Hawkeye-DSLR

[Stan Jelavic]

Thanks David. The Magic Lantern did its magic. Pretty happy with the results. The 30FPS capture should work out OK for you.

[Stan Jelavic]

Stan, your toothed pulley is very complicated to print.

I tried to get a good finish on the teeth and the notches.
I think the best is to split the model into 2 parts to get it with great precision.
because of the two floors, we cannot put supports that would damage the part too much.

See example below:

For the Frame film guide, I have no idea for the moment but I am thinking about it.

Thanks Kamel. I have these capstan parts from EUMIG Mark-S-709.
https://photos.app.goo.gl/qGctCoMDmutfjufq7

Would need to add the synch wheel.



The stepper is from amazon:
https://www.amazon.com/gp/product/B00PNEQKC0/

[Bruce Davis]

Hi Stan, that is a very large stepper motor, high torque for your application and could rip the film perforations quite easily. It does not say, but assume it is a 1.8degs per step, a 0.9deg stepper would be more accurate. I know that torque can be controlled with the driver and micro stepping will give you rotational accuracy. You probably have plenty of room to fit the stepper so would not matter, most of the 3d printer drivers used contain the Trinamic TMC2209 chip, they are quieter than most and have internal 256 micro stepping, they operate in two modes, spreadCycle and stealthChop, you probably already know all this so I will stop.
Regards - Bruce

[Stan Jelavic]

Thank you Bruce. Not familiar with this controller but there are development boards available. The idea is to try this setup with the sprocket pulley and if it works then switch to a friction rubber pulley based transport.

[Stan Jelavic]

Did a bit of a research on this controller.

I plan to use the Wolverine controller for testing. If this works then then could try one of the eval boards.
https://www.mouser.com/ProductDetail...zNw9eZzg%3D%3D

Possibly with the controller
https://www.mouser.com/ProductDetail...81DwIrfA%3D%3D

It may be possible to drive the BOB board directly with the RPI or even MSP430.
The IC data sheet is also available:
https://www.trinamic.com/fileadmin/a...sheet_V103.pdf

[David Brown]

I have now tried video capture at the 30fps speed. There seems to be random speeds. I tried several times and speeds vary. This is only evident in the position of the "blurred frames". It's around 200 frames +- that their position in the 15 columns moves full cycle. They move to the left or to the right, but are never constant.
The 3 frames.


and the progression.


This could be that I am using a Winait brand (China) and not the Wolverine (Taiwan). I tried 3 shutter speeds; 1/30, 1/60, & 1/250. My mount is not rock solid and there could be some movement between the camera and the film gate. I always have 3 blurred frames even at 1/250s.

I don't want to resolve this, I'm moving on to the single frame capture.

So Stan, is the "capstan" project going to use the same extra circuit board, or be completely different? I would be interested in a new transport method not using the claw. I think the claw can be unstable at 2fps. Gate pressure is a balance between vertical and horizontal movement. With my Wolverine/Hawkeye, I always run the slowest speed and have very small framing errors easily corrected in post. I over-scann the captures and fix tiny framing issues using the "frame and crop" tool in Vegas. It probably has the same name in all editors.

[Stan Jelavic]

David I see only 15 columns in the image that you sent me. I did not have issues at 30 FPS. Was a small drift but still could capture a long scan with several stable columns.
The first test with the new capstan will be with the Hawkeye and new firmware. The new stepper will be driven by the Wolverine power board.

[Bruce Davis]

Hi Stan, David and Kamel, that driver/controller combination is very expensive (for just one driver), have you looked at 3D printer driver boards from BigTreeTech or Fysetc. The BIGTREETECH SKR MINI E3 V2.0 has 4 built in drivers onboard (spares just in case) only costs $39 USD https://www.bigtree-tech.com/product...r-ender-3.html

FYSETC E4, https://wiki.fysetc.com/E4/
https://www.aliexpress.com/item/1005001704424175.html
only $28 USD

These two companies are the main ones in China providing this type of product, the BigTreeTech board seems to be the most popular amongst the 3D printer users (cheap is best).

Just a thought Stan, not sure if they would be suitable, run these boards with a RPi (you probably have a few of those) and use a program like Klipper, its very configurable and simple to use https://www.klipper3d.org/

Marlin 3D printer software has been around for a long time, does not need a RPi, but I don't use it any more, it has become too complex and too many options. Reprap software/firmware is also too hard to program/use, in my opinion.

Regards - Bruce

[Stan Jelavic]

Thanks Bruce. The boards that you listed are good price. They are designed for 3D printers. For this application I need to be able to quickly start and stop the stepper which these boards support but I need access to the lowest interface (UART) in order to cut down on latency. Will dig into it more this week.

[David Brown]

OOPS, I must have been working on this too much too late! I lost a column! There are only 14 in the picture. post #111

On a second look, this is what I found.

1. Check the # of columns (15) and use the PREVIEW Window to check for blurred frames. Some are obvious, some are not.

2. It is possible to select 1 column using File Explorer even with over 12,000 frames! Use a window to select.

3. The blurred frames (2-4) move from right to left. Pick a column to the right of the last blurred frame.

I captured 3 batches and only changed the shutter speed. I don't know how the shutter speed could affect the frame rate, but I saw real problems with using 1/30s. It might just be a random problem or the stepper motor was not able to hold a stable speed.

1/30 second, had timing jumps after 4,000 frames. This is where the blurred frames column either jumped forward or backward multiple columns.

Here is a single page with 15 columns and 11 rows. Maybe the line power hiccuped?



1/60 second and 1/250 second both were stable with close to 10,000 clean frames from a single column. That's about 150' of film. Well beyond the typical 3"/50' reel.

[Stan Jelavic]

David, you are running 30 FPS. That is 1/30 s per frame. Setting the shutter to 1/30 is too slow and close to the frame duration.

[Stan Jelavic]

Redesigned the sync disc. The first one did not work well. It is to thin and translucent which does not work well with the optical detector. Not sure what I was thinking when I did that. The new one is designed for the small capstan with 16 sprockets, It should have better torque and less jitter.

https://github.com/vintagefilmograph.../sync-disk.stl

[David Brown]

Hey Stan! I used 1/30s shutter speed to more easily identify the 1st and 4th blurred frames in the thumbnails. It was too slow and adds other artifacts. Even 1/250s is not fast enough to freeze the claw advance.

Always glad to hear you are moving forward!

Here is my second temporary mount. I added the Neewer x/y macro slider. It is a worm drive and does not need a set screw as did my older version. It's problem was the offset caused by the locking screw. Very annoying to guess how much.

I borrowed part of a panorama head for the gate mount that moves in the Z axis. Had same problem with the locking screw on that slider. The post and the connecting angle removes most all the motion between the camera and gate. Not all. Next I plan to modify the original facade of the Winait machine for a final setup.

[Stan Jelavic]

Thanks for sharing David. Looking at your setup I just realized that I have one of those sliders.
https://photos.app.goo.gl/DnJAAw9pX72DxRrr9
Will have to revise my rig to incorporate it since the stand that I currently use is not as stable and pretty hard to adjust the focus with it.

[Stan Jelavic]

Created another thread for the homemade telecine that uses a stepper and a timing wheel.
https://8mmforum.film-tech.com/vbb/f...emade-telecine
https://photos.app.goo.gl/dHvhDfJV4ePiuGAAA