ALCS bolex crystal sync motors project 2026

[Aapo Lettinen]

I still have possibility to make Bolex crystal motors in 2026 if there is possibility to get enough paid preorders so that I can buy a reference bolex with 1:1 axle as I only have 8:1 older versions. And get enough budget for cnc machining tests, these have more complex mechanics than most of my motors so the tests cost a lot.

The plan is to make one crystal motor version with two slightly different mounting systems so that there is versions for both 1:1 and 8:1 bolexes available. Not promising the motor part would be exactly the same, it is possible that I would need to make two entirely different motors but the features would be approx the same on both. 

Works at 14.8v batteries so mini-vlock batteries etc work fine with these. At least 4 crystal speeds but can be more, will know in Summer about speeds if the project is possible to start now in Spring.

These projects always have the financial risk of not getting enough paid orders and I would then need to make the motors with huge losses and the schedule would overshoot a lot. Additionally it is sometimes challenging to estimate the exact price of the motor with these lower cost ones because it is so uncertain how much demand there is and the batch size affects directly the parts costs.

So in the case of this particular project there would be a deposit which needs to be paid when placing the order. IF the project would not get made then the deposit would be returned (in full if wire transfer or paypal friends&family, otherwise the paypal costs taken off first and the rest returned). IF the project gets made but you decide to not pay the rest for not needing the motor after all, then the deposit won't be returned but you could use it as partial payment for other products I am offering like the 4-speed motor or Aaton Counter etc. 

When there is enough orders so that it is certain the project would be made, then the rest of the price is paid. This would be between February and April 2026.

I need to start the project in March 2026 so there is couple of months to collect orders now. I can only make one batch of motors in Autumn2026 so this won't be available later.

The plan is to make as many Bolex motors as possible in 2026 so that there will be as many crystal sync cameras as possible available for aspiring filmmakers when I stop making motors in 2027.

I estimated the Bolex motor would cost between 900 and 1050 usd with shipping. The exact price is known when I have all the orders in and can calculate the exact parts costs.

Both the 1:1 version and 8:1 version is available so these should fit all Bolexes. The 1:1 mounts to the mounting points on the camera side and the 8:1 has a mounting bracket which is attached to the bottom of the camera and possibly to one corner too to keep the motor in place.

Deposit 250usd when placing the order. The remaining amount and exact final price is calculated when there is enough orders in to start the project.

Available for order now. Let me know asap, you can DM here or on Instagram(aaplet14). 

[Aapo Lettinen]

If someone has multiple Bolexes, I can trade a crystal motor for fully working H8 Reflex which has 1:1 axle and motor mounting points. Can include lenses but I can use my own ones too, we can check the approximate value of the kit comparing it to ebay prices of similar condition gear. 

Would work easier this way than me needing to buy a reference testing camera from ebay in unknown condition

[Aapo Lettinen]

The 1:1 version of the Bolex motor is moving forward now! I just ordered a reference H8 Bolex to run tests and take dimensions from.

Contact me asap if wanting to order, it speeds up the development if getting more orders early on and I can then run more tests and the end result will be more refined. 

Dm on Instagram(aaplet14) or here on the forum. Prices as mentioned in the previous posts.

[Jason Thompson]

Are these motors going to work with the MM and/or WM motors to support the 400ft film magazines for later model Bolex cameras?

[Aapo Lettinen]

7 minutes ago, Jason Thompson said:

Are these motors going to work with the MM and/or WM motors to support the 400ft film magazines for later model Bolex cameras?

I am adding some kind of support for the magazine motors. Either small external box can be ordered which switches on the power to the mag motor each time the crystal motor is running, OR if seems possible I may integrate this feature to the crystal motor itself if it does not take too much internal space. The magazine motor connector needs to be changed in any case but otherwise should work fine

[Aapo Lettinen]

Started to design the axle adapter for the 1:1 version. Ordered a test version to see how the fitting works with the current dimensions. Looks like the adapter can just be aluminium but will run tests. 

The motor will have a kind-of-secret-for-now slip disc design to protect the camera mechanics when the motor is stopped or if there is film jam etc. Working on the prototype and will show the final one when the time is right and it is tested and everything 🙂 

 

[Brandon Paterno]

the bolex doesn't already have a clutch there? 

[Aapo Lettinen]

1 hour ago, Brandon Paterno said:

the bolex doesn't already have a clutch there? 

No, the camera does not have any protection and one could shear the axle pin or damage gears if the motor would not have any protection device. 

Additionally the 8mm versions need precise stopping by the mechanical trigger so that they stop shutter closed and the previously exposed edge of the film is not fogged mid take

[Brandon Paterno]

26 minutes ago, Aapo Lettinen said:

No, the camera does not have any protection and one could shear the axle pin or damage gears if the motor would not have any protection device. 

Additionally the 8mm versions need precise stopping by the mechanical trigger so that they stop shutter closed and the previously exposed edge of the film is not fogged mid take

re the shutter flashing: II wanted to say the bolex infamously leaves the shutter open. I was told a few times over the past few years that that was a thing to expect. but it might just be the shutter being misaligned?... a few of the films ive made with a super rex 5 + a motor never exhibited this flashing even though I was going over the film roll 3-4 times. 

on the motor lacking a clutch.... dang.... even the cine Kodak special 1:1 shaft has protection. I want to say the JK motors for optical printing attach these giant synchronous ac motors to the shaft, which always seemed a bit disturbing considering one would probably print on polyester film.  

[Dom Jaeger]

3 hours ago, Aapo Lettinen said:

Started to design the axle adapter for the 1:1 version. Ordered a test version to see how the fitting works with the current dimensions. Looks like the adapter can just be aluminium but will run tests. 

The motor will have a kind-of-secret-for-now slip disc design to protect the camera mechanics when the motor is stopped or if there is film jam etc. Working on the prototype and will show the final one when the time is right and it is tested and everything 🙂 

 

Hi Aapo,

In case you're not aware, the 1:1 shaft pin was changed to an asymmetric pin in 1968 (after serial number 240400 on RX5 models, something similar on other models, and on all bayonet models SB, SBM). This means the drive adapter needs a larger (at least 2.5mm wide) slot on the side corresponding to the red dot on the shaft, facing the front in the stop position, in order to work with most 1:1 cameras. As found in MST, ESM and other 1:1 motors.

[Dom Jaeger]

4 minutes ago, Brandon Paterno said:

re the shutter flashing: II wanted to say the bolex infamously leaves the shutter open. I was told a few times over the past few years that that was a thing to expect. but it might just be the shutter being misaligned?... a few of the films ive made with a super rex 5 + a motor never exhibited this flashing even though I was going over the film roll 3-4 times. 

on the motor lacking a clutch.... dang.... even the cine Kodak special 1:1 shaft has protection. I want to say the JK motors for optical printing attach these giant synchronous ac motors to the shaft, which always seemed a bit disturbing considering one would probably print on polyester film.  

The only Bolex model that does not stop with the shutter closed is the EBM. All other models, when correctly set up, should stop fully closed and not allow light to leak past the shutter. That's why they are good animation/time lapse cameras.  If you run a Bolex until the spring runs out, then it can stop anywhere, so ideally wind the spring fully before each take and try not to run it all the way down. This also keeps your speed more consistent. 

The governor drive gear can slip like a clutch, and on some models the stop pawl is mounted to a spring plate to absorb some of the force when the camera stops, but for external electric motors any sort of slipping clutch needs to be in the motor itself.  If you think about it, you can't have a slipping clutch in a 1:1 drive shaft, since the orientation is critical to the camera function. If the shaft slipped under load, the shutter closed stop position would keep changing relative to the motor locating position. 

 

[Brandon Paterno]

Just now, Dom Jaeger said:

The only Bolex model that does not stop with the shutter closed is the EBM. All other models, when correctly set up, should stop fully closed and not allow light to leak past the shutter. That's why they are good animation/time lapse cameras.  If you run a Bolex until the spring runs out, then it can stop anywhere, so ideally wind the spring fully before each take and try not to run it all the way down. This also keeps your speed more consistent. 

The governor drive gear can slip like a clutch, and on some models the stop pawl is mounted to a spring plate to absorb some of the force when the camera stops, but for external electric motors any sort of slipping clutch needs to be in the motor itself.  If you think about it, you can't have a slipping clutch in a 1:1 drive shaft, since the orientation is critical to the camera function. If the shaft slipped under load, the shutter closed stop position would keep changing relative to the motor locating position. 

 

that makes a lot more sense. and I must be misremembering with the bolex, because maybe the advice was to not run it down to the end if avoiding flashing was critical. I shot with a motor though, so it's weird that it never really stopped open. I'll have to look at the film again and see

Shows what I know... so it is possible to have a continuous drive shaft that translates a full rotation of its shaft to the full rotation of the 1:1 shaft, but it would not have an absolute position if it were allowed to slip out of alignment with a known position? I guess allowing some slack via springs that allow for a bit of extra force in an emergency would be fine as long as it sprung back to the critical positions it needed to be in.