Is the Skymax 180 Pro really that good?

great_bear · September 9, 2010

Maks are seldom cloomatiable well without a proprt optical set-up rig. I know people say they have done it but I have read enough articles by Mak'sperts' who say its not really possible.

You can't use a Cheshire of course - but obviously possible - indeed relatively simple - to do it using an artificial star.

as well as flock the interior of the tube.

The OTA tube wouldn't help much. The baffle tube on the other hand - now that's something I'd take a shot at - if I had more time... :blob10:

Astro_Baby · September 9, 2010

Really GB - I have read that its near on impossible to get a Mak perfect without some heavyweight gear because of various issues - I cant pretend to understand all of the optical theory - just enough to know that people much smarter than me with an 'ology' after their name say you shouldnt mess with them :blob10:

I can believe it because if you had to collimate a newt from scratch with only an artificial star you could do it but I suspect it would be a long old process. Star testing would work ok once your close to the limit. If I had to fit a cooling fan to the back of the 180 it would mean a near total strip down so when its rebuilt it would need collimating from waaaay out of whack.

If I took it to bits I might try just for fun to recolimate from scratch but theres plenty of advice online which says 'dont do it'

great_bear · September 9, 2010

know that people much smarter than me with an 'ology' after their name say you shouldnt mess with them.

Wow... I'm shocked you (of all people) would take such a view.

People's qualifications mean nothing in isolation - instead, the facts and arguments that such people present need to stand up to scrutiny on their own merit - I couldn't bear to live in a society that didn't respect that philosophical principle.

Anyway - all I'm interested in is the procedure itself and the difficulty - or absence thereof - in performing it. When people say "collimating a Mak is difficult - don't do it" - I want to understand what precisely is it that they are referring to with regards to difficulty?

And I'm sure you'll find that it's the fact that many Maks (probably most Maks actually) simply aren't designed to be collimated outside of the factory. You have to perform a fairly comprehensive and fiddly dismantling exercise in order to get to the screws - screws which will already have sealant dropped onto them - so there willl be cracked bits of red varnish floating about the place (not nice for a scope). And those screws may not be designed for extensive tweaking and may thread / fall-out etc. Once you're done, you've got all that reassembly to do. No wonder people tell you not to collimate such Maks!

I've been inside a 100mm Mak, and no - I wouldn't dream of experimenting with the collimation.

But we're not talking about those Maks are we?

We're talking about the Skymax 180 Pro, a scope which is designed to be user-collimated.

GazOC · September 9, 2010

If someone ever finds out HOW to remove the corrector cell off the end of these things (Or at least my MAK150!) I'd be interested. Aside: Those "rivets" on the 150 are of course M2.5 hex screws. Idem the 180? E.G. a slightly shorter dovetail bar on the 150 might facilitate attachment of a dew shield... and more besides.
By analogy, The MAK127 has a threaded corrector cell - Just grip the OTA between the knees and twist... I sense a "brave volunteer" is needed.
P.S. The price of these MAKS does encourage a bit of experimentation, thoughbut.
I would not want to be drilling holes into the OTA of an "AstroPhysics" (whatever).

Mak,

I have a spare 180mm Mak/Cass, the primary was broke in transit and Steve from FLO (in addition to sending me another) allowed me to keep the other scope for spares.

If a get time over the next week or so I'll remove the meniscus and let you know how I got on.

Gaz

beamish · September 9, 2010

FWIW

When I rec'd my Intes I had to remove the meniscus, 2ndry and primary, had the primary re-coated, put back all the bits and re-collimated within an hour, star-tested , tweaked and creamed in amother 20-30 minutes.

AND....... the only bit of specialist kit required was a set of allen keys and and a colly cap and a screw driver !

read about it here, it worked !

http://stargazerslounge.com/equipment-discussion/109736-mak-cass-collimation.html

Whippy · September 9, 2010

Really GB - I have read that its near on impossible to get a Mak perfect without some heavyweight gear because of various issues - I cant pretend to understand all of the optical theory - just enough to know that people much smarter than me with an 'ology' after their name say you shouldnt mess with them

It's not that bad, really. If anything, the SW maks (if they have the collimation screws of course) should be a bit easier because you haven't got the secondary to worry about as it's a silvered spot on the meniscus.

Tony..

beamish · September 9, 2010

Having said that it IS designed for user collimation :blob10: being a Rumak

michael.h.f.wilkinson · September 10, 2010

Now I'm leaning towards a C8 - much lighter and more flexible, as has been pointed out. And it is probably better built.

I absolute love my C8. The GP mount is very easy to align (very good polar axis finder!)

Astro_Baby · September 10, 2010

Well Bear I do take that view - with newts they are pretty much designed to be user collimated but even with the humble newt its not easy to find solid advice on them and certainly when I started messing with mine at first it was a nightmare because so few guides bother to mention the issues surrounding fast refeflectors and the traditional (and oft seen) collimation guides never mentioned the offset issues. Offset itself causes all soprts of misunderstandings on forums as a quick look an any astro forum will testify. If it handt been for Jason taking pity on me I might still be attepmting to collimate it now

Thats for a relatively simple, straight forward type of scope. Albeit one I am comfy with. In part my collimation guide was written for me as much as anyone else to knock the priciples into what I am pleased to call my brain :eek: but also to try and spare other newbies from having to learn the hard way and suffer the slings and arrows of outrageous collimation.

I know next to zip about Maks, I understand the basic principles but to me theres a big difference between understanding the principles of flight and being able to fly yourself. Same for me and the Mak - I read a fair bit and very much the conclusion I came to was that I'd rather not mess with it unles the need was dire. On the principle of 'first do no harm' I'm a bet reluctant to trust advice when as I say people with apparent expertise all say 'forget it - its too tough'. The only other Mak I have is the Nexstar 4 and that really is a non starter to collimate yourself and thankfully no one should ever have to.

Now I agree the MAk 180 has some easy to access collimation screws but that doesnt mean its there for you to mess with. My old Vauxhall VX4/90 had easy to access cam follower adjustment screws but it would be a rash person who would mess with them I could twist the collimation scrtews about and get concentric circles but how would I ever know if it was in perfect collimation ? You cant even rely 100% on star testing because Maks (from what I read) seldom show the classic intra and extra focus type results.

The answer for me is I dont know, the only way of finding out would be to mess the collimation up and see if I can fix it. Even if I assumed I had fixed it how would I ever know for sure ?

At the moment its all academic because I might not even keep mine. If I sold it it would become someone elses problem for the future. If I keep it then mine would almost certainly be stripped down to effect some fixes to it and that would lead to recollimating in which case I may have a go but I suspect I'd get it done by someone more competent than me just so I could be sure its working at its peak.

omneferuss · September 11, 2010

Astro_Baby,

I suggest you reread your post after rereading the quotation you have in your sig, and ask yourself if they are compatible ??

great_bear · September 11, 2010

Now I agree the MAk 180 has some easy to access collimation screws but that doesnt mean its there for you to mess with.

Then why does the instruction manual (for the Orion version) contain collimation instructions?

great_bear · September 11, 2010

people with apparent expertise all say 'forget it - its too tough'.

I'd like them to explain precisely what aspect of adjusting three pairs of screws is beyond their capacity - otherwise it just looks like a sweeping generalization that might not apply in all cases. One can't trust such an empty statement.

You cant even rely 100% on star testing because Maks (from what I read) seldom show the classic intra and extra focus type results.

Yes - it's a design feature - but that doesn't affect collimation procedures.

the MAk 180 has some easy to access collimation screws but that doesnt mean its there for you to mess with

The user manual contains collimation instructions.

(Orion version)

dweller25 · September 11, 2010

Collimating the 180 Pro is as easy as collimating a newt. I did mine at x540 on a really good night and it was spot on.

Astro_Baby · September 11, 2010

omneferuss - theres nothing incompatible in my sig to my post ta very much. Its not pessismistic to state that if you fall out of a 20 story builing you'll die or by attacking the parachute regiment while armed only with a rolled up copy of the guardian you'll get seriously injured Neither is it pessimistic to suggest that I dont want to mess with something I know little about in case of problems- Plenty of folk on here have done this at one time or another through either ignorance or a surfeit of optimism and found to their cost it wasnt a smart thing to do.

GB - I'm at a bit of a loss to answer your comment about collimation above -

Quote:
You cant even rely 100% on star testing because Maks (from what I read) seldom show the classic intra and extra focus type results.
Yes - it's a design feature - but that doesn't affect collimation procedures.

You seem to be saying 'yes you cant use a star test but that doesnt affect collimation procedures' that exactly what I mean - I can twiddle the knobs about and do what I think is right (thats the easy bit) but how do I know at the end of it if IT IS right. If I cant star test then how do I know if its ok. I foresee star testing with the mirror shift inherent in the scope is going to be painful.

The user manual for lots of things contains instructions which you as the user are better ignoring in my experience. By the way the 180 came with no instructions at all. I dare say some might be online in much the same way as there are manufacturers instructions about polar aligning (and we all know ho much use they are right :eek: ).

People do say they have collimated these ok but pardon me for sounding sceptical I see plenty of posts wehere people claim to have collimated their newt perfectly (me included a long time back) whose collimation was subsequently shown to be out by a country mile. The same thing happens in other stuff - people who claim they tuned the car fine with a Halford kit even though you can hear the valves are being knocked to hell.

My own view (as already stated) is IF the 180 performs then I'll keep it. IF I keep it it will be stripped to bits to imporve it somewhat. IF after stripping it, upgrading it and rebuilding it I will make a first pass at collimation. IF I feel its not right I'll get an expert to take a look and get their input to assess as to how well I done.

Assuming that all goes forward you can be sure I will be writing the definitive guide on it online complete with pics so no one else has to worry in the future - cos I am nice like that.

Personally I am stopping this thread here cos its already way off topic - In a nutshell either (a) someone is going to get a chance to acquire a mint 180 or ( I am going to be doing lots of mods to improve the 180 and the world will get a guide on how to take one of these to bits, collimate it and tune it.

great_bear · September 11, 2010

GB - I'm at a bit of a loss to answer your comment about collimation above - You seem to be saying 'yes you cant use a star test but that doesnt affect collimation procedures'

No.

I didn't say you can't use a star test.

I just said that the fact that intra/extra focus patterns are different, doesn't affect collimation procedures.