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Steve Switaj

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  1. I'm not familiar with the Arri S/B's. Where's the power connector? Is it a blind mate to that little metal pin at 7 o'clock on the motor face?
  2. Buy some good screwdrivers before you start. You want the type gunsmiths use, with the ground, parallel sides. You can buy the kind with one handle and a set of 1/4" hex tip inserts to save some coin, but you want a set with a good variety of tip widths and thicknesses to choose from. If you use "normal" tapered screwdrivers from the home improvement store - even good ones - the blades will not fully fill the slots side-to-side and top-to-bottom and will concentrate force on 2 points at the top of the slot. Combined with the force need to dislodge some of the old fasteners, you *will* bung up these old, soft, slotted screws.
  3. By the way, that black thing the film runs through just before the first roller might be a timing light. A lot of these cameras were used for industrial measurement, so it was important to know how fast they were actually running (which was at best an educated guess). Many of them were equipped with a little neon bulb that would flash at a certain rate, say, 100 times a second, and put a steady timing pip on the edge of the film so you could measure exact event timing.
  4. >> Well, I am afraid to tell you that... I don´t know what do you mean with framing camera. My WF 14 is basically this one: Cool! I have one of these in a box somewhere! Never did get to use it, sadly. Anyhow, there were a few different options for the drum cameras, they were available as "framing" cameras or "streak" cameras. Framing cameras... well, they basically make individual frames, like normal film cameras. They are for high speed cine work. Streak cameras, on the other hand, move the film continuously behind a thin slit. This is useful for certain technical applications where you're photographing linear motion. It's basically a long still photograph *of* time going by, but it won't make sense as a movie. One common example of streak photography is the photo finish camera at a horse race track. Check out this cool write up for more insight into how it works... https://www.donttakepictures.com/dtp-blog/2019/5/8/winning-by-a-nose-the-history-of-the-photo-finish Anyhow, you can easily tell what kind of camera you have if you take off the lens port and look inside while you turn the drive sprocket. If you see a prism spinning in there behind the lens, you have a framing camera. The prism is geared to the drive sprocket and turns in sync with it. Light going through a square prism displaces the image as the prism turns through an angle (you can see this effect looking through a thick sheet of glass). This "sweeps" the transmitted image vertically along the face of the film on the sprocket behind the prism. The image moves along at the same speed as the film on the drive sprocket, that way the image stays sharp(ish) and the film never has to stop. As far a focusing, when you look through the finder, yes, you may see an image even if you don't have focusing film in the camera. The lens is always making an image at the focal plane, even if there's nothing there to show it (an aerial image hanging in space). But you still want to use a piece of focusing film because it's impossible to tell where exactly the plane of focus is with any precision. The focusing film behaves like the ground glass in a view camera, acting as a placeholder for the exact plane the film is soon going to occupy. You want to be careful that you place the frosted side (and therefore your focal plane reference) facing outside on the drum, where the emulsion side of the film is going to be. As for framing... mine has a circular hole that shows most(ish) of the middle of the frame, but you don't really know where the exact frame lines are. At least you can find the center and this was probably plenty good enough for the original technical applications.
  5. Pro tip: Whenever you have to get a part custom made, always price out getting two, maybe three. The setup charges are often the largest cost of a custom piece. Once the setup is done having the 2nd or 3rd part run is usually much less expensive. Depending on the exact part, if you need it, there's a fair chance someone else needs one too, and by selling your spare you can effectively recoup some of the cost of the NRE. I'm always amazed when I do a custom electronics design and the client only asks for one. The NRE design cost itself is usually 80% of the bill, the actual fabrication ... is just a board. It's not unusual for me to quote something like "1 unit $2500. 2nd unit $1000, subsequent units $500 each"
  6. Hi Guys; Fear not - You can easily do it yourself. It used to be that making shim sets was a pain because cutting the thin stock cleanly is pretty difficult without making a mess. But cheap laser cutters have changed all that. If you have enough skill to make a full sized pattern in a vector-graphics program, you can have your local laser engraving house cut out a dozen perfect shims from a sheet of plastic. I like the color-coded polyester stock that's used for "official" machinist shims. It's a known thickness and is as thermally and mechanically stable as you can reasonably expect from a thin film. It's available from .0005" to .030" (0.01 to .75mm) , so... something for everyone, basically. In the States, you can get it in 5" x 20" sheets, which is probably enough to make 7 or 8 if you space them well, available from McMaster-Carr for $4.26 ( https://www.mcmaster.com/shim-stock-rolls/color-coded-shim-stock-6/material~plastic/ ) or here's an assortment of 15 thickness for $44 https://www.mcmaster.com/9513K42/ In a pinch, you can try using some filter gel. Hate to admit it, but that has worked for me more than once. Some laser cutters can also cut thin sheets of stainless steel. Stainless foils can be found from about .001" and up ( https://www.mcmaster.com/metal-foil/stainless-steel/shape~foil/ ) If you prefer this option, try to find a commercial specialty graphics house, many of them will be familiar with using this material for masking friskets or paste stencils and have the tools at hand.
  7. Hi Guys; I'm rebuilding an old camera and need to find a couple of rolls of scrap 35 mm film for tuning the servos. I've managed to snap all my test rolls into little ten-foot pieces, and now I need some more. Maybe one or two rolls of, say, 250' plus. It's strictly for physical testing, emulsion is not important to me, the film can be flashed or outdated, just so long as it's in decent mechanical shape.
  8. Holy crap! I never throw anything out! This is the second weird connector request that I've found in my stash this week! Two of them, this time. No, I'm not a hoarder.... I'm a .... motion control guy. Yeah, that's it! There's definitely a difference. For sure. DM me.
  9. I don't know if this applies to the Cannon parts, but on most versions of the Switchcraft XLR connectors, the inner contact block is held into the connector body with a screw, usually on the latching side. On those connectors, if you have a connector you need to change but a backshell style you want to keep, you can simply find a generic 4 pin XLR and swap the contact block between backshells. Don't know if this is the case with the Cannon brand parts, they are not common on this side of the pond, but it might be worth pulling it off and taking a peek underneath.
  10. Aapo: I think I'd strongly suggest you use a smaller selector switch.. That long toggle seems awfully close to the exposed bottom edge right at the back, it feels like it's just crying out to get damaged from being pushed back on a shelf or dropped into a case at the end of the day. Maybe some kind of small rocker switch.
  11. Also, I found one of those weird, WPI 9-pin connectors made out of unobtanium in a box of... well.. weird connectors. If anybody has a need for it, they can have it for what I paid, which was probably about $30, plus postage to wherever it's going. DM me.
  12. Holy Crap, I apparently never throw anything out ! I had one of those "wait... I might have something.. " moments, and I dug around in some old project files, and in a folder marked "Aaton" I found a paper printout of part of an email conversation I had with Clive Tobin 21 freaking years ago about Aaton sync. To be an FX camera guy is to be a technical packrat. I don't know the exact question I was asking, but IIRC, I was in Australia working on the Matrix sequels and I wanted to use a couple of LTR's as 2nd-angle witness cameras for some effects we were shooting on VistaVision plates. I think.
  13. 3/3 The final user controls closely follow the pattern of those on the Arriflex 435 - I figured that any professional operator would be familiar with that. One thing that I felt was a big improvement was that I replaced the original 25-hole speed sensor disk with a modern 800 count quadrature encoder. Having 32 times more resolution dramatically improves speed control, but more importantly it allowed me to derive the signals I needed to update the accessory port from the original Fries type to an industry-standard 11-pin Arri port. This camera will be used in complicated VFX settings, so it has to interface with all the equipment that modern cameras are expected to work with.
  14. 2/3 A few years ago it coughed and sputtered out the magic smoke and decided it would run no more. It sat on a shelf for several years till the owner asked me if I could return it to operation. After about 30 minutes of tracing my way through the original circuits I realized that it wasn't going to make any sense trying to repair the mid-80's electronics. Fries had closed years ago and there was no information at all available, and even if there were, the design was built around old analog circuits and it didn't seem like a good basis for a camera controller in 2022. I figured simply rebuilding it from the bottom up was the best way forward. I designed two new boards for the camera. The first was the main control board, this included the user interface, external interface, and an LCD display. Oddly, the new boards kind of look older than the originals. The original boards used surface-mount chips but the new boards use through-hole chips so that anything programmed or exposed to an external interface could be socketed for easy replacement. Truth be told, I would have liked to use a better display. This old-school yellow/green LCD kinda screams “1990's vending machine” to me, but with supply chains being what they are, and this being a one-off, it didn't make sense spending the the time to do anything more complicated, especially since our user base only cares about the data, not the look. The electronics are otherwise straightforward. At the center is a PIC24EP family chip at 70MHz that coordinates everything. This chip has a built-in quadrature encoder interface and three PWM generators, so it makes motor control easy - once you decode the truly byzantine Microchip datasheet for these modules. There are 3 motor drivers, one each for the camera motor, takeup hub and supply hub (for backwinding). The motor drives are all unidirectional (the camera motor has a hardware reverse switch) so the 3 drivers are all 1-quadrant, simply a big MOSFET driving the low leg. The switching frequency is 20KHz to make it inaudible, which I soon realized was pointless since the camera sounds like a washing machine when it runs - it was obviously not designed for sync-sound work. The speed is variable from 1.000 to 36.000 FPS in .001fps intervals. The control system is a standard PID loop updated at 1KHz. Between the fact that a camera motor is commanded to run a constant speed, and the large rotating mass involved, the derivative term is basically useless, so after a little testing I just dropped it.
  15. Hi Aapo; I've been following your cool CP-16 crystal sync project with great interest, and I wanted to share my own camera controller project. I'm kind of working at the other end of the scale, though. I got a project rebuilding the electronics for one of the old Fries VistaVision conversions. This thing is monstrous, It weighs in at 40 pounds without lens, mag, film or even finder.
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