Hope to save a D5500

[Mikey Antonakakis]

That would be great, thanks!

 

[Joel_L]

That would be great, thanks!

Here you go, the column roller and filter wheels. Unless you have a very good printer, the filter wheels are can be a pain. I have two heads, one I printer the filter wheels for, one I just cut them from some surgical tubing. Both work fine.

 

[Mikey Antonakakis]

Here you go, the column roller and filter wheels. Unless you have a very good printer, the filter wheels are can be a pain. I have two heads, one I printer the filter wheels for, one I just cut them from some surgical tubing. Both work fine.

Awesome, thank you! I'm going to try some latex or silicone tube for the filter motors first.

 

[Mikey Antonakakis]

Filter drives for my first head all fixed up now, need to do light seals before I test it out, and I'm not convinced the latex I used is stiff enough, but it will be very easy to replace with silicone or polyurethane tubing at this point, if needed. I documented the process here: https://www.photrio.com/forum/threads/omega-d5500-filter-wheel-rubber-repair.78208/#post-2772427

 

[Mikey Antonakakis]

Okay, I ditched the latex and stopped at the local dirt bike shop on the way home to get parts for the enlarger - 1/4" ID fuel hose, polyurethane I think. Seems to work great! Powered up the enlarger and the filter plates all seem to move easily, and aren't so grippy that the motor bogs down at the top of the travel (e.g. when pressing the "white" button).

Next step, try to get it calibrated. My yellow keeps running when I press the "white" button while the other two stop after a few seconds. Pressing the "filter" button and dialing in some numbers for the channels basically works.

I understand the offset adjustment thanks to the writeup by @ic-racer but I haven't been able to find any info on the gain adjustment. I've got plenty of experience working with analog data acquisition amplifiers so the principle makes sense to me (offset adjusted when zero light is reaching the sensors, gain presumably adjusted given a known color output), just don't know what my target should be. Filters all the way in the down position? Dial in some specific value on all the keypad? Any pointers on that procedure would be appreciated! I've got a service manual on the way, but it would be nice to get it dialed in before it arrives

 

[Mikey Antonakakis]

My green filter looked like it might be a little faded, so I found a new-in-box 50mm Wratten filter, should be here in a few days. I wasn't totally sure what I was doing, but playing with gain (while dialing in values in "filter" mode) I was able to get yellow to reach 199 (although I need to change the offset now, wouldn't get back to zero). Magenta won't seem to go over 145 or so, and cyan gets to about 188 (although I didn't mess with cyan much). Maybe the non-zeroing yellow was throwing off the results to the other channels a bit. Feels great to be at the point where mostly what's left is calibration! I could make a print right now if I wanted!

I was doing this in "filter" mode - do I need to use calibration mode? If so... how? (massively appreciate all the info from @Joel_L and @ic-racer!)

 

[ic-racer]

I don't have the service manual with me now as I type, but will check later for the proper calibration and I see you have a service manual on the way too, which is good.

One thing that did mess me up, in terms of channels not zeroing, was the one head that had a broken wire in the connector to the sensor on the mixing box. Though that head came from a commercial lab where it was plugged and un-plugged many times.

Mikey, which controller do you have? The smaller one or the larger "translator controller?"

 

[Mikey Antonakakis]

Awesome, thank you. I am definitely going to keep the potential connector issue in mind.

Both of mine are the 402-921 “Controller II.”

 

[Mikey Antonakakis]

@ic-racer no need to look for service manual, mine arrived today (earlier than expected!)

Gain calibration is quite straightforward, but I would not have guessed it on my own:
-With lamphouse fully assembled and in "ready to print" condition, remove the front cover
-Turn it on, then press "white" button
-If/when motors stop turning, press the "0" key - this will give a continuous readout of each of the values from the sensors
-As needed, adjust the gain pots to get between -30 and 30 on the readout; I was able to get all of mine to between -2 and 0

Also, my yellow channel did not want to stop running, so I went to "filter" mode, keyed in lower and lower values for yellow (starting with 30, which I could achieve, and working my way down), adjusted gain pot until I could key in zero and reach it (motor stops turning relatively quickly).
After that, I did the gain calibration process, and yellow was reading -43 after pressing the "0" key, at that point it was easy to adjust to exactly zero.

Will re-do offset next, then probably go through both gain and offset one more time (since there is a little dependence of gain on offset if you have to make big adjustments like I did).

I should have a new Wratten 99 filter arriving in a few days, so I'll re-do the gain and offset cals at that point.

 

[ic-racer]

Good you got it calibrated!

For color one might want to do that before every session. For B&W I only do that about once a year or when changing mixing boxes.

 

[Mikey Antonakakis]

I did forget to check the lamp voltage - I've got a fairly old Fluke meter, I love it, but I suspect it is not True RMS, and I suspect the service manual is adamant about using a True RMS meter because the power to the lamp is not a pure sine wave... I suppose I could use my oscilloscope but it looks like Harbor Freight has a $25 True RMS meter which will come in handy any time I need it, without having to break out the 'scope.

I did check with the Fluke, but adjusting R2 in "filter" mode only got me to about 64V, instead of the 82V specified in the service manual.

EDIT: got myself a “True RMS” multimeter, it initially read 83.6V. Got it adjusted down to 82.0V (spec is 81.9-82.1V) with no issues (in filter mode, in white mode it turns the voltage down a bit, spec is 76-80V and I was at 78.6V after adjusting in filter mode). That threw off the gains just a bit, so I readjusted all back to zero.

Next adjustment will be alignment. I took a quick stab at it already, front-back is way off. I suspect I will want to fix up the fine elevation wheels first?

 

[ic-racer]

Loosening the center screw for alignment causes the whole lensboard to drop forward, so, to set the front-back alignment, it requires some trial and error. Loosen, adjust, re-tighten and check, etc.

I cut the short end shorter on an SAE Allen wrench to make it easier to get to the screws. The screw/knobs that hold the lensboard plate in place can get in the way.

Alignment of the negative stage to the baseboard (not as important) is done by shimming the column on the baseboard.

If you are really compulsive you can make an adjustable baseboard top. I made one for each enlarger but it is not needed as baseboard alignment is not that critical in retrospect. I went back to just the shims on the column on one of the enlargers.

 

[Mikey Antonakakis]

Ah, that's a clever baseboard leveler! And thanks for the shim photo, I was wondering what shape/size to use (service manual just says "use shims" more or less). I've got plenty of sheet stock laying around that will work for that.

My negative stage is pretty far out of alignment fore/aft with respect to baseboard, so I just disassembled the column, figured it would give me a chance to inspect the fine elevation control - I guess it's time for new rubber lol:

Oh, and for what its worth it seems like most of the smaller fasteners/thumb screws on this enlarger are 8-32. That's the size I ended up using to do you suggestion of replacing the front cover clips, quick and easy job.

 

[Mikey Antonakakis]

For documentation: remnant of the original fine elevation rubber wheel is 42mm OD

 

[Mikey Antonakakis]

I managed to cast some 60A urethane fine elevation wheels - they are currently curing for a few more hours, and for a first attempt came out pretty nice. 3D-printed 2-piece mold worked well, but was a little difficult to remove. Will do a little redesign on it before making more.

 

[ic-racer]

Is that flexible enough to fit over the flanges on the spool? Or is it cast right on the spool? Or is the spool a new 3d printed piece?

 

[Mikey Antonakakis]

Is that flexible enough to fit over the flanges on the spool? Or is it cast right on the spool? Or is the spool a new 3d printed piece?

I'm not sure if they're flexible enough to fit over the flange - if they are, it would be tough. I simply removed the outer halves of the spools, installed the new urethane, and pushed back together by hand.
The mold was a standalone deal, two pieces. I will redesign before I make any more rollers but it worked better than I expected!

 

[ic-racer]

Wow, very nice!

 

[Joel_L]

I managed to cast some 60A urethane fine elevation wheels - they are currently curing for a few more hours, and for a first attempt came out pretty nice. 3D-printed 2-piece mold worked well, but was a little difficult to remove. Will do a little redesign on it before making more.

Is casting Urethane a big deal, nasty components, messy.... , does it cure on it's own, do you need an oven?

 

[Mikey Antonakakis]

Is casting Urethane a big deal, nasty components, messy.... , does it cure on it's own, do you need an oven?

It's quite similar to working with any 2-part liquid epoxy, but thankfully less smelly. Messy depends on how careful you are, but it wasn't bad at all (a few drops here and there is all I spilled, I worked on top of a paper towel and had no issues). I used Smooth-On ReoFlex 60, relatively thin and easy to pour, but there are higher and lower viscosity resins available. Being somewhat middle-of-the-road viscosity made it easy enough to pour with very few bubbles (I did not vacuum degas, although that is definitely an option), but thick enough that it poured slowly and in controlled fashion, and importantly barely any leaked out of the gap between the molds. This was the first time I've ever worked with it for what that's worth.

This particular resin, as many others, does its main cure (i.e. when it's in the mold) at room temperature (instructions call for 23C/73F), takes 16 hours. Then reaches full mechanical properties after another week, or you can accelerate that to 4-6 hours at 65C/150F. For the purpose of the fine elevation wheels or filter motor roller "full mechanical strength" is probably not needed, but I don't mind waiting another 4 hours

I have a cheap toaster oven, cost about $20 new, that I have dedicated to use for "shop stuff." After 16 hours I removed it from the mold (used Smooth-On "One Step" mold release agent) to do the 150F 4-hour cure. Due to the shape of my mold it takes a few minutes to get it out, but it's not bad at all. I had some brass 0.005" sheet stock and cut a piece the size/shape of a tongue depresser and in a few minutes had both out of their molds with zero damage to parts or molds.

My first revision works great, although they are a bit slippery because I did not try to remove any residual mold release.

My second revision with slightly redesigned mold seems to be better, easier to remove and I changed the dimensions slightly (1mm smaller on ID and 1mm bigger on OD). A quick wipedown with paper towel and Isopropyl alcohol to remove residual release agent seems to have significantly increased the friction.

My shop is a little cool, ~67F, so I let them do the initial cure on top of my PC, from 75F to 80F depending on where I place them.

 

[Joel_L]

Thanks, I might look into this stuff. Might have some uses for it.

 

[Mikey Antonakakis]

Small update: first of my two D5500s has made some black and white prints So far, a single 4x5 and a single 6x6 negative have been used (been spending my free time amassing darkroom supplies/accessories and restoring a Yashica-12), but working great! Enlarger sitting on the floor of my multi-purpose basement shop/darkroom at the moment, need to either wall-mount or build a decent table for it. I've also got a B66 with Chromega B head and I definitely enjoy using the D5500 more.

 

[Joel_L]

Glad you got one working. I also like the D5500. I need to clear out a corner of my basement to do a darkroom. I keep saying that, I just need to get to it.

 

[mr_muggs]

Glad you got one working. I also like the D5500. I need to clear out a corner of my basement to do a darkroom. I keep saying that, I just need to get to it.

I'm new to the forum, and I noticed this thread on the D5500. For whatever reason, I decided it might be fun to get back into film and build a darkroom. I found a D5500 with the Dichroic Head and controller that I purchased fairly cheap. After rebuilding the drive wheels in the head and fine height adjustment, and removing the 3 dead fossilized mice in the column it appears to be working. The one thing that I'm not sure of is the intensity of the projected image to the easel. While it's been 40 or 50 years since I worked in a darkroom, it seems that the image should be brighter. I've checked the voltage to the lamp with an oscilloscope and a true RMS meter and the voltage appears to be correct. I also purchased a new lamp, which does seem very slightly more bright. Does anyone know of a good way to read or verify that the light output is what it is supposed to be? By the way, a big thank you to IC-Racer for your posts. Your photos and explanations made it possible for me to complete the rebuild.

 

[Mikey Antonakakis]

I'm new to the forum, and I noticed this thread on the D5500. For whatever reason, I decided it might be fun to get back into film and build a darkroom. I found a D5500 with the Dichroic Head and controller that I purchased fairly cheap. After rebuilding the drive wheels in the head and fine height adjustment, and removing the 3 dead fossilized mice in the column it appears to be working. The one thing that I'm not sure of is the intensity of the projected image to the easel. While it's been 40 or 50 years since I worked in a darkroom, it seems that the image should be brighter. I've checked the voltage to the lamp with an oscilloscope and a true RMS meter and the voltage appears to be correct. I also purchased a new lamp, which does seem very slightly more bright. Does anyone know of a good way to read or verify that the light output is what it is supposed to be? By the way, a big thank you to IC-Racer for your posts. Your photos and explanations made it possible for me to complete the rebuild.

You can check the voltage to the bulb (carefully), if you have a True RMS volt meter. I’ll come back a bit later with the spec.