Film-Tech Forum ARCHIVE: NC1200C Bulb Adjustment Questions

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Posted by Steve Kraus (Member # 476) on 11-12-2018, 07:03 PM:

To recap:

A while back we discussed what my next bulb would be.
Being a screening room we don't rack up lots of hours so this was only going to be the third. I'd been running 2000W Osram film bulbs with the aperture thing in place to keep current at a healthy range. Given the bad rep Osram has gotten recently (and I did pull my 2nd bulb early due to arc waver), I was going with Ushio. Cost per hour was about the same digital bulb vs. film. If I could go down to a 1500W bulb it would save a little power but that's not really important.

Since no one could be certain that the lower wattage digital bulb would be sufficiently bright over its life I went with an Ushio UXL-20SC 2000W film bulb. It's been sitting waiting for me to install it. The past few months I've been running off some hours on my original Osram bulb (and I will still have a couple hundred hours left so I can keep it as a spare)

Today I put in the Ushio. I did the numeric alignment per DCC software. But I seem to be having a problem getting the brightness low enough on 1.85 without being at the bottom of current range and then bright enough on Scope. (We are common height so Scope requires the most power.) Is it okay to run this bulb right at the bottom? I ended up playing with the Z axis (bulb focal position) but I'm not entirely happy.

Also, I confess I am way behind on updating the projector so this bulb is not listed. For the time being I indicated I put in another Osram 2000W film bulb. It has the same 60-85 current range. So why does the projector tell me we're at or near 100% when it's only in the mid 70 amps?

Posted by Dave Macaulay (Member # 813) on 11-12-2018, 10:48 PM:

Lamps may have multiple limits - amps, volts, watts. Maybe the Osram has a voltage limit lower than the Ushio's operating voltage?

Posted by Steve Kraus (Member # 476) on 11-13-2018, 08:54 AM:

I think you are exactly correct. Was probably peaking on Watts. Tiny differences between brands on pressure and precise gap length would cause it to vary the voltage to pump whatever current through.

While it was *probably* okay to run this way I don't want to chance doing harm to the new bulb so going back to Osram until I can update which I will wait til I have several days just in case. I'm not familiar with updating but what I have is 4.222 which itself is probably out of date but hopefully no one has any issues with it.

With the Osram 2K back in I am at about 78A Scope and 62A 1.85. That's for 16 fL on center as I like it just a touch bright.

Posted by Steve Guttag (Member # 268) on 11-13-2018, 10:20 AM:

NEC doesn't have a lamp designation for the UXL line, only the DXL line. Any UXL lamps that may be in your list was put in by others or possibly was on an early iteration of how the factory configured the projectors. However, such lamps, with each successive software update (where they reserve their certified lamps) will push non-certified lamps further down on the list.

Ushio lists the UXL-20SC with a current range of 50-85 so it is safe to operate within that range. Max wattage is 2000W so the projector will likely say it is at 100% when you hit 2000W regardless of what the current is.

Posted by Steve Kraus (Member # 476) on 11-13-2018, 10:50 AM:

Ah. Thanks. Can I add a bulb type & specs?

Posted by Steve Guttag (Member # 268) on 11-13-2018, 12:00 PM:

Yup...sure can.

Posted by Steve Kraus (Member # 476) on 11-13-2018, 11:46 PM:

How do I do that? I'm playing with DCC and the projector emulator.

Service Mode -> LAMP -> Setup -> New Bulb (Entry List) -> Edit

It won't let me alter an existing entry nor add a new one. So how does one enter new parameters? Or is it in another place?

PS: On the NEC film bulb adapter, do you happen to recall the size of the set screws? 2mm is too small, 2.5mm too large. I've been using whatever SAE Allen seemed closest but not an exact fit as I would presume it's a metric size.

Posted by Steve Guttag (Member # 268) on 11-14-2018, 06:46 AM:

I don't have the screw size memorized. You have to do lamp entries in the STAND BY mode.

Posted by Steve Kraus (Member # 476) on 11-14-2018, 07:22 AM:

I've tried that. Perhaps because I'm playing with the emulator* not the real thing but going to Bulb Entry and clicking on Edit opens the box with parameters but it does not allow typing into any parameter except one is able to enter Warranty Hours. Does not matter if it's the currently selected bulb or another. Selecting "reserved" and the Edit button is grayed out. I'm surprised there is no "NEW" button.

I'm going to try a newer DCC and see if that matters. Not sure which one this is as there is no "about" page but it's from a few years ago.

*PJEmulator NC2000C as there was none for the 1200. Should be similar.

Posted by Dave Macaulay (Member # 813) on 11-14-2018, 12:12 PM:

The emulator doesn't let you change much anything.

Posted by Steve Guttag (Member # 268) on 11-14-2018, 01:07 PM:

It works in emulator.

You need to select an available line number and then "edit" it.

You have to get past the "Reserved" ones that NEC is keeping available for themselves.

* Some entries in the graphic above may not be considered "valid" for the projector in question.

Posted by Steve Kraus (Member # 476) on 11-14-2018, 08:29 PM:

Thanks, Steve. I never thought to look at the end. I know what max kW is (and good on NEC for capitalizing the W) but what does "typical" mean?

Posted by Steve Guttag (Member # 268) on 11-15-2018, 08:07 AM:

Typical = Nominal. If the lamp has a rated voltage and current (not just the range but an actual rated current), those two would be the "typical" wattage. conversely, if the lamp has a range that would allow a higher wattage, that would be the MAX. So a 2KW lamp could have a typical wattage of 2KW and a MAX of say 2.1KW. Absent information to the contrary, it is not uncommon for the Max and typical to be the same value for a given lamp.

Posted by Mark Gulbrandsen (Member # 72) on 11-15-2018, 10:13 AM:

Thinking back on this, I used to do this on NEC's back about 2010 with some of the LTI High Output Cinema Lamps. But it was only on a few occasions at one site and not for very long as almost every one of those lamps lost it's seal well before warranty. I think we switched to Osram 2kw DC Lamps after that on those screens and an old NEC update already had that lamp in it. I will add that the Osram DC lamps were brand brand new then and almost as notorious for failure as the LTI lamps... It was at that point I switched to Ushio exclusively.

Mark

Posted by Steve Kraus (Member # 476) on 11-20-2018, 09:52 AM:

I am still puzzling over the exact size of the set screws in the brass adapter for film bulbs. 2mm is too small. 2.5mm too large. I thought maybe SAE 3/32" which is 2.38125mm but that's till too large. I ground down each facet of the latter to make it fit but I'd rather get the proper size. I'd been using some random tool--possible SAE--exerting side pressure but that's wearing out the opening. As I change bulbs so seldom it's not a huge priority but I would still like to know. Maybe NEC will tell me.

I tried taking a closeup photo of the screw with 2.5mm and 3/32" tools close by for reference so I could measure by pixel in Photoshop but it didn't work with enough precision to be of value.

I wonder if the screw is standard in terms of size and thread but they use some version with an oddball opening and they should just be replaced with standard ones.

Posted by Steve Kraus (Member # 476) on 11-20-2018, 04:07 PM:

NEC-Brandi says her documentation says a hexagonal wrench with "width across flats 5mm." I don't doubt the screw itself could be 5mm but no way regarding the opening and the tool for it. I'm not going to pull the bulb just to screw around with it (yes,a pun) but I'll try to remember to have some 5mm set screws to test next time. Ones with some sort of standard opening.

Posted by Mark Gulbrandsen (Member # 72) on 11-20-2018, 08:20 PM:

You would need to measure it with a thread micrometer to be absolutely sure. Or take the brass adapter to Bolt & Nut Supply in Salt lake City and get your self a box of 100 spare set screws for a few bucks.

Mark

Posted by Steve Kraus (Member # 476) on 11-21-2018, 07:32 AM:

Does no one else around here use the adapter?

Posted by Mark Gulbrandsen (Member # 72) on 11-21-2018, 03:59 PM:

I did use a couple adapters initially with those LTI short gap lamps, but that was short lived because Digital Lamps started coming on the market within a few months of those projectors hitting the theaters, plus the LTI lamps were awful. Most of those brass adapters are laying in a box some place in those booths. I didn't toss them or the extra apertures.

Mark

Posted by Dave Macaulay (Member # 813) on 11-21-2018, 07:19 PM:

Since it's Japanese it will/should have metric fasteners. Maybe that part was made in the USA in a panic when "digital" lamps were unavailable?
Possibly someone ham-handed it and ruined the hex hole?
There is no metric Allen key between 2mm and 2.5mm.
Brandi is pretty good but doesn't know every part and fastener. There are 5mm cap screws in the projector, those use a 5mm key. Nice that metric cap screw keys are the same size as the thread.

Posted by Steve Kraus (Member # 476) on 11-22-2018, 12:32 PM:

She specifically said measured across the flats so there's no ambiguity about the overall screw size versus the tool.

She followed up with "that tool size should be 5/64." At first I thought 'great...mystery solved." Then I did a little calculating:

5/64" is 0.078125". Multiply by 25.4 and you get 1.984375mm. So a touch under 2mm? 2mm was already too small. The beat goes on.

3/32" / 2.38125mm is too large (and was the basis of my self-ground tool).

I do believe there is a 2.25mm wrench. That might do it or be close enough to work as is.

Posted by Gordon McLeod (Member # 33) on 11-23-2018, 01:36 PM:

There were 3 vintages of the brass adapter the latest that came with the machines are split design and screwless the first ones were SAE the later ones with a screw were a standard metric 2mm

Posted by Steve Kraus (Member # 476) on 11-24-2018, 11:38 AM:

My projector is from 2012 but which version of the adapter out of their basket got included could be random although obviously it is not the split design.

As I said, 2mm was too small. 2.5mm too big. And no SAE worked other than by angular pressure. As my handmade tool was ground down from 2.38mm (SAE 3/32") my current guess for a quasi standard size is 2.25mm. I hope I have no need for any tool for a few years.

Posted by Mark Gulbrandsen (Member # 72) on 11-24-2018, 12:18 PM:

Seems like the ones I used worked with a standard metric allen key. But that was back in mid 2010 when these first came out.

Mark

Posted by Steve Kraus (Member # 476) on 11-24-2018, 01:15 PM:

It will frustrate me now because the mystery will remain unsolved but it would be completely illogical to disturb the bulb just to try other tools! [uhoh]

Posted by Mark Gulbrandsen (Member # 72) on 11-24-2018, 03:41 PM:

Just locate a theater equipped with NEC's and you will find a whole box of those adapters in the booth. Any Marcus Theater has NEC...

Markus Filmiticus