Nuarc 26 1k questions

[Brian Bullen]

Mike, thanks. Actually my plan was to build a unit also and I thought the same thing as you when I saw this listed for that price. I can't build one for that little.

 

[Jorge]

It is a great deal, i just got lucky really, right place at the right time. She was so happy to have it out of her way and didn't really know what it was for. Now I just need a densitometer at that price. Every UV densitometer I've seen are going for $300 to $400. Patience pays off though.

If you are patient and do a search for an x rite 369t instead of the 361 that everbody wants you can have them really cheap, I got mine for $80.

 

[Brian Bullen]

If you are patient and do a search for an x rite 369t instead of the 361 that everbody wants you can have them really cheap, I got mine for $80.

Wow thats a good deal too, unfortunatly I have been searching for the 369 as well with no luck. And the Gretag/Macbeth.
Someday soon.

 

[lallan]

As for the bulb, I recommend the USHIO metal halide lampt for the NuArc 26-1K. It is less expensive than the replacement bulb NuArc sells for the unit, but has about the same spectral power distribution curve and actually reaches full output faster than the mercury vapor lamp sold by NuArc. USHIO makes two of these lamps, the one you want for Pt./Pd. printing is the MHL-1000/1. NuArc may not recommend the USHIO lamp, at least they did not when I spoke to them about it a couple of years ago, but lots of people use it and by all accounts it works as well or better than the mercury vapor lamp.

Sandy

Sandy, do you have the 26-1K or the 26-1KS? I emailed Nuarc today about lamps for the 26-1K and this was the reply:

"We tried unsuccessfully for a couple of years to come up with a Metal Halide Lamp that could be used in the very popular 26-1K. We then found that we had to come up with a different style of power supply to work with a newly designed Metal Halide Lamp. This unit is the 26-1KS which replaced the old 26-1K somewhere around the mid 90's, if I remember correctly. These lamps are not interchangeable. ......The original GW114 lamp in the 26-1K has several rather narrow peaks with the only light within the area that you need being between 360 and 370 nm. The NP80 lamp in the 26-1KS as a comparison has a strong output that begins at 320 nm and continues thru 450 nm."

thanks....lyle

 

[sanking]

Sandy, do you have the 26-1K or the 26-1KS? I emailed Nuarc today about lamps for the 26-1K and this was the reply:

"We tried unsuccessfully for a couple of years to come up with a Metal Halide Lamp that could be used in the very popular 26-1K. We then found that we had to come up with a different style of power supply to work with a newly designed Metal Halide Lamp. This unit is the 26-1KS which replaced the old 26-1K somewhere around the mid 90's, if I remember correctly. These lamps are not interchangeable. ......The original GW114 lamp in the 26-1K has several rather narrow peaks with the only light within the area that you need being between 360 and 370 nm. The NP80 lamp in the 26-1KS as a comparison has a strong output that begins at 320 nm and continues thru 450 nm."

thanks....lyle

I have the Nuarc 26-1k. The Ushio metal halide lamp appears to work perfectly in this unit.

Sandy

 

[lallan]

BTW, the integrator is adjustable so that you can make one unit equal just about whatever you want it to equal, but it makes sense to make to make a unit a second. However, you could calibrate it so that one unit equals 10 seconds, or whatever you will. If you have any questions about this after you get the unit post another message here.Sandy

Sandy, how do you adjust the integrator? For that matter, where is it and how do you clean it?

On another note, I am a bit confused over the lamp/spectral output issue. Presently, my 26-1k has a Caprock CD/GW-114 mercury vapor lamp. It is new - came with the machine. According to Caprock, it has a peak output of 365nm. It prints MUCH slower than my Aristo platinum printer (tubes) which Aristo's web site claims is in the 350nm range. Why would this be if they are in the same ballpark of output? Since some sites list 'peak' output, others a range, could a narrow peak affect things that much (assuming the Caprock has a narrow range)? The USHIO sites lists the MHL-1000/1 as 350-370nm range and is metal halide. The newer 26-1kS units use metal halide over the mercury vapor and Nuarc claims this is faster. Do metal halide lamps have a wider spectrum? More light output for the same wattage?

And....what do folks do for working in the same room while the Nuarc is blasting away? I tried a curtain around the unit but it got real hot.

Finally, is it correct to have the dot pattern on the glass under the lamp facing the bottom and also perpendicular to the lamp?

thanks,

...lyle

 

[sanking]

The photo cell of the integrator is located just under the front of the top lid. To access it you must remove all of the screws that hold the lid to the main unit, and carefully move it to the rear. You can adjust the timing in two ways: 1) by the angle at which you point the front of the photo cell toward the lamp, and 2) by adjusting the filter on the front of the cell, which controls the actual amount of light that can reach the cell. What you want to do is adjust the cell so that 0.1 unit of integrator value is equal to about one second of exposure.

The greater speed of your Aristo platinum printer compared to the Nuarc 26-1k is probably more the result of distance from the light source to the printing frame than the spectral distribution power of the lamp. In fact, most people who print with UV fluorescent banks of BL tubes, either home-made or units like Edwards Engineering, find that printing is faster with these units than with the NuArc 26-1k or 26-1ks.

I have compared the SPD of the GW-114 mercury vapor with that of the USHIO MHL-1000/1 and there is not a lot of difference. Both have a mximum peak at about 360 nm, another one of less power at 400 nm, and a third of about 85% of the powr of the first at about 430 nm. In fact, these peaks are very similar to what you see with the BL tubes, though the BL peaks at 350 nm, and the spectrum is much wider.

Regarding location, I positioned my unit in a small space offered by a dormer window, with a black pull-down shade on the front. It does not produce a huge amount of heat during normal exposures which are for me in the 3-5 minute range.

I don't have an answer to your question about the dot pattern. The original piece glass that came with my unit was broken and I replaced it with a piece of plain tempered glass of the same thickness.

Sandy

Sandy, how do you adjust the integrator? For that matter, where is it and how do you clean it?

On another note, I am a bit confused over the lamp/spectral output issue. Presently, my 26-1k has a Caprock CD/GW-114 mercury vapor lamp. It is new - came with the machine. According to Caprock, it has a peak output of 365nm. It prints MUCH slower than my Aristo platinum printer (tubes) which Aristo's web site claims is in the 350nm range. Why would this be if they are in the same ballpark of output? Since some sites list 'peak' output, others a range, could a narrow peak affect things that much (assuming the Caprock has a narrow range)? The USHIO sites lists the MHL-1000/1 as 350-370nm range and is metal halide. The newer 26-1kS units use metal halide over the mercury vapor and Nuarc claims this is faster. Do metal halide lamps have a wider spectrum? More light output for the same wattage?

And....what do folks do for working in the same room while the Nuarc is blasting away? I tried a curtain around the unit but it got real hot.

Finally, is it correct to have the dot pattern on the glass under the lamp facing the bottom and also perpendicular to the lamp?

thanks,

...lyle

 

[boyooso]

I have had many problems using the ushio bulbs, they either won't start or start for a while and then won't start anymore. Has anyone else experienced that?

Corey

 

[sanking]

I have had many problems using the ushio bulbs, they either won't start or start for a while and then won't start anymore. Has anyone else experienced that?

Corey

Have you compared the performance of your machine using the Ushio bulbs and the -114 bulb that Nuarc sells for the 26-1k?

Sandy

 

[boyooso]

The nuarc bulbs actually seem to work for longer. When the ushio bulb works, it works fine...

What aspect of performance are you referring to?

Corey

 

[sanking]

The nuarc bulbs actually seem to work for longer. When the ushio bulb works, it works fine...

What aspect of performance are you referring to?

Corey

u

What I meant was this, have you compared the performance of the Nuarc 114 bulb with the Ushio bulb in terms of how quickly it turns on? I assume this would mean comparing new bulbs, or at least bulbs of the same age.

I have been using the same Ushio bulb for about two years and it works perfectly in my Nuarc 26-1k. Comes on immediatley, consistently, and has obviously lasted quite a number of hours since I print a lot.

It is possible that your unit has some type of problem with the ballast or the power supply, or perhaps the problem is just with the Ushio bulbs. However, that is definitely not a problem here. I began using the Ushio bulb on the advice of a technician who worked at a graphic arts company that had two Nuarc 26-1k units in shop, both of them using the Ushio bulbs exclusively for more than a year, and they were satisfied enough with the bulbs to recommend them to me.

Sandy

 

[boyooso]

Sandy,

With my unit the nuarc bulb has always come on immediately,however the ushio bulbs have been a bit more hit or miss. I've had 2 ushio bulbs, 1 never started, the other took some time to start, and then started more quickly ( 5 seconds) then after some use took longer until it wouldn't start at all.

I trouble shot the problem for some time, replaced the start circut board and in the end the nuarc bulb solved the problem ( on the advice of the technician that told me the nuarc people wouldn't really talk to you until you tried a nuarc bulb).

I am curious of others' expreriences that is why I inquired

Corey

 

[sanking]

Sandy,

With my unit the nuarc bulb has always come on immediately,however the ushio bulbs have been a bit more hit or miss. I've had 2 ushio bulbs, 1 never started, the other took some time to start, and then started more quickly ( 5 seconds) then after some use took longer until it wouldn't start at all.

I trouble shot the problem for some time, replaced the start circut board and in the end the nuarc bulb solved the problem ( on the advice of the technician that told me the nuarc people wouldn't really talk to you until you tried a nuarc bulb).

I am curious of others' expreriences that is why I inquired

Corey

Assuming that your comparison is "new Ushio bulbs to new Nuarc bulbs" your experience would suggest that all Nuarc 26-1k units are not identical in terms of their ballast and start-up circuits, and some don't work with the Ushio bulb. I just don't know enough about the difference between metal halide circuitry and mercury vapor circuitry to comment on this, though in some commrecial ballast units it is not at all uncommon for the bulbs to be interchangeable. I used a large commercial Luminaire 1000-watt unit for a couple of years, and during that time I tested it with both mercury vapor and metal halide bulbs. Both worked, though the metal halide bulb reached peak output much faster than the mercury vapor bulb, about two minutes for the former and five minutes for the latter. I also found this to be the case in comparing the Nuarc 114 bulb to the Ushio bulb in the Nuarc 26-1k, though the difference was not as great as with the commercial unit.

To this point, however, you are the first person I have heard from who has had problems with the Ushio bulb. I too am interested in hearing from others to learn of their experiences.

Sandy

 

[reggie]

Are these metal halide bulbs multi-spectrum? If so, could a filter be used to filter out most of the UV light? Would the remaining light be of enough intensity to print AZO or faster papers?

Thanks.

-R

 

[sanking]

Why would you want to filter out the UV light. AZO is very sensitive to UV.

The problem you would have in printing AZO with a Nuarc 26-1k is that exposure times would be ridiculously short, though I guess you could tape some large neutral density filters over the glass underneath the bulb.

Sandy

Are these metal halide bulbs multi-spectrum? If so, could a filter be used to filter out most of the UV light? Would the remaining light be of enough intensity to print AZO or faster papers?

Thanks.

-R

 

[reggie]

Why would you want to filter out the UV light. AZO is very sensitive to UV.

The problem you would have in printing AZO with a Nuarc 26-1k is that exposure times would be ridiculously short, though I guess you could tape some large neutral density filters over the glass underneath the bulb.

Sandy

I didn't know AZO was so sensitive to UV light. That is good to know. Are graded bromide papers also sensitive to UV light?

Thanks.

-R

 

[Silverpixels5]

The glass underneath the bulb is tempered to withstand the high heat from the lamp and will cost a fair amount to replace if you break it.

Sandy

Any idea what temperature this piece of glass is rated to? I need to order a new one. Also would anyone know the dimensions of it? Thanks!

 

[Brickbird]

26-1K Glass

Any idea what temperature this piece of glass is rated to? I need to order a new one. Also would anyone know the dimensions of it? Thanks!

I do not know about the temp rating of the glass but my dot-patterned original top glass is 18.5x18.5 inches. For what it's worth I bought my 26-1K through the NuArc repair tech here in Dallas. He is Jeff Dowlen and I believe that his Dad was the NuArc rep here in Dallas for a fair amount of time. Jeff knows his stuff about NuArcs and has parts, motors, circuit boards,pumps and probably anything else one would need. You can reach him at 972-816-7383 and I would bet he could answer the question about the bulb war and if the mh would work as good as the mv bulb. Good luck all.

Tav Walraven

 

[JBrunner]

I didn't know AZO was so sensitive to UV light. That is good to know. Are graded bromide papers also sensitive to UV light?

Thanks.

-R

Hi Reggie,

I like to use the vacuum frame on my NuArc for printing silver, but the light in the unit is simply to bright and uncontrollable exposure time wise. An easier solution than a kluge on the unit is to affix a conventional clip on light that has a reflector pointed up into the NuArc reflector. The lamp reflector shades the frame from direct off axis illumination, and the light striking the NuArc reflector provides an ideal level for contact printing. (I found fixing a bare light under the hood to be too close for even illumination, and too bright.) You can then plug that light into a timer. Takes about thirty seconds to install and uninstall, and your NuArc remains ever ready for alternative process.

 

[Nicholas Lindan]

The nuArc HID systems are not designed for film and regular paper,
the exposure just won't be controllable enough and there is way
too much light.

The best inexpensive dual-use solution is to have a flip-top platemaker for alt process and have a point source contacting light hanging above the platemaker. Flip-top platemakers normally go for much less than the 26 1K machines. But the avarage flip-top makes a 26 1K look like a little baby of a thing.

nuArc's equipment gets pretty big, you walk inside to change the
bulb:

http://www.mrprint.com/en/productoverview.aspx?id=27

But the small f/t platemakers are about the size of a washing machine.