Mount for 150mm Refractor

[Analogue]

Hi everyone,

I'm new to the group so please be gentle

I have recently bought a 150mm Refractor OTA, all up weight is around 7Kg. It has been suggested that I could use the EQ3-2 Deluxe mount although the EQ5 would be better. As I have the opportunity to obtain the former, at a good price, I wondered what your thoughts would be?

All the ads for the EQ3-2 Deluxe just seem to mention Skywatchers' blurb and don't mention the load capacity.

Thanks in advance for your help.

Clive.

[GazOC]

Which 150mm refractor is it Clive, the f5 or the f8? The f5 will be just about OK on the EQ3/2 but the f8 won't.

[dweller25]

Hello Clive,

If you bought the 150mm F8 you will need an EQ6 for sure.

Because refractors are so long the eyepiece end is close to the ground when observing at the zenith. The answer is to raise the tripod as high as possible but this is also the least desirable for stabiity so the sturdier the mount the better. Additionally on a weak mount you will get loads of focus jiggles as the moment of force is a long way from the mount axis.

D25

[John]

Clive,

I had one of the 150mm F/8's for a short while. It started on an EQ5 mount but was way under-mounted. Then tried an HEQ5 which was OK for visual use. I agree with the other views that an EQ6 would be the best option.

John

[Analogue]

Hi Guys,

Thanks for all your help.

I do have the F8, you have confirmed what I pretty much thought. Looks like the EQ5 Deluxe is the way to go for now (the EQ6 would be too heavy for me).

I tried the scope out on a CG5 last weekend (thanks Ian) and it was fine, deliberately pushing on the counterweights induced hardly any movement.

The CG5 was mounted on a pedestal and, as Dweller mentioned, it was no fun grovelling on the floor to see through the scope

One final question, if you don't mind; when manufacturers do mention the load capacity of the mount (which seems rare??) are the counterweights likely to be included in the figure, i.e 8Kg load = 5Kg scope + 3Kg counterweight?

Thanks again,

Clive.

[dweller25]

Hello Clive,

The mount loading recommendation is for the OTA only and assumes a similar balnce weight loading.

For example my HEQ5 holds a 9KG OTA plus 10kgs of balance weights = 19kgs and it is fine. The manufacturer sells it as a 13kg mount.

My HEQ5 would not handle the focus jiggles of a 1200mm refractor - it's not the weight of the OTA it's the distance of the focuser to the mount support.

D25

[philsail1]

Hello Clive,

I have a TAL100RS (which is 1,150mm long) and my HEQ5 holds is OK (see photo).

(click to enlarge)

I only need to use one of the 11lb balancing weights which came with the mount (I bought the mount with a Skywatcher 200mm Newtonian Reflector - which I still have).

The only negative I have noticed (and have to agree with Analogue and Gax O'c) that I do get some minor "jiggles" when focussing, particularly when using a high power). Whilst this is a minor inconvenience, if you are in a position to obtain a sturdier mount (HEQ6), I would agree with the others and recommend the HEQ6.

Hope this helps,

regards,

philsail1

[Stardust]

Hi Phil

can't help but thinking your skyview is lacking somehow! are you looking for micro organisms in the bricks?

and the Tal 100 does look nice, stop tempting me.

Dave

[iancandler]

Welcome to SGL lil brother...

Guys this is my brother clive that I have spoken about before.. he's not a newb at astronomy but is with the gear he has now (the 6" frac)

This is clive and his frac on my mount at the weekend.

[philsail1]

Dave,

It's not as bad as it looks!

(click to enlarge)

But it could be better!!

I've got a clear uniterupted view to the South East, and right round to the North - from an angle of about 30 degrees! No view to the North East or East at less than 70 degrees.

Regards,

philsail1

[Stardust]

Phil that's a better view

Clive the 6" frac looks a beaut, what make is it?

Dave

[Analogue]

Hi Dave,

The scope is the Phenix F8 1200mm.

I am aware of the CA problems associated with refractors and before I bought it I availed myself of a WO VR-1 minus Violet filter.

This combination provided delightful views at the weekend, I was impressed.

Ian kindly pointed out that I posted my question in the wrong place, that's what 'newbies' do, so I guess I posted it in the right place...(Psychology...Ahrrrgh). Apologies to all either way.

Apologies also to Ian for knocking off his DEC knob with the RA motor.......I don't suppose 'it was dark' is much of an excuse :nono:

Thanks again to all for your help and making me feel welcome.

Clive.

Current scopes.

80mm Refractor

102mm Newt

150mm Refractor

150mm SCT

250mm Dob

[barkis]

I own a 152mm f8 and it is mounted on a Astro5 mount. I have had my ED80 and the frac. mounted on a duo plate sise by side, and it drives in both axis with no problems at all. I am going to get an EQ6 Pro shortly, that mount will cover all my options, including mounting my LX90 M12" OTA, should the LX90 Guiding via the AP Module give me any headaches. An article in an edition of the Sky at Night Magazine informed me that

Mounting the 12" on the EQ6 was easily done, and a few readers had actually done it.

Ron.