Newly acquired Durst AC800 Elite needs some work.

[sruddy]

I was just given a Durst AC800 Elite enlarger. It was in pieces and I wasn’t sure everything I needed was included, but It looks as though I may have everything except the base board, the top light compartment cover, and a few negative masks. The main track was damaged however I removed it and unbent it. The plastic track has snapped in half but all teeth look good so I’m going to give it a try. I would like to find a new one though. I had an extra base board from a Bessler 45 so I attached the Durst rail to it and cleaned and re assembled everything. In the process I discovered the the shouldered nylon rollers for the head have lost parts of their shoulder, so the head twists left to right. I haven’t found anyone with replacement parts so I will have to fabricate some, any ideas? I have already removed the Bessler 23CII that it will replace so I better get it working! I’m pretty excited about the unit and hope I can restore and use it. I have 5 enlargers and have always wished for one with more machined parts and nicer fit and finish. This one looks to be in that category.

 

[AgX]

Ignorant of the rollers in question I tend to advise to look for a machine shop in your vicinity that got nylon rods at hand and have them turn copies for you.
Maybe the rollers are even generic, metric parts.

 

[gordrob]

I have a Durst AC800 that one of the circuit boards failed so I have retired it and was about to strip it and sell the parts. If you are interested in any of the parts send me a PM.

 

[sruddy]

I got it installed and discovered the Auto Focus doesn't work and it won't manually focus either! I really want to get this thing working and don't initially care about all the auto features I just want to use it manually for awhile. If I can't fix the AF, I will by pass the circuit, and put on a reversing switch on the side panel. If I can do this and repair the rollers I'll be in business. Here is a shot of one of the broken rollers.

I will only be doing black and white until my new darkroom is constructed. The unit has three modes. negative, transparency and black and white. I made a black and white program last night and I discovered I can only adjust density exposure time. I don't want to use under the lens contrast filters so I assume I'll need to use the negative mode and use the color filters as contrast filters. I would like to hear your experience with that.

I also need to find a service manual. I have two different owners manuals and found another online. This one has the most illustrations. https://www.yumpu.com/en/document/read/27602231/durst-ac-800-manual

 

[Johnkpap]

Hi welcome to the world of the AC800
Forget trying to use the inbuilt filters they only work for colour printing
Yes you need to use Multigrade filters and program it for each channel eg grade 1 is Chanel 1 there was a nice instruction manual posted online
A few years back but the site is now gone

If you pm me a email address I can send you a copy,

You may have to get someone with a lathe to make you some new rollers parts for durst enlargers are non existent

Johnkpap

 

[sruddy]

Hi welcome to the world of the AC800
Forget trying to use the inbuilt filters they only work for colour printing
Yes you need to use Multigrade filters and program it for each channel eg grade 1 is Chanel 1 there was a nice instruction manual posted online
A few years back but the site is now gone

If you pm me a email address I can send you a copy,

You may have to get someone with a lathe to make you some new rollers parts for durst enlargers are non existent

Johnkpap

Thanks John, I'll pm you m email adress. I found this thread https://www.photrio.com/forum/threa...black-and-white-printing.102171/#post-1351368 however the author hasn't been round for years and the link is no good.

I found a 3D printer to make me all new rollers for around $100 but don't want to spend any money until I decide if I can use it to advantage, on black and white, and get the focus to at least work manually.

 

[Johnkpap]

I have sent the documents to your E-mail let me know if they are helpful

Johnkpap

 

[AgX]

I found a 3D printer to make me all new rollers for around $100 but don't want to spend any money until I decide if I can use it to advantage, on black and white, and get the focus to at least work manually.

Until then you might cut such collars from ABS or metal sheet for the rollers yourself push them on and fix by hot-melt glue, in case there is lateral tolerance or you could laterally adjust the rollers.

 

[sruddy]

Until then you might cut such collars from ABS or metal sheet for the rollers yourself push them on and fix by hot-melt glue, in case there is lateral tolerance or you could lateral thr rollers.

Great idea, I'm going to remove one of the rollers today.

 

[Randy Stewart]

Man, this was one of Durst's most automated medium format enlargers, as I suspect you know. Looks like you bought a full cripple, full of dedicated electronics and custom designed parts, none of which are available. No factory support, and flying blind. After way to much time and money poured into it, you may be lucky to come out with a basic enlarger functioning as well as my M700 or M800 from the late 1970s. More likely, you'll never get it fully functional. If you aren't using the automation of an AC800, there is absolutely no rational reason to use one at all, as the extra process requirements still distract and waste time, plus any electronics failure puts you on the edge of junking the whole thing. Why do you think the guy above wants to make you an offer you can't refuse on his?.

 

[sruddy]

Man, this was one of Durst's most automated medium format enlargers, as I suspect you know. Looks like you bought a full cripple, full of dedicated electronics and custom designed parts, none of which are available. No factory support, and flying blind. After way to much time and money poured into it, you may be lucky to come out with a basic enlarger functioning as well as my M700 or M800 from the late 1970s. More likely, you'll never get it fully functional. If you aren't using the automation of an AC800, there is absolutely no rational reason to use one at all, as the extra process requirements still distract and waste time, plus any electronics failure puts you on the edge of junking the whole thing. Why do you think the guy above wants to make you an offer you can't refuse on his?.

Well first of all it was free. Second, even if I can't repair it so it functions as designed, converting it to a manual enlarger will blow away my 23CII. So far I replaced resistors at a cost of a few cents each. I most likely can repair the rollers with parts on hand and if not $125 for 3D printed rollers is not that big of an expense. Finally no one is trying to sell me their enlarger. I have only had correspondence with people willing to help me get mine fixed.

 

[AgX]

So far I replaced resistors at a cost of a few cents each.

Replacing resistors is the last I would think of, if at all. Unless obviously overheated.

I would start with electrolytic capacitators.

 

[Johnkpap]

Man, this was one of Durst's most automated medium format enlargers, as I suspect you know. Looks like you bought a full cripple, full of dedicated electronics and custom designed parts, none of which are available. No factory support, and flying blind. After way to much time and money poured into it, you may be lucky to come out with a basic enlarger functioning as well as my M700 or M800 from the late 1970s. More likely, you'll never get it fully functional. If you aren't using the automation of an AC800, there is absolutely no rational reason to use one at all, as the extra process requirements still distract and waste time, plus any electronics failure puts you on the edge of junking the whole thing. Why do you think the guy above wants to make you an offer you can't refuse on his?.

The Durst AC 800 is a superbly made multi format enlarger, once setup it is capable of producing a working print first time !!! NO TEST STRIPS it was made in the 1980's/1990' where things could be maintained and repaired, it is built from standard off the shelf electronic components. I have had mine for many years
The only thing i have done is give everything a clean and replace the NICAD Battery.

if you wish you can over-ride the automation(it is designed that way) eg set a smaller f stop to burn in or increase the the exposure time to get a darker print for toning ect.
I suspect you have never used a AC800, otherwise you would have a understanding of what it is capable of doing, Steve so has proven to be a very capable technician and I expect he will have it up and running .....and as for parts :- try and buy a new carrier for any old enlarger and you have a problem no matter the brand. By the way ....I am the guy above but l live Down Under..... I all ready have a working AC800 why would I want another and pay the shipping to Australia WTF

 

[sruddy]

Update! A friend turned me a new set of rollers and they are installed. I have also did the alignment and auto focus programming. I located the author of the Black and White with Multigrade filter printing document. He has made a revision and wants my feed back. I'll post the document here after testing. Today I need to shoot a solid background and end up with an 18% gray negative to do the channel programming for each multi grade filter. I don't have a densitometer so i'm not sure how to determine the amount of gray.

 

[MattKing]

Today I need to shoot a solid background and end up with an 18% gray negative to do the channel programming for each multi grade filter. I don't have a densitometer so i'm not sure how to determine the amount of gray.

Use s solid grey background - anything approaching a mid-tone should be easiest, although technically you could use anything from dark grey to near white.
Make sure the light is even, and somewhere near daylight colour temperature. Overcast sky illumination through a large window would work.
Using a good, reliable meter, expose the film at box speed and develop it normally.
That should give you a good negative for calibration purposes.

 

[zebra-k]

Hi All,
I am new in this forum and owner of Durst AC800 Elite. I'am desperately looking for service and repair manual for AC800. Is such available somewhere? I'm also searching for information about Factory pre-setting of AC800, described in the user manual section 5. You can enter to the pre-set by pressing Mode Select during power on. There are some values, but what do the letter L and P mean in the pre-set. Does it any impact on the filters or quality of light? Thanks for any hint.

 

[sruddy]

Hi All,
I am new in this forum and owner of Durst AC800 Elite. I'am desperately looking for service and repair manual for AC800. Is such available somewhere? I'm also searching for information about Factory pre-setting of AC800, described in the user manual section 5. You can enter to the pre-set by pressing Mode Select during power on. There are some values, but what do the letter L and P mean in the pre-set. Does it any impact on the filters or quality of light? Thanks for any hint.

I haven't found a service manual yet. What are you trying to achieve and are you printing color or Black and White?

 

[zebra-k]

I haven't found a service manual yet. What are you trying to achieve and are you printing color or Black and White?

Hi Sruddy,
Thanks for responding to my post. I do both B&W and color from time to time.

 

[odell1618photography]

You may find this helpful:
http://www.dantestella.com/technical/ac800.html
It really helped me better understand how to set mine up.

 

[zebra-k]

You may find this helpful:
http://www.dantestella.com/technical/ac800.html
It really helped me better understand how to set mine up.

Thanks for the link. Unfortunately, my case is more complicated as it also applies for color prints too and factory pre-settings.

 

[odell1618photography]

Thanks for the link. Unfortunately, my case is more complicated as it also applies for color prints too and factory pre-settings.

What are you trying to find out or needing to know ?

 

[zebra-k]

What are you trying to find out or needing to know ?

I would like to find out the following:

1) Understand how color and density under-corrections described in section 5.5 of user manual impact calibration. Especially that the color and density under-correction takes priority over the calibration settings in all the memory channels.

2) What is the factory pre-settings under P and L as displayed when pressing Mode Select during power on and what should be original values there?

3) Setting the correct factory pre-settings. I bought my AC800 from second hand I am not sure if the codded values are correct. If factory-pre-settings impact calibration then leaving them without control may cost time and money during calibration and production.

4) Service and Repair manual. The equipment is very old and there is no or just a single technician who can repair it in my area. Replacing battery or faulty element without the manual may lead to disaster.

 

[John51]

How does the AC800 measure the column height and focus distance? To what accuracy?

fwir, it's sort of a 2 axis cnc enlarger and I'm curious as to how they achieved that.

 

[odell1618photography]

I would like to find out the following:

1) Understand how color and density under-corrections described in section 5.5 of user manual impact calibration. Especially that the color and density under-correction takes priority over the calibration settings in all the memory channels.

2) What is the factory pre-settings under P and L as displayed when pressing Mode Select during power on and what should be original values there?

3) Setting the correct factory pre-settings. I bought my AC800 from second hand I am not sure if the codded values are correct. If factory-pre-settings impact calibration then leaving them without control may cost time and money during calibration and production.

4) Service and Repair manual. The equipment is very old and there is no or just a single technician who can repair it in my area. Replacing battery or faulty element without the manual may lead to disaster.

I’ll check the manuals that I have. I have one from the original sales person that has info not in the factory manuals.

 

[sruddy]

I would like to find out the following:

1) Understand how color and density under-corrections described in section 5.5 of user manual impact calibration. Especially that the color and density under-correction takes priority over the calibration settings in all the memory channels.

2) What is the factory pre-settings under P and L as displayed when pressing Mode Select during power on and what should be original values there?

3) Setting the correct factory pre-settings. I bought my AC800 from second hand I am not sure if the codded values are correct. If factory-pre-settings impact calibration then leaving them without control may cost time and money during calibration and production.

4) Service and Repair manual. The equipment is very old and there is no or just a single technician who can repair it in my area. Replacing battery or faulty element without the manual may lead to disaster.

I have looked forever for a service manual with no luck. I have replaced my AC800 memory battery and can post photos with the procedure if you like. Pretty easy though just un solder the original and solder the negative and positive leads from a battery holder filled with batteries adding to the same voltage printed on original. The circuit board is marked + and - as well. I was told by another owner to use NICAD batteries or I'll F it up, so I followed the recommendation!

How does the AC800 measure the column height and focus distance? To what accuracy?

fwir, it's sort of a 2 axis cnc enlarger and I'm curious as to how they achieved that.

There is a plastic geared channel on the column which has a geared wheel that tracks the height. It's very accurate. I'll post a photo later.