ACL motor

[Pavan Deep]

Does anyone know how to build a new motor for the ACL?

Pav

[Aapo Lettinen]

On 10/31/2020 at 1:56 PM, Pavan Deep said:

Does anyone know how to build a new motor for the ACL?

Pav

by "new" you mean completely new or modifying an existing Eclair motor to work with it? 

One can use either a carbon brush DC motor or a brushless motor as a base for crystal sync motor. Brushless is smaller and higher power compared to weight and size but the control electronics are more complicated to make which is why I am making one-off modifications only to carbon brush motors where the circuitry is easier to design and manufacture. 

If you can fit and couple a brushed or brushless motor mechanically to your ACL then it is possible to make that motor run in Crystal Sync no problem. If it is not supposed to be mass produced (being a one-off modification) I would use a brushed motor for the task to save lots of design work and costs and especially time.

You need to know the approximate power the motor needs to be in Watts. And need to figure out then how to couple it to the camera mechanically. The motor needs some kind of encoder disc which is used to get RPM feedback for the Crystal system. You need to know the gear ratio between the motor and the camera as well so that it is possible to calculate what the actual motor RPM would be for each frame rate. You can usually figure out the gear ratio just by marking the input axle and turning it watching the shutter and calculating revolutions needed per frame. You need to also figure out which framerate presets and possible additional features you would need and what type of user interface the motor would have to select different speeds (buttons, switches, rotary switch, thumbwheels, display+buttons, etc.)

After having this information it would be possible for you to fit the motor mechanically to the camera and leave the electronics part to someone specialised in that. These systems need custom programming and circuit designing and the boards can be challenging to manufacture and assemble and fine tune, so it is easiest to concentrate on the mechanical part and outsource the electronics stuff :) 

If your original ACL motor has the brushed motor itself and the mechanics still working, then it would be possible to just update the control electronics and keep the rest of the motor original. This would save lots of mechanical work so would be cheaper

[Aapo Lettinen]

you can ask AZ-Spectrum about the modification possibilities as well http://www.az-spectrum.com/acl.html

[Aapo Lettinen]

I am developing a "universal crystal motor" system as well which is just a basic simple brushed dc motor with encoder and control electronics installed which can be fitted to different camera bodies by the end user... by making the mechanical fitting by yourself one could install this to different camera bodies with reasonable amount of work. This may be handy if you want to save on costs and the system does not need to be perfectly optimized in size and weight for every camera body (which would require designing it from ground up every time and choosing different components for every different version like using different type of motor and speed selector interface for every camera. that is pretty expensive) . I am just choosing motors for this system, let me know if you are interested in having one ?