C8 on Porta II

[TimB]

Hi. I'm swapping my SW  MAK 127 for a Celestron C8. My Mak 127 is fab on the Porta II. Weight for weight they both fit in with the spec for the Porta II (mak127 5kg and C8 5.67kg) I understand that this is not a new gab and go idea, but i was wondering how usable this set up is? Maybe the TS optics AZ mount is better. Thanks for any advice given.

Tim

[Peter Drew]

Should be fine, I wouldn't be surprised if it was more stable than on the Se mount.  

[andrew63]

Just don't blow to hard 

 

andrew

[Philip R]

As per @Peter Drew's answer above, it should be fine for grab'n'go visual. I was tempted to get the Porta, (I think it was the Mkl when they were released). I purchased an ETX-105, and decided that I needed a dual-mounting side-by-side mount.

Photo of my C6 & ETX-105 on a Giro Mkll

 

My setup (see photo) is not the same mount/OTA config/weight as yours, but I can mount my C6 on my Giro Mkll on its own and it is OK. I have seen a C8 mounted on a Giro Mkll or Mklll elsewhere on i'net.

Edited June 5, 2017 by Philip R

[TimB]

Nice set up. Won't blow hard.....windy and rainy in Coventry today...blow it!

The SkyTee-2 Alt-azimuth mount might be an option for a C8. Do you need counter weights if you only have one OTA on one side? I can't find info to say yes or no or does it depend which way the wind's blowing? Counter weight requirement is counter to grab and go.....

Tim

[andrew63]

I think a problem you could have, and you would only know by trying, is the diameter of a 8" scope in relation to the arm of the mount. How far can you get to the zenith without obstruction ?

 

andrew

[Racey]

7 minutes ago, andrew63 said:

I think a problem you could have, and you would only know by trying, is the diameter of a 8" scope in relation to the arm of the mount. How far can you get to the zenith without obstruction ?

 

andrew

Very good point Andrew. Just out of idle curiosity I tried to mount our 8" EdgeHD on our Star Discovery Mount for no other reason than "because I can"...

But I encountered exactly what you alluded to... Maybe the Vixen gives more clearance. But I doubt by much. 

Also I'd point out that even with the cooling vents our SCT is anything but "Grab and Go" thermal equalisation takes about an hour...

And I would never try single handedly mounting the SCT dovetail to a "side on" mount ever again unless I could point the clamp towards the ground and have clearance. 

I introduce the SCT to our Ercole with the Corrector Plate facing the ground. Once introduced to the clamp I can hold the SCT by its handle. This allows my other hand to tighten the clamp. 

Trying to do same with clamp pointing horizontally as required by the Star Discovery is something I don't want to attempt again...

?

[TimB]

Hi. Maybe i'll just attach a cupboard door handle to the top of the OTA to help with one handed side-on dovetail fitting. Anyhows, why don't OTAs have better ergonomic handles? Is it in the manufacturer's interests to have us drop them occasionally?  Are there any after market OTA handles available other than from BnQ? Too many questions. 

I understand that the altitude range of movement for the C8 on the Porta II will be restricted so I'll look elsewhere for a mount and get my Mak127/PortaII hybrid up for sale soon.

Great help here! Thanks.

Tim

Edit.....just noticed the C8 comes with handle already attached 

Edited June 5, 2017 by TimB
Being a bit slow headed

[Cosmic Geoff]

What's your definition of grab'n go? Go out to the backyard, or to the dark countryside?

I would not call my C8 Nexstar SE a grab'n go, but as set up with the Starsense, I can pick up the whole scope/mount/tripod assembly, lug it outside, put it down, remove covers , connect battery, start up the alignment, and have it ready for use (asides from cooling down) within a few minutes.  Note that I do not do any dangerous mounting of the scope to dovetail clamp or any time-consuming assembly or leveling.

For quick deployment, I can have my AZ-4 mount outside and one of the small scopes on it in a couple of minutes.

[Racey]

1 hour ago, TimB said:

Edit.....just noticed the C8 comes with handle already attached 

That's what I said. But it's no use for mounting onto a horizontal side on clamp...

Edited June 5, 2017 by Racey

[Mrs Racey]

5 minutes ago, Racey said:

That's what I said. But it's no use for mounting onto a horizontal clamp...

I can vouch for this. It's a two person job to get a C8 into a horizontal side on mount. 3 hands are required ?

It is the most risky and potentially disastrous thing to attempt by one person. 

It was the swearing and cussin' that alerted me to this the one and only time it was attempted.., 

Edited June 5, 2017 by Mrs Racey

[TimB]

1 minute ago, Cosmic Geoff said:

What's your definition of grab'n go? Go out to the backyard, or to the dark countryside?

I would not call my C8 Nexstar SE a grab'n go, but as set up with the Starsense, I can pick up the whole scope/mount/tripod assembly, lug it outside, put it down, remove covers , connect battery, start up the alignment, and have it ready for use (asides from cooling down) within a few minutes.  Note that I do not do any dangerous mounting of the scope to dovetail clamp or any time-consuming assembly or leveling.

For quick deployment, I can have my AZ-4 mount outside and one of the small scopes on it in a couple of minutes.

Hi. Grab and Go for me means light and quick. I've had several set ups in the past and then gave up.  I had a Nexstar 8se for awhile and had to keep it in an upstairs bedroom so with carrying OTA, then Mount, then Powertank downstairs, waiting for alignment (yawn), waiting for cool down and then finding the alignment hadn't worked i just sold up. 

Lately i came across the term Grab and Go and read more about it. Now i keep my MAK127 with PortaII mount in my shed with 32 Plossl attached and it takes me literallly 45 second to get out and set up with no cool down and i'm finally buzzing about astronomy again. No goto or equatorial for me this time. Easy to take on hols too.

Hence my inquiry about 8se on a Porta II. The MAK127 is just a little small, so i'm trying to put together a 8se Grab and Go setup. 

Tim

[Dave In Vermont]

I'm using the Vixen Porta II for a Skywatcher 150mm F/12 Maksutov. Aside from a night with winds gusting at 35 - 40mph, it was very nice and stable in it's handling this. The slow-motion cables did an exemplary job in keeping up with our Earth's rotation at up to 124X (as high as I wished on my target). I'm sure it could have handled 2X this easily.

I am quite satisfied with this mount. And I'm sure it will be fine with a C8 SCT.

Well done!

Dave

[Racey]

25 minutes ago, TimB said:

Hence my inquiry about 8se on a Porta II.

 

25 minutes ago, TimB said:

waiting for cool down and then finding the alignment hadn't worked i just sold up. 

It's not going to cool any quicker on a Porta ?

Edited June 5, 2017 by Racey

[TimB]

2 minutes ago, Racey said:

 

It's not going to cool any quicker on a Porta ?

Hi. The Porta II Tripod goes higher than the Nexstar Tripod so cool down is faster at higher altitude .

But seriously i keep my OTA and mount in my shed now so have no cool down issues. 

Tim