ALCS 4-speed Universal Crystal motor for Kinor16, Eclair ACL, etc. cameras

Aapo Lettinen · January 30

I am moving forward with the 3d-printed 4-speed motor design now in Spring. Will make something similarly working than the 4-speed motor but larger and with motor body which can be 3d printed so that one can attach the DIY 4-speed kit inside with minimum amount of work. I may have to design a control panel for it here as they often need to be aluminium and I can make them much cheaper here, typically about 2usd a piece which is way cheaper than getting them made by yourself.

The idea is that I would sell the "DIY" 4-speed kit like seen here and the control panel included. And then you would have the cad file of the motor casing you can print by yourself. If someone wants to order this kind of kit is is already possible but you will need to wait with the shipping so that I will have time to test the casing design fully to finish the control panel.

this 3d-printed 4-speed motor would use the same mounting parts than the normal 4-speed motors. the mounting parts need to be cnc machined metal so you can't save on those, but it is possible to save a lot if the motor casing is made of plastic. not as good as the metal one but may be just what is needed for certain applications 🙂

Edited January 30 by Aapo Lettinen

Aapo Lettinen · February 4

3D printing a temporary spacer for Krasnogorsk3 camera to correct the ffd. The K3 I have here does not have the original spacer and they are different thickness for different camera models, I think might be different for individual cameras so it is easiest to try to replicate the shape of the original spacer and make the crystal motor axle cutout to the cad model at the same time. Installing my crystal motors requires cutting a hole to the side of the camera for the motor axle and the spacer needs a cutout as well. The 3d printed temporary spacer can be used to determine the exact thickness needed to focus to infinity and when knowing that exact number, one can get the final spacer made out of aluminium. Testing the shape of the model still but it should work already, will see later today. I will include the spacer cad model with motor orders, the way-too-thick 5mm one which one can cut to the desired height in software and then get made. And precut models which are spaced in 0.05mm steps. One can use aluminium tape to get the close-enough thickness to exact one quickly. On my own K2 camera the original spacer was 2.12mm thick and it was different on my K1 so I really guess these do vary and I have tested that using another camera's spacer on different camera often does not work. Additionally DIY lens mount modifications may ruin the original ffd and require different spacer thickness.

Aapo Lettinen · February 4

I uploaded these Krasnogorsk spacer files to the same folder than the 4-speed mounting parts are in.

There is files in 0.05mm steps for spacer thickness and one can cut a custom thickness from the 5mm version in cad software.

Normally Krasnogorsk cameras have a spacer of about 2mm thickness but it can vary a tiny bit from camera to camera so one basically needs a custom thickness for every camera. For example my Krasnogorsk2 had a thickness of 2.12mm but it does not fit my Krasnogorsk1 and is wrong for Krasnogorsk3 too. I think it varies by manufacturing batch, likely not from camera to camera but that could be possible too. And if your camera has gone through a lens mount change then the ffd may be way off and you need to make new custom thickness spacer after figuring out the exact new thickness for it by testing.

Anyway, I think metal 3d printing from stainless steel would be good way to make the final spacer when knowing the exact thickness you want. A plastic 3d printed temporary version would probably last for couple of months in use as long as you make sure every now and then that the ffd has not changed too much. So one could basically probably manage with plastic spacers even but when knowing the exact thickness it is pretty easy to get a permanent one made out of metal.

Aapo Lettinen · February 5

10-speed motor on Krasnogorsk3 !

the 4-speed motor would install exactly similarly with same mounting parts.

Aapo Lettinen · February 5

I talked about a 3d-printable 4-speed crystal motor earlier. Printed a prototype last night, there is a sneak peek of it on this video where I am finishing the 10-speed installation on Krasnogorsk 😄

Aapo Lettinen · March 4

Ordering deadline for the rest of the orders this Spring is 15th March. So orders for products which will be delivered between April and June.

On 16th I will finally start building the large NPR motor batch, assembling A-minima magazines and other stuff so will likely stop reading messages for about 2 weeks to concentrate fully on assembling work, between 16th March and 1st April.

In early April I will continue normally, taking further orders for Summer2026 batches and the 2nd batch of A-minima magazines and some NPR and Bolex motor models.

Price increaces on most products will apply from 16th March onwards. Typically something like 20% increase is expected on most products. Looks like I will still keep USD pricing in April but will calculate new higher prices to counter inflation and the Trump wars which affect parts prices.