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Konvas 6vt to 12vt crystal sync conversion?


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#1 James Steven Beverly

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Posted 20 August 2008 - 12:12 AM

I just picked up an extra rheostat 6 volt motor for my Konvas KSR-1m It's in fairly rough shape so i was considering having it rebuilt but then I started thinking, why not see if it's possible to rehouse a 12 volt, crystal sync motor in the framework. I wanted to use 2 400 ft mags I have with anamorphic lenses and a de-anamorphic viewfinder and gate I've already installed on the little KSR. The mags fit well but I was cincerned about the 6 volt motor having the strength to pull the 400 foot mags with a full film load. The spare motor has the complete transmission housing and round mount. If it were possible to remove the 6 volt motor from the assembly and replace it with a 12 volt crystal sync motor, it would solve any possible tork and pulling issues while still keeping the single frame animation and hand cranked capabilities that I so dearly love about this cool little camera.

The only major concern I could see aside from cost is the drive gears. The camera cog is made of either fiber or some kind of plastic and the drive cogs have a sloped side that allow a notched side to slide into place but allow the animation hand crank to be turned backwards without engaging the camera mechanism. The newer stabilized and sync 1Ms use an slotted notch with corresponding cog and were not designed to use the hand crank. I can't help but wonder if the sloped cog of the KSR-1 is inherently less stable and far less suited to crystal sync than the slotted solid cog of the 1m. Is then a crystal sync, 12 volt motor conversion a waste of time and money? My KSR-1 is in near MINT condition with almost every accessory available for the KSR and 1m. The only problem I can see is I want it to shoot with 400 ft mags in anamorphic to make it practical to use as the B camera on my productions. A crystal sync and barney would allow me to use it in conjunction with the Kinor on a 2 camera shoot if it were set back far enough out side. I would love to have the option of a wild motor and a sync motor. If a 12 vt conversion is impractical or even impossible, can a 6 vt rheostat motor be converted to crystal sync even if it's 24-25 FPS only? :unsure:

Edited by James Steven Beverly, 20 August 2008 - 12:16 AM.

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#2 James Steven Beverly

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Posted 20 August 2008 - 12:18 AM

Oh and if anyone might have an idea of what that might cost, let me know. B)

Edited by James Steven Beverly, 20 August 2008 - 12:20 AM.

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#3 Freya Black

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Posted 20 August 2008 - 02:52 AM

I've toyed with this idea too, mostly because my rheostat motor arrived completely trashed as the seller just threw the camera in a cardboard box with a tiny bit of newspaper. (Netzerg if anyone thinks to buy off the guy). He promised to send me a replacement motor too but never did. Avoid.

Anyway I've seen an interlavometer connected to the old grey automat but never a full sync motor but I'm guessing that just means nobody has tried it.

I would guess that the rheostat motor will have no problems with the 400ft mag. Yes it is 6volts but have you sen the amount of amps it draws! Scary stuff! How are you powering yours? People often have to come up with innovative powering solutions. Also as it is a rheostat motor, even if it runs a bit slower with 400ft then you can just turn up the speed!

The big question would be where are you going to get the 12 volt crystal motor to fit inside the casing!
It seems to me it would be easier to find a way to attach the motor mounting (from the rheostat) to an existing 12volt motor and to attach that to the Konvas.

As for the Konvas motor mounts I've also often wondered why they changed the mounting. I've always guessed it was because the newer mountings were easier to make as the older grey automat mounting looks very solid but potentially hard to manufacture reliably. I suspect it would work fine with a crystal motor. In fact I guess the older motor mount had to put up with a lot more what with people using animation cranks and fluctuating motors on it.

Oh and I suspect that it will be easier to just replace the 6v motor than attempt to cystal sync it. Even if you could convert it then you still have a 6volt motor that needs a ton of amps. Kind of a pain. Better to just put a new motor there that can easily work with the crystal circuit.

The really big problem with Konvai is always the motors.

love

Freya
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#4 Freya Black

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Posted 20 August 2008 - 02:59 AM

accessory available for the KSR and 1m. The only problem I can see is I want it to shoot with 400 ft mags in anamorphic to make it practical to use as the B camera on my productions. A crystal sync and barney would allow me to use it in conjunction with the Kinor on a 2 camera shoot if it were set back far enough out side. I would love to have the option of a wild motor and a sync motor. If a 12 vt conversion is impractical or even impossible, can a 6 vt rheostat motor be converted to crystal sync even if it's 24-25 FPS only? :unsure:


Oh BTW the Konvas will still sound like a tractor with a barney. Maybe if you were shooting with the b camera through a window or something.

You could build a blimp to go over the barney tho?

love

Freya
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#5 James Steven Beverly

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Posted 20 August 2008 - 03:39 AM

How am I powering it, small portable 6 vt battery charger. It seems to wok but I do need to have the camera serviced. It probably sat on a shelf in some Soviet propaganda office alone and forgotten because it SURE don't look like it's been used at all. The paint isn't even worn. I got it as a Christmas present from my parents a few years back and come t think of it, I THINK they got it from that same guy, Netzerg.

The stuff came packaged well (probably after you complained he may have decided it wasn't worth the hassle to scrimp on packaging), The problem they had was it took FOREVER for it to arrive, well after the holidays. They finally had to threaten him with getting the authorities in Russia involved which seemed to work because it got here soon after that, then I did something phenomenally stupid. I picked up the cylindrical lens case for the 135mm Lomo mouse eared lens by the top, not realizing it just slid on and as I lifted it out of the box the bottom half WITH MY MINT CONDITION LENS DROPPED ABOUT 2 FT TO THE CERAMIC TILED FLOOR OF MY PARENT'S LIVING ROOM!!!!! It fell straight with the lens staying in the case bottom but when it struck the floor, the round, black metal frame mask in the back of the lens popped out, and I can't to this day get it to stay in OR know if I put it in properly. I don't know if it will work without it but I'm relatively POSITIVE they put it in there for a reason SOO I may have to send that in to be fixed as well as my 50mm anamorphic lens which seems to be stiff and is missing the pin that locks the two halves together when focusing.

I managed to pull the aligning pins out of the base of my spherical matte box without damaging the as I don't have the corresponding alignment hole in the base of my KSR-1 so that I could use it and low and behold, they're the same size as the missing focus pin (gotta love those Russians.....unless of course they're invading your country. The problem is the focus is stiff which is probably why the pin popped out in the first place. I suppose I could grip tape it if push came to shove but since I don't want headaches, I'll just get it fixed. I sill need to find a focusing stink for them too. Do they make gear rings for the mouse eared Lomos that will work with the standard Kinor double sided follow focus or do you know? How bout the 2 piece anamorphics?

Edited by James Steven Beverly, 20 August 2008 - 03:44 AM.

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#6 James Steven Beverly

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Posted 20 August 2008 - 03:50 AM

That should be focusing STICK ( I really shouldn't type when I'm tired)
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#7 James Steven Beverly

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Posted 20 August 2008 - 04:00 AM

Oh BTW the Konvas will still sound like a tractor with a barney. Maybe if you were shooting with the b camera through a window or something.

You could build a blimp to go over the barney tho?

love

Freya

How 'bout one of those booths they used to use in the early days of sound. :D . I'm hopping if I set it back aways and throw a blanket around it in addition to a barney It'll be OK outside. I haven't seen a decent blimp for a Knovas yet. (or ANY blimp for that matter except for that unfinished one on the old Commiecam site.) Weird you woulda thought with all these little suckers running around all over the world, somebody would built a few by now especially with all the sync ones available.

Edited by James Steven Beverly, 20 August 2008 - 04:03 AM.

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#8 Olex Kalynychenko

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Posted 20 August 2008 - 05:06 AM

I just picked up an extra rheostat 6 volt motor for my Konvas KSR-1m It's in fairly rough shape so i was considering having it rebuilt but then I started thinking, why not see if it's possible to rehouse a 12 volt, crystal sync motor in the framework.


Konvas-1 camera ( KSR-1, KSR-1M ) created a many years ago and motor building industry do not had a many types of DC motor for drive of camera.
The other questions - the version of speed control of camera drive.
And this must be trusted device.
The designer of Konvas build of 25M-8M drive.
25M-8M drive included of DC motor with stator and rotor windings.
This type of DC motor can control of speed of rotation of axis by control of current of stator or rotor windings. And designer choose of current type of speed control by rheostat with hand control.
The camera ask of high torsion torque and ask of high power of DC motor (25..30W ).
From other side, we do not have many types of compact accumulators at time of building of Konvas-1 camera and designers choose of battery from 5 pcs of silver-zinc cell SC-25, 25ah.
25M-8M drive ask of 8 v or 6 v power source and have two version of winding and rheostat connections.

About technical peculiarity.
Konvas-1 had multi type of drive and had :
- mechanical, spring drive,
- single shooting crank drive,
- normal speed crank drive,
- electrical motor drive.
That's why, the desin of mechanism of camera have additional reducer for hand crank rotation with normal speed shooting, have special stopping mechnaism for spring drive.


If it were possible to remove the 6 volt motor from the assembly and replace it with a 12 volt crystal sync motor, it would solve any possible tork and pulling issues while still keeping the single frame animation and hand cranked capabilities that I so dearly love about this cool little camera.


If we compare of next version of Konvas cameras ( Konvas-1M, 2M ) and next generation of Konvas motors ( 15EPSS, 17EP-16 APK... ) we can see, Konvas-1 camera have other type of connection of axis of mechanism with axis of reducer of motor and other type of motor mount.
Yes, of course, If you create of special part for connect of 12 v motors with axis of Konvas-1 camera and part of body of reducer with view of Konvas-1 motor mount, you can attach of 12 v motor with Konvas-1 camera.
But, this can be complex project of upgrade.
From other side, the plastic mirror disks of Konvas-1 camera rare now and you can have problem at searching of spare shutter disks.
Konvas-1 do not have a possiblity of adjust of position of shutter disk, because, this procedure do at factory only and do not adjust at time of use of camera.

Konvas-1 mechanism have ball bearings and have more high value of noise from Konvas 1M,2M mechanisms with friction bearings.

After you study of all trhis ideas more detailed, you can think, you need upgrade of 12 v motors for Konvas-1 or can be better If you take of Konvas-1M, 2M body ?

As my opinion, the DC motors with stator and rotor windings ask of current control and do not compatible with modern pulse-width modulation of proportional, integral, derivative speed control.
I hear about a few projects of analog systems of speed stabilization of 25M-8M motors.
This was systems without feed back and hand manual adjust of speed only.
This was like electronic rheostat speed setting.
This systems build on old high power germanium transistor, ask of high power radiator and lost a some part of power of battery.

I will be glad, to discuss of any opinion about building of speed control systems of 25M-8M drive.

The great result at modern pulse-width modulation of proportional, integral, derivative speed control had DC motors with permanent magnet and hollow armature ( without magnetic circuit of rotor ).
This is type of DC motor ( like of russian DPR motos ) have very small inertia of rotor, have less self-induction.


The camera cog is made of either fiber or some kind of plastic and the drive cogs have a sloped side that allow a notched side to slide into place but allow the animation hand crank to be turned backwards without engaging the camera mechanism. The newer stabilized and sync 1Ms use an slotted notch with corresponding cog and were not designed to use the hand crank. I can't help but wonder if the sloped cog of the KSR-1 is inherently less stable and far less suited to crystal sync than the slotted solid cog of the 1m.


Yes, This is true.
The Konvas-1M, 2M version of conenction of axis of mechnaism with axis of motor ( slotted notch with ribber tubes) have more stable connection. And this very important for any automatic system of speed stabilization.
Because, the motor have two side of control : to increase of speed and braking.
The the sloped cog of connection of mechanism and motor of Konvas-1 have one side toothing only and can increase of speed only.
At mode of breaking the sloped cog will turning without cohesion.
The sloped cog work like one side free-wheel clutch.


The only problem I can see is I want it to shoot with 400 ft mags in anamorphic to make it practical to use as the B camera on my productions. A crystal sync and barney would allow me to use it in conjunction with the Kinor on a 2 camera shoot if it were set back far enough out side. I would love to have the option of a wild motor and a sync motor. If a 12 vt conversion is impractical or even impossible, can a 6 vt rheostat motor be converted to crystal sync even if it's 24-25 FPS only? :unsure:


About 400 ft magazines.
If you have Moskinap made version of Konvas-1 camera, 400 ft magazines of Konvas-1M, 2M cameras must be full comatible with your camera.

If you have KMZ made Konvas-1, sorry, this do not compatible and 400 ft magaziones super rare.

About upgrade of Konvas-1 on crystal sync speed, we can have two version:
- upgrade of axis of mechanism, motor mount for attach of crystal sync speeds motor of Konvas 1M, 2M cameras
or
- upgrade of mechanical speed stabilizator device of Konvas-1.
If you install of modern DC motor with feed back on hole of speed stabilizer and install of gear on axis of motor, you can run of mechnaism.

All of this projects of upgrade can be complex.
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#9 James Steven Beverly

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Posted 20 August 2008 - 10:12 PM

Well, the 400 ft mags fit and turn so I must have the right camera. I would be interested in either option on this motor. As I mentioned the spare motor I have is not in good condition so what ever will work, Can you give me an idea of what it would cost to have a crystal sync motor set into the spare Konvas-1 motor housing? Would it be easier and cheaper to use a modern Russian stabilized 6 volt motor? Once ramped up would the sync motor and / or stabilized motor stay synced or stabilized.
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#10 James Steven Beverly

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Posted 24 August 2008 - 02:47 AM

Olex?
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#11 Olex Kalynychenko

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Posted 26 August 2008 - 03:18 AM

The original 25M-8M motor of Konvas-1 can run of camera with 200 ft and 400 ft film magazines.
I do not know any ideas about install of any other type of DC motor on body of 25M-8M motor.
The DC motor must have high power, near 30..50 W.

May be, need take of motor block of 18EP-16 APK, 5BDS of Konvas-2M camera, ( the motor block included DPR-72 DC motor, reducer and taxo ) to install on body of Konvas-1 and, I can install of crystal sync speed conrtoller on this system.
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#12 James Steven Beverly

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Posted 27 August 2008 - 03:04 AM

How much do you estimate that modification might cost? I can send you the spare 6 volt motor if you would like to experiment with it. If it is prohibitively expensive to adapt a 18EP-16 APK, 5BDS with a crystal sync speed controller to the original 25M-8M motor drive housing or simply can not be made to work with it, then as a second choice, I would like to get the 6 volt motor repaired to use as a spare. Could you give me an estimate on both options? You can email or PM me if you would prefer. Thanks-Steve

Edited by James Steven Beverly, 27 August 2008 - 03:07 AM.

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#13 Olex Kalynychenko

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Posted 28 August 2008 - 09:35 AM

Sent PM.
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#14 James Steven Beverly

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Posted 29 August 2008 - 12:32 AM

Got it and sent you an email.-Steve
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