3-D Printed Enlarger Parts

[tom williams]

After a lengthy search for an OEM under-the-lens filter holder for an Omega Automega E-5 enlarger, I happened across an ebay vendor (bitbybitphoto) who supplies printed photographic parts. After exchanging a few pleasant emails and CAD-style mockups with the proprietor (also a photographer, with an eponymous website), I received the 3.5"x3.5" filter holder that I wanted (photo below) just a few days after ordering. It's an excellent part, exactly what I wanted/ordered, and considerably less expensive than I expected to pay for a used OEM part, had one been available. Kevin Brown at KHBPhotografix has been a great resource for my E-5 restoration project - I probably could not have progressed to completion without certain parts only KHB stocked. But for out-of-stock items, or for parts that are otherwise too expensive, I'll be looking to bitbybitphoto.

 

[tom williams]

My mistake, that's bitbybitphoto. Fixed that for you

 

[Donald Qualls]

Is this the same fellow who produces negative carriers?

 

[tom williams]

Is this the same fellow who produces negative carriers?

He does produce a variety of negative carriers, along with a number of other parts: lens cones, filter trays, an easel, a drying rack, a scanning tray, and more. Prices are ridiculously low. Custom work done as well. He (Tim Soderstrom) is a real find for me.

 

[Donald Qualls]

Prices are ridiculously low.

This is one of the beauties of 3D printing: once the design files are completed (and the time for 3D CAD work amortized), it's just machine time and filament costs. Filament is cheap -- around $20-$30 per kg for the common stuff, a bit more for particular properties (high temperatures, more chemically inert, glass or carbon fiber reinforced, or metal bearing), and machine time ought to be a good bit less than human wages if one is set up to produce goods for sale.

 

[tom williams]

This is one of the beauties of 3D printing: once the design files are completed (and the time for 3D CAD work amortized), it's just machine time and filament costs.

For the one-off parts, the charm of making the part, and perhaps the necessity of having it, may be the agents of amortization. I've been looking into learning 3-D printing, based on a need for new gears for the E-5 enlarger. I haven't found them available anywhere. KHB has a waiting list, but the wait time is unknown. I have a few considerations wrt printing gears, that make me hesitate:

- I wonder if I can model the gears accurately enough with the tools at hand.

- Can printed teeth withstand the load? Especially when the head is parked for periods of time?
I'm not sure what the failure modes for such a part and process are. I'm assuming plastic teeth.
My impression is that aluminum desktop 3-d printers are not available in an affordable package.

- Are the layers the printing material is laid down in bonded well enough to withstand shear under
expected stresses? On the E-5 and similar enlargers, the elevation gears are engaged with the
relatively thin (just under 0.09") toothed flange of the main vertical columns.

No doubt a knowledgeable 3-d printer could at least estimate the probability of success. I've watched
a few youtube videos introducing 3-d gear printing, but I'm a few more away from expert status.

 

[Donald Qualls]

Well, let's see -- making gears that mesh correctly isn't too difficult; there are plug-ins for the common 3D CAD packages that will automatically model teeth of the correct pitch and form, and test for mesh (similar to the way they can print threads that engage correctly). And printing in metal these days doesn't require a special printer, just an upgrade nozzle for your standard filament printer, a spool of special filament, and sending the printed part off to the filament maker to be baked out and sintered. A software shrink allowance is provided (i.e. you print the part so many percent oversize to accommodate the dimension loss from burning out the plastic carrier and sintering the metal powder). Bronze and stainless are the easiest metals to print this way.

 

[tom williams]

... printing in metal these days doesn't require a special printer, just an upgrade nozzle for your standard filament printer, a spool of special filament, and sending the printed part off to the filament maker to be baked out and sintered.

I like the idea of printing at home and being able to sinter the part at a specialty shop.

Thanks Donald - looking into this. I realized that replacing the plastcic gears with metal gears is probably a bad idea. Presumably, the original gears are plastic so that they will wear out rather than causing wear on the toothed flanges of the main columns. And there do seem to be some "engineering grade" plastics that could be suitable.

 

[Donald Qualls]

An Ender 3 can print in nylon -- which is probably what the original gears were.

That said, printing in nylon isn't as simple as turning up the extruder temperature; you're likely to need an enclosure. TPU might be another option; the grades I've seen are closer to shopping buggy wheels than gasket material, but might still be a good bit softer than the original nylon gears. HDPE is another option, a bit easier to print than nylon and almost as durable (and slightly better self-lubricating).

If you want to print these parts yourself, I'd suggest starting with PLA and PETG to get your printer dialed in and get used to managing it (and there are a lot of photographic things you can print in those materials).

 

[keisisqrl]

To get to nylon you need a new extruder and... I forget if it wants a heated enclosure, but definitely an enclosure. Metal-fill filaments are mostly for the look and they'll eat your nozzle. TPU... it doesn't like bowden tube extruders. Which is a shame, it's fun stuff if you can get it to work.

PETG's nice properties mostly have to do with chemical resistance and the look. At this point there are PLA formulations with physical properties good enough that ABS filament is all but dead. PLA+ or PLA Pro from eSUN is pretty remarkably strong (it's favored by firearm experimenters) and might suffice for gears. Just print them with the teeth perpendicular to the build plate (I want to say the obvious way - gear laying flat) because the weak point in most prints, if brittleness doesn't get you, is the bond between layers. Polymaker PolyTerra PLA has similar properties and a matte finish.

I've gotten one-off steel prints from Shapeways before. It's not cheap (and there are other providers that might be cheaper now, you'd need to look around) but it's very cool.

 

[mshchem]

Did Omega use off the shelf parts? Maybe there's another source??

 

[mshchem]

https://webstore.ansi.org/sdo/agma

 

[mshchem]

https://www.rushgears.com/?referrer...y44Fs2Iwi0H9eyALqT_tfG7lJcHmBzWYaAjNcEALw_wcB

Custom gears.

 

[tom williams]

Did Omega use off the shelf parts? Maybe there's another source??

Good question. According to KHBPhotografix the E-5s were manufactured in 1955 through and 1973. I wouldn't bet on the availability of off-the-shelf-parts from that era being off-the-shelf items today. But my ignorance on this matter is complete. I did search for gear manufacturers on the web, of which there are many, and investiagted half a dozen, sorting for the most obvious parameters: gear style, crown OD, hub OD, number of teeth, center bore etc.) without finding a match. I suspect that's an approach that could consume countless hours.

Donald's suggestion chimes with me: stagger investment in the part by developing a model gear with lower cost materials and a basic printer. Then maybe farm the gear out (with the proven design in hand) to a printing house with greater capability.

 

[tom williams]

https://www.rushgears.com/?referrer...y44Fs2Iwi0H9eyALqT_tfG7lJcHmBzWYaAjNcEALw_wcB

Custom gears.

Great site. I'm checking it out.

 

[Auer]

I bought a printed 6x9 neg holder for my Beseler 45M from bitbybit, nice guy who communicates well.
https://www.ebay.com/str/bitbybitphoto

I havent used it yet, just setting up for a project but I see no reason why it would not work well.
I will get one for 9x12 glass negs as well, as soon as I hear hes ready to make them.

 

[tom williams]

I bought a printed 6x9 neg holder for my Beseler 45M from bitbybit, nice guy who communicates well.
https://www.ebay.com/str/bitbybitphoto

I havent used it yet, just setting up for a project but I see no reason why it would not work well.
I will get one for 9x12 glass negs as well, as soon as I hear hes ready to make them.

Last I heard, he's taking custom work...

 

[tom williams]

https://www.rushgears.com/?referrer...y44Fs2Iwi0H9eyALqT_tfG7lJcHmBzWYaAjNcEALw_wcB

Custom gears.

Well, Rush Gears got back to me: for 3 week delivery time, 2 nylon gears, only $1125 USD each. Good thing I'm not in a rush. KHBPhotografix, on the other hand, is charging only about $45 USD for a pair of gears, but no delivery time is available. In between, buying an Ender 3 V2 Pro and the accessories necessary to print with nylon, about $385 USD.

I'm rediscovering the virtues of patience.

 

[mehguy]

There seems to be someone on thingiverse who made Paterson tong replicas. Looks really easy and simple to print I'll give it a go tonight. I've been looking for a pair since the typical rubber ones are hard to slip under paper when it's stuck to the bottom of the Yankee tray that doesn't have deep grooves.

https://www.thingiverse.com/thing:4560860

 

[tom williams]

Looks really easy and simple to print I'll give it a go tonight. I've been looking for a pair since the typical rubber ones are hard to slip under paper when it's stuck to the bottom of the Yankee tray that doesn't have deep grooves.

I'm curious, mehguy, if you print photographic (or similar) parts, aside from the tongs? What kind/model of printer do you use?

 

[VinceInMT]

It’s truly impressive what is being 3D printed these days. I have 40-year old electric pencil sharpener that quit working because one of the gears had cracked. I was ready to toss it but found a guy on eBay who printed a new one and it was $8, delivered.

I have a background in CAD so the idea of drawing up my own files is no problem and I understand that there are plenty of places that 3D print from the files you upload. Hmmm, I have a few old radios that are missing knobs……

 

[Donald Qualls]

If you're going to do much of this, it makes economic sense to buy a low-end filament printer (under $200) and apply a couple basic upgrades (glass bed surface is IMO the most important one you can't print for yourself). My Ender 3 (not the Pro or 2.0) has long since paid for itself in parts I either couldn't buy at a reasonable price, or couldn't buy at all because I had to design them myself.

 

[mehguy]

I'm curious, mehguy, if you print photographic (or similar) parts, aside from the tongs? What kind/model of printer do you use?

I haven't printed photographic parts specifically yet, but I've printed all types of dodads and useful things that I use around the house. I use an Ender 3. I paid $150 for and makes good enough prints for me.

 

[BHuij]

I'm using a souped-up Ender 3. Haven't played with any of the hotter printing filaments yet (Nylon, Polycarbonate), but it's amazing what you can do with just PLA+ and PETG.

Gears are tricky. Nylon is probably the right answer. An Ender 3 could do it, but you'd need to upgrade to an all-metal hotend and definitely an enclosure if not a heated enclosure. To be clear, it would be easy to print the gears in PLA+ or PETG, and they would work, but they would fail quickly. Those filaments aren't really good at standing up to long-term medium/heavy stresses.

Also, FWIW, you can print an easy bowden-to-direct-drive conversion piece that will allow you to print TPU. I have some 98A shore hardness TPU and some 95A. They're not rigid enough to use for gears (at least not small/thin ones), but that filament is nearly indestructible when you print parts out of it. It just flexes and deforms a little and then springs right back. The force required to break, shatter, or tear it is astonishing.

 

[Donald Qualls]

I have some 98A shore hardness TPU and some 95A. They're not rigid enough to use for gears (at least not small/thin ones), but that filament is nearly indestructible when you print parts out of it. It just flexes and deforms a little and then springs right back. The force required to break, shatter, or tear it is astonishing.

This is very similar to the material used for caster wheels in applications like shopping carts (often overloaded and rolled on rough pavement) and similar. It's also pretty temperature tolerant; the glass transition is much closer to the printing temperature than is the case with PETG or PLA.