Nuarc

[David Aimone]

I have been given for free a NUARC 26-1K-LC exposure unit. It works, but it needs a little TLC, and I can't find much on this particular unit (the LC version).

So, asking for help here.

1. Anyone with a user's manual for this?
2. I am not sure what kind of bulb is in the unit, but it takes a long time to come on and then brighten up fully. The person who gave it to me said I should try one of these in it from Amazon (http://amzn.com/B00QPFZH02).
3. I am not sure how to use the timer. This one has an extra button on it (manual) and I cannot seem to get the light to automatically come on and off with the timer.
4. The glass under the bulb is broken (see photo). I can replace it, but it seems to have a lightly printed dot pattern right under the bulb. Do I need to recreate this somehow for the replacement glass, or not worry about it?

THANK YOU!!!!

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[Tin Can]

All I have of one is the bottom vacuum panel, but it makes a great contact printer.

Others use one like yours for alt prints.

Did you get the rather expensive vacuum pump?

[David Aimone]

I want to use it for contact printing of Alternative Prints. I'm not sure which pump is in it, but that part seems to work great.


All I have of one is the bottom vacuum panel, but it makes a great contact printer.

Others use one like yours for alt prints.

Did you get the rather expensive vacuum pump?

[Jim Noel]

You need to replace the broken glass with one from the manufacturer, not just any glass.
The bulbs whether mercury or the newer replacement do take some time to warm up the first time. I usualy dial in50 units and run it prior to exposing a print.
To put in a number of units is simple. for example to set up for 50 units push the "5",then the "0" twice. This will be 50.0 units. pres "S" and the unit will start. the countdown will be slow at first but speed up as it heats up.
You can download a manual from the web site. Once you have it, you need to also clean the sensor.

[David Aimone]

Is this the company you are referring to?

http://www.mrprint.com/en/CustomerService.aspx

I will email them, i don't see info on this unit there.


You need to replace the broken glass with one from the manufacturer, not just any glass.
The bulbs whether mercury or the newer replacement do take some time to warm up the first time. I usualy dial in50 units and run it prior to exposing a print.
To put in a number of units is simple. for example to set up for 50 units push the "5",then the "0" twice. This will be 50.0 units. pres "S" and the unit will start. the countdown will be slow at first but speed up as it heats up.
You can download a manual from the web site. Once you have it, you need to also clean the sensor.

[Keith Pitman]

When you email mrprint, include the serial number from your unit and they will send you a PDF of the manual.

I believe tha glass that is broken in your is tempered glass. I would strongly suggest you replace it with the proper glass from the manufacturer. You don't want shards of broken glaas or from a broken bulb raining down on your hands.

I have a different model, but to make the timer work, you preset the time and then press start. I don't think I have a manual button.

Yours may or may not have an electric eye that will let you calibrate the timer. The manual will help.

[Tin Can]

Ask for the Large Format version trade in allowance. Only kidding, but look at his unit. 94x180 inches...

http://www.mrprint.com/en/Screen%20Exposure%20Units%20&%20CTS%20Systems/Screen%20Exposure%20Systems/Screen%20Printing%20Exposure%20Units/HELIOS%20Large%20Format%20Screen%20Exposure%20System

[David Aimone]

WOW..........

Does Arches or COT even come that size???


Ask for the Large Format version trade in allowance. Only kidding, but look at his unit. 94x180 inches...

http://www.mrprint.com/en/Screen%20Exposure%20Units%20&%20CTS%20Systems/Screen%20Exposure%20Systems/Screen%20Printing%20Exposure%20Units/HELIOS%20Large%20Format%20Screen%20Exposure%20System

[Jim Jones]

The vacuum tables I used years ago came with a light source that used two 5kw metal halide lamps. When they came on, they produced about half power. It took about half a minute for them to reach full power. At one time they used an electric eye to compensate for that warm-up, but we never bothered with it. A larger problem was the light source being fairly close to the 32x40 inch table. This resulted in fall-of in the corners. For duping tint plates, I made a large flag to dodge the center of the table to even out the exposure. The other operators didn't bother with this. Sometimes good enough is good enough.

[David Aimone]

I'll have to check what this has. I'll email the company to get the specs and work from there. I have a really good UV light source for up to 16 x whatever, but I'd like to do 20 x whatever, so I'll see if I can get this thing in shape!

At Steve Sherman's darkroom, he had a unit similar to this and it worked very well. I'm hoping to achieve that here.


The vacuum tables I used years ago came with a light source that used two 5kw metal halide lamps. When they came on, they produced about half power. It took about half a minute for them to reach full power. At one time they used an electric eye to compensate for that warm-up, but we never bothered with it. A larger problem was the light source being fairly close to the 32x40 inch table. This resulted in fall-of in the corners. For duping tint plates, I made a large flag to dodge the center of the table to even out the exposure. The other operators didn't bother with this. Sometimes good enough is good enough.

[Michael Mutmansky]

You need to replace the broken glass with one from the manufacturer, not just any glass.
The bulbs whether mercury or the newer replacement do take some time to warm up the first time. I usually dial in 50 units and run it prior to exposing a print.
To put in a number of units is simple. for example to set up for 50 units push the "5",then the "0" twice. This will be 50.0 units. pres "S" and the unit will start. the countdown will be slow at first but speed up as it heats up.
You can download a manual from the web site. Once you have it, you need to also clean the sensor.

Tempered glass is fine...

Nuarc makes/made a glass that has a ceramic fritting on it to even out the exposure, but most people I know don't have that and it works well enough for pt/pd printing, just don't print all the way out into the edges.

DO NOT exchange lamps (these are not 'bulbs'!) unless it is deemed compatible by the manufacturer! The mercury vapor lamps of the original units may operate with a different starting voltage or capacitor in the circuit than the metal halide lamps. You can get a suitable generic lamp replacement for these, but first, figure out exactly what the correct lamp is supposed to be so you can find a suitable equivalent.

Looks like you need a vacuum frame glass as well. That should be tempered, too.

Before you spend a lot of money on glass, you should look into whether the unit functions correctly. These older units have some old timer pieces, etc., that do fail, and you may have to spend some money to get the parts for repair.

Does the lamp flicker a lot before striking? If that is the case, it may need a replacement lamp. First place to start. The one in the link looks correct, but I do not know what the "LC" designation is for. My old unit didn't have the "LC" I don't believe.

These exposure heads often get corrosion on the contacts between the lamp and the exposure unit. You may want to unplug the unit, take the lamp out (with gloves to keep the oils off the lamp) and see if the contacts are in good shape. If not, clean them with an eraser and maybe a little alcohol if needed. You can also use contact conditioner on them if needed.

There should be no reason to be pre-heating the lamp if everything is working correctly. The light integrator will count light units, not time, so while the lamp heats up and the output increases, the integrator should count correctly for you.

However, when doing critical testing or critical final prints, it is always best to be absolutely consistent, so I recommend that people get the unit warmed up with test prints and other preliminary work before getting to the final prints, and then try to keep the units in the same conditions for every print after that if possible. Don't go to lunch and then return and expect it to produce a print just like before lunch, for example. Even the best of these won't be that consistent.


---Michael


---Michael

[David Aimone]

So, I did talk to support at NUARC, and learned a lot, and a lot of agrees with what i'm told here.

A few differences/additions:

First, they recommend a dedicated 20 amp circuit for the unit, and to measure the actual voltage and "tune" the power supply in the unit to actual line voltage. How many alternative photograph printers do this?

Second, there's foam under the edges of the pad which is decaying, and they suggest replacing that with velcro.

Other than that, yes, the bulb is specific and in the 350nm area so that should be fine. This unit does have the sensor and compensating timer so that's good to go. The glass on the vacuum area is fine, and they said not to worry about the piece missing from the glass under the bulb (or I could replace with tempered glass and not worry too much about the diffusion pattern).

But he did say that there is a 1/2 to one full stop vignetting from the center to the edge.

So I have to decide whether to put time and energy into this, or expand my T8 actinic bulb unit to take prints larger than 16x20.



Tempered glass is fine...

Nuarc makes/made a glass that has a ceramic fritting on it to even out the exposure, but most people I know don't have that and it works well enough for pt/pd printing, just don't print all the way out into the edges.

DO NOT exchange lamps (these are not 'bulbs'!) unless it is deemed compatible by the manufacturer! The mercury vapor lamps of the original units may operate with a different starting voltage or capacitor in the circuit than the metal halide lamps. You can get a suitable generic lamp replacement for these, but first, figure out exactly what the correct lamp is supposed to be so you can find a suitable equivalent.

Looks like you need a vacuum frame glass as well. That should be tempered, too.

Before you spend a lot of money on glass, you should look into whether the unit functions correctly. These older units have some old timer pieces, etc., that do fail, and you may have to spend some money to get the parts for repair.

Does the lamp flicker a lot before striking? If that is the case, it may need a replacement lamp. First place to start. The one in the link looks correct, but I do not know what the "LC" designation is for. My old unit didn't have the "LC" I don't believe.

These exposure heads often get corrosion on the contacts between the lamp and the exposure unit. You may want to unplug the unit, take the lamp out (with gloves to keep the oils off the lamp) and see if the contacts are in good shape. If not, clean them with an eraser and maybe a little alcohol if needed. You can also use contact conditioner on them if needed.

There should be no reason to be pre-heating the lamp if everything is working correctly. The light integrator will count light units, not time, so while the lamp heats up and the output increases, the integrator should count correctly for you.

However, when doing critical testing or critical final prints, it is always best to be absolutely consistent, so I recommend that people get the unit warmed up with test prints and other preliminary work before getting to the final prints, and then try to keep the units in the same conditions for every print after that if possible. Don't go to lunch and then return and expect it to produce a print just like before lunch, for example. Even the best of these won't be that consistent.


---Michael


---Michael

[Michael Mutmansky]

Yes, it's funny that they use a 15-amp plug when they really should be using a dedicated 20-amp plug:

http://www.amazon.com/Leviton-5366-CA-Industrial-Grounding-Black-White/dp/B0026H1C9I

I know that most people don't typically run a dedicated circuit, but you'll trip the breaker if anything else is on there (and possibly even if nothing else is, depending on the volume of use and the breakers in the house).

I ran a dedicated 20-amp circuit for mine so I didn't have to fret it.

Note that the fuses in the unit (in the one photo) are not common fuses, so you should get some on-hand before you blow a fuse and it shuts you down for a few days. You can't get them at the local home center. I had to order them on-line.

Unless you are going all the way out to the corner, you probably won't see that falloff, so I wouldn't worry about it until you have seen problems with that. At that point, you could always burn in the edges (or dodge the center, however you want to look at it) with some cardboard. Just make sure you have proper eye and skin protection. (I use dark UV glasses, long sleeves, and keep a tube of SPF 60 or similar to put on my hands). The UV will burn you if you are not careful.

---Michael

[Steve Sherman]

Hi David,
I know Michael Mutmansky well, Michael is a lighting engineer by trade and as advanced a Pt. / Pd. as you'll find anywhere. In fact he maybe on par if not more knowledgable about Nuarc's than the Nuarc rep you spoke with.

2 cents SS

[David Aimone]

thanks everyone! Sometime in the next week I'm going to spend a day with the unit and it's previous owner and give it some TLC, and install a dedicated circuit when I have the chance...

[bob carnie]

I am in the market for a Nuarc if anyone has a unit for sale-

[Michael Mutmansky]

Hi David,
I know Michael Mutmansky well, Michael is a lighting engineer by trade and as advanced a Pt. / Pd. as you'll find anywhere. In fact he maybe on par if not more knowledgable about Nuarc's than the Nuarc rep you spoke with.

2 cents SS

I doubt that, but I have used them for what we are talking about, and the M&R folk generally don't understand the whole alt-process stuff. They are a great resource though, and especially if the timer gives you trouble, because there are a few generations of the timer mechanism, and they do sometimes require work.

For the cracked coverglass:

There are a few important things about it to consider. First, there is an interlock switch between that and the lights source, so if the CG is missing, the light should not function. This is there for a few reasons, but one is non-passive failures of the lamp. You don't want to be anywhere near one of those units when a lamp explodes, especially if there is no cover glass (think molten glass and hot metal flying everywhere). Second, there are probably UV B and C wavelengths that the glass absorbs. These aren't useful for printing, and are very detrimental for your eyes and skin, so you really don't want to be exposed to that too much if you can help it. The cover glass takes care of those two issues, and with the fritting on the glass, also evens out the exposure on the easel appreciably.

If the missing glass is appreciably substantial, I'd replace it with tempered glass rather than leave an opening that risks these other issues.

Hope it works great; I had the big brother to that one, the 40-1K, for years until I moved to California, and didn't have room for it. I bought the modern Amergraph unit to replace that beast about 2 years ago.


---Michael

[David Aimone]

Thanks, Michael. If I go through the whole renovation process with this I will replace the upper glass with new tempered glass. Right now it's missing about the rear 4 inches or so, angled from about two inches from one back corner to about 4 inches from the other back corner. So it's covering about 80% of the area, with an opening in the back, and I guess it's contacting the interlock switch.




I doubt that, but I have used them for what we are talking about, and the M&R folk generally don't understand the whole alt-process stuff. They are a great resource though, and especially if the timer gives you trouble, because there are a few generations of the timer mechanism, and they do sometimes require work.

For the cracked coverglass:

There are a few important things about it to consider. First, there is an interlock switch between that and the lights source, so if the CG is missing, the light should not function. This is there for a few reasons, but one is non-passive failures of the lamp. You don't want to be anywhere near one of those units when a lamp explodes, especially if there is no cover glass (think molten glass and hot metal flying everywhere). Second, there are probably UV B and C wavelengths that the glass absorbs. These aren't useful for printing, and are very detrimental for your eyes and skin, so you really don't want to be exposed to that too much if you can help it. The cover glass takes care of those two issues, and with the fritting on the glass, also evens out the exposure on the easel appreciably.

If the missing glass is appreciably substantial, I'd replace it with tempered glass rather than leave an opening that risks these other issues.

Hope it works great; I had the big brother to that one, the 40-1K, for years until I moved to California, and didn't have room for it. I bought the modern Amergraph unit to replace that beast about 2 years ago.


---Michael