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

[Aapo Lettinen]

Axle adapters arrived for mounting the 4-speed motor to the Krasnogorsk cameras! 

will wait for the side plate mounting system to arrive too before mounting the motor to the test camera but the axle adapter works fine so it will be really cool after getting the rest of the parts here 😄

 

[Aapo Lettinen]

my November "black-friday-ish" sale is for next year's batch of diy 4-speed motor kits!

the circuit board is way too difficult and risky to assemble diy so I am assembling and testing them here. But one can save 150 bucks by assembling the other parts of the motor by oneself. I is a maximum of half day 's job but can be done even in couple of hours in best case. 

Soldering tools and epoxy glue, some locktite and superglue is needed. And tools like screwdrivers etc. Possibly a power drill with mm sized drillbits but I will try to make the kits so that holes are pre trimmed here and finishing drilling not needed. 

One needs to make the power cable for the motor too but I will include the necessary connectors so one mainly just needs some wiring and the soldering tools and screwdrivers and the glues to assemble this device.

[Aapo Lettinen]

work in progress. testing the 4-speed motor with Krasnogorsk2 body before installing it to K3. 

 

[Aapo Lettinen]

[Aapo Lettinen]

 

[Aapo Lettinen]

Briefly tested the motor with 35mm Konvas1M too!

it seems to work up to 33fps with 14.4v battery and 200ft magazines. Might be possible to run higher speeds 48fps and 50fps with 18v battery but will continue testing when getting the cnc machined aluminium mounting plate here next week. the 3d printed test plate is not sturdy enough to run tests.

I am also working on a 15mm rod baseplate for the 1M konvas because needing it for a project in January.

 

[Aapo Lettinen]

DIY KIT CANCELLED.

I seemingly set the price point wrong and there was not enough orders to fund it. The tutorial materials would had been lots of work to make compared to the very low demand so it woud had generated too much losses.

I may have some campaigns on the readily assembled 4-speed motors later on. And might at some point try to design a 3d printable motor which would be so much cheaper to manufacture that it would make a diy kit possible at more attractive price range. With these cnc machined aluminium parts I could not get the diy kit cheap enough to make it attractive. I would had needed to be around 400usd to gain enough orders it seems.

Take care and let me know if needing readily assembled 4-speed motors! looks like I will make a extra batch or two next year before replacing the basic model with the v2.0 so there is still lots of good chances of getting the basic 4-speed version 🙂 

On 11/18/2025 at 3:26 PM, Aapo Lettinen said:

my November "black-friday-ish" sale is for next year's batch of diy 4-speed motor kits!

the circuit board is way too difficult and risky to assemble diy so I am assembling and testing them here. But one can save 150 bucks by assembling the other parts of the motor by oneself. I is a maximum of half day 's job but can be done even in couple of hours in best case. 

Soldering tools and epoxy glue, some locktite and superglue is needed. And tools like screwdrivers etc. Possibly a power drill with mm sized drillbits but I will try to make the kits so that holes are pre trimmed here and finishing drilling not needed. 

One needs to make the power cable for the motor too but I will include the necessary connectors so one mainly just needs some wiring and the soldering tools and screwdrivers and the glues to assemble this device.

 

[Aapo Lettinen]

4-speed seems to work fine with Konvas 1M up to 33.333fps with 200ft magazines at 14.4v battery. I am pretty sure it could make 48fps and 50fps if using 18v battery but 33.333fps is fine for most shooting and this would be pretty cool indie setup when I get the battery mounted to the camera and get the final aluminium 15mm baseplate back from machining 🙂

 

 

[Aapo Lettinen]

Longer video with explanation! and showing my 15mm rods baseplate design too! Will shoot a shortfilm on this in January when having all the aluminium plates machined and tested and having the cheeseplate design ready for mounting the battery to the side of the camera

 

[Aapo Lettinen]

Like mentioned, when purchasing the 4-speed motor, even if just the motor without extras, one gets link to the cad files of all of the currently available mounting parts and accessories for the motor. Currently there is 4 camera models and the better inching knob design and the battery plate mounting bracket which is really handy with Kinor. Will add new stuff to the folder when having them finished and tested first. These are customers-only proprietary stuff. I do have some freely available designs like viewfinder adapter and handle etc which are on separate folder, posted the link on the forum earlier.

Almost everything is meant to be cnc machined out of aluminium. These just can't handle the stress if 3d printed, plastic does not hold reliably enough. But one can 3d print the mounting parts for evaluation to see how it looks like with the camera build for example before getting it made out of metal. 

 

[Aapo Lettinen]

closer look of the Konvas mounting parts. the finished aluminium plate arrived today 

 

[Aapo Lettinen]

I figured out I could make adapter system to use my 4-speed Universal Crystal Motor with the old straight-viewfinder Konvas 1KCP cameras, the ones which had the hand crank and spring drive option with the large round spring motor cavity on the side of the camera. 

The adapter is a little more complex than on my other 4-speed mounting kits so the price is a little higher, for preorder 900usd with 4-speed motor and later on 980usd if there is still stock available. 

I need to replicate the big round mounting plate to hold the motor which is why it costs a bit more than other 4-speed mounting kits, much larger aluminium parts which are more expensive to cnc machine. 

The standard 4-speed crystal motor run the Konvas 1m fine with the 200ft magazines so it would work fine with the older 1KPC which has those smaller magazines too.

If I get orders before January could start working on it in Spring2026 and hopefully shipping in April. 

By my knowledge there has never been original crystal motors available for this older 1960's Konvas model so this would be the first one made.

(straight finder 1KCP with the original rheostat motor)

[Aapo Lettinen]

I do have this kind of 4-speed motor version too if someone is planning some special camera modification and just wants to have some motor which runs at stable crystal speeds. Basically it is the same components than the Universal 4-speed but it does not have the cnc machined motor body, the motor is separate instead. Will add some kind of protection for the cable. 

this does work with the mounting parts kits I designed for the Universal 4-speed normal version but needs a plate on the motor side with the same mounting the kits have. I can make a cad model of a suitable plate if people order this version.

500usd with shipping. 6 crystal speeds and works at 14.8v, same specs than the normal 4-speed motor because the electronics and motor drive are the same. 

empty casing in the reference photo but the control panel is exactly the same than on my other 4-speed versions you saw in photos and videos

[Aapo Lettinen]

I have one standard 4-speed kit available for order with the Krasnogorsk mounting kit and pink 4-speed motor body. 

the Krasnogorsk kit has a faulty mounting plate which does not have all the threads, there is not 1/4" mounting threads. I will manually tap the M4 threads for motor mounting. 

If bought now in December the outside-EU price is 680usd with shipping as you are only paying for the motor and axle adapter, the mounting plate is free of charge. Shipping will be in January-February once I assemble the pink motor.

There is possibility that I could have another similar kit with faulty plate for 680usd but will see later. This one is at least on sale.

Edited December 4, 2025 by Aapo Lettinen

[Aapo Lettinen]

And of course I have a Christmas campaign too! 

the campaign motors will be assembled in late Spring but I will order the aluminium parts already this year so need the orders before 15th to arrange the parts. At the moment looks like that most of the motors will be Champagne colored and most mounting parts grey but will see after the orders are in what colors will have on these.

 

[Mark Dunn]

I'm not in the market, but I love this idea of random colours. It would be Champagne for me, of course🍾

[Aapo Lettinen]

1 hour ago, Mark Dunn said:

I'm not in the market, but I love this idea of random colours. It would be Champagne for me, of course🍾

Yes it is nice to have other colours for change than just the basic black and dark grey typical on camera accessories 🙂 

I am also testing how the different colours look like on the anodizing finish so that can plan better the future accessories I am making.

btw made this really basic cheeseplate for Konvas, mounts in place of the strap mount next to the magazine. enough space to mount a mini-vlock plate to power the 4-speed motor and the spacing is such that the plate can be mounted sideways, upright or at 45 degree angle. the test pieces will be cobalt blue to test that colour 🙂 

 

[Aapo Lettinen]

Just designed this heavy duty plate for my Konvas 1M. Cnc machined aluminium and standard 1/4" and 3/8" threads.

Can be bought for very good package price with my 4-speed Konvas motor kit or my other Konvas motor systems. Available separately too if needed, will know the price if getting orders for these but relatively affordable in any case.

Probably will include a set of basic black aluminium rods.

The rod mount block is a Smallrig one and it is possible to mount similar block underneat the plate to the same location if needing another set of rods for handheld operating etc. Or one can mount stuff to the extra 1/4" mounting points. 

15mm rods at correct height and centering. The multiple tripod mounting threads on optical axis rather than the one offset thread the camera originally has. 

lots of extra 1/4" mounting holes to add heavy duty handles or a set of additional rods, or for rigging this to a car etc. 

The plate is fastened to the camera so that the rod mount is in contact with the camera's front part, thus preventing pretty well the plate from twisting even when it is only mounted with one screw to the camera body.

Plate is mainly meant to be sold at very good package price with my Konvas motors but it is possible to purchase these separately too if needed. Probably will include a set of basic black aluminium rods with the plate but will see if getting orders for these.

[Aapo Lettinen]

On 12/16/2025 at 12:25 PM, Aapo Lettinen said:

Just designed this heavy duty plate for my Konvas 1M. Cnc machined aluminium and standard 1/4" and 3/8" threads.

Can be bought for very good package price with my 4-speed Konvas motor kit or my other Konvas motor systems. Available separately too if needed, will know the price if getting orders for these but relatively affordable in any case.

Probably will include a set of basic black aluminium rods.

The rod mount block is a Smallrig one and it is possible to mount similar block underneat the plate to the same location if needing another set of rods for handheld operating etc. Or one can mount stuff to the extra 1/4" mounting points. 

15mm rods at correct height and centering. The multiple tripod mounting threads on optical axis rather than the one offset thread the camera originally has. 

lots of extra 1/4" mounting holes to add heavy duty handles or a set of additional rods, or for rigging this to a car etc. 

The plate is fastened to the camera so that the rod mount is in contact with the camera's front part, thus preventing pretty well the plate from twisting even when it is only mounted with one screw to the camera body.

Plate is mainly meant to be sold at very good package price with my Konvas motors but it is possible to purchase these separately too if needed. Probably will include a set of basic black aluminium rods with the plate but will see if getting orders for these.

I calculated that the 15mm Konvas baseplate is 150usd if purchased with my 4-speed Konvas motor kit. I may have campaigns every now and then but the normal price is pretty good too.

Or 200usd if one wants to buy only the baseplate and nothing else.

The baseplate includes a set of black 15mm rods which are about 20cm in length on the current batch. The local store sells Smallrig rods and usually possible to arrange different length rods instead if needed. 

Edited December 23, 2025 by Aapo Lettinen

[Aapo Lettinen]

preparing Krasnogorsk3 camera for crystal motor installation. One needs to take the camera fully apart to install but it is a great way to learn about film camera mechanics and these cameras are inexpensive so there is very little risk doing this despite it being quite extensive modification. Recommended to do CLA to the camera at the same time when needing to full take it apart anyway 🙂

will post second part later when having the motor installed and tested.

 

[Aapo Lettinen]

second part of installing the 4-speed and 10-speed to Krasnogorsk3 : drilling holes to the camera body to install the side plate which holds the motor and closer look how the axle adapter works.

Will make part 3 when having the installation finished.