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jask
Joined: 17 Mar 2006
Posts: 10165
Location: kamloops BC
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 Link Posted: Fri Jan 22, 2021 5:01 am Post subject: |
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Leave the top cover off the projector and mount the rest of the lower case to the chassis and then flip it over to the regular roof mounted orientation. I used lag bolt to secure each of the tops of the 4 chains. The ok gets strapped to a plywood platform that had an eyebolt secured to each corner eyebolt has a sling of Dacron tubular braid and an s hook securely taped off to the end of the loop so it can not slip loose and fall at an inconvenient moment and then you just go around and round a few links at a time untill the PJ is up to the mounting point. Have a few shims to allow you to lift it the last bit into place and secure the hardware.... ( National geographic magazines are great shims...
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kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 17860
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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| Link Posted: Fri Jan 22, 2021 3:02 pm Post subject: Re: CRT projector installation questions |
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| Zebra wrote: | I'm not looking for general rear projection info. I've built many rear projection set-ups in my time. I'm specifically interested in the lenses people use for CRT rear set-ups.
I've always needed a short throw lens when I've built DLP rear projection set-ups. I want to know if these were commonly sold for CRT projectors. |
Generally speaking there are not many (very few) short throw lenses.
Unlike the DLPs you built, better CRT projectors have part of the "lens" directly attached to the tube as the c-element. it's the first lens element and works together with the removable part of the lens. That coupled with the fact that the lenses are very heavy and have different mounting methods to the projector (as distance is very critical given the short f-stop) means that you can't just take a lens from projector A and use it in projector B (usually).
Is there a reason you don't want to identify the projector in question?
Kal
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My basement/HT/bar/brewery build 2.0
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kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 17860
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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Zebra
Joined: 02 Jul 2020
Posts: 87
Location: NJ USA
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| Link Posted: Tue Jan 26, 2021 7:31 pm Post subject: Re: CRT projector installation questions |
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| kal wrote: | | Zebra wrote: | I'm not looking for general rear projection info. I've built many rear projection set-ups in my time. I'm specifically interested in the lenses people use for CRT rear set-ups.
I've always needed a short throw lens when I've built DLP rear projection set-ups. I want to know if these were commonly sold for CRT projectors. |
Generally speaking there are not many (very few) short throw lenses.
Unlike the DLPs you built, better CRT projectors have part of the "lens" directly attached to the tube as the c-element. it's the first lens element and works together with the removable part of the lens. That coupled with the fact that the lenses are very heavy and have different mounting methods to the projector (as distance is very critical given the short f-stop) means that you can't just take a lens from projector A and use it in projector B (usually).
Is there a reason you don't want to identify the projector in question?
Kal |
I already know that nobody here owns or knows anything about the projector I'm currently setting up and I don't intend to keep this particular one anyway. The questions I'm asking are all general non-model specific.
E.g. My asking how people here lift their CRT projectors is more about assessing the viability of future CRT projector purchases. Moving a 200-300lb projector downstairs to my basement and mounting it is significant concern that might limit my choice. So I wanted to know how others do it.
I can tell from the one I'm messing around with now that a larger and heavier 8" or 9" one would be more than I could lift on my own without a trick.
On my short throw lens question. I didn't ask about mounting lenses meant for other projectors or decoupling C elements. I'm asking about the removable focus lenses and a general question if short throw lens options was a thing with CRT projectors.
Potential answers might be:
A) No, no short throw lenses were sold for CRT projectors. CRT rear screen set-ups were achieved exclusively with mirror rigs
B) Some of the CRT projector manufacturers offered a short (or shorter) throw lens option for some of their high end models
C) Yes, short throw lenses were readily available for all CRT projectors. They were made by brands like XX and XX.
For now I'm going to assume the answer is A or that nobody here knows.
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kal
Forum Administrator
Joined: 06 Mar 2006
Posts: 17860
Location: Ottawa, Canada
TV/Projector: JVC DLA-NZ7
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| Link Posted: Tue Jan 26, 2021 8:05 pm Post subject: |
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| Zebra wrote: | | I already know that nobody here owns or knows anything about the projector I'm currently setting up ... |
That's a very odd thing to presume to know. 
The answer to your A-C list is none of the above.
Generally speaking short throw lenses aren't available on CRT projectors as they're already fairly short to begin with and have fixed throw. IIRC some manufacturers do have lenses with varying throw lengths including very short but they're incredibly rare, usually specialty purpose use like simulators that required curved screens. Going by memory here. Not all CRT projectors will have this option as not all CRT projectors were used for speciality purposes. Some more than others.
While lenses (generally speaking) are not interchangeable between projectors, some CRT projector manufacturers did use stock lenses that had shorter throws than others. The HD215 used on my previous Zenith 1200 had shorter throw than average: At 1.2 screen width they were shorter than most which are around 1.4 - 1.5 screen width.
If you want short throw you'll need to do some research into which CRT models uses lenses with the shortest throw to begin with. That's probably your best bet. This "all about lenses" thread is probably the best place to start: http://www.curtpalme.com/forum/viewtopic.php?t=2761
Reading through you'll find that people mention that HD114 were fairly short throw. Manakin.1 lenses as well. Some may only work well with torus (curved) screens however and as mentioned before you can't just stick any lens on any projector.
One thing is true in all this: The odds of finding specialized (non-stock) lenses for any CRT projector is going to next to impossible given the general lack of interest in CRT today, let alone interest in specialized items like non-standard lenses.
Two able bodied people should be able to lift any CRT projector if it's been gutted (all boards/cards/lenses removed). Mount it gutted and then fill it. That's what I've usually done. Heaviest CRT projector I know is the Sony G90 at 242 lbs. Most others are under 200. That's completely filled. The lenses are darned heavy. Just removing those really helps.
Kal
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My basement/HT/bar/brewery build 2.0
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26690
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Link Posted: Wed Jan 27, 2021 2:29 am Post subject: |
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I moved the SONY 1252 downstairs on a sled. Made from a sheet of plywood bolted to the bottom of the projector with 2, 2x3's as the sliders. A rope tied to the projector wrapped around the back of the person at the top. One guy down stairs acting as a brake.
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CRT.
HD done right!
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jask
Joined: 17 Mar 2006
Posts: 10165
Location: kamloops BC
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| Link Posted: Wed Jan 27, 2021 4:34 am Post subject: |
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Zebra... If you " know " that already why are you wasting everyone's time? Many manufacturers made short throw lens and a few manufacturers spec'd them for special case use... Did you already know that as well? You probably also know that most of the secondary market buyers threw those lenses away when they parted out or repurposed those units from cubes and sims.
If you are looking at rear projection you might want to look at second surface RP so you can have better lens options.
Since most suppliers worked with lens manufacturers to develop lenses and housing specific to the systems they built you should probably check the manuals for the model you have or develop adapter plates for yourself.
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Zebra
Joined: 02 Jul 2020
Posts: 87
Location: NJ USA
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| Link Posted: Fri Jan 29, 2021 7:21 pm Post subject: |
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| jask wrote: | Zebra... If you " know " that already why are you wasting everyone's time? Many manufacturers made short throw lens and a few manufacturers spec'd them for special case use... Did you already know that as well? You probably also know that most of the secondary market buyers threw those lenses away when they parted out or repurposed those units from cubes and sims.
If you are looking at rear projection you might want to look at second surface RP so you can have better lens options.
Since most suppliers worked with lens manufacturers to develop lenses and housing specific to the systems they built you should probably check the manuals for the model you have or develop adapter plates for yourself. |
I think you misread what I wrote.
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Zebra
Joined: 02 Jul 2020
Posts: 87
Location: NJ USA
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| Link Posted: Fri Jan 29, 2021 7:49 pm Post subject: |
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| AnalogRocks wrote: | | I moved the SONY 1252 downstairs on a sled. Made from a sheet of plywood bolted to the bottom of the projector with 2, 2x3's as the sliders. A rope tied to the projector wrapped around the back of the person at the top. One guy down stairs acting as a brake. |
That's a good idea.
I don't have a bunch of heavy (enough) extra adults to tie one to but I could lower one down the stairs using my electric hoist.
I got that thing to move my CNC machine but it lacked the power. For going down stairs though, gravity could do the work.
You obviously have better friends than me. I somehow can't see my friends being super responsive if I ask them to come over so I can tie a rope around them to lower something heavy down some stairs. They'd be even less enthusiastic about being the just in case brake guy at the bottom...
Not sure I'd want to be on bottom of the stairs brake duty for that Barco 7120a but I might risk it for a regular 9". I've been offered an Ampro 4300, a 9500lc and an 8" Barco 808. At least with those an accident would probably be a broken foot vs crushed to death.
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26690
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Link Posted: Sat Jan 30, 2021 1:03 am Post subject: |
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| Zebra wrote: | | AnalogRocks wrote: | | I moved the SONY 1252 downstairs on a sled. Made from a sheet of plywood bolted to the bottom of the projector with 2, 2x3's as the sliders. A rope tied to the projector wrapped around the back of the person at the top. One guy down stairs acting as a brake. |
That's a good idea.
I don't have a bunch of heavy (enough) extra adults to tie one to but I could lower one down the stairs using my electric hoist.
I got that thing to move my CNC machine but it lacked the power. For going down stairs though, gravity could do the work.
You obviously have better friends than me. I somehow can't see my friends being super responsive if I ask them to come over so I can tie a rope around them to lower something heavy down some stairs. They'd be even less enthusiastic about being the just in case brake guy at the bottom...
Not sure I'd want to be on bottom of the stairs brake duty for that Barco 7120a but I might risk it for a regular 9". I've been offered an Ampro 4300, a 9500lc and an 8" Barco 808. At least with those an accident would probably be a broken foot vs crushed to death. |
My lat Ampro 4000 got walked UP the stairs one at a time. That was fun, 2 grown men working against each other to get the projector upstairs with no safety net. Made it though and found out you can fit an Ampro 4000 in the trunk of a Crown Vic with the trunk closed. Also you get some great winter traction with a 9" projector over the rear axle.  Made it out of Montreal with nary a slipped wheel.
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CRT.
HD done right!
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AnalogRocks
Forum Moderator
Joined: 08 Mar 2006
Posts: 26690
Location: Toronto, Ontario, Canada
TV/Projector: Sony 1252Q, AMPRO 4000G
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| Link Posted: Sat Jan 30, 2021 11:34 am Post subject: |
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| Zebra wrote: | [
I don't have a bunch of heavy (enough) extra adults to tie one to but I could lower one down the stairs using my electric hoist.
You obviously have better friends than me. I somehow can't see my friends being super responsive if I ask them to come over so I can tie a rope around them to lower something heavy down some stairs. |
I was up top. I got roped into it.
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Tech support for nothing
CRT.
HD done right!
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gjaky
Joined: 05 Jun 2010
Posts: 2790
Location: Budapest, Hungary
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| Link Posted: Mon Feb 01, 2021 7:08 am Post subject: |
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| Zebra wrote: |
Not sure I'd want to be on bottom of the stairs brake duty for that Barco 7120a but I might risk it for a regular 9". I've been offered an Ampro 4300, a 9500lc and an 8" Barco 808. At least with those an accident would probably be a broken foot vs crushed to death. |
Electrohomes are super easy to take apart, very modular construction, you can basically take it into pieces in less than an hour, from that you don't have to lift anything havier than 5-10 kgs..
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projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB, VIM-DB
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virusc
Joined: 11 Apr 2007
Posts: 322
Location: Massachusetts
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| Link Posted: Fri Feb 26, 2021 2:18 pm Post subject: |
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Zebra, you seem like being a person that is the reason I don't like responding or asking questions on forums
I have some short throw lenses for CRT projectors. They are the HD-9 variant and HD-103/106 I believe. Just like you question that you didn't like about DILA I answered for you here it is. All of the short throw lenses I have seen for 8" and 9" crt projectors were mostly plastic element and made for stage use. They were terrible focus on edge and seemed to have light loss as well near the edge. I quickly removed them from non use road CRT projectors to turn them back into HT use. I installed many projectors rear projection and we never had a problem with clients as we used a mirror system with HD-10's etc.... I have seen good short throw lenses for 7" crt projectors that include usage in retro blocks. I guess you could rip some out of a retro block but they were all LC.
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