Crayford focuser

[snug]

Hi folks

ok ive made the decision to go with a dob. At first i thought 10" but now re-looking at the 8" mainly due to portability. (8= $549 & 1= $699 + post) So both are at Bintel the only difference apart from size and cost going by the net site are

* 1o".... 'are equipped with a smooth 2" Crayford focuser featuring extra smooth 10:1 fine control for precise focussing even at high power'

* 8"... 'are equipped with a smooth 2" Crayford focuser without backlash.'

1st... im assuming these are different. If so is it the focusser on the 10" more desirable. Can i then ask the man at bintell to include it on the 8.

2nd...If i buy the 8 it will also leave me a little money up my sleeve. I've been reading up on the Telrad. Is that also something a beginner will use. I also thought maybe a 2x barlow.

I must admit my daughter and i are having a ball with the binoc's & a star chart at the moment. If anyone can give me some feedback on the focuser etc that would be great. This will be my last 'big' purchase for a bit and i want to get best value for money (dont we all..lol)

Ta Snug

[tnbk00]

I got one of the last bintel 10"s without the 10:1 and now im going to upgrade.

The focuser assembly seems to be exactly the same with the exception of a bolt on bit that has a geared knob that changes the ratio i.e 10 turns of the black bit will give you one turn of the main bit. Look on the bintel site under ATM supplies for some more info about the focuser's.

[Starkler]

Go for the 10:1 definately!

After upgrading and getting one I wouldnt ever be without it. With it there is no doubt as to whether you have got the best focus.

[Jupiter]

I use my 2" Barlow nearly all the time, especially on the planets.

[erick]

Maybe the Bintel folks will swap the existing Crayford for a 10:1 Crayford, for a small changeover price? You can ask.

I have the nomal Crayford and was going to replace it with a 10:1 ($119 on Bintel's website. Difference in listed price for the two focusers is $20). But I then got a second-hand electric motor focuser and fitted that instead (need some skills to do that - it wasn't a straight drop-in fit for the electric motor and the focuser) and it's a much better result since you keep your hands of the scope which is a benefit at higher magnifications.

If you have handyperson/engineering skills, this option could be worth considering - but, if they will do it, a Bintel swapover option should cost less for a different, but also good result.

[Tannehill]

The fine focus control option of the 10:1 makes focusing easier. The f5 10" GSO dob will be a more touchy focus point than the f6 8". The in-focus point is narrower with the f5 (faster) scope, because the light cone is "steeper" coming in from the primary mirror. I have the 10" f5 Bintel Dob and notice the absence of the 10:1 option which i have on a different (faster) scope, so I, too, was going to upgrade to the 10:1. It's on SALE!

The absolute gain is probably modest, and most noticed on scopes in the f4-4.5 range. But if the difference is cheap (it seems to be!) AND you really like planets, you might find it does make a difference on the enjoyment factor. Collimation tool and accuracy are probably more important overall by the way...

Scott

[snug]

hi

Well i just emailed Bintell to see how much it will be to swap the focusser. I'll let you know how i get on. If it looks like costing to much or delaying me getting it I think i may look at the 10".

Thanks for your comments. The more im learning the more questions i have (smile) & i do appreciate the time people take to answer

Snug

[snug]

Hi

Well just had an email from Bintell, saying they have just got new stock in and they can change the focuser for $30 (On the 8"). Also that postage to Woolgoolga is $50 (overnight!!) The 10" ends up being $150 dearer. So I think the 8" will be will be the one with a telrad.

How good is that!

[astronut]

Hi Snug,
Congratulations on the new scope. Regardless of size you're going to see some great views through it.
So far as the dealer goes, Bintel would have to be the best company to deal with:thumbsup:
Make sure you post a first light report.:)

[erick]

You won't be sorry (until you start wondering what the view would be like through a 16"!). I've very happy with my Bintel 8" - my first scope. Yes, a Telrad plus a Barlow lens would be very useful. :thumbsup:

[snug]

Thanx guys

I just ordered the 8...a little part of me is still screaming.."Go the ten!!!" but if i did that would wipe me out financially & i couldnt get any extra.

I also ordered the telrad (god i hope it comes with instructions). I really want a Barlow but all i can afford now is the Bintel 1.25" at $49. So i was unsure whether it would be worth it, or wait till i have more money.. What do u reckon lads

[erick]

Seems to me is best to learn about these scopes on something manageable first. You'll be able to sit for all your observing with the 8" - might need a cushion or two on the chair for the zenith! Save a few more dollars and get the Bintel 2". Alternatively, ask in the Classified pages - someone may be happy to sell theirs?