Show Us Your Dobs

[Stu]

20 minutes ago, Stardaze said:

I have a slight blemish on one of the vertical panels but wasn’t enough to raise, looks like a bumped corner. I’m going to replace my base in the autumn I think with an OO version. I’m not a good chippy myself so I’ll take the easier option. 
Those that have had the OO bases: does the ota detach with the tube rings etc all in place, or do you have open up the rings? How smooth in practice are the OO bases?

Might have a go at mucking a wheeled base though to use in places.

The OTA lifts off the OS dob bases with the rings and alt bearings attached. I just have to remove the brake on mine then it lifts straight off, I think the later designs mean you just have to loosen the brake off not remove it.

Generally the are very good, although sometimes the tolerance in build can make it challenging to get it all working without the side supports rubbing on the reunion blocks; I’ve had to pack out slightly with washers on one of mine. The 8” f8 works well although was difficult to get optimum tension on the az bearing, too loose and it wobbles, too tight and it is jerky to move. I’m experimenting with a lazy Suzan bearing which runs much more easily, but too easily currently so I need to work out how to address that. I think the larger sizes or shorter, more standard sizes work well.

[johninderby]

When I had my 14” OO dob fitted a TS Ebony Star ring to the base and it did make az movement smoother. Pity it’s no longer available. FORMICA stardust HGP F1782 laminate is about the same but only seems to be available in huge sheets. ££££ 😥

Edited May 22, 2020 by johninderby

[Stardaze]

1 hour ago, Stu said:

The OTA lifts off the OS dob bases with the rings and alt bearings attached. I just have to remove the brake on mine then it lifts straight off, I think the later designs mean you just have to loosen the brake off not remove it.

Generally the are very good, although sometimes the tolerance in build can make it challenging to get it all working without the side supports rubbing on the reunion blocks; I’ve had to pack out slightly with washers on one of mine. The 8” f8 works well although was difficult to get optimum tension on the az bearing, too loose and it wobbles, too tight and it is jerky to move. I’m experimenting with a lazy Suzan bearing which runs much more easily, but too easily currently so I need to work out how to address that. I think the larger sizes or shorter, more standard sizes work well.

 

16 minutes ago, johninderby said:

When I had my 14” OO dob fitted a TS Ebony Star ring to the base and it did make az movement smoother. Pity it’s no longer available. FORMICA stardust HGP F1782 laminate is about the same but only seems to be available in huge sheets. ££££ 😥

Thanks chaps. Bit annoying when you pay all that for them, nothing seems perfect these days. Did I read somewhere that delivery scales are quite a bit?

[faulksy]

you could drive there, and get them to pre assemble it ?

[Stardaze]

19 minutes ago, faulksy said:

you could drive there, and get them to pre assemble it ?

I probably would collect it at the time as I do pass that way. However, if the overall build of the components isn't perfect, then the assembly wouldn't make a difference, would it?

[Stu]

5 minutes ago, Stardaze said:

I probably would collect it at the time as I do pass that way. However, if the overall build of the components isn't perfect, then the assembly wouldn't make a difference, would it?

But at least you could see it working and get them to fix any issues...

[markse68]

1 hour ago, johninderby said:

When I had my 14” OO dob fitted a TS Ebony Star ring to the base and it did make az movement smoother. Pity it’s no longer available. FORMICA stardust HGP F1782 laminate is about the same but only seems to be available in huge sheets. ££££ 😥

Group buy? I’ve been looking for something for my new dob base and have same issue- if a few were interested maybe we could sort something out? I think Formica can be laser cut 🤔

[markse68]

2 hours ago, Stu said:

The OTA lifts off the OS dob bases with the rings and alt bearings attached. I just have to remove the brake on mine then it lifts straight off, I think the later designs mean you just have to loosen the brake off not remove it.

Generally the are very good, although sometimes the tolerance in build can make it challenging to get it all working without the side supports rubbing on the reunion blocks; I’ve had to pack out slightly with washers on one of mine. The 8” f8 works well although was difficult to get optimum tension on the az bearing, too loose and it wobbles, too tight and it is jerky to move. I’m experimenting with a lazy Suzan bearing which runs much more easily, but too easily currently so I need to work out how to address that. I think the larger sizes or shorter, more standard sizes work well.

Hi Stu, is there much flex in the unsupported top corners of the box construction? In my old worn out wooden dob base they’re pretty floppy but that’s mainly give in the joints

[johninderby]

9 minutes ago, markse68 said:

Group buy? I’ve been looking for something for my new dob base and have same issue- if a few were interested maybe we could sort something out? I think Formica can be laser cut 🤔

https://shop.morlanduk.com/formica-f1782-stardust-3050x1300x0-7mm-laminate-quarry-single-sided

The thin stuff is useful as it can be used for alt bearings as well as the Az. Also thin enough to be cut with a utility knife.although you’ll use up a few blades.

Edited May 22, 2020 by johninderby

[markse68]

We’re going a bit off topic so will start a thread in diy 👍

[faulksy]

1 hour ago, Stu said:

But at least you could see it working and get them to fix any issues...

as stu says. you know it will be right.

as stu said earlier they only need a couple of washers to shim them out. then they are brilliant. very small foot print and very compact and strong

[johninderby]

I found I had to run a drill bit through a few of the holes as the powder coating in the holes was just enough to stop a few bolts lining up. 

[Stardaze]

You lot are far too handy 🤣

[Stardaze]

17 minutes ago, faulksy said:

as stu says. you know it will be right.

as stu said earlier they only need a couple of washers to shim them out. then they are brilliant. very small foot print and very compact and strong

I do like the base being quite compact and as I keep mine in a corner of the dining room, little bumps (you never know with a 4 year old around) might be better suited. 

[John]

38 minutes ago, Stardaze said:

I do like the base being quite compact and as I keep mine in a corner of the dining room, little bumps (you never know with a 4 year old around) might be better suited. 

Same here. I have a "scope corner"

 

[Stu]

36 minutes ago, John said:

Same here. I have a "scope corner"

 

Skittles! 😱😱😉

[Barry-W-Fenner]

37 minutes ago, John said:

Same here. I have a "scope corner"

 

Lovely collection there John. I can only imagine what images these instruments provide!

I was on the Orion Optics page earlier today looking at the VX12, Out of interest do you know what PV the primary mirror is in your dob? Is there any benefit to ordering on of the higher grade mirrors? 

 

Regards

 

Baz

[Barry-W-Fenner]

4 minutes ago, Stu said:

Skittles! 😱😱😉

If I had that collection there is no way I could store them like that with my two little bam bams! 🙂

 

 

[Stardaze]

2 minutes ago, Barry-W-Fenner said:

If I had that collection there is no way I could store them like that with my two little bam bams! 🙂

 

 

Me neither. 

The squared base of the OO does give a slightly smaller bottom profile to tuck into a corner better though.

[Barry-W-Fenner]

7 minutes ago, Stardaze said:

Me neither. 

The squared base of the OO does give a slightly smaller bottom profile to tuck into a corner better though.

Agreed, Its a much nicer compact footprint to my 8" Skywatcher base.

[John]

No kids here now - all grown up and flown the nest

@Barry-W-Fenner The mirror in my dob is, according to the test sheet, around 1/9th wave PV and has a .987 strehl rating.

With Orion Optics I feel that there is no point in spending out unless you go for one of their better quality mirrors. The mirrors from the far east are probably as good as the "standard" quality OO mirrors so you might as well step up a level or two. It's what OO are best at.

 

[John]

2 hours ago, Stardaze said:

Me neither. 

The squared base of the OO does give a slightly smaller bottom profile to tuck into a corner better though.

The base of mine is 40cm x 40cm so quite a small "footprint" for a 12 inch dob. My old 12 inch Lightbridge (below) was quite a bit larger and much heavier.

 

[johninderby]

Ypu don’t want to know how big the base of my old 16” Lightbridge was. Had to be turned on it’s side to fit through the door. 🙀

Moonshane seems to have got on well with it though.

Edited May 22, 2020 by johninderby

[John]

I thought @Moonshane's 16 was an OO ?

 

[Stardaze]

1 hour ago, John said:

No kids here now - all grown up and flown the nest

@Barry-W-Fenner The mirror in my dob is, according to the test sheet, around 1/9th wave PV and has a .987 strehl rating.

With Orion Optics I feel that there is no point in spending out unless you go for one of their better quality mirrors. The mirrors from the far east are probably as good as the "standard" quality OO mirrors so you might as well step up a level or two. It's what OO are best at.

 

It's not the kids I have to be careful with though, I can be just as clumsy. I haven't divulged my own misdemeanour earlier in the week.... whilst carrying a dining room chair back from the kitchen (the little one was using it to stand on to bake cakes) I tried to nudge the chair in front a touch to push it over. Yup, it fell on my new dob 😂 A slight dink. I've tried to push it out but need to get a small hammer in there. It's hardly anything, so...

50 minutes ago, johninderby said:

Ypu don’t want to know how big the base of my old 16” Lightbridge was. Had to be turned on it’s side to fit through the door. 🙀

Moonshane seems to have got on well with it though.

That's a monster! How was she in use? I bet a PITA to move around though.

Edited May 22, 2020 by Stardaze