Promoting astronomy discussion.
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astronomy-chat.net Promoting astronomy discussion. |
about a prototype telescope whose mirror is made of composites. The 16" telescope (unclear exactly what they're talking about, but it appears to include the mirror, some kind of mirror mount, and the truss tube, all in what I take to be a Cassegrain configuration) weighs 20 pounds. It was built by Kansas University, San Diego State University, Dartmouth College, and Composite Mirror Applications in Tucson. Apparently it's a prototype for larger telescopes--the next one will be a one meter mirror. But if someone started making this sort of telescope for amateurs... Of course, I suppose the cost of materials would outweight (sorry for the pun) any savings from the construction method. An earlier story (before they built the prototype) is at http://www.ljworld.com/section/archive/story/148016. And http://www.physics.ku.edu/facilities/ultra/specsfin.html is a rfp for the one meter scope. Mike Maxwell |
>> I wonder how it would do in a stiff breeze? A mirror's larger mass can be advantageous at times, especially when anchoring a large OTA. >> Pretty soon the eyepieces are going to outweigh the telescopes. It could be difficult to adapt to a Dobsonian mount. >> Those Meade keting folks would have a field day with it. A whole new set of superlatives might have to be invented... Mike Maxwell wrote: > An article at http://www.ljworld.com/section/kunews/story/192798 talks > about a prototype telescope whose mirror is made of composites. The 16" > telescope (unclear exactly what they're talking about, but it appears to > include the mirror, some kind of mirror mount, and the truss tube, all > in what I take to be a Cassegrain configuration) weighs 20 pounds. It > was built by Kansas University, San Diego State University, Dartmouth > College, and Composite Mirror Applications in Tucson. > > Apparently it's a prototype for larger telescopes--the next one will be > a one meter mirror. But if someone started making this sort of > telescope for amateurs... Of course, I suppose the cost of materials > would outweight (sorry for the pun) any savings from the construction > method. > > An earlier story (before they built the prototype) is at > http://www.ljworld.com/section/archive/story/148016. And > http://www.physics.ku.edu/facilities/ultra/specsfin.html is a rfp for > the one meter scope. > > Mike Maxwell |
"Mike Maxwell" <maxwell@ldc.upenn.edu > wrote in message news:cs13oj$s0h$1@netnews.upenn.edu... > An article at http://www.ljworld.com/section/kunews/story/192798 talks > about a prototype telescope whose mirror is made of composites. The 16" > telescope (unclear exactly what they're talking about, but it appears to > include the mirror, some kind of mirror mount, and the truss tube, all > in what I take to be a Cassegrain configuration) weighs 20 pounds. It > was built by Kansas University, San Diego State University, Dartmouth > College, and Composite Mirror Applications in Tucson. > > Apparently it's a prototype for larger telescopes--the next one will be > a one meter mirror. But if someone started making this sort of > telescope for amateurs... Of course, I suppose the cost of materials > would outweight (sorry for the pun) any savings from the construction > method. > > An earlier story (before they built the prototype) is at > http://www.ljworld.com/section/archive/story/148016. And > http://www.physics.ku.edu/facilities/ultra/specsfin.html is a rfp for > the one meter scope. I think you have 'hit the nail on the head', with the cost of materials 'outweighing' any savings. The obvious design idea, is to keep weights down, and distortions from the weight down, on larger scopes. I'd doubt if the design is economic/practical for scopes any smaller than the prototype, and even on this, if produced in quantity, is still likely to be more expensive than a simple 'glass' and carbon fibre tube design... Best Wishes |
<rogerspamignored@ttelmah.demon.co.uk > wrote: > >"Mike Maxwell" <maxwell@ldc.upenn.edu> wrote in message >news:cs13oj$s0h$1@netnews.upenn.edu... >> An article at http://www.ljworld.com/section/kunews/story/192798 talks >> about a prototype telescope whose mirror is made of composites. The 16" >> telescope (unclear exactly what they're talking about, but it appears to >> include the mirror, some kind of mirror mount, and the truss tube, all >> in what I take to be a Cassegrain configuration) weighs 20 pounds. It >> was built by Kansas University, San Diego State University, Dartmouth >> College, and Composite Mirror Applications in Tucson. >> >> Apparently it's a prototype for larger telescopes--the next one will be >> a one meter mirror. But if someone started making this sort of >> telescope for amateurs... Of course, I suppose the cost of materials >> would outweight (sorry for the pun) any savings from the construction >> method. >> >> An earlier story (before they built the prototype) is at >> http://www.ljworld.com/section/archive/story/148016. And >> http://www.physics.ku.edu/facilities/ultra/specsfin.html is a rfp for >> the one meter scope. >I think you have 'hit the nail on the head', with the cost of materials >'outweighing' any savings. >The obvious design idea, is to keep weights down, and distortions from the >weight down, on larger scopes. I'd doubt if the design is >economic/practical for scopes any smaller than the prototype, and even on >this, if produced in quantity, is still likely to be more expensive than a >simple 'glass' and carbon fibre tube design... > >Best Wishes > I could see this same argument occuring when they switched from speculum metal to glass for mirrors. -Rich |
"RichA" <none@none.com > wrote in message news:4ng9u056icereh85dhdb1lthnv38g4h73d@4ax.com... > On Tue, 11 Jan 2005 21:30:17 GMT, "Roger Hamlett" > <rogerspamignored@ttelmah.demon.co.uk> wrote: > >> >>"Mike Maxwell" <maxwell@ldc.upenn.edu> wrote in message >>news:cs13oj$s0h$1@netnews.upenn.edu... >>> An article at http://www.ljworld.com/section/kunews/story/192798 talks >>> about a prototype telescope whose mirror is made of composites. The >>> 16" >>> telescope (unclear exactly what they're talking about, but it appears >>> to >>> include the mirror, some kind of mirror mount, and the truss tube, all >>> in what I take to be a Cassegrain configuration) weighs 20 pounds. It >>> was built by Kansas University, San Diego State University, Dartmouth >>> College, and Composite Mirror Applications in Tucson. >>> >>> Apparently it's a prototype for larger telescopes--the next one will >>> be >>> a one meter mirror. But if someone started making this sort of >>> telescope for amateurs... Of course, I suppose the cost of materials >>> would outweight (sorry for the pun) any savings from the construction >>> method. >>> >>> An earlier story (before they built the prototype) is at >>> http://www.ljworld.com/section/archive/story/148016. And >>> http://www.physics.ku.edu/facilities/ultra/specsfin.html is a rfp for >>> the one meter scope. >>I think you have 'hit the nail on the head', with the cost of materials >>'outweighing' any savings. >>The obvious design idea, is to keep weights down, and distortions from >>the >>weight down, on larger scopes. I'd doubt if the design is >>economic/practical for scopes any smaller than the prototype, and even >>on >>this, if produced in quantity, is still likely to be more expensive than >>a >>simple 'glass' and carbon fibre tube design... >> >>Best Wishes >> > > I could see this same argument occuring when they switched from > speculum metal to glass for mirrors. > -Rich Except glass was every bit as heavy... I'd suspect the key is to look at the cost of supporting a mirror. If you look at small mirrors (up to about 12"), the extra costs involved in supporting it are practially nil, and potential savings just don't really exist. As you go up in size to perhaps 24", the costs rise, and by the time you reach perhaps 36", they have become really significant, with the weight of the glass, being greater than any other part in the scope, and maintaining a rigid structure, to the accuracies needed when dealing with light, have become a real bind. The materials involved in this technology, may well fall in price in the future, but not because of the extra demand from astronomers (most of the composites involved, are used in the aerospace industries, in quantities far larger than astronomers are ever likely to want). Hence my expectation, is that though 'production' units will be a lot cheaper than the prototype, it is not likely to affect the prices of scopes much below perhaps 24" in aperture. Though this may make some of the current largest amateur observers, able to move up from 24" scopes to 36" scopes, it is not likely to affect the purchasing of most 'normal' amateurs.... Best Wishes |
<rogerspamignored@ttelmah.demon.co.uk > wrote: >I think you have 'hit the nail on the head', with the cost of materials >'outweighing' any savings. >The obvious design idea, is to keep weights down, and distortions from the >weight down, on larger scopes. I'd doubt if the design is >economic/practical for scopes any smaller than the prototype, and even on >this, if produced in quantity, is still likely to be more expensive than a >simple 'glass' and carbon fibre tube design... But it might eventually bring meter-class scopes into a price range where some amateurs could afford them (say, where 20" RCs are now). The intriguing thing is that with 1m optics you are getting into the range where true adaptive optics becomes a possibility. _________________________________________________ Chris L Peterson Cloudbait Observatory http://www.cloudbait.com |
future. Thuis could prove *very* interesting from an economic- keting point of view... Lets assume for a moment cost of materials falls, precipitously - as they will of course. Lets assume the costs of these materials falls below the cost of traditional materials, as I think they will. This then potentially makes the whole cost of a decent telescope fall, say preciitously. How would this impact the economics of telescope sales. The answer is quite simple. The current cost or even higher costs (due to inflation) could not be justified on the basis of materials and labour alone. Another formula would have to be sought. That formula would have to rely on some premise in the supplier-consumer relationship not previously exploited. I believe that premise will be: "we supply people *telescopes* - telescopes are *rare*! Telescopes represent a *rare opportunity*. The same (bogus) premise is now being slipped in to justify other commercial transactions, and people buy it. It could become the justification for the monetary costs of telescopes in the future, after materials and labour have slipped to a all time low. Kerry Roger Hamlett wrote: > "Mike Maxwell" <maxwell@ldc.upenn.edu> wrote in message > news:cs13oj$s0h$1@netnews.upenn.edu... > > An article at http://www.ljworld.com/section/kunews/story/192798 talks > > about a prototype telescope whose mirror is made of composites. The 16" > > telescope (unclear exactly what they're talking about, but it appears to > > include the mirror, some kind of mirror mount, and the truss tube, all > > in what I take to be a Cassegrain configuration) weighs 20 pounds. It > > was built by Kansas University, San Diego State University, Dartmouth > > College, and Composite Mirror Applications in Tucson. > > > > Apparently it's a prototype for larger telescopes--the next one will be > > a one meter mirror. But if someone started making this sort of > > telescope for amateurs... Of course, I suppose the cost of materials > > would outweight (sorry for the pun) any savings from the construction > > method. > > > > An earlier story (before they built the prototype) is at > > http://www.ljworld.com/section/archive/story/148016. And > > http://www.physics.ku.edu/facilities/ultra/specsfin.html is a rfp for > > the one meter scope. > I think you have 'hit the nail on the head', with the cost of materials > 'outweighing' any savings. > The obvious design idea, is to keep weights down, and distortions from the > weight down, on larger scopes. I'd doubt if the design is > economic/practical for scopes any smaller than the prototype, and even on > this, if produced in quantity, is still likely to be more expensive than a > simple 'glass' and carbon fibre tube design... > > Best Wishes |
> I think you have 'hit the nail on the head', with the cost of materials > 'outweighing' any savings. > The obvious design idea, is to keep weights down, and distortions from the > weight down, on larger scopes. I'd doubt if the design is > economic/practical for scopes any smaller than the prototype If this turns out to be true, it would provide a nice excuse to make much larger amateur telescopes (as some other postings to this thread have suggested). I can easily put a saucer sled in the back seat of my small car. I would guess such a sled is a meter or so across. If that fits, so would a meter-wide mirror (in a protective case). And a knock-down truss assembly would fit, too. BTW, while the original was a Cass, I don't suppose there's any problem in principle with using a composite mirror in a Newtonian, in which case a Dob mount should be feasible. Then again, I'd have to fit the ladder in my car :-(. Or could a very deep mirror work, with some sort of corrective optics to flatten the field? I'm getting beyond anything I know now, but it's sure fun to speculate about eyeballing galaxy clusters with a one meter mirror! Mike Maxwell |
"Mike Maxwell" < > wrote ... > > BTW, while the original was a Cass, I don't suppose there's any problem in > principle with using a composite mirror in a Newtonian, in which case a > Dob mount should be feasible....... Mike, A few years ago I saw a guy at Stellafane with a home-made (mirrors and all) 16-inch F/8 RC Cass that was on a Dob style mount. It had a third flat mirror that sent the light out through the center of the altitude bearing where the focuser was mounted. The observer sat in a chair to use it and of course the eyepiece never changed height off the ground. I suppose that if it had a 'GoTo' drive the observer could sit on the mount and go along for the ride! George Normandin |
at Chiefland and it was truly memorable. But low weight does not solve the entire problem, that scope was still the size of a small car. The priy weighed about 200 lbs. Presumably a lighter scope still does not imply a much faster scope, at least until there are huge gains in eyepiece technology. This means portability and setup issues are still significant. k Pippin Mike Maxwell wrote: > Roger Hamlett wrote: > > I think you have 'hit the nail on the head', with the cost of materials > > 'outweighing' any savings. > > The obvious design idea, is to keep weights down, and distortions from the > > weight down, on larger scopes. I'd doubt if the design is > > economic/practical for scopes any smaller than the prototype > > If this turns out to be true, it would provide a nice excuse to make > much larger amateur telescopes (as some other postings to this thread > have suggested). I can easily put a saucer sled in the back seat of my > small car. I would guess such a sled is a meter or so across. If that > fits, so would a meter-wide mirror (in a protective case). And a > knock-down truss assembly would fit, too. > > BTW, while the original was a Cass, I don't suppose there's any problem > in principle with using a composite mirror in a Newtonian, in which case > a Dob mount should be feasible. Then again, I'd have to fit the ladder > in my car :-(. Or could a very deep mirror work, with some sort of > corrective optics to flatten the field? I'm getting beyond anything I > know now, but it's sure fun to speculate about eyeballing galaxy > clusters with a one meter mirror! > > Mike Maxwell |
carbon fiber replication mirrors have been around for a while. In his 2001 presentation at Stellafane, Dr. Peter Chen shared the results of the technology at that time. He was then working on a 52" priy that weighed in at 27 pounds. Up to 50 mirrors could be made between cleanings of the precision mandrils: http://www.astro-nut.com/stchen.html Cheers, Paul --- http://www.astro-nut.com --- |
It is the same guys this time . K.U. is on this project with some other university partners including a private company that is actually Peter Chen and Romeo . Not having any inside information, it looks as if Chen and Romeo are just chasing project funding and grant money from whatever sources they can manage to further their technology . best regards, matt tudor "Astro-nut" <pghyndman@yahoo.com > wrote in message news:1105568539.142243.175040@f14g2000cwb.googlegroups.com... > Extremely light weight, collapsable (yes... you read that correctly) > carbon fiber replication mirrors have been around for a while. > > In his 2001 presentation at Stellafane, Dr. Peter Chen shared the > results of the technology at that time. He was then working on a 52" > priy that weighed in at 27 pounds. Up to 50 mirrors could be made > between cleanings of the precision mandrils: > > http://www.astro-nut.com/stchen.html > Cheers, > > Paul > > --- http://www.astro-nut.com --- > |
Astro-nut wrote: > In his 2001 presentation at Stellafane, Dr. Peter Chen shared the > results of the technology at that time. He was then working on a 52" > priy that weighed in at 27 pounds. Up to 50 mirrors could be made > between cleanings of the precision mandrils: I presume the mandrils give you a mirror that is roughly the right shape, then you have to figure it? They can't give you an accurate figure without post-processing, can they? Mike Maxwell |
them between cleanings, then you can run off another batch with the same mandrill! Paul --- http://www.astro-nut.com --- "Mike Maxwell" <maxwell@ldc.upenn.edu > wrote in message news:cs91sf$3602$1@netnews.upenn.edu... > > Astro-nut wrote: >> In his 2001 presentation at Stellafane, Dr. Peter Chen shared the >> results of the technology at that time. He was then working on a 52" >> priy that weighed in at 27 pounds. Up to 50 mirrors could be made >> between cleanings of the precision mandrils: > > I presume the mandrils give you a mirror that is roughly the right shape, > then you have to figure it? They can't give you an accurate figure > without post-processing, can they? > > Mike Maxwell |
> An article at http://www.ljworld.com/section/kunews/story/192798 talks > about a prototype telescope whose mirror is made of composites. The 16" > telescope (unclear exactly what they're talking about, but it appears to > include the mirror, some kind of mirror mount, and the truss tube, all > in what I take to be a Cassegrain configuration) weighs 20 pounds. It > was built by Kansas University, San Diego State University, Dartmouth > College, and Composite Mirror Applications in Tucson. > > Apparently it's a prototype for larger telescopes--the next one will be > a one meter mirror. But if someone started making this sort of > telescope for amateurs... Of course, I suppose the cost of materials > would outweight (sorry for the pun) any savings from the construction > method. the theory is quite sound. I have seen a few of their interferograms. the process needs some work but it is getting there. In theory 1/10 wave optics could be produced on GSO/synta scales. the cost of materials would be considerably less than pyrex. even if the materials and labour were to cost more you would still be able to justify the expense of a lighter telescope. for one it is more convenient and portable. for another you will save thousands of dollars on a mount. A G11 will hold that tube as solid as a paramount will hold a glass 16". in other words, even if the OTA costs $9000 more it will be offset by the mount savings. Ian Anderson www.customopticalsystems.com |