Help-does this mount fit the scope?

[domstar]

Hi, I've been offered a bresser 152/760 for a good price. It's a good price even without a mount but I don't have enough money to buy another one. I wanted to know if I fixed the mount that it comes with, would it be ok on this. It looks like an az mount and I'm concerned that it would be totally unsuitable for a scope that probably weighs more than 8kg. I'd rather use an az if possible. I don't mind if it takes a bit of time to stop wobbling but I dont want it to tip over. I would really appreciate any thoughts.(For visual only of course).

[Putaendo Patrick]

What is the telescope that is on the mount at the moment? It looks more or less at its limit, so if it's anything smaller than a 100mm refractor, I would say categorically NO. If it is 100mm, then you might be able to use the mount with the 152mm WITH A LOT OF CARE. Not ideal, but at least your Bresser is the shorter tube model which should hold a more central point of balance. Not ideal, so don't blame me if......

[domstar]

1 minute ago, Putaendo Patrick said:

What is the telescope that is on the mount at the moment?

That's the 152/760 on the mount in the picture isn't it? It should be.

[Putaendo Patrick]

Right you are! From the angle of the photo, it looked smaller at first glance. I'm just being a bit thick today (just for a change).

I'd say it's right on the limit of the limit  - but if the original owner used the tripod carefully and it didn't come to harm, with the same care you should be able to do the same.

This photo (off the internet) might give you a better idea of its size:

[domstar]

Thanks. It's so difficult to get a scale without people in the picture. It can't be that much longer than my 70/700 can it? I know it weighs 10 times more. Bearing in mind that one leg is held with duct tape.

I don't know. I've been looking at 102mm fracs but this is the same price and I can't imagine I'll get the chance for something this big again. I need to use it on the balcony in winter or in the car and maybe a 70m walk when it's a bit warmer.

As a frac guy, how attached are you to big apertures?

(thanks for all the help this week)

[domstar]

43 minutes ago, Putaendo Patrick said:

I'd say it's right on the limit of the limit 

When it's on the limit does that mean it'll wobble too much or that it'll fall over? Would it be more stable pointing up high or lower. Is there anything I can do to mitigate this ( hang a weight under it or take the finder off)?

[Cosmic Geoff]

The mount looks a bit like an AZ-3, though that's a Sky-watcher mount, not a Celestron.  The AZ-3 has a nominal capacity of 5Kg and reportedly has a tendency to let the scope tip forward or back.  It costs a little over £100 here, so I suggest you base your buying decision on the asking price of the Bresser and mount compared with a new OTA. The OTA costs around £500 here. You may find that an alt-azimuth mount for a 10KG telescope is rather expensive (even a AZ-4 is only rated for 7KG), but an alt-azimuth mount is not high tech, so you might possibly get one made locally for less than the price of an import. 

[Starlight 1]

There is definitely a sky watcher mount , the plastic have snapped off inside the aluminium under that duct tape . So basically it's got 2 legs and a bit of duct tape to hold the scope up.

[Starlight 1]

26 minutes ago, Cosmic Geoff said:

The mount looks a bit like an AZ-3, though that's a Sky-watcher mount, not a Celestron.  The AZ-3 has a nominal capacity of 5Kg and reportedly has a tendency to let the scope tip forward or back.  It costs a little over £100 here, so I suggest you base your buying decision on the asking price of the Bresser and mount compared with a new OTA. The OTA costs around £500 here. You may find that an alt-azimuth mount for a 10KG telescope is rather expensive (even a AZ-4 is only rated for 9KG), but an alt-azimuth mount is not high tech, so you might possibly get one made locally for less than the price of an import. 

Yes you are right AZ3 that come with SW 120 Scope  my one snapped off down were the bolt go  so it only got about 7mm inside the legs .

[ronin]

Yes, the scope is a bit (bit more then a bit) too big for the mount. However I read the post as it comes with it free, and you cannot run off and buy another mount at this time. So you may as well take it as look into what you can do to make it at least functional without the duck tape. Not sure exactly how but I guess pop rivits and 2 part epoxy are going to come into it.

If you are any good with wood and have the tools you could (MAYBE) build 3 legs from wood to replace the present ones. I would guess the catch with that idea is that you would need to cannibalise the aluminium mount for bits to make a working wooden one.

Another idea is to make a sort of pier on legs and put the head onto that. Again I guess wood will be the simple material. Thinking this sort of thing: Pillar Mount just a simpler construction.

You will need a bigger mount in time, and a fair bit bigger for a 152mm achro.

[John]

The mount is the Celestron version of the Skywatcher AZ-3. These mounts are OK for short, light scopes such as the F/5 80mm or 102mm achromats. I tried a 100mm F/9 refractor on one and the scope was too much for the mount except at very low power. Any 150mm / 152mm refractor is going to swamp the mount completely - when you get to see one you will see why - they are big scopes !

I am not 100% sure that the scope in the photos is a 152mm refractor though - it does not look large enough to me

But the perspective of the photos could be fooling me !

 

[alanjgreen]

I'm with John, that looks too small to be a 152?

Although, The focuser knob may be to the same scale as the one on the EQ mount so maybe it is the same !

Wouldn't fancy using a mount with only  2 good legs though. The legs are not offering enough spread for that large scope.

[Putaendo Patrick]

If the Alt-Az head holds up, you might be able to get new legs. They come up for sale from time to time on Astroboot - although you will need to be sure they will fit or can be converted. Don't know, though, if this is a realistic option for the Czech Republic.

http://www.astroboot.co.uk/AstroBoot/spare-parts-for-telescopes.html?needle=sky+watcher

[Starlight 1]

Make 2 new tops from wood , last a lot longer.

[domstar]

Thanks everyone. I can only assume it is a 152 otherwise why bother trying to sell it as such? There's a photo of the little panel on the side but it's out of focus so I can't read it.

Just to be clear- if I managed to put wooden legs on, would that solve my mount problems or would there still be issues with the top bit? You don't see heavy scopes advertised on az tripods.

[Cosmic Geoff]

3 hours ago, domstar said:

You don't see heavy scopes advertised on az tripods.

That's true, but some people seem to like alt-az mounts for heavier scopes.  The 'top bit' does not look ideal, but would let you try the scope out while you arrange a better mount. You have mentioned that you want to observe from a balcony, so perhaps you could have a custom alt-az mount made up that fits better on the balcony than the standard tripod, and gives you more room to get behind the scope.

[John]

The scope is very undermounted on that mount even if you put wooden or 2" steel tubed tripod legs on it. The whole design of that mount is for light and short telescopes. A 152mm 780mm focal length scope is neither of those things. The scope might be just about useable at very low magnifications on targets that are low in the sky but anything over around 50x and I think the view will wobble about like a jelly.

If you buy that your are buying the optical tube really and would need to budget for a replacement mount very quickly to get a satisactory outfit.

 

 

[domstar]

1 minute ago, John said:

If you buy that your are buying the optical tube really and would need to budget for a replacement mount very quickly to get a satisactory outfit.

Yes you're right. It was a nice dream but I'll go back to looking for something more suitable (lighter and more portable). Think it is my first brush with aperture fever-with a refractor!

Thanks everyone for your time and tact.

[Moonshane]

I don't believe that's a 152mm frac in the image either. The cradle looks completely different too. I suspect he's measured the 'aperture' of the dewshield which assuming a 100mm frac would be about 150mm looking at the cell.

[domstar]

18 minutes ago, Moonshane said:

I don't believe that's a 152mm frac in the image either.

Wouldn't it be written on the scope? It's been a weird experience but trying to sell the wrong scope would take the biscuit. (I'd rather have the 127 anyway and he's asking for about 260 quid for it)

[Cosmic Geoff]

It's usual for scopes to be labelled with their aperture and focal length, so I am a little surprised that this is still in doubt.

[Starlight 1]

well here a sw 150mm f1200 for size.

[domstar]

5 minutes ago, Starlight 1 said:

 

well here a sw 150mm f1200 for size.

 

 

Beautiful-you lucky devil

[Starlight 1]

The tube ring bar is 13 ins long, ok the one we are looking is not f1200  ,and the dew cover on my one is 170mm to fit over 150mm lens. so I think that one is only a 100mm

[Moonshane]

Here's a 102mm f5 on an az3

Dimensions look similar to me