removing the counterwieghts & retracting the bar). Longer term the only option is to saw about 4" off the top of the pier. This is not going to be easy since the steel is 6mm thick- but I reckon with good quality hacksaw blades & a spare day or two, it's do-able.

Even with the pier lowered slightly- the buisness end of this Newtonian is going to be about 8 feet off the ground when near the Zenith. I have invested in a six step ladder for access- but since I mainly want to image with this particular scope it shouldn't be too much of an issue.

The saddle plate of the mount had to be upgraded on this old type EQ6 to accomodate the larger scope and it's Losmandy style dovetail plate.

The scope in it's temporary park position. I don't want to leave it like this for long, since without counterweights there is undue strain on the mount's north azimuth bolt. I'm fairly sure it won't hold polar alignment if left like this?

The 'small' scope on top is an SW ED80 which is intended to be the guide scope or an alternative imager. Having played with the balance of this rig I think I also need another 2x 5kg counterweights. The old EQ6's are not compatible with the new counterweight extension bar.

Just waiting now for the dark skies 'first light' of this scope. It worked okay in the light polluted skies of the Midlands:

so it will be interesting to see the difference here in Wales?

[alan g]

WOW !!!!!!!!

[The Sailor]

Thats not a beast, it's a monster, but a nice one, well done

Jim

[nightvision]

That looks amazing, makes sense to go big and bold when you have such a great location and obsy. Is it correct, that for imaging, increasing aperture will get you a deeper reach in terms of magnitude and greater resolution?

[robin-m]

If you have access to an angle grinder you can get 1mm thick abrasive cutting disks from just about any hardware store (yep even the dreaded B&Q). A couple of those would shorten the time to cut the pier from days to 15 mins with a lot less arm ache involved.

[r3i]

If you have access to an angle grinder you can get 1mm thick abrasive cutting disks from just about any hardware store (yep even the dreaded B&Q). A couple of those would shorten the time to cut the pier from days to 15 mins with a lot less arm ache involved.

I would second this - an angle grinder will make short work of slicing through your pier. When building my observatory I used an angle grinder to cut 20mm stainless steel threaded rods to size - it was like a hot knife through butter.

Fantastic looking scope - no wonder you need 4 counterweights to balance it

[laser_jock99]

That looks amazing, makes sense to go big and bold when you have such a great location and obsy. Is it correct, that for imaging, increasing aperture will get you a deeper reach in terms of magnitude and greater resolution?

Increased apperture always helps, but usually goes hand in hand with increased focal length and therfore smaller field of view. Smaller scopes, like the ED80 refractor, with short focal lengths are usefull for wider fields of view spanning several degrees of sky. What is important in imaging is the Focal Ratio- i.e. the relationship between aperture and focal length. A 12" F4 scope is regarded as 'fast' instrument, the ED80 perched on top is relatively slow at F6. So increasing aperture is good for small targets (e.g. galaxies) but the magnified view is more demanding of the mount and guiding system.

If you have access to an angle grinder you can get 1mm thick abrasive cutting disks from just about any hardware store (yep even the dreaded B&Q). A couple of those would shorten the time to cut the pier from days to 15 mins with a lot less arm ache involved.

I had thought about using the angle grinder, but the one I have is the big 300mm discs. If I thought I could make a neat and level job using it then that would be the way to go. I think my dad has a 4" grinder somewhere though, maybe I'll borrow that? My intention with the hacksaw was to cut in close to a pre leveled guides (i.e. a pair of outsized Jubillee clamps).

[robin-m]

I used one large jubilee clip when doing my pier which was 5" dia 5mm mild steel. Place the clip on the cut line below the cut i.e. not the waste side, clamp the pier horizontally with a workmate or similar. It's easier to work when you're over the cut rather than with the pier upright. Run the grinder lightly round the tube holding it against the clip to make a groove, rotating the pier as needed, then you can remove the clip. The disc will then follow the groove as you cut through. You stand a much better chance of a clean cut that way then by hand with a hacksaw.

Robin

[robin-m]

p.s. If you go down the grinder route make sure you get the thin cutting discs rather than the standard 5mm or so grinding discs one of those would make a right old mess.

p.p.s The ED80 is native F7.5 sloooooww add a 0.8 FR and it becomes 480mm @ F6

p.p.p.s Very nice scope BTW...

[fondofchips]

First of all thanks for sharing your project with SGL as I'm looking at doing a smaller version of what you have there.

Angle grinder will make short work of shortening the pier, but BEWARE as the sparks are very hot & any flammable material will quickly catch light.

Best to have someone watch out while you cut the pier & best done away from the observatory.

[laser_jock99]

Angle grinder will make short work of shortening the pier, but BEWARE as the sparks are very hot & any flammable material will quickly catch light.

Best to have someone watch out while you cut the pier & best done away from the observatory.

Good advice- don't want to see my 3 year long project burn down in flames!

[Gina]

Make sure you protect yourself too. Please be very very careful. Good luck

[badgerchap]

Erm...Hubble appears to have landed in your Obsy Great looking scope mate, and it's in a lovely house too.