Calibrating a NuArc integrator... Sandy King?

[Nicholas Lindan]

I have the 26-1K ...The bulb looked old
and was quite blackened so I got a new one ... the new [bulb] stopped working ... the fuse ... was blown.

The 26-1K isn't one I am all that familiar with. I assume it has the simple 1-channel integrator. Some of the 8-channel units have little plug-in cards that set the detector sensitivity. With age the contacts get cruddy and integrator operation is erratic. I am not sure if the 1K's integrator has plug-ins, if it does, and they are easy to get to, then unplug and plug them a few times, ditto with the cable from the sensor.

An old bulb is the #1 cause for erratic light output. It should have a white
coating on the inside of the bulb. If the quartz has melted and distorted then there is something seriously wrong, though it may just be a blocked fan.

If the new bulb went out after 10-30 seconds (maybe longer) and/or the fuse blew then I would double and triple check you have the right bulb. Just because it matches the old one doesn't mean it is the right one, it is quite possible the old bulb was also the wrong type [the sort of problem that can give endless frustration].

Don't be afraid to call nuArc. Their support staff is very helpful and will aid you with used equipment. nuArc isn't what it used to be, what with computers doing all the pre-press work, and they are now a part of M&R Print, but I have heard the customer suppor is still the same high quality and 24-7.

http://www.mrprint.com/en/department.aspx?id=14

The 26-1K is still in production, so nuArc will be familiar with the unit and will have lots of spare parts available if you need them.

The 26-1K is a reliable and popular unit that has been around for 30 years [I first saw one in '79, when I was designing their instant-start power supply] and there shouldn't be any great problem getting it humming along.

[SusanV]

Here's what I've found out today. Both of the little "barrel" fuses mounted
in the case of the Nuarc were the wrong type. One is supposed to be a 5
amp, 250v, but instead it was an 8 amp 250v. The other was supposed to
be a 20 amp., 250v "slo blo", and it was a fast acting fuse instead. it's the
one that blew. I guess a "slo blo" or "time delay" fuse allows for some short
spikes of current flow at start-up, and the fast acting fuse... acts fast .
Maybe?

So those things are now corrected.

The new lamp is the correct one, I double checked that. it works great now
that I changed the fuse that was blown.

I finally got it adjusted so that one unit = about 1 second when the
lamp is fully illuminated. (Very helpful when discussing the process with
others, and troubleshooting any problems I or someone else might have)


Nicholas... per your suggestion I checked all the connectors, and slid them
off and on a few times to make sure they were making good contact. There
was a lot of fine dust on and in this unit, but the little connectors are all
covered with plastic protectors, which is a help. While doing that though...,
I also found TWO ground wires that were barely connected... just hanging
there with the nut (that's supposed to hold them tight...), all the way out
to the end of the bolt, about to fall off! Glad I found that. I also have
noticed another green wire that's not connected to ground... just has a piece
of electrical tape wrapped around the end of it. Will be checking into that
some more tomorrow.

Hopefully I'll also be making some gravures

thanks for the help, I really appreciate it. Hopefully I'm all set now
::: crossing fingers::::

Susan

[rtuttle]

Susan:
I don't have a lot of experience with this unit but I do have tons of experience using Nuarks fliptops and contact units. That little light probe in the back should have a phillips head screw in the middle. If you loosen it up ever so slightly you can turn it so the aperature changes. If the time is too slow open it, and vice versa. There is no harm in doing this as that is it's function. Nuark equipment is functional and sometimes clumsy. They also have a long history of changing suppliers for things like daughter boards and not telling everybody in their employ. You should be able to do what your looking to with it though.

[SusanV]

thanks... it's workin like a charm, now!

susan

[sanking]

thanks... it's workin like a charm, now!

susan

I am curious to know if the light integrator on your 26-1k gives consistent results if you make exposures one after the other? A freind who uses a 26-1k told me that he can not get repeteable results with his unit unless he always alllows it for the same period of time before making the exposure. This seems to defeat the idea of the integrator, but in discussions with someone at NuArc very recently one of the technicians there suggested that the problem might be that the light sensor of the integrator reads visible light, not UV. I thought this was odd, but as I said, it did come from one of the technicians at NuArc.

Before acquiring my Amergraph ULF-28, which gives beautiful consistenty with multple prints, I also used a NuArc 26-1k for kallitype and pt/pd printing. I recall having some problem with consistency, but at the time attributed it to coating and humidity conditions.

Sandy King

[RobertP]

Amergraph ULF-28....Got it on my wish list. But I find my 26 1K integrator to be pretty accurate. I always turn it on for 200 units before I start printing then I allow plenty of time before I try to restart. Restrike isn't the best with these but very seldom do I print past 1000 units. But I'm all for cutting down on the work prints when doing ULF pt/pd prints

[Peter Cane]

Nicholas:

Thanks for your comments on the Nuarc-I've been loking for one in the Maryland area for awhile-just missed one being tossed out in DE by two days!! (light table with it too) What a shame. Anyway, I use the fstop timing method in my darkroom and love it. I have a tape that reads out stops and third stops since I can't use one of your timers with my D2. Can the Nuarc be set up with your fstop timer?

Thanks

Peter