Homemade Telecine

[Stan Jelavic]

No problem David. Ultimately this looks like a good solution. The 3D parts were done in freecad that you can download for free and from there export into a format as needed. Not sure what material that is. Medium softness would be good to reduce the slippage.
Here is the info on what material was for the pinch rollers:
The film rollers and pinch rollers were printed in Shapeways' frosted detail plastic, as this gives a good smooth surface for gripping the film edges. First version in white standard nylon slipped more. The pinch rollers use bearing races so they can rotate freely. The film rollers fit steppers with a 5mm D shaped shaft. A little bit of electrical tape was used on the shaft to make a tight fit.
These beams were used for idler arms and some other mounting assemblies:
https://www.amazon.com/MakerBeam-200...dp/B01LYO8FAE/

Looks like these bushings would fit. They are 14mm OD and the roller is 13.2mm.
https://www.amazon.com/605-2RS-Groov...dp/B08JKG1N3D/

[David Brown]

Sorry about that last post, I should have deleted it! I was in a hurry and tried to find some pictures to explain my point.

I thought you ordered different rollers with very small inner dia.

I see how the shaft works now. I was suggesting a bolt that could be mounted to any bracket.

And now I have that parts list, thankyou for that link!

And here is a picture from that list showing a bearing. Not neccessary up front. Your plastic block should be ok.


I'm sure (without looking) I can print from that parts list. I will take a look at it tomorrow.

I once printed a set of film rewinds and used roller skate sized bearings on the cranks. They are just pressed in place, like the roller in the picture above.

[Stan Jelavic]

Hi David. I am still working on a simple pinch roller proto. Got a few parts today and will try to put something together. In the meantime the images that you posted are. or at least one of them is from the Kinograph project.
https://forums.kinograph.cc/t/my-rpi...mms-design/639
It is based on rpitelecine
https://github.com/Alexamder/rpitelecine
The github project contains all the necessary info to build the project including the mechanical.
The pinch roller design looks pretty good but I do not have the 3D printer to experiment with it. Not sure what material is used. Should not be to rigid.
https://github.com/Alexamder/rpitele...ler-detail.jpg
The tension is controller by a rubber band in the bottom of the image.
The idler arm could have some play because the idler roller fits into the stepper roller which eliminates the lateral play. In my case the rollers are not locked together and the lateral play must be minimized.

[Stan Jelavic]

Not sure how the images above work exactly. I plan to do a simple mount first to test if I can sync the film. Got another set of rollers from amazon:
https://www.amazon.com/gp/product/B088BXFT44/
These are 2.5mm inner diameter.
Will drill one of the rollers for a press fit onto the stepper shaft. The other roller will be used with the 2.5mm shaft. The shaft is press fit into the roller. The other side of the shaft goes through a hole in a piece of plastic block with a stopper on each end. Then somehow arrange the plastic block close to the stepper to form a pinch assembly.

[David Brown]

The rollers you were looking at had a 1.5mm center diameter. Pretty small.

Not sure how you're assembling this with a shaft.

I'd use a bolt instead of a shaft. Place a nut on either end of the roller. Loose, and the roller rotates on the bolt. For a smoother rotation, add a roller bearing to the bolt. Words fail me here. These pictures fail me too!



This is not the best, before I invest more time, what's with the shaft?

[Stan Jelavic]

Received the pinch rollers today. Looking at the ways of installing the idler roller. Possibly use the
2.5mm shaft
https://www.amazon.com/uxcell-Lathe-...dp/B07KY8RJ6J/
and the end stoppers
https://www.amazon.com/Accessories-P...dp/B089YYZ2VX/

[Stan Jelavic]

[QUOTE=David Brown;n44067]

So about micro steps, this homemade telecine could then be adapted to 16mm, with another gate, or even to a future HawkeyeII? For those like Kamel with damaged perforations or others, if it improved the gate stability over the claw?

Yes it could work with any size film providing the gate is changed and possibly the reel mounts.

[Stan Jelavic]

Yes, it is twice the precision, theoretically anyways. I bought the one with 128 steps and believe that it should be enough precision but we will see. Most of the projectors and cameras with a claw use that type of the cam design. It is pretty ingenious. Someone spent lots of hours trying to figure out how to put this together, I am sure. DaVinci, maybe Never mind, silly me.
The Wolverine pinch roller idea is a good one but as you said it it would have to be an external assembly. The Nema17 motor is pretty big, perhaps something smaller may work.

[David Brown]

256, that's twice the movements. That is 200*256 positions?

I don't know enough about stepper motors and controllers to evaluate the extra cost. The software that comes with the controller looks very detailed, but can it be used with this application?

I watched the software demo and found it fascinating. I have a lot to learn.

The claw is a very precise method. That is if it is designed well. The Wolverine has problems and that could be the gate pressure or it's claw motion and size. I remember the Wolverine claw cam and thought it was clever. I found the same plastic claw cam in the Kodak S8 camera I just tore down.

So about micro steps, this homemade telecine could then be adapted to 16mm, with another gate, or even to a future HawkeyeII? For those like Kamel with damaged perforations or others, if it improved the gate stability over the claw?

Just an illustration to show the motor and rollers mounted outside the housing. I'm not sure it could fit inside.

[Stan Jelavic]

Found a stepper controller with 256 micro-steps but it is more money.
https://www.pololu.com/product/3141

[Stan Jelavic]

Actually found another stepper controller that runs from 12V. It is also 128 microsteps.
https://www.amazon.com/gp/product/B0...M55UG43X&psc=1
The interface is TTL which can be connected directly to the MSP.

That is a nice looking camera. Reminds me a bit of the SX-70.

[David Brown]

Thanks, Stan that is valuable information about the Super 8 cartridge.

Posted in 2019, unexpected. Saves me from buying another cartridge if I were to mess up the first one!

A projector is the first choice over a camera. A thrift store once was the best place to find one. That might not be as easy today as it was 20 years ago.

I bought the Super8 camera for $5. It was a Kodak XL. I thought it was an interesting design, like binoculars. But it' been in a box for years. I never intended to use it, just put it on a shelf.

[Stan Jelavic]

That worked out very well David. Great idea to use the cartridge. It has a pressure plate and might do the trick.
https://www.youtube.com/watch?v=dsUwhHv5HZI

[David Brown]

Not so bad, opening up the gate. It went pretty fast once I got some tiny files. Must be made of aluminum. I'm waiting on the Super 8 cartridge, about a week from now. If the pressure plate works out, I'll move on.


I have retired the Winait scanner. I'm able to use any parts from that.

[Stan Jelavic]

Printing the gate could work out ok. If done right the gate and the pressure plate should not be touching the image area of the film, only the sides which should minimize the chances of scratching.
I am waiting for pinch rollers and once I get them I will do a quick test with my existing prototype rig.
I am also thinking of getting rid of the Wolverine power supply and replacing it with a 128 micro-step controller. Possibly something similar to this one.
amazon.com/EASON-DC20-50V-Subdivision-Controller-MicroStepping/dp/B08RHLDZD5/
That way the only components used from the Wolverine would be the reel components which can be relatively easily replaced with something else. But Wolverine may be willing to sell these and generally their part costs are not that bad.