I note that a few people have paid a lot of money for these knobs from Bintel, but that is not my experience.
A set of six knobs, 3 collimating and 3 locking, for a 12" Meade LB, or the GSO 12", just cost me $54.00 including postage from Bintel to central Victoria. The price was confirmed over the phone at time of purchase.
Great service, as always, from a very reliable Australian supplier.
Hi all, I don't get all this fuss about the knobs. Maybe it's because my 10" Lightbridge is still new.
I applied a very small drop of sewing machine oil to all the thumb screws and the truss tube mounting screws, with a wipe with a tissue to prevent any possible run-off from the oil. All threads should be lightly lubricated which results in minimum force to tighten and loosen, otherwise most threads tend to bind and wear. Anyway, maybe if I can get to use my scope more often I might find that I'll also will be looking for Bob's knobs.
I think thumb screws for the secondary is a good idea.
I think a clear distinction needs to be made about the issues of "Is the collimation set: (a) too expensive here in this country, (b) BinTel charging too much, or (c) or just expensive alltogether.
For example, the parts for a 10" Lightbridge from Astronomics in the USA:
- a set of primary and secondary knobs is $49.95 USD (here)
- a set of springs $16.95 USD (here)
- Total $66.90 USD or $84.65 AUD (at current exchange rate)
- Cost at BinTel (everyone seems to be quoting them) $96.00 AUD
That's only $12 more. Seems totally reasonable price to pay in this country, considering the USD price to a US resident.
I had them fitted to the LX90 on purchase and I believe they are a worthwhile addition to any scope, particularly SCT's with the fiddling around near the corrector plate.
hoo roo,
I think a clear distinction needs to be made about the issues of "Is the collimation set: (a) too expensive here in this country, (b) BinTel charging too much, or (c) or just expensive alltogether.
For example, the parts for a 10" Lightbridge from Astronomics in the USA:
- a set of primary and secondary knobs is $49.95 USD (here)
- a set of springs $16.95 USD (here)
- Total $66.90 USD or $84.65 AUD (at current exchange rate)
- Cost at BinTel (everyone seems to be quoting them) $96.00 AUD
That's only $12 more. Seems totally reasonable price to pay in this country, considering the USD price to a US resident.
I had them fitted to the LX90 on purchase and I believe they are a worthwhile addition to any scope, particularly SCT's with the fiddling around near the corrector plate.
hoo roo,
Stephen
Yes, I agree Stephen ... the prices are not that much different, so obviously go OZ. I will when I finally get them.
As Chris says - a set of 6 knobs for primary mirror is $54 incl postage.
I need springs as well, and would like secondary knobs too so puts price up to around the $100 ish.
I don't think anyone claimed that Bintel were gouging, just that Bob's Knobs are expensive. They make collimation significantly easier, but don't actually enable you to do anything new and that is what you should bear in mind when deciding to buy some.
Also, looking at the link given above, if you know the correct screw thread and knob dimensions, you could probably buy the same for a fraction of the price.
Buying the knobs may not allow you to do anything different, BUT.......the job of collimation will be significantly better and easier.
On my 12"LB, the original configuration needed a flat blade screwdriver for the primary and phillips head screwdriver for the secondary.
Consider trying to insert a flat blade driver onto the screw head in the dark!! or holding a p.h driver over your secondary to collimate it, with the possibility that it could slip from your grasp and fall onto the primary!!
All of a sudden the $80 - $100 for the improved versions appear quite cheap.
I don't think anyone claimed that Bintel were gouging, just that Bob's Knobs are expensive. They make collimation significantly easier, but don't actually enable you to do anything new and that is what you should bear in mind when deciding to buy some.
Also, looking at the link given above, if you know the correct screw thread and knob dimensions, you could probably buy the same for a fraction of the price.
No worries, I was just trying to clarify the original argument for Liz.
You are quite correct also with sussing out a DIY alternative. As Nightstalker suggested, the company: http://www.smallparts.com.au/store/categories/knob/ looks like a great source of parts for this purpose. I have bookmarked them also.
And to perhaps end this thread I would just like to congratulate everyone for managing 30 posts on Bob's Knob's without a single 'knob' joke! I don't know about anyone else, but I've found it quite hard!
And to perhaps end this thread I would just like to congratulate everyone for managing 30 posts on Bob's Knob's without a single 'knob' joke! I don't know about anyone else, but I've found it quite hard!
And to perhaps end this thread I would just like to congratulate everyone for managing 30 posts on Bob's Knob's without a single 'knob' joke! I don't know about anyone else, but I've found it quite hard!
I've put the secondary knobs on my skywatcher dob, and they've made collimation significantly easier. no tools, and you can turn your attention to which way the mirror needs to go instead of figuring out why the allen key is slipping.
And to perhaps end this thread I would just like to congratulate everyone for managing 30 posts on Bob's Knob's without a single 'knob' joke! I don't know about anyone else, but I've found it quite hard!
... I think I must have an innocent mind.
"I've put the secondary knobs on my skywatcher dob, and they've made collimation significantly easier. no tools, and you can turn your attention to which way the mirror needs to go instead of figuring out why the allen key is slipping.
well worth the $30 bucks or so."
Did you get ones for the primary too Nathan, or just the secondary?
Just the secondary. The primary collimating knobs supplied on my skywatcher are very similar to bob's knobs. I may need to upgrade the springs, but my scope holds primary collimation very well (imo) already.
I've put the secondary knobs on my skywatcher dob, and they've made collimation significantly easier. no tools, and you can turn your attention to which way the mirror needs to go instead of figuring out why the allen key is slipping.
well worth the $30 bucks or so.
i wonder how long till they make skywatcher primary mirror knobs i suppose its all supply and demand
mozzie
And to perhaps end this thread I would just like to congratulate everyone for managing 30 posts on Bob's Knob's without a single 'knob' joke! I don't know about anyone else, but I've found it quite hard!
Dobs Knobs cant be that hard,
you should try an SCT when you cant reach yr knobs whilst looking into the EP.
However, it is much easier if you stick a bicycle spoke into the side of yr Knob first
Stop thinking those thoughts and look at the piccy.
How close would the primary threads on a GSO 8" Dob be to the equivalent Skywatcher? My SW just has allen head screws on the primary, so a set of Bob's would be a significant advantage. I'm surprised that they're not available.
so puts price up to around the $100 ish.
or holding a p.h driver over your secondary to collimate it, with the possibility that it could slip from your grasp and fall onto the primary!!
... I think I must have an innocent mind.
clever! thanks.
