Celestron CPC series. Unanswerable question?

[old dave]

Is there such a thing as a generally accepted lifespan for the electronics of these scopes? I have no personal experience of GoTo etc.The context involves the possible purchase of a used scope without being able to see it or try it out first or even have knowledge of the owner (apart from phone calls). I realise that it could depend on the age, how it has been kept and used and your luck. I am simply trying to assess the risk involved. I also appreciate that a brand new one could be faulty and that you may have no problems for many years. However excluding the extremes and the possibility of a lemon or an unscrupulous seller is there anything specifically to look out for? I quite understand that it would be best to see and try it out beforehand.

Thanks

Dave

[nightfisher]

I dont think its fair to try to answer this, i think you have to pay the money and take the chance, good luck with the decision

[astrofox]

Conventially electronics has what is known as a bathtub reliability curve. That is it suffers a higher failure rate at the begining due to manufacturing defects. The burn in period usually not longer that 6 months  but with failures tending to occur almost immediatly. After that the failure rate is low and constant until wear out measured in years ( say >10yrs) However our electronics are married to mechanical devices which themselves have seperate reliability curves. I would suggest mechanical failures dominate long term reliability.

We still get failures due to operator error ( reverse polarity and the like) Eventually connectors and cords fail due to continuing insertions. In my opinion the standards manufacturers use on their connectors is willfully poor. RG style telephone jacks and concentric plugs.

[AstroJOE]

Dave, there's always going to be an element of risk when buying anything second hand I suppose however I'd imagine anyone who'd parted with their hard earned cash to buy one of these in the first place would have been a fool not to look after it.

I have the CPC1100 and I can vouch for the fact it's a solid piece of kit. Only had mine for about 9 months so I can't comment on the lifespan of the electronics although I don't recall ever seeing a post on this forum regarding the electronics failing from other owners.

I guess it depends how good a deal there is on the table - although if it's too good to be true it's probably not worth the risk.

Any idea how old the one you've been offered is?

James

[old dave]

Dave, there's always going to be an element of risk when buying anything second hand I suppose however I'd imagine anyone who'd parted with their hard earned cash to buy one of these in the first place would have been a fool not to look after it.

I have the CPC1100 and I can vouch for the fact it's a solid piece of kit. Only had mine for about 9 months so I can't comment on the lifespan of the electronics although I don't recall ever seeing a post on this forum regarding the electronics failing from other owners.

I guess it depends how good a deal there is on the table - although if it's too good to be true it's probably not worth the risk.

Any idea how old the one you've been offered is?

James

Hi James, I can`t answer your question as I have not contacted anyone about this.  I am really trying to cover some aspects outside my experience. Your replies are appreciated.

Dave

[ronin]

Very difficult to supply an answer, from reading elsewhere when they became part of Synta the components used eventually dropped in quality and also tolerance. Celestron originally used components that were easily capable of doing the job. In effect one of the older ones may well prove a better option then a newer one.

There was here on SGL a spell of reports of failed electronics on Sky Watcher and Celestron Electronics, went on for about 18 months with reports appearing, they seem to have dropped off now so perhaps something has changed/improved. However most were the Synscan and occasionally the SE series, however I cannot recall any with respect to the CPC series. Suspect they are better manufactured.

The mechanical side, the Celestrons had a beter reputation then Meades. That may have been down to the manual wording:- Meade said "Tighten the clutch", Celestron were a bit more specific. People with Meades tightened the things too much, so motors and gear train failed. Result was Meade changed the manual wording. So that depends on the owner, however if the drive is working smoothly that likely means no damage. I have a small old Meade that is 12+ years old with plastic cogs and working fine, everyone swears blind the drive will fail if you look at the scope.

In general the CPC's seem to be the better model they made and unlike the other models I cannot recall any complaints, even here it is Synscan and SE's that gets mentioned, cannot recall anyone asking about a CPC. So seems they are a fair bet.

Will say if it works leave it, don't start trying to update the firmware. In general you usually gain little and if the update fails you could have nothing.

A lot depends on the cost and the impression you have of the seller. Unless it was a long way off I would prefer to see the scope, mainly as I guess you are looking at something around the £800+ mark depending on the model. Think they did an 8", 9,25" and an 11". However I am a bit more central then you are.

[brantuk]

I wouldn't spend so much money on a second hand scope without first seeing it and trying it out for myself. If it were new and from a reputable dealer then you get the warranty's and after sales service that go with the price.

That said - the CPC's seem very reliable - I've had two including the 800 from new for 2yrs and the 925 s/h for around 3yrs. Never had a problem with the electronics on either - in fact I haven't had any problems at all with either one.

If you're in phone contact with the seller, try and ascertain where they are, what they do for a living, and which astro club they're in. A few open ended questions thrown in at random during conversation can reveal a lot. If they're forthcoming and seem to have nothing to hide then your chances of getting done over may be reduced - especially if you follow up with a little research afterwards and confirm their story.

If they seem a bit cagey then I'd pull out of the purchase and try elsewhere - there's never any rush cos the stars aren't going anywhere soon.

[Northern Soul man]

Hi ya Dave (I've left the "OLD" out), I have the 1100 and bought it new just over 12 months ago - really nice - no problems - I really would suggest YOU GO AND HAVE A LOOK at any scope you want to buy.

There's only 2 main things with all scopes :-

Optics

Electrics.

Firstly - optics, just a general look down the wrong end of the scope - there may be dried water marks due to dew (is that a double entande !!) - if there is, it shows that the scope has been used and dew built up - the larger the scope the more prone to dew they are, depending on what dew control they have used, easy fix with a clean - maybe only the corrector, with care, this can be done by you - there's enough video's about showing you how to strip and clean correctors - that's about it regarding optics, a quick look through an EP at night against a star will reveal any collimation issues - again, easy fix with plenty of video's on the subject.

Just before you try the electrics - loosen the clutches on each axis, Altitude, the azimuth - try in each case - should be smooth - there has been issues with the azimuth bearings giving very poor rotation - jerky and inconsistant - easy fix with a ball bearing mod - well documented - can be done by you.

Next - Electrics - try out the GOTO, Align - try a few objects, listen to the motors whilst slewing - should be consistant with no erratic change in sound/pitch of the motors, IMPORTANT - just try the slew rates whilst observing a planet with a higher magnification - change the slew rate 1-4, then 5-9 and see if there is any motor backlash issues - whilst pressing the GOTO arrows, watch to see if the motors start up with a "jerky" action - people have said that the worm drive needs to be adjusted if this occurs - easy fix by you, - also people have mentioned a "ticking" sound whilst the scope is tracking, with a "jump" in the tracking - most have done the ball bearing mod - then this ceases.

Then just a general "look" over the scope - you will see straight away if the scope has been looked after within the first few minutes - regarding your issues with the electronics - just follow what has been mentioned by other Astronomers on here.

This is what I have picked up over the years and as we all do - worry if its not the right purchase, but remember, these scopes are mass produced, if you look hard enough, you will find problems with all of them - even heard of buying brand new with problems out of the box, all the electronics are plug and play - so if there is an issue - its just the cost of a new board.

With the advice of all the above Dave, within the first few minutes of looking at a prospective purchase, you will pick up on anything - Don't think that we are being negative, but the old saying "Buyer Beware" but I would definitely "try before you buy".

Then there's post purchase - the minute your up and running with the night sky above you - I think you will understand what you have before you.  Hope that helps a little Dave, the night sky has given me a tremendous amount of pleasure over the years and given me some amazing views of the Moon/Planets/DSO's - and all from the light polluted Midlands - Good luck with whatever you decide mate.  Regards   Paul.

[old dave]

Hi ya Dave (I've left the "OLD" out), I have the 1100 and bought it new just over 12 months ago - really nice - no problems - I really would suggest YOU GO AND HAVE A LOOK at any scope you want to buy.

There's only 2 main things with all scopes :-

Optics

Electrics.

Firstly - optics, just a general look down the wrong end of the scope - there may be dried water marks due to dew (is that a double entande !!) - if there is, it shows that the scope has been used and dew built up - the larger the scope the more prone to dew they are, depending on what dew control they have used, easy fix with a clean - maybe only the corrector, with care, this can be done by you - there's enough video's about showing you how to strip and clean correctors - that's about it regarding optics, a quick look through an EP at night against a star will reveal any collimation issues - again, easy fix with plenty of video's on the subject.

Just before you try the electrics - loosen the clutches on each axis, Altitude, the azimuth - try in each case - should be smooth - there has been issues with the azimuth bearings giving very poor rotation - jerky and inconsistant - easy fix with a ball bearing mod - well documented - can be done by you.

Next - Electrics - try out the GOTO, Align - try a few objects, listen to the motors whilst slewing - should be consistant with no erratic change in sound/pitch of the motors, IMPORTANT - just try the slew rates whilst observing a planet with a higher magnification - change the slew rate 1-4, then 5-9 and see if there is any motor backlash issues - whilst pressing the GOTO arrows, watch to see if the motors start up with a "jerky" action - people have said that the worm drive needs to be adjusted if this occurs - easy fix by you, - also people have mentioned a "ticking" sound whilst the scope is tracking, with a "jump" in the tracking - most have done the ball bearing mod - then this ceases.

Then just a general "look" over the scope - you will see straight away if the scope has been looked after within the first few minutes - regarding your issues with the electronics - just follow what has been mentioned by other Astronomers on here.

This is what I have picked up over the years and as we all do - worry if its not the right purchase, but remember, these scopes are mass produced, if you look hard enough, you will find problems with all of them - even heard of buying brand new with problems out of the box, all the electronics are plug and play - so if there is an issue - its just the cost of a new board.

With the advice of all the above Dave, within the first few minutes of looking at a prospective purchase, you will pick up on anything - Don't think that we are being negative, but the old saying "Buyer Beware" but I would definitely "try before you buy".

Then there's post purchase - the minute your up and running with the night sky above you - I think you will understand what you have before you.  Hope that helps a little Dave, the night sky has given me a tremendous amount of pleasure over the years and given me some amazing views of the Moon/Planets/DSO's - and all from the light polluted Midlands - Good luck with whatever you decide mate.  Regards   Paul.

Paul,

What a very helpful post and I thank you for it. I have just joined SGL in the past few days and I happened to mention in my `welcome` introduction my impression of the members on this site. The proof of this particular pudding has been in the eating and you and your colleagues above have lived up to my hopes! You mention that you live in the light polluted midlands, well I am fairly fortunate in that the nearest villages to me are 1 mile in one direction and 3 miles in the other. I live on a smallholding and am surrounded by farmland. I am approx. 700 feet above sea level and my main pollution is mist, low cloud and rain (not to forget snow, sleet and hail)  ; however when the seeing is good these lights in the sky seem to `ping`. And it does tend to be quiet! However last year was a washout just like everywhere else. In fact it seemed that my head was always inside the clouds - great improvement this year.

I will definitely keep your points in mind.

Thanks

Dave

[ollypenrice]

I'm not too negative about these mass produced electronics but these scopes are not at all good for DS imaging, though for planetary imaging they are great.

However, if you buy a nice simple push-pull Dobsonian for visual use with your cash you have two moving parts to worry about. Two is a small number!!! I'd rather have that 'two moving parts' as a guarantee than any amount of consumer protection on 1000 electronic bits on a circuit board.

In asking the question you identify yourself as a wise worrier, maybe. If this is correct you might be happier with a nice simple Dob with more aperture and a far wider field of view for your cash.

Olly

[Northern Soul man]

Nice 1 Dave, its a pleasure mate.  I think one of the main concerns is that when people come into the hobby the starter scopes tend to be a little basic, especially the "toy shop" telescopes which everyone should steer clear of, years ago the next step was to spend a lot of money on something that you really couldn't research or get feedback on, now, its so easy to do your "homework" with special sites like the SGL - an absolute wealth of information, with members who know what they are talking about because they have done it or they know someone who has.

Don't get me wrong, the hobby is very technical, especially if you decide to do any Imaging/Photography - the costs of equipment, alone, reach many thousands of pounds - but the images produced are absolutely stunning.

I'm into purely visual astronomy, by the sounds of it mate your skies and location is the envy of a lot of us on here, so you have a head start - the darker the skies - the better.  For me, it was just taking the love of the night sky, a little further - getting a telescope - then another - then another, working my way up to the set up I have now, very important, I found, was to understand, that visually, I'm not going to see detail that the images/photos show, for me, it was more about just seeing the "stuff" up there, understanding how long the light has travelled to reach the eyepiece, the absolute wealth of detail that you can see.

As said, with your skies, you have a good start, yes, your a little apprehensive (as we all were) with our first purchase, I've owned a number of scopes over the years and have found each one really worth it.

Now, I think, with the amount of good quality scopes out there, you can tailor the hobby, to whatever you want.  The constant "up technology" from all the different manufacturers, means each brand is more or less the same, I've owned Meade and Celestron, the Meade I had for about 5 years, never had a problem with it and have settled with the SCT type of scope.

The next few months are going to be amazing, we have Jupiter coming into the evening skies, followed by Mars, fingers crossed, a naked eye Comet.

Keep your eyes peeled Dave, keep reading all the reviews - the CPC's, rock solid mount (dual fork arm) very accurate GOTO. All the best Mate.   Paul.

[old dave]

Nice 1 Dave, its a pleasure mate.  I think one of the main concerns is that when people come into the hobby the starter scopes tend to be a little basic, especially the "toy shop" telescopes which everyone should steer clear of, years ago the next step was to spend a lot of money on something that you really couldn't research or get feedback on, now, its so easy to do your "homework" with special sites like the SGL - an absolute wealth of information, with members who know what they are talking about because they have done it or they know someone who has.

Don't get me wrong, the hobby is very technical, especially if you decide to do any Imaging/Photography - the costs of equipment, alone, reach many thousands of pounds - but the images produced are absolutely stunning.

I'm into purely visual astronomy, by the sounds of it mate your skies and location is the envy of a lot of us on here, so you have a head start - the darker the skies - the better.  For me, it was just taking the love of the night sky, a little further - getting a telescope - then another - then another, working my way up to the set up I have now, very important, I found, was to understand, that visually, I'm not going to see detail that the images/photos show, for me, it was more about just seeing the "stuff" up there, understanding how long the light has travelled to reach the eyepiece, the absolute wealth of detail that you can see.

As said, with your skies, you have a good start, yes, your a little apprehensive (as we all were) with our first purchase, I've owned a number of scopes over the years and have found each one really worth it.

Now, I think, with the amount of good quality scopes out there, you can tailor the hobby, to whatever you want.  The constant "up technology" from all the different manufacturers, means each brand is more or less the same, I've owned Meade and Celestron, the Meade I had for about 5 years, never had a problem with it and have settled with the SCT type of scope.

The next few months are going to be amazing, we have Jupiter coming into the evening skies, followed by Mars, fingers crossed, a naked eye Comet.

Keep your eyes peeled Dave, keep reading all the reviews - the CPC's, rock solid mount (dual fork arm) very accurate GOTO. All the best Mate.   Paul.

Paul and Olly,

Thanks a lot for this. For the sake of accuracy I should point out that I have had a scope for a couple of years and it is a cracker. I already mentioned this in my `self introduction` so I decided not to repeat here; but now I will as I can understand that readers of the different forums will not regularly read the `welcome` one for new members. I managed to buy a (now) 25 year old reflector with a 10" aluminium tube containing an 8.5" mirror. I believe that the mirror is by David Hinds. The scope is by Astro Systems . The previous owners had purchased the scope new from AS and had used it for a long time. When I asked them how often they had to collimate it the reply was -`never`. I repeat - `never`. I drove this instrument of beauty (not really just a scope) home for over 250 miles, set it up the next day/night. Did I have to collimate it? NO! I had crystal clear views of Jupiter, all 4 moons and then I got stuck into Orion.  

Mr Peter Drew : I believe this to be one of your wonderful inventions. I salute you, sir. Should you read this would you please stand up and take a bow.

The main reason I started off this thread was that I was thinking of experiencing a GOTO. I have been using my present one manually. The tracking motors do not function and I have not bothered doing anything about it. I was told about it when I got it so nothing was hidden from me. I should really rectify this. The finder scope is really quite tricky to align but that is probably down to me. It does not stop me seeing some sights. The tripod could support a horse. I remember the previous owners saying that it had been specially strengthened before they bought it. I should probably get in touch with a local astro club to get a few pointers. I have no intention at present of going into imaging but one never knows the future (thank goodness).

To anyone whom I have bored by repeating myself - apologies.

OLLY,

I know what you mean about these electric thingies. Some time back I had to change my car so now I am the proud owner of a 9 year old automatic. I spoke to a mechanic friend and said that `automatic` was just another thing to go wrong. He hummed and he hawed (don`t know how you spell this) and said - I suppose so. I still bought it and it has been OK - so far. New cars and lorries : they are all computerised!! Problems waiting to happen. mechanics have to be whizzos on mother boards etc and they have difficulty working on old motors. But I digress. Age does catch up and I sometimes meander a bit. At least I have clarified my situation. I have also thought about big dobs but - hey- I already have a scope that I should bring back to perfection before I start walking down `greedy` road.

I am now thoroughly enjoying myself. If anyone, including Sir Peter Drew, has any suggestions to educate an ignorant old codger in the dark arts of astronomical instruments, especially the older scopes, then fire away. Out of interest I would also like to find out if Astro Systems Newtonians were known to hold collimation for lengthy periods of time.

Kind regards

Dave (now in my element).

[Northern Soul man]

Dave, great stuff, I wasn't aware you already had a scope, you mention the mirrors by David Hinds - they should be fantastic, my first home built scope had a set of David Hinds' mirrors in it - absolutely fantastic, the planetary detail was amazing, it was an 8" F8 mirror set, with all the other stuff bought and assembled, I think I had the scope for a number of years on an home built EQ mount - the views were really amazing, the detail on Jupiter was breathtaking, just around the time when Comet Shoemaker Levy ploughed into the cloud tops of Jupiter, there was a lot of speculation, wether we would see anything in our backyard scopes, let me tell you it was like an "Owl" looking down on us, the scars left were unbelievable.

You mention that you want to try GOTO - the CPC 800 will give you a little less high mag contrast compared to the scope you already have, also a narrower field of view, moving up to the 925 and the 1100 won't i'm afraid, be really noticeable, maybe just a slight increase in brightness and allow a little higher mag to be used, but with a much shorter tube assembly and GOTO, with the ability to move from object to object at your leisure.

I really miss that scope i put together with the Hinds' optics in, a fantastic scope that I have fond memories of, keep us informed mate with the outcome - regards.    Paul.

[LukeSkywatcher]

I dont think its fair to try to answer this, i think you have to pay the money and take the chance, good luck with the decision

I agree. Electronics are electronics. They might last 2 weeks or 20 yrs.................or a lifetime. Some come with a certain "life span" garauntee while others dont.

Electronics are fickle that way.

[kirkster501]

Modern, properly designed and constructed electronics are astonishingly reliable - with MTBF (Mean Time Between Failure) measured in many, many years.  Decades even.  Thats why they are found everywhere nowadays from car electronic engine management systems to fly by wire commercial aircraft to toothbrushes.  In short, don't worry about it.  I'd be more worried by the condition of the corrector plate.

[old dave]

Modern, properly designed and constructed electronics are astonishingly reliable - with MTBF (Mean Time Between Failure) measured in many, many years.  Decades even.  Thats why they are found everywhere nowadays from car electronic engine management systems to fly by wire commercial aircraft to toothbrushes.  In short, don't worry about it.  I'd be more worried by the condition of the corrector plate.

Thanks for this. I don`t suppose that NASA would get very far trying to send their rockets up with manual gear boxes! Are one of you lot going to tell me that, somewhere deep in their workings they actually have one?

When I asked this question I had no intention of starting a war of words amongst you BUT this is one of the many strong points of this forum. Anyone who wishes can advance an opinion whether or not they agree with a previous speaker and it looks like the members are strong enough in their ideas to voice them. People who seek assistance or ideas from those who have more experience/knowledge will not be able to make  sound decisions without information. So keep giving us your tuppenceworth. It`s worth a tenner to me! And I need it. So keep it coming. I do not have a technical background in any shape or form; but I do like the night sky. It just so happens that to enjoy it as fully as possible I need gadgets and some of them are a wee bit beyond me at present. It`s something like jumping out of a Mini and into a Ferrari for the first time. If you don`t kill yourself you will improve with practice.

Cheers

Dave

[kirkster501]

Thanks for this. I don`t suppose that NASA would get very far trying to send their rockets up with manual gear boxes! Are one of you lot going to tell me that, somewhere deep in their workings they actually have one?

When I asked this question I had no intention of starting a war of words amongst you BUT this is one of the many strong points of this forum. Anyone who wishes can advance an opinion whether or not they agree with a previous speaker and it looks like the members are strong enough in their ideas to voice them. People who seek assistance or ideas from those who have more experience/knowledge will not be able to make  sound decisions without information. So keep giving us your tuppenceworth. It`s worth a tenner to me! And I need it. So keep it coming. I do not have a technical background in any shape or form; but I do like the night sky. It just so happens that to enjoy it as fully as possible I need gadgets and some of them are a wee bit beyond me at present. It`s something like jumping out of a Mini and into a Ferrari for the first time. If you don`t kill yourself you will improve with practice.

Cheers

Dave

Wow, sounds like a Kennedy speech from the early 60's  You ought to get yourself elected  - I'll vote for you  

One of the great things about SGL is that people will tell you as it is, from personal experience, without any commercial interests to protect or agendas to promote.  We all love Astro talk.  That's our raison d'etre

[Pig]

If the worst happens you do not need the motor.

The scope pivots on all axis and you use it like a Dob

I often use mine as a point and go if it is going to be a quick session

[old dave]

Kirkster,

You have got me well and truly dated.

[old dave]

Pig,

If I pivot much more I`ll be sick on the way down to Oz.

[Pig]

Luckily its the mount that performs all the pivoting

[paulastro]

Well, just about everything has been said really, just a couple of quick points.  In buying second hand, I am more personally concerned about what strange mods the owner may have attempted or if they have just taken it apart to see how it works!  Over the years I've come across this several times.  Often there are outward tell-tale signs that the scope has been interfered with, but this isn't always the case.  Believe me, the complexity of the instrument won't prevent even the inexperienced sometimes taking the drive mechanism apart to examine it.

I'd avoid buying any SC that has even been flocked - the person may well not have put the corrector plate back into the correct position and it makes me wander what else they may have done.

I know full well many people reading this will be thinking that they did it and they knew what they were doing.  I'm sure this is true, but personally I wouldn't take the risk.

I recently bought an 8SE second hand as I wanted the scope to try the StarSense on (it works great!), though I had my fingers crossed.  As it was also a reasonable price, I thought if the drive has any faults (it sounded ok when I picked it up) then at least I would still have the tube to use on one of my altaz mounts if all else went.....the wrong way up!  The astronomy gods were with me, so far the drive has been fine, phew!