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2 Attachment(s)
DIY 8x10 (or larger) Enlarger Chassis
I have a DeVere wall mount 5108 I use for printing my 8x10 negatives, but I've always sort of wished it was a floor standing model. Recently I've been doing some research into converting it to a floor standing model, but I haven't come across someone getting rid of the base yet, and buying the base from DeVere costs more than I'm wanting to spend. For that reason, This past weekend I started toying around with the idea of building a floor standing 8x10 enlarger chassis myself.
The basic design is similar to the DeVere in which all the focusing controls (lens stage, head, and table movements) can be controlled from the table. The table has 3 wheels mounted to the front, which turn pulleys mounted to the table's carriage which rides up and down the center column. Two of those pulleys have anchor points attached to the lens stage and head, so by turning the wheels those stages can be moved up and down relative to the table. The third wheel turns a spool with a cable anchored to it on one end, and the column on the other. Turning this wheel will move the table up and down, but since the pulleys for the lens and head are also anchored to the table, those stages will also move with the table, (hopefully) keeping the image in focus while all three stages are moved up and down. The three moving assemblies (table, lens, and head) are all counterbalanced with weights in the pulley system. Most enlargers use constant force springs, but finding the correct tension springs for sale in the right lengths is expensive since I only need one of each, so I opted for counter weights instead. The counter weights will run through the tubes you can see anchored to the back of the column
Also, because I'm working towards building a trailer darkroom which won't be very large, I designed the table so that it can be folded up when not in use. I'm not certain that idea will work, it may make alignment difficult.
One of my goals for this was to make building it less expensive than buying the drop table for my DeVere, which would cost me around $2000. So far the chassis construction will cost about $1500 I believe, which leaves $500 left over for constructing an LED light source, which I believe will be doable. I've sourced most of the parts from McMaster-Carr, with the one exception being the linear bearings for the carriages. I found someone on eBay who sells plastic bearings which work with aluminum extrusion. They probably aren't as strong as the metal ones, but the cost is far less (metal ones would cost $750 for the amount I need) and because this enlarger is designed for an LED head which weighs far less than normal ones, I don't think it will be an issue.
I'm currently contemplating how I can build a mechanism for raising the head to allow for inserting a negative carrier. The two ideas I have are a cam mechanism like DeVere has, or a lever like omega and beseler use. Neither of those options seems great to me, so if you have any other ideas please share them!
Below are images of the whole construction, and the cable layout (which it seems is sideways, sorry!). I also included a link to my google drive where you can download the fusion 360 CAD file for the design, if you want to take a look at it. Because it's all made of aluminum extrusion and somewhat modular, it should be possible to change the head out for larger sizes, and with a DIY LED head, making it an 11x14 enlarger or some other ULF size shouldn't be that difficult.
Attachment 216950
Attachment 216952
https://drive.google.com/file/d/1KCu16rHMdFX_nCyEx6VpA52a0O7EA8pg/view?usp=sharing
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Re: DIY 8x10 (or larger) Enlarger Chassis
When it comes to 8x10 enlargers, not that I have that much experience with them, I'm a fan of keeping it simple . . .
WOW! I can't imagine having a Durst 8x10 enlarger. Talk about Complicated! . . . And, Heavy! . . . And, Big! (My darkroom is about 6' x 8'.:))
I have a Zone VI Type II 8x10 enlarger, and I've always liked it for it's convenient size and simple operation. One might even call it a minimalist 8x10 enlarger. And, it has a minimum of circuitry. It's a VC enlarger, so it does have an internal feedback mechanism to maintain each color and an internal heater to help maintain consistency. But, that's it.
It is helpful that I use a Zone VI compensating timer with both my 8x10 head and my Beseler 45s head that's adapted to the Zone VI enlarger. This timer sure simplified the electronics for the 45s head. The electronics in this customized head boils down to two wires that run the fan and another two wires that go directly from AC power to the two leads in the quartz halogen lamp, all be it with a rectifier spliced into one side. A 45s head does have a circuit board with lots of stuff on it, but using the compensating timer enabled me to by-pass all of that.
I think that existing paradigms have equated 8x10 enlarging with big, heavy, and complicated. But, it need not be so.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Ethan
I have a DeVere wall mount 5108 I use for printing my 8x10 negatives, but I've always sort of wished it was a floor standing model. Recently I've been doing some research into converting it to a floor standing model, but I haven't come across someone getting rid of the base yet, and buying the base from DeVere costs more than I'm wanting to spend. For that reason, This past weekend I started toying around with the idea of building a floor standing 8x10 enlarger chassis myself.
The basic design is similar to the DeVere in which all the focusing controls (lens stage, head, and table movements) can be controlled from the table. The table has 3 wheels mounted to the front, which turn pulleys mounted to the table's carriage which rides up and down the center column. Two of those pulleys have anchor points attached to the lens stage and head, so by turning the wheels those stages can be moved up and down relative to the table. The third wheel turns a spool with a cable anchored to it on one end, and the column on the other. Turning this wheel will move the table up and down, but since the pulleys for the lens and head are also anchored to the table, those stages will also move with the table, (hopefully) keeping the image in focus while all three stages are moved up and down. The three moving assemblies (table, lens, and head) are all counterbalanced with weights in the pulley system. Most enlargers use constant force springs, but finding the correct tension springs for sale in the right lengths is expensive since I only need one of each, so I opted for counter weights instead. The counter weights will run through the tubes you can see anchored to the back of the column
Also, because I'm working towards building a trailer darkroom which won't be very large, I designed the table so that it can be folded up when not in use. I'm not certain that idea will work, it may make alignment difficult.
One of my goals for this was to make building it less expensive than buying the drop table for my DeVere, which would cost me around $2000. So far the chassis construction will cost about $1500 I believe, which leaves $500 left over for constructing an LED light source, which I believe will be doable. I've sourced most of the parts from McMaster-Carr, with the one exception being the linear bearings for the carriages. I found someone on eBay who sells plastic bearings which work with aluminum extrusion. They probably aren't as strong as the metal ones, but the cost is far less (metal ones would cost $750 for the amount I need) and because this enlarger is designed for an LED head which weighs far less than normal ones, I don't think it will be an issue.
I'm currently contemplating how I can build a mechanism for raising the head to allow for inserting a negative carrier. The two ideas I have are a cam mechanism like DeVere has, or a lever like omega and beseler use. Neither of those options seems great to me, so if you have any other ideas please share them!
Below are images of the whole construction, and the cable layout (which it seems is sideways, sorry!). I also included a link to my google drive where you can download the fusion 360 CAD file for the design, if you want to take a look at it. Because it's all made of aluminum extrusion and somewhat modular, it should be possible to change the head out for larger sizes, and with a DIY LED head, making it an 11x14 enlarger or some other ULF size shouldn't be that difficult.
Attachment 216950
Attachment 216952
https://drive.google.com/file/d/1KCu16rHMdFX_nCyEx6VpA52a0O7EA8pg/view?usp=sharing
And I gave 3 chassis away two years ago, and one went to the landfill. L
https://www.largeformatphotography.i...ghlight=DeVere
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Re: DIY 8x10 (or larger) Enlarger Chassis
Define your goal, precisely
Ok, 8x10 neg, but what is the biggest Print desired
Next, what dimensions are the trailer, my DR trailer is 78" tall, 14 ft long x 78" wide plus V nose
It get's too hot, I was just in it and bailed
I have tested AC in it, needs a second shade over the roof, a common cure in desert, but here it is hot and humid, so no
It has heat, I am mid USA
I might instal a spare Beseler CB7 which can handle a Beseler 8X10 conversion head, but why?
I am not a relic from the past of imaging, I am an old 70, who learned LF on this from 2011 and still learning
I grabbed some of the 8X10 enlargers Chicago was throwing away last decade
MANY MANY were scrapped after 2008
and now 3 people want one
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Luis-F-S
I saw that post when looking to see if anyone had a lower chassis. That was around the time I got my first 8x10 camera, and I only joined the forum a couple months later. Sometimes my timing isn't the best it seems
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Tin Can
Define your goal, precisely
Ok, 8x10 neg, but what is the biggest Print desired
Next, what dimensions are the trailer, my DR trailer is 78" tall, 14 ft long x 78" wide plus V nose
It get's too hot, I was just in it and bailed
I have tested AC in it, needs a second shade over the roof, a common cure in desert, but here it is hot and humid, so no
It has heat, I am mid USA
I might instal a spare
Beseler CB7 which can handle a
Beseler 8X10 conversion head, but why?
I am not a relic from the past of imaging, I am an old 70, who learned LF on this from 2011 and still learning
I grabbed some of the 8X10 enlargers Chicago was throwing away last decade
MANY MANY were scrapped after 2008
and now 3 people want one
My goal for print size is 32x40. I don't imagine I'd print many that large, not too many people have the room for something like that in their house, but it'd be cool to have a few for myself in my opinion. My current concept for the trailer is to build a structure on a tiny house style trailer frame. I haven't started that yet, as it, like so many other projects, requires more funding than I currently have. Is your trailer based on a standard box trailer? I looked into that, but after insulating it and adding all the necessary modifications to it, building a tiny house style trailer is about the same cost. I live in the northeast, so for me insulating the trailer is more to conserve heat, rather than keep it out. The current plan is a 8x16 foot frame, which would leave me with about 7.25x15.25 feet of usable space, just enough for a full size 8x10 enlarger and a sink large enough for 32x40 prints.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Yes, insulate the floor too
How tall, is this thing going to get towed a lot or just a nice field. Trailers bounce a lot
There are many forums, youtubes and full websites about tiny house on wheels
I look at them daily
We should move this part of your discussion to ongoing threads like this
https://www.largeformatphotography.i...stions-in-2021
also visit http://www.tnttt.com/
I have had many rigs, since 1977
https://live.staticflickr.com/65535/...6318641647.jpg1TIN CAN COLLEGE BiZ card by TIN CAN COLLEGE, on Flickr
https://live.staticflickr.com/65535/...a4f9e0980d.jpg1MFA RIG Day of 911 by TIN CAN COLLEGE, on Flickr
https://live.staticflickr.com/65535/...fa9b2c1c46.jpg1Current Rig by TIN CAN COLLEGE, on Flickr
https://live.staticflickr.com/65535/...65c397ebf4.jpg1TIN CAN License by TIN CAN COLLEGE, on Flickr
Quote:
Originally Posted by
Ethan
My goal for print size is 32x40. I don't imagine I'd print many that large, not too many people have the room for something like that in their house, but it'd be cool to have a few for myself in my opinion. My current concept for the trailer is to build a structure on a tiny house style trailer frame. I haven't started that yet, as it, like so many other projects, requires more funding than I currently have. Is your trailer based on a standard box trailer? I looked into that, but after insulating it and adding all the necessary modifications to it, building a tiny house style trailer is about the same cost. I live in the northeast, so for me insulating the trailer is more to conserve heat, rather than keep it out. The current plan is a 8x16 foot frame, which would leave me with about 7.25x15.25 feet of usable space, just enough for a full size 8x10 enlarger and a sink large enough for 32x40 prints.
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Re: DIY 8x10 (or larger) Enlarger Chassis
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Re: DIY 8x10 (or larger) Enlarger Chassis
Have you considered horizontal? No counterweight or baseboard; wheels and simple track.
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Re: DIY 8x10 (or larger) Enlarger Chassis
My home-made additive 8x10 color enlarger for sake of 30X40 prints is 14 feet tall, but that allows me to use a 360mm lens with a comfortable height easel position. It's built like a tank and certainly does not look homemade; it's a beautiful machine better built than most commercial units. This is earthquake country, so solid is the name of the game. But if I need to, I can also print 30X40 color CMY subtractively on my smaller Durst L184/CLS system. I've been down the horizontal enlarger road, and it simply took up too much floor space.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Drew Wiley
My home-made additive 8x10 color enlarger for sake of 30X40 prints is 14 feet tall, but that allows me to use a 360mm lens with a comfortable height easel position. It's built like a tank and certainly does not look homemade; it's a beautiful machine better built than most commercial units. This is earthquake country, so solid is the name of the game. But if I need to, I can also print 30X40 color CMY subtractively on my smaller Durst L184/CLS system. I've been down the horizontal enlarger road, and it simply took up too much floor space.
If you're able, I would love to see some images of how you built yours. One of my concerns is that the column design I have won't be rigid enough, it's made from aluminum extrusion, but I'm contemplating whether some steel rods or something like that to strengthen it would be needed.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
ic-racer
Have you considered horizontal? No counterweight or baseboard; wheels and simple track.
I'm trying to make it as compact as possible while still being a full size enlarger. Horizontal enlargers would take up too much space in my opinion.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Wouldn't it be far easier to simply use your existing wall-mount chassis and build a suitable drop table assembly from 8020 then to recreate the whole thing? This solution would be far more rigid in a mobile scenario - more so than even the OEM floor standing unit.
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Re: DIY 8x10 (or larger) Enlarger Chassis
As all this MUST fit in a tiny trailer, how will you develop big sheets of paper?
I struggle with 20X24 and have decided 16X20 is big enough once it is matted to far bigger and framed
which may be larger than 26 X 30, few have walls for that
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
calebarchie
Wouldn't it be far easier to simply use your existing wall-mount chassis and build a suitable drop table assembly from 8020 then to recreate the whole thing? This solution would be far more rigid in a mobile scenario - more so than even the OEM floor standing unit.
While that is a definite possibility, if I can make a rigid enough system myself, I would prefer to do that. I'm not sure it's a great reason but I would like to have a cohesive system, rather than cobbled together components. Building the chassis and head myself also lets me make some upgrades, such as having color control on the table, rather than having to use a stepladder to reach the knobs on the head.
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Re: DIY 8x10 (or larger) Enlarger Chassis
A CB7 has power up and down with power focus, with push button timer at front edge of base
It can be operated from a wheelchair and that is why I got 2, 1 for spares
I have 240mm Nikkor enlarging lens with custom lens board that fits on any OE Beseler, 2X3 to 4X5 to Beseler 45V-XL Enlarger Chassis
I bought the 45V-XL lens and mount from a highly respected photographer
I mounted it just like he did, on wall perch that extends out enough to make 40X60 prints
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2 Attachment(s)
Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Tin Can
As all this MUST fit in a tiny trailer, how will you develop big sheets of paper?
I struggle with 20X24 and have decided 16X20 is big enough once it is matted to far bigger and framed
which may be larger than 26 X 30, few have walls for that
My concept for processing paper, which is another thing I'll need to do some tests on, is to make a sort of developing reel. Inspired by the reels used for processing roll film. It would hold the sheet of paper in a spiral, making processing in a narrow, but taller, tray/tank possible.
also might try scrolling
Attachment 216976
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Re: DIY 8x10 (or larger) Enlarger Chassis
Those were invented long ago
Make them from PVC pipe
I have a few factory made, somewhere
I have a 'reel' aversion to reals
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Tin Can
Those were invented long ago
Make them from PVC pipe
I have a few factory made, somewhere
I have a 'reel' aversion to reals
for pvc pipe ones, are you thinking of just a drum the print goes in? A drum with a circumference large enough for a 30x40 sheet would take up a lot of space, so my thinking is that by spiraling the paper it can be put in a smaller tray
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Re: DIY 8x10 (or larger) Enlarger Chassis
Ethan, my column was made of a parallel strand structural beam. Unlike a glue-lam beam it is homogenous throughout, so can be resized, that is, if you happen to have access to 440 volt 22 inch diameter blade table saw like I did! With this kind of beam material, the wood strands are all completely bound together in phenolic resin, making it exceptionally dimensionally stable, better than steel beam, and much more vibration-resistant too. After the beam was resized and perfectly squared off, I then further pickled it in marine epoxy and laminated it with black formica, and then added the corner trim to match all the stainless fittings on the rest of the enlarger.
The additive colorhead itself is a rather complex topic, so I won't discuss that. But the cast precision 30X40 vacuum easel was cannibalized from a 22 foot long process camera left behind in a building renovation, and weighs nearly 400 lbs. I can stand on it without deflecting it. The support system for the colorhead and platform below are likewise massive. The colorhead housing is made of 3/8 inch thick black phenolic (Garolite), so is itself quite heavy. Everything is securely bolted to both the wall behind and the concrete floor below. The master yaw correction mechanism is machined bronze and micrometer driven, and a dumb luck free military surplus find that once served as a sighting mount to a big ship artillery gun. It's far more strong and precise than any kind of professional tripod gearhead. The focus mechanism was cannibalized from a Sinar P camera, but with a big custom bellows and special oversized lens board capacity. The carrier is pin registered, and completely made by myself. It was a fun project, but took 3 yrs off n' on to complete, and around 15K in materials and components, including the colorhead parts and primary lens. I doubt 75K would be enough to subcontract one.
But the electronics for complex additive systems like these can be temperamental at times, and one has to carefully protect from any voltage surge or EMI (electromagnetic interference). I've run out of big color roll paper, and Fuji distribution seems disorganized this year due to pandemic chaos, so this big enlarger is not in usage at the moment. I did make some 20X24 color prints with my smaller Durst 8X10 color enlarger this past spring, until that paper ran out too. Getting color paper per se is not a problem, but the specific types I prefer is dicey right now. I'll just wait it out until mfg and distribution issues stabilize, and do black and white work in the meantime.
Processing drums are obviously a different topic, but the spiral concept you are contemplating will be much harder to load and need far more chemistry than a larger-diameter ordinary hollow tube. It will have to be outright full for every print, whereas I need only 12 fl oz of developer to do a 30X40 inch print in one of my custom drums. A completely full drum also requires a more powerful gearmotor due to all that extra fluid weight. Unless you want to roll a big drum back and forth on a sidewalk like some people actually do, get a serious gearmotor regardless. Nothing like the tiny, too revved-up motors on Jobo equipment, for example, are suitable for big processing drums.
Trays take up way more space than a drum system anyway. But you could look into something analogous to the old Kodak color processors, where the paper is attached to a netting OUTSIDE the drum diameter, rotating in a bath trough below (total darkness needed, unlike processing a print INSIDE a drum),
or try to find an old Metz semi-automated vertical-cabinet drum processor.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Too many dreamers here,
I am out
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Drew Wiley
Processing drums are obviously a different topic, but the spiral concept you are contemplating will be much harder to load and need far more chemistry than a larger-diameter ordinary hollow tube. It will have to be outright full for every print, whereas I need only 12 fl oz of developer to do a 30X40 inch print in one of my custom drums. A completely full drum also requires a more powerful gearmotor due to all that extra fluid weight. Unless you want to roll a big drum back and forth on a sidewalk like some people actually do, get a serious gearmotor regardless. Nothing like the tiny, too revved-up motors on Jobo equipment, for example, are suitable for big processing drums.
I was going on the assumption that however I processed the large paper it would require a large amount of chemistry, but your drum thought has intrigued me. Are they just wide diameter pvc tubes?
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Re: DIY 8x10 (or larger) Enlarger Chassis
No. All but the small test drums are made of Noryl, a very expensive thermoformable plastic known for excellent temp retention or insulating properties even thin-walled. For anything mid-sized and affordable, I'd simply use ordinary thick-walled black ABS DWV (drain/waste/vent) pipe. Bigger still, opaque irrigation pipe, hard to find in urban areas, but commonly used for irrigation. My former office had a big plastic pipe specialist diagonally right across the street - everything from tiny micro-pipette medical tubing to a huge selection of industrial chemical piping up to seven feet in diameter; and valves, oh my ... if a local refinery needed a $5000 pure teflon valve, they had it in stock. It's amazing what's out there; but affordable is a slightly different topic, so I'd look to more ordinary sources like agricultural irrigation.
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Re: DIY 8x10 (or larger) Enlarger Chassis
I wonder if galvanized steel would work for tubes? I'll probably just buy some to test with. a 12" wide duct sealed with some epoxy and a cap on either end should work I think, as long as the material doesn't affect the chemistry
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Re: DIY 8x10 (or larger) Enlarger Chassis
Consider T-slot aluminum extrusion, very common for mechanical industrial low volume devices. Here is just one example:
https://www.alufabinc.com/
Bernice
Quote:
Originally Posted by
Ethan
I wonder if galvanized steel would work for tubes? I'll probably just buy some to test with. a 12" wide duct sealed with some epoxy and a cap on either end should work I think, as long as the material doesn't affect the chemistry
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Re: DIY 8x10 (or larger) Enlarger Chassis
Bernice jogged my memory
I have used the older company, one is in Ohio and the other Indiana
In factory we used https://8020.net/history as soon as it came out for prototypal assembly line and test fixtures
I have a Dreamer 14X17" camera on hold, started 6 years ago, using 8020 with sliding bearings
I will get it out of deep storage and post pictures, perhaps today
I already posted it 5 years ago in DIY, but may have deleted the images
ULF film holders are expensive, I also made several DIY ULF conversions, those pictures are in DIY, search for Levy Process camera under Randy Moe
Quote:
Originally Posted by
Bernice Loui
Consider T-slot aluminum extrusion, very common for mechanical industrial low volume devices. Here is just one example:
https://www.alufabinc.com/
Bernice
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Bernice Loui
Consider T-slot aluminum extrusion, very common for mechanical industrial low volume devices. Here is just one example:
https://www.alufabinc.com/
Bernice
I am planning on using t slot extrusion for the chassis. The thought on galvanized steel ducts was about processing tubes for large prints
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Re: DIY 8x10 (or larger) Enlarger Chassis
Here is my base sled, I will be restarting a DIY thread about it, so as to NOT step on your toes
You have re-inspired me
Thank you
https://live.staticflickr.com/65535/...7fb4f1eb_c.jpg14X17b by TIN CAN COLLEGE, on Flickr
https://live.staticflickr.com/65535/...0dffbe32_c.jpg14X17a by TIN CAN COLLEGE, on Flickr
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Tin Can
Looks good! The black anodized aluminum definitely looks nicer than the plain, if it wasn't more expensive I would definitely use it for my enlarger design.
How are you planning on controlling focus? A few months ago I toyed around with the idea of building a lightweight 8x10, which had a belt driven focusing system. Even though gear slop really isn't an issue for large format cameras, my thought was that a belt system would be even smoother. I abandoned the project since the carbon fiber needed to make it started pushing it into the price range of already available carbon fiber 8x10s, but it was a fun thought experiment.
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Re: DIY 8x10 (or larger) Enlarger Chassis
I don't do thought experiments
I wake up with a plan for reality
I have started my own thread, where I will try to show and tell
Quote:
Originally Posted by
Ethan
Looks good! The black anodized aluminum definitely looks nicer than the plain, if it wasn't more expensive I would definitely use it for my enlarger design.
How are you planning on controlling focus? A few months ago I toyed around with the idea of building a lightweight 8x10, which had a belt driven focusing system. Even though gear slop really isn't an issue for large format cameras, my thought was that a belt system would be even smoother. I abandoned the project since the carbon fiber needed to make it started pushing it into the price range of already available carbon fiber 8x10s, but it was a fun thought experiment.
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4 Attachment(s)
Re: DIY 8x10 (or larger) Enlarger Chassis
Here's the finished chassis design. It's looking like the chassis will cost $1900 to build, which is a bit more than I had been hoping for, so I might fiddle around with it some more and see if I can knock the price down on some things. It looks very reflective in the renderings, but the real extrusion is fairly dull, and I'll paint everything inside the bellows area black. Might also get some sheet metal shrouds made for it at some point after it's built, but that's an idea for later down the road.
Attachment 217012
Attachment 217009
Attachment 217010
Attachment 217011
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
Ethan
It's looking like the chassis will cost $1900 to build,
About five times less than a KIENZLE. You can undercut the competition with a good profit margin if you want to sell some of them.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Quote:
Originally Posted by
ic-racer
About five times less than a KIENZLE. You can undercut the competition with a good profit margin if you want to sell some of them.
Hah! though somewhat true I suppose, my main passion is shooting the photographs, not making the equipment. I do enjoy designing and building things, but after a few of the same it starts to get boring. That price estimate is also only for parts, and it will probably take a fair amount of labor to assemble it.
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Re: DIY 8x10 (or larger) Enlarger Chassis
In working on the timer, I spent today figuring out the math behind f-stop printing. I compiled my equations in a Desmos (online graphing calculator) graph, which you can look at here:
https://www.desmos.com/calculator/zltt8ccfik
The way I laid it out, you start in a test strip mode where you set your base exposure, size of each increment (ranging from 1/12 of a stop to 1 stop), and then the number of increments you want. You then start the test strip, where for each time you expose, it will change the time accordingly with the size of a stop you selected. After processing the test strip, you input the number of stops needed for the best exposure, and it will calculate the total time based on that. I plan on having a memory function as well, where it will remember several exposures so that I don't have to recalculate when I change filters for split filter, and I'll also be able to input the stops at at the start if I've already calculated the exposure for that print.
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Re: DIY 8x10 (or larger) Enlarger Chassis
block-style T-slot extrusions can get expensive, though I have a certain amount on hand I got for free, useful for misc props and jigs. But its metric, so not compatible with most US dimensional product. If contemplated it myself for neg carrier applications, but found a more space-saving alternative even more precisely aligned .... long story. Sometimes I do get that shop itch. People across the street work on a speed boat every weekend. Another neighbor tries to restore classic cars. Others like fooling with vintage motorcycles. Why not enlargers? There's a certain amount of satisfaction in making one which not only works well, but looks good too.
... was just reminded why I went with wood structural beam material instead of metal .... a nice one two minutes ago, about 3.0 on the Richter scale. Whole house swayed. No damage. But we get significantly bigger ones sometimes.
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Re: DIY 8x10 (or larger) Enlarger Chassis
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Re: DIY 8x10 (or larger) Enlarger Chassis
I'm working on writing the code for the color controller. I want to have two modes for CMY and RGB color, because RGB is more useful for black and white in my opinion, but CMY is the more traditional printing scale. The issue I'm running into though, is that I don't know how to convert them. the RGB values LEDs can understand go from 0 - 255, and the traditional enlarger CMY scale goes from 0 - 200. However, digital CMY which is all I can find conversion charts for, goes from 0 - 1, or 0% - 100%. Do any of you know how the 0 - 200 darkroom printing CMY scale converts to the digital one used by photoshop, etc?
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Re: DIY 8x10 (or larger) Enlarger Chassis
So... more thoughts on the info from my last post.
I've learned that there's no simple conversion, since color filters don't apply evenly or linearly to the light source, and the (usually tungsten) light source itself isn't uniform either.
The way to program a conversion then, is to take a bunch of color readings of a dichroic head, and calibrate the LED head until they match. For this I'll need a color meter, which I don't currently have. I can get an older minolta one on eBay for an amount I think is reasonable, but the newer ones cost too much.
Here is my current issue / maybe not an issue. Old color meters only read red, green, and blue light, and assume the light source is full spectrum, meaning that the light is roughly even across all frequencies. LED lights do not emit full spectrum light, they have peaks and low points in the color of light they emit. Because of this, most people say not to use old color meters, and that a modern one which takes into account those dips and peaks is needed. When I read this I was disappointed, because I'm not about to spend $1600 on a color meter I only need for one project.
However, I thought about it some more, and now I'm wondering, is the limited sensitivity of old color meters even an issue? Multigrade black and white papers are only sensitive to blue and green light, and RA4 papers only to blue, green, and red... so if the color meter can only read blue, green, and red light, would the measurements still be fine for calibrating the enlarger head for paper?
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Re: DIY 8x10 (or larger) Enlarger Chassis
Very cool, Ethan.
Quote:
Originally Posted by
Ethan
Here's the finished chassis design. It's looking like the chassis will cost $1900 to build, which is a bit more than I had been hoping for, so I might fiddle around with it some more and see if I can knock the price down on some things. It looks very reflective in the renderings, but the real extrusion is fairly dull, and I'll paint everything inside the bellows area black. Might also get some sheet metal shrouds made for it at some point after it's built, but that's an idea for later down the road.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Here is a reference, a $20,000 FOTAR 10X10 made very much like a DeVere but bigger. 8ft column, no safeties, no head, no film carriers.
It has a very difficult cable/capstan system with lots of HEAVY balance weights
I used it for a few years with several DIY heads
In the picture I have 5X7 Saltsman glassless film carrier, LED head. I think the table was 32X40"
Sold it 4 years ago for a profit, when I bought it, the big photo store was asking $250 on eBay, they disassembled, loaded into my pickup, the young man almost lost his hand, when he tried to stop a heavy weight by wrapping the cable in his bare hand. My buddy and I were not allowed to touch it, until the hand...owners orders, aka insurance fear
When all was balanced the 2 hand wheels moved it by fingertip, and the same single finger could lock it tight, very smooth
To do that I had to replace the nonexistent old head with 30 lb barbell
https://live.staticflickr.com/65535/...ddcd93f9_c.jpgFOTAR by TIN CAN COLLEGE, on Flickr
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Re: DIY 8x10 (or larger) Enlarger Chassis
Sounds like a very ambitious project. Are you a good enough "machinist" type of do-it-yourselfer to make this stable/strong enough? My biggest concern is how stable the enlarger head and printing base are relative to each other and will your design actually give you the stability you will need.
My 8 x x10 enlarger is an old 8 x 10 Kodak 2D camera with a cold light head pushed up against the ground glass. I found the cold light head (a 10 x 10 Durst) somewhere for a couple of hundred bucks. It sits on the counter in my darkroom on a simple horizontal track I built and project it onto the wall. I haven't made prints larger than 16 x 20 before, but no reason I can't make them as large as you are wanting to do.
Your project seems pretty complicated for something you might not use very often. But, it also sounds like it could be a lot of fun building it.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Update-
I've made a lot of progress on the arduino code for the control unit, it's almost done I think. If you want to check out the code, you can test it out using this simulator here:
https://wokwi.com/arduino/projects/302878866181980685
I'm not a very experienced coder, so there's probably ways it could have been done more simply, but it works, and that's what matters for me. The controls are as follows:
the keypad is for inputting numbers. 1-9 are as they seem, * is exit, # is the enter key, B is a period for decimal numbers, and C is a / for fractions.
red, blue, and green buttons: input color values for RGB between 0 and 255
black button: input print exposure time via base exposures, stop size, and stop number. these are input by pressing the black button, typing in the base exposure on the keypad, pressing #, inputting the stop size as a fraction using / and then entering it with #, and finally typing in the stop number you are exposing at, the pressing # one final time. Then you press:
Yellow Button: EXPOSE. this button just prints !EXPOSE! in the serial window for now, the actual LED head will be connected to the arduino via an xlr cable and a DMX 512 encoder and decoder. DMX512 is a lighting control standard used for stage lighting, and works well for this design, because by using it for control, the same controller can control any LED head wired with a DMX512 decoder. I haven't simulated the encoder, since it isn't available in the simulator, but its just a little pcb with 4 inputs and 3 outputs which gets wired to digital output pins on the arduino.
Orange button: this is for f-stop test strip mode. after pressing it, you input the print info the same as with the black button, but this time it outputs a exposure time for every stop value. which you print by sequentially hitting the expose button.
there are two switches wired in as well, one is for manual mode where you input a time as you would on any other enlarger, that part isn't coded yet, but won't take long I think. The other switch is for switching to CMY values, but I won't be able to code that until I build the light source and can compare its light output to a dichroic head.
You'll also notice one or two white bars underneath the print time on the display. these tell you if the data has been input properly, and only when both are showing will it be able to print. If there's only one you probably need to hit the enter (#) button one more time.
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Re: DIY 8x10 (or larger) Enlarger Chassis
There is no standard, but some heads use (CC = log d x 100). So 10cc = 0.1 log d or 1/3 stop, 15cc = 1/2 stop, etc.
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Re: DIY 8x10 (or larger) Enlarger Chassis
I've made some changes to the enlarger chassis design. I was inspired by seeing the heiland enlarger which was announced yesterday to make all the movements of my enlarger motorized, like they have done. My first thought was to motorize the pulleys in the first design, but after some thought I've opted for a system which uses lead screws. There are three lead screws which will run the length of the enlarger, and on each there will be a carriage which one of the stages will be mounted to. by turning a motor one direction the stage will move up, and by turning it the other direction the stage will move down. This new design will require more electronics and coding, but mechanically will be much less complex.
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Re: DIY 8x10 (or larger) Enlarger Chassis
In case you have not seen, the Durst L1840 also uses that style of drive to move the head up and down. In the case of Durst, the 240V AC motor control circuit pulses and senses the back emf to determine the motor speed, and keeps it constant. Otherwise going down will be faster than going up.
I suspect that in your case (now 30 years later than the Durst motor control circuit) a brushless motor can easily be controlled to give constant up and down speeds. Another thing the Durst control circuit does is to power the motor even when it is stationary to 'lock' it in position. The motor is always humming.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Also, from an engineering standpoint I'll point out that the twisting torque from the weight of the head, centered around the drive point pictured above, is countered by a pair of ball bearings that ride against a track at the back of the hollow tube on which the up/down carriage rides. Durst CLS2000 head is 24Kg (53lb) per the manual with its center of gravity almost 1/2 meter out from the lift point.
Even though your LED head will be lighter, it will need to be far out from the column if you want big enlargements.
Also, in case you have not seen, the Omega 8x10 does have a forward slanted column like their 4x5 enlargers. This would give a shorter lever arm of the head on the lift mechanism for the same maximum print size.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Thanks for the heads up on the new Heiland, I did not know, and here is a link. Personally, as I near retirement, I'd be able to afford a new enlarger if my Durst ever breaks. So the demise of Durst Pro USA is not such a bad thing any more.
https://www.facebook.com/PhotoKlassi...5399669230275/
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Re: DIY 8x10 (or larger) Enlarger Chassis
I was aware durst had made some similar mechanisms, but I hadn't been able to take a close look at them, so thanks for those images! is that an oiling port on the side?
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This is my design for the rollers which will support the cantilevered weight of the stages to keep strain off the threaded rod. I'm also using a 3/4 inch lead screw, which I'm fairly certain will be strong enough, I'm not sure what the diameter of that durst one is, but it doesn't look like 3/4 to me
The heiland enlarger does look amazing, I'm guessing it will have a hefty price to match though. A friend of mine heard a rumor that it will be $24,000, which seems too high to me, but all the Heiland prices seem a bit high to me.
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Re: DIY 8x10 (or larger) Enlarger Chassis
More pictures of the drive. These are from 2008 and I have not had it apart since then. As I recall the drive shaft is off to the side toward the front, and the track with two straddling rollers is on the same side toward the rear, so it is not a symmetric assembly.
The oil hole aligns with a hole in the housing for easy access when it is all together.
I think the worm drive is about 2cm in diameter.
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Re: DIY 8x10 (or larger) Enlarger Chassis
Of course the more distance between your rollers, the better support. This Saltzman is probably overkill for a LED head but probably set the standard for enlarger stability at the expense of size and weight.
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