cooling fan on Durst 138?

[Liquid Artist]

I finally got my Durst 138 up and running, and what surprises me is the amount of heat coming from the bulb.

So I am wondering if a cooling fan would keep it cooler, and hopefully extend the life of the bulb.

What are your thoughts on it?

[Jason Greenberg Motamedi]

How many watts is the bulb? I run a 150 watt bulb in my 138S and it never seems to get very hot. The Durst manual I have calls for a fan at 300 watts.

[LabRat]

Depends...

Some enlargers like the Leitz V35 have NO cooling fan (and the lamp is enclosed in a thickish aluminum housing ,but with a heat sink/cooling fin arrangement) that keeps the lamp warm, and cooling slowly (to avoid thermal shock)... (These go through lamp sockets like crazy!!!) Or heads with a lot of plastics (nylon gears, plastic dials, wiring, etc) that need not letting heat build-up in them and NEED a fan... (And mechanicals that can bind up from heat expansion...)

I felt some color heads that you can cook an egg on... (Halogen bulbs get HOT!!!) But bulb life will be generally greater if the bulb is allowed to cool off gradually, so too much fan action can actually hurt the bulb from thermal shock... (But there's the bulb chamber, and the rest of the head...)

Steve K

[Liquid Artist]

Thank you for your replies,

I believe that it's still the factory bulb, so Durst must have thought that it's alright.
I wouldn't care as much if I could still get factory replacement bulbs.

[LabRat]

But on some later Durst's, I have seen where they put nylon parts very near the lamp assy., and the parts were brittle and breaking... (What were they not thinking!?!!!) Don't assume with Durst...

But survey inside the head to see how much plastic is around... (I think the earlier heads were mostly metal) If metal, then you can safely use most bulbs...
And if there is some bottom to top of head air/convection flow path, to allow convection cooling...

One upgrade to allow for better cooling is that any place that joins to the bulb chamber, (or any plates that get hotter than others), clean the seams where the plates join to bare metal, and get a good quality heat sink compound (from the electronics or computer store) and apply inside of the seams... This will keep the heat moving, instead of concentrating it in one area...


Steve K

[Liquid Artist]

Thank you once again Steve,
I will take a look tomorrow.
It's nice getting my darkroom finally up and running again,

[ic-racer]

Yes, you will want to us the LAFAN blower with lamps greater than 300 watts. Do you miss this in the manual?

[Liquid Artist]

What is a Manual ic-racer?
I thought that booklet was just there to throw in the recycling bin.
Since I got my enlarger third hand, someone beat me to it.

I actually remembered reading something in the downloaded version. However I basically look at such suggestions as guidelines. I have also come to realize that someone with experience using these enlargers may have different / better ideas through trial and error.

Besides the fact that Durst had no way of knowing the bulb production would halt before all their enlargers hit the scrap yard.

[ic-racer]

I thought that booklet was just there to throw in the recycling bin.

I suspect you are joking, however, I hope you realize specialized equipment like the Durst 138 can kill you in more than one way if you don't know what you are doing. The prudent operator will have the instruction manual memorized. If anything I'd be more careful with the equipment than the indicated recommendations, seeing as how the equipment is irreplaceable.

I can just imagine the news report..."Liquid Artist succumbed today to injuries sustained in a fire that started in his home darkroom yesterday. Apparently he had been operating vintage lab equipment outside of manufacturer's safe operating specifications based on advice he received on an internet forum..."

[Jac@stafford.net]

I wouldn't care as much if I could still get factory replacement bulbs.

Are you sure there are not equivalent bulbs (https://www.interlight.biz/light-bulb/WW-1AHD-7?dfw_tracker=9554-WW-1AHD-7&gclid=CjwKEAjwpaqvBRCxzIGoxs6v2TkSJADel-MIb2T02UK6BNTiS1BpKMfD-BmF-MilSDYb8ijjMX8SlBoCUPjw_wcB)? Pardon my ignorance.

For Edison type bulbs, I use ceramic sockets. Of course then the first thing to go is the wiring at the base. :)

Aside - a Leitz enlarger was mentioned - The early Valoy could be had with an extra cooling bonnet to allow 250W bulbs. I wish it worked on the IIA.

Right here on the bench I have a large lens cone (pyramid shape) that is a frame with two thin plates on each side, one inside, one outside. It permits ventilation without leaking light. I think its design was to allow atmospheric balance at altitude, but it serves another purpose, too.

Plastic gears are made to be broken, fried brittle. It might be worth perusing McMaster-Carr for metal replacements.

OP, is this (https://www.trippingthroughthedark.com/files/durst138/Durst%20Laborator%20138%20Instructions.pdf) the proper instruction book?

.

[Jason Greenberg Motamedi]

What is a Manual ic-racer?... Besides the fact that Durst had no way of knowing the bulb production would halt before all their enlargers hit the scrap yard.

There are many different 138S manuals available online, just do a search (https://www.google.com/search?q=durst+138+manual).
As others on this site have pointed out, 150 watt G40 bulbs seem to be the best replacements. They work very well, and (from my tests) have the same fall-off on 5x7 as the original Thorne bulbs.

[Luis-F-S]

I would use a cooling fan on the 138 regardless of the bulb wattage . It is absolutely required for 300 W and I would also use it for 150 and 200 W.

[Liquid Artist]

Thank you Luis, and everyone else

In suddenly thinking. I must be able to hook up a thermal switch so it only turns on after a point.
I'm only thinking of a computer style cooling fan, so not much air movement. Just enough.

Besides a more noisy fan would drive me nuts.

[Ginette]

Thank you Luis, and everyone else

In suddenly thinking. I must be able to hook up a thermal switch so it only turns on after a point.
I'm only thinking of a computer style cooling fan, so not much air movement. Just enough.

Besides a more noisy fan would drive me nuts.

Take the time to look at the online manuals, at least 3 versions online. PM me if you cannot found your exact model I have theses manuals.
Most 138 heads have a fan outlet on the top and also at the side.
G140 150W could be a nice option to reduce heat. Just test one 7$ on Amazon.ca
Other option but more expensive, an Ilford 500 head over the Durst 138. Newvision photo on eBay sell these adapters. Reproduced from the original Ilford adapter design. This adapter will cover the 5x7 format with the use of the right Durst condensers.

[ic-racer]

Thank you Luis, and everyone else

In suddenly thinking. I must be able to hook up a thermal switch so it only turns on after a point.
I'm only thinking of a computer style cooling fan, so not much air movement. Just enough.

Besides a more noisy fan would drive me nuts.

The electronic-controlled Durst heads run the fan when the lamp is on and turn the fan off when the lamp goes off. The thermal switch keeps the fan on longer than the lamp, if needed.

[Luis-F-S]

FWIW, keep in mind that the Durst Lafan output is 70 CFM. L

[ruilourosa]

i rebuilt a color CLS 300 head and changed to led 100w chips that i mounted ober huge heatsinks and use a quiet a (nd vibration free cooling fan mounted on rubber poles, they are originally sold for computers, i advise everyone to change to led.

[Luis-F-S]

i rebuilt a color CLS 300 head and changed to led 100w chips that i mounted ober huge heatsinks and use a quiet a (nd vibration free cooling fan mounted on rubber poles, they are originally sold for computers, i advise everyone to change to led.

Care to post some photos? We'd all be interested. How well does it work? How even is coverage? How applicable would it be to condenser enlargers? There have been many attempts with the L-138 written about on this website, mostly unsuccessful ones. To date the most used replacement for the original Thorn incandescent bulbs has been the G40 150 W ornamental bulb. L

[ruilourosa]

Hello

I will try to make some photos. My enlarger has a cls 300 color head not the condenser one, but i think it would be easyer to make a light bulb substitute (and a powerfull one) for the condenser model.

The chips i used are these ones: http://reefbuilders.com/files/2009/05/led100wcloseoff.jpg

I had to use a led driver (a current transformer from 220v to 32-25v) beware the wattage... my experience shows that a bit more capability in watts of the transformer turns the led faster (mine has a delay similar to the halogen light that equipped the enlarger before, two tubes of 1000 watts... too much heat...)

then i discovered that a 100w led is hot as hell

I also had to use a heat sink, the bigger the better, copper does fine, aluminium too, do not forget to use a thermal glue to bind the led chip to the heat sink!

like this or bigger: http://i00.i.aliimg.com/wsphoto/v0/1797881652_2/multi-color-100w-grow-led-lens-heat-sink-aluminum-cooling-fan-constant-current-driver-full-spectrum.jpg

Then, to rest my mind i also use two 8 cm super quiet, vibration free (it´s mounted over rubber poles) computer fans.

it looks like this: http://www.quietpc.com/images/products/nf-s12a-pwm-large.jpg

If i started now i would buy the complete cooler... the fan coolers must be quiet and vibration free. You could mount the all thing on rubber poles. Something like this: http://www.topledlight.com/images/v/201404/13978213520.jpg

The light is super efficient and more even than the halogen tubes. The two 1000 watt tubes spent a lot of power and released a lot of heat, the huge LAFAN is incredibly noisy and runs forever... no thanks

the two white light leds give less light than the halogen but is more than enough for focusing and it´s much more actinic than halogen so times are shorter.

Colour may be scrambled and contrast through colour filters also, but i tend to use filters in the drawer over the mixing box. Contrast is a bit higher than in my Laborator 4x5 using the same grades but since i am not in a quest for enlarger contrast consistency (i have a few... it would be crazy) it works very well.


i spent around 50 euros and a lot of waiting as i ordered in ebay


Probably you have to make a mixing box of a proper size over the led, i would make it out of shiny aluminum or even mirrors with a 3mm white plexy over it, it should be very easy. You could just cover the walls of your lightbulb chamber of aluminum thermal adhesive tape and put the plexy covering the window that goes toward the mirror.


i will try to take pictures!!!!


cheers

rui

[Drew Wiley]

No cooling fan? That's like running a car with no radiator. You don't necessarily need a matching Durst fan. You can get basic squirrel cage fan from sources like Grainger. Just make sure the ducting is heat rated, and exhuast the air outdoors. Heat buildup in colorheads can not only be hazardous, but will cause premature
deterioration of the filter, seals, etc, and also induce color shifts in the performance of dichroic filters themselves. Cold lights are a different subject because they
are relatively cool. I won't comment on LED's. That's kinda a Wright Brothers thing a this point in history. Expect a few crashes.

[ruilourosa]

Led light is a bit cooler... and there are cars and motorcicles without radiators...


My led adaptation works for me, the heatsink reaches 60ºc after 5 minutes on... with a cooling fan...

hope it helps someone else.

[Drew Wiley]

Regardless, cars and motorcycles move themselves thru the air and aren't intended for confined spaces where heat builds up. My own main concern about LED's
is the adolescent stage of the technology - build something today, and matching repair/replacement components might all be different tomorrow. But I commend anyone experimenting.

[ruilourosa]

There are purpose made led light sources for a lot of enlargers...

And most of enlargers do not have fans... Czec Meopta never heard of them... Durst use them just on large format ones, LPL, Leitz, Kaiser, Beseler, Nikkor, Omega ... but i believe they should... my L1200 has one that is not very disturbing but the LAFAN of the cls 300 in my L138 is VERY disturbing and the modification i made to LED lowered power consumption to 10%, heat generation by a huge amout, by tons of decibels noise, so it WORKS...

Another thing... the main issue with fans is that until very recently they had a tendency to vibrate, and that´s not a very interesting quality in an enlarger. Sure you can have a pipe pumping fresh air into the head... and another sucking it out, but most of the time, it´s not needed... the heat it´s not that high, and there is heat shield glass etc... Manufacturers tended to be a lot pragmatic...

And i believe that led is the future of a dead industry :)

LED produces less heat and more actinic (if needed) light

and LED it´s not that a new technology...

besides: the announced lifespan of the chips is 50.000 hours (i think it will be forever... 50.000x60=3.000.000 minutes let alone tomorrow) and the electronics is as easy as a childs play...

the only thing i would like to improve is start time, although the halogen light that equipped the enlarger had the same or even longer start time i would like to reduce it, but it´s not a LED problem, it´s the Driver... and as it works with 220v to 32v i cannot put the timer between the driver and the led chip...

Just a minor issue, that is fully workable

I think i made a good job, that it works for me, maybe most people do not enjoy a good DIY but i do... and besides... i´m poor

cheers

rui lourosa

[ruilourosa]

About cars and motorcicles... good argument but not easely comparable...

:)

Cheers


rui

[ruilourosa]

Here are some photos...

139451139452139453139454

[ruilourosa]

139455139456


You can see the heatsink and the chip

the fan is mounted over the hole that i covered with a pipe in a circular manner, it proved enough, as i said after 5 minutes the back of the heatsink is quite cool.

however if the chip fails i can buy another for 1,50€

rui

[analoguey]

Wow! You've used an existing setup to install led inside? Nicely done. Which side are the fans you refer to?

[ruilourosa]

On the left side, in the piping continuum

cheers

rui

[analoguey]

I see. I wondered about the pipe -it seemed to recirculate hot air - the outlet for hot air to escape is elsewhere? (on top, maybe?)

[ruilourosa]

The pipe has holes in the upper part, but i made them just for peace of mind... not needed, even the fan is a plus... makes the chip lasts longer...

[Luis-F-S]

the only thing i would like to improve is start time, although the halogen light that equipped the enlarger had the same or even longer start time i would like to reduce it, but it´s not a LED problem, it´s the Driver... and as it works with 220v to 32v i cannot put the timer between the driver and the led chip...rui lourosa

Maybe a compensating timer like the Metrolux or one of the RH designs would compensate for the start time of the LED. Pretty slick setup nonetheless. I have an extra CLS 301 head I may try something similar! L

[thomas ciulei]

you might want to think about a radial fan attached via a flexible pipe. radial fans draw a lot more air than regular fans. on my cls301 head thats what is used. Fan is mounted above enlarger, the flexible pipe also acts as a damper so vibrations d'ont transmit to head. It has a gigantic output to cool those 2x300w bulbs.139542

[ruilourosa]

I just used a couple of inexpensive computer fans... :)

[ic-racer]

You should start a dedicated thread to discuss that enlarger so more people can see it.

[Storformat]

Here are some photos...

139451139452139453139454

Hi,
Nice work
What kind of LED are you using. How many W?
If you would like to cool maybe a peltier cooler could be used. Or just have the Colling flanges on the outside.

BR
RIkard

[Luis-F-S]

I just used a couple of inexpensive computer fans... :)

Are you still using the CLS 300 head's dichroic filters and only replaced the light source, or is the LED source unfiltered? Also, can you post a link to the LED's, heat sink and driver? Thanks, L

[Tin Can]

Are you still using the CLS 300 head's dichroic filters and only replaced the light source, or is the LED source unfiltered? Also, can you post a link to the LED's, heat sink and driver? Thanks, L

But you don't acknowledge LED usage as viable. http://www.largeformatphotography.info/forum/showthread.php?128164-LED-light-source-for-Durst-138-45s&p=1354249&viewfull=1#post1354249

And mine for the Saltzman will happen on my schedule.

[Luis-F-S]

But you don't acknowledge LED usage as viable.

Still not convinced that it's a better mousetrap!

[Liquid Artist]

this is perfect timing bouncing this back up.
It looks like I am buying another 138 with the intention of modifing it for 8x10
So I will hopefully be trying some LED's or a cold light setup.

[ruilourosa]

Each LED chip puts out 600 watts, the dicroic filters work!!! they do not however filter in the same way!!

I´m hoping high CRI led´s to come out in higher wattage!

[Luis-F-S]

.......they do not however filter in the same way!!

And that's just one of the problems!

[Luis-F-S]

I'm not saying it can't be made to work but the design compromises IMHO do not make it superior to a well designed dichroic head, and halogen bulbs are cheap!

[ruilourosa]

I do not print color and i calibrate my color head for my variable contrast paper. And usually use graded paper or vc filters...

I did this led enlarger head out of necessity, cls 300 with the dedicated fan and driver are scarce and most are out of order, i just did what made sense to me, and still does.

Doubts and questions are good, but questioning the exequibility of a thing that works for me is just being a "velho do restelo", i´m not seeling the design, just using it!

cheers!!!!!

[ruilourosa]

"Superior design" is a bit of presumptuous! industry does not make superior designs most of the time, artisans do!

i made a superior design enlarger for my purposes

I´m no electronic nor mechanic engeneer but i make what works for me

[Luis-F-S]

I do not print color and i calibrate my color head for my variable contrast paper. And usually use graded paper or vc filters...
I did this led enlarger head out of necessity, cls 300 with the dedicated fan and driver are scarce and most are out of order, i just did what made sense to me, and still does.
Doubts and questions are good, but questioning the exequibility of a thing that works for me is just being a "velho do restelo", i´m not seeling the design, just using it!
cheers!!!!!

I was not being critical of what you did, only to point out that it is not a simple bulb swap to go from Dichroic to LED as many seem to believe. If I had been in your shoes, I would probably have tried a lot of what you tried. There are issues with coverage, color temperature and spectral qualities of the LED source to name a few. Even if you're not selling it, it might be nice if you would expand on what you did so other folks who may be in similar predicament to yours could benefit.

The problems you had with your CLS 300 are some of the reasons I do not use my Durst SM-183, and if I chose to use it, I have both the condenser head with original Durst bulbs and an Aristo D57 cold light head for it, so I don't have a horse in that race. There are numerous threads on this forum from very knowledgeable folks and their repairs to the Durst's 40 year old electronics. My printing is done with a much simpler De Vere 5108 with a Dichroic head.

[W K Longcor]

I "inherited" a durst 138 with a Lektra color head many years ago. The Lektra head was out dated equipment by the mid 1960's, but I continued to use it anyway. It had (I think) a 500watt bulb. The cooling fan was large and mounted on the wall. Air was sucked through the system by way of a 3" flexible hose. I sounds clunky ( and was very noisy), but did a good job, and did not seem to cause vibration or dust problems.

[Luis-F-S]

I "inherited" a durst 138 with a Lektra color head many years ago. The Lektra head was out dated equipment by the mid 1960's, but I continued to use it anyway. It had (I think) a 500watt bulb. The cooling fan was large and mounted on the wall. Air was sucked through the system by way of a 3" flexible hose. I sounds clunky ( and was very noisy), but did a good job, and did not seem to cause vibration or dust problems.

Kind of amazing how long that stuff lasts! Mostly really overbuilt, particularly in our throw away society!

[Tin Can]

Kind of amazing how long that stuff lasts! Mostly really overbuilt, particularly in our throw away society!

Do dichroic filters last decades of use?

I don't know, but almost anything with color fades with exposure to light.

[ruilourosa]

[QUOTE=Luis-F-S;1354938]I was not being critical of what you did,

Yes you were!

But usually people tend to be, as the unknown is always a leap. I would love to have a bigger better, purpose build and not adapted enlarger and darkroom. My bad!!!

If you saw the enlarger working and printing you would be surprised! and the problems that i have found are of no consequence, more: in portugal i cannot buy large format enlargers easely!

[plaubel]

Do dichroic filters last decades of use?

I don't know, but almost anything with color fades with exposure to light.

Randy, I don't know the exact lifespan of the dichroic filters, but depending on their principle, some decades are realistic.
These are no coloured (and based on this fading) glasses.

I have found, that replacing my bulbs and sockets (CLS 2000 - 2x100W) is easy, replacing every reflectors ( yes, the "fade") is well constructed by Durst, but replacing the dichroics wasn't intended, and cleaning them from dust has been somehow filthy.

Ritchie

[Luis-F-S]

[QUOTE=Luis-F-S;1354938]I was not being critical of what you did,

Yes you were!
No dude when I'm being critical I leave very little doubt. Frankly I really don't care what light source YOU use because I have complete enlargers that I can use, which is all I really care about. Until we actually see prints made with your light source well just have to take your word for it!

[Luis-F-S]

Do dichroic filters last decades of use?

I don't know, but almost anything with color fades with exposure to light.

My DeVere was made in 1994 ish and the filters are fine. That's two decades!

[Drew Wiley]

Dichroic filters do not fade. They are optical coatings, not dyes. But with excessive heat over a long time, little bits of coating can gradually spall off the glass,
affecting performance. There are a couple other inherent issues. One is the incidence of the light passing through them, the other is that they can shift spectral
sensitivity with temperature. All this kind of thing can be studied in optical engineering manuals. Most halogen bulbs employed with these are "blackbody" light
sources producing a continuous spectrum, which then is then subtractively filtered for only the three general wavelengths which color printing materials respond to. But LED sources are discontinuous, with only a few of them beginning to fool the eye into a sense of natural light. So even a relatively high CRI can be a bit deceptive in this case. I personally suspect it's a bit premature for LED colorheads, but certainly applaud anyone willing to experiment.

[ruilourosa]

[QUOTE=ruilourosa;1355023]
No dude when I'm being critical I leave very little doubt. Frankly I really don't care what light source YOU use because I have complete enlargers that I can use, which is all I really care about. Until we actually see prints made with your light source well just have to take your word for it!

I had no doubts, and you do seem to care :)

and take my word for it, the "dude" is honest most of the times

i am very willing to experiment as a strong believer in research and a reflexive practice towards arts, i do my testing and my thinking, and my enlargers are all quite fit to BW printing (the one that i do) and as are the various enlargers in the university where i teach. I follow the way of Richard J. Henry and Jonh B. Williams in the matter of technique: i test! and if it works and suits me, fine, otherwise i move on. Like i´m doing with this thread:

Cheers!!!