size matters??

[the bishop]

Hi,

I sorta have the chance of a sw10 inch dob for not a lot!!

have not as yet seen it and as present owner can’t remember size it could be a 200

What i need to know is if there is any technical reason why a dob ota could not be fitted to an eq mount and back

again to a dob as/if and when required?

Would it really just be a simple case of fitting a pair of tube rings and a dovetail bar?

Or is there something lurking in the background to turn around and bite me in the bum as it were?

Also this brings the question of a tidy mount...just what is the considered max newt ota size

that an HEQ5 would be happy with? its ok with a 200p...and It would be for Viewing not AP purposes

so if it is a 250 ota would it be a bridge to far for my heq5 mount or just enough?

Many thanks

gra

[Peter Drew]

A full tube Dob can be fitted to an EQ mount with the appropriate tube rings. A 200 would sit comfortably on a HEQ5 for visual, a 250mm would be doable but right on the limit.

[JamesF]

You'll want to be sure you can safely lift it onto the mount, too. It's a fair way to lift a big tube.

James

[Aronnax]

...

What i need to know is if there is any technical reason why a dob ota could not be fitted to an eq mount and back

again to a dob as/if and when required?

Would it really just be a simple case of fitting a pair of tube rings and a dovetail bar?

Or is there something lurking in the background to turn around and bite me in the bum as it were?

...

The only problem I can envisage is if the dob mounting brackets that are attached to each side of the tube get in the way of the mounting rings, or at least in the way of getting a good position of the OTA to achieve a good balance on the EQ mount.

These mounting brackets are screwed into the dob tube and can be removed, but this would not be a good solution if you wanted to swap between the two on an as-and-when basis.

However, if these don't get in the way, then I can't see a problem in theory.

Hope that helps,

Clear skies

[the bishop]

Thanks

Umm Yes the Dob Mounting Brackets... I suspect there are 6 or 8 nuts, washers and swarf

inside the tube just waiting to cause problems if removed even on a tilt...

I see that FLO do a real long dovetail bar that might be enough to get the rings fitted

well out of their way and get the tube into a tidy viewing position...

but until I see the tube I won’t know for sure the true size of these mounts or the possible problem they pose.

Mind you that said I have no real idea of the weight of a 250 ota!!

the jump from a 6 to 8” newt was a surprise and I assume that is the same sort of jump ratio

ftom an 8 to a 10”

The HEQ5 is more than man enough for a 200p

Has anyone out there got a 250 ota Mounted onto a SW HEQ5???

thanks

[umadog]

Dob-mounted Newts tend to be quite long focal ratio compared to News that are normally sold for Eq mounts. So they're quite long and heavy. That means the mount will need to be really beefy.

[RikM]

The HEQ5 is more than man enough for a 200p

Has anyone out there got a 250 ota Mounted onto a SW HEQ5???

thanks

For visual use, the HEQ5 is good with an f/5 200P Explorer and will carry an F/6 200P Skyliner. I wouldn't want to put a 250PX on an HEQ5.

I do exactly what you suggested with my Skyliner 250PX tube and an NEQ6. The Dob mounting ears are only held on with two screws per side and couple of washers, but I didn't need to remove them to get the bigger tube balanced. I use it up on the NEQ6 for imaging but more often on the original Dob mount for visual.

[the bishop]

WOW what a beast, thats fantastic!!

ok now i can see there is quite a leap in size/ weight,

also easy to the tube rings position...yes the heq5 is not going to do it,

i showed your pic of your 250 setup to the wife but sorry but i cant repeat her comments

but i can say it started with... and you want what!!

the middle had a bit along the lines of me moving into the shed

and ended with

some comment about the price of an neq6...

ha ha isn't love wonderfull...

thanks for the info

gra

[RikM]

Took me 2 years to save up for it, but for what it can do, the NEQ6 is a bargain

The HEQ5 is just as good and is a fair bit lighter to carry about, just won't carry as much weight, that's all.

[the bishop]

Hi,

Scope update,

I got to see the scope today... oh dear never mind,

it belonged to my friends son who went to NZ several years ago and it has been at the back of a

rundown garden shed ever since.

Where do I begin? Well to start with its a 200 not a 250...

The dob mount is damp and split and in a right state,

however the ota is worse if that is possible...a huge dent half way along where a garden slab has fallen onto it??

in fact slab was still on it and what I think with my limited view inside is a dead mouse welded to the primary mirror.

So all in all a bust really, but I have received good info along the way so thanks folks.

[fondofchips]

There will be other scopes, a new Dob is not too dear & they hold their money, OK when you want to ugrade.

On the side of a mountain, spot on location much darker & clearer than Murky Midlands.

Patience will pay off, clear skies.