Convert 2 Perf to 1 Perf-How to Remove/Replace sprockets

[Alain Lumina]

Hello;

 

I bought a basically unused bolex H16 Serial number 67068, it

still has the warranty card in the case and no scratches anywhere.

 

It is 2 perf,

I need to grind off sprocket teeth.

 

Are the teeth to be removed the ones near the base of the sprockets, or at the end away from the mount ?

 

 

I found the set screws on the sides of the sprockets and was able to loosen them, but this

doesn't release the sprocket, unless something else is holding it in there

that I don't see. IS it just friction on the spindle?

 

Does someone know of a manual PDF that instructs how to get them off put them back on?

 

Is there a failsafe key for replacement so they go back at the right rotation or

to you have to do some kind of fine tuning synch?

 

Thanks.

[Chris Millar]

I didn't know Bolex made 2R cameras...

 

Anyway, if its reasonably 'Bolex' in its make up then I take a stab at it:

 

Top sprockets come off

 

Before you take the rollers off scratch a registration mark of where one tooth is sitting with respect to the camera body on each roller... Once you have taken them off DONT RUN THE CAMERA or otherwise move the exposed shafts. If you don't put a registration or run it out of sync somehow you wont know where the teeth should sit and at worst your loops wont form properly. Its a chore trying to get it right again if you don't do this as you've got two variables...

 

They should come off once those two grub screw thingies are loosened - the newer models at least you have to rotate the rollers so the film guides slide through a slot in the rollers - hard to describe but you should get it if you look...

 

Heres a cheat way of doing it - use the shafts like a lathe - simply run the camera and push a file against the teeth, mind where the swarf/filings end up however and don't drive it too hard - patience ! heh heh

 

If this isn't making sense maybe the design is different - take a photo of the area we are talking about

[Paul Bruening]

Heres a cheat way of doing it - use the shafts like a lathe - simply run the camera and push a file against the teeth, mind where the swarf/filings end up however and don't drive it too hard - patience ! heh heh

 

That's darn clever.

[Alain Lumina]

Hi;

 

Thanks for the advice, I examined the sprockets more closely and there are

TWO set screws which go into the side of the sprocket perpendicular to the spindle.

 

Loosening the two screws on the sprocket definitely releases the sprocket from the spindle.

 

Now the only barrier to removing the sprocket is that the film guide ( see pic)

intrudes into the side opening of the sprocket and prevents the sprocket

from lifting off the spindle. I can only see one very small screw fixing the film guide

to the camera wall and I hope it doesn't have to be removed because the screw is so

small the blade slot for the screwdriver is about as thin as a razor blade.

 

I'm trying to post a pic, thanks for input.

[Ian Cooper]

...Are the teeth to be removed the ones near the base of the sprockets, or at the end away from the mount...

 

 

First a warning, I don't have a Bolex and I've never used one. However, on my K3, Beaulieu R16 and now Eclair the film is loaded with the sprocket holes at the bottom, ie. nearest the inside of the camera and furthest away from the loading door. This means the teeth to be removed would be the 'top' set, those nearest the loading door and least buried in the camera.

 

Perhaps the safest way to check would be to purchase a shiny new 100ft roll of film (which will be 1R) then attempt to load that correctly into the camera - you should be able to clearly see which set of teeth need to be removed for it to load.

 

Best of luck with it. :)

[Chris Millar]

Hi;

I'm trying to post a pic, thanks for input.

 

Its a bit low res there to really see what is going on ...

 

Ok well those loading guides are there only for well, loading - I don't think moving them will let the loop form an extra sprocket larger but I suppose its possible - this is more 'timed' by the relative position of both rollers and the claw, so you can see, lots of combinations of timing to get right, you want a clean loop that doesn't bunch/pinch or get too big and rub on the guides... So make sure you scratched your registration marks - you did didn't you ? If you didn't just fess up now and I'll explain how to fix it :lol:

 

Anyways, so I cant tell how your rollers work, but if they are like most Bolex rollers they will have a slotted section that you align with the guides and out they pop - hard to say but you might want to undo those little screws that allow the guide position to move, this might give you the movement needed to get the rollers out... But again register where they were in case moving them allows the top loop to go a frame bigger (which will likely equate to rubbing on the guide).

 

The whole lot can be removed if you're keen - just be careful around the claw, if removed this also can be put back in as many ways incorrectly as there are teeth on a particular cog (minus one ... the correct one). Getting this wrong will mean you're pulling down whilst the shutter is open.

 

But having said all that grinding them off just sounds ugly to me, get yourself a nice fine metal file, jeweler style and do the 'lathe' trick - honestly - I'm not joking ...

Edited November 11, 2009 by Chris Millar

[Alain Lumina]

>But having said all that grinding them off just sounds ugly to me, get yourself a nice fine metal file, >jeweler style and do the 'lathe' trick - honestly - I'm not joking ...

 

Thanks a lot for making sure I remember to check WHICH TEETH to grind. Forgetting THAT would be a good way to brick your cam hahaha.

 

I'm starting to lean towards lathing them to in-camera or paying someone to do it.

 

Too bad I can't get a vacuum in there while I'm lathe/filing to suck out all the particles.

Maybe I can tape some 1.2" hose onto a small vacuum so as I file

all the dust is sucked out and then I don't have to get figure out how to file the damn rollers off.

 

 

If I have to start diasssembling geared parts I am headed for Perdition.

 

Wait, I'm a screenwriter and independent film producer- I'm already there!!

[Chris Millar]

Yup - smaller hose on the end of a vacuum (with a hole so the motor doesn't overload) - or do it upside down like I do ;)

 

Heres another option:

 

File the gate to ultra 16 - keep the teeth and use 2R film (special order from Kodak) - but also open it up and play around with the governor so that it will go 100fps+ (I've seen an RX4 run a full wind without a governor once, can report that you'll be replacing broken parts after this kind of carry on) - I've been told by a Bolex tech (a real one :lol: ) that the older two perf models have a different claw design that lends itself to better registration and higher possible speeds ... I've done it but it was a 1R parallax model not suited to the RX lenses I have here (boohoo, another project on the shelf).

 

Anyways, people here will be jealous if you do that

 

hmmm - hang on - is 2R film still available even as a special order ?

[Alain Lumina]

Wa-hoo! NOW we're talkin'--blowing up the camera with hell-bent overclock! Man, that's some serious

rock filmmaking.

 

Sort of makes me think, much as I resist, --there's no real filmmaking equivalent of smashing your guitar, is there?

 

I could send the Bolex down a flight of stairs........

 

maybe getting in fights with the actors is the entry point for insanity in film.

 

Speaks to the corrupting size of capital base needed to make films...

 

Thanks for the upside-down suggestion!

[Chris Millar]

Wa-hoo! NOW we're talkin'--blowing up the camera with hell-bent overclock! Man, that's some serious

rock filmmaking.

 

Sort of makes me think, much as I resist, --there's no real filmmaking equivalent of smashing your guitar, is there?

...

Thanks for the upside-down suggestion!

 

Crash-cam - cameras set up with well protected film chambers that are sent flying into car crashes, water, explosions, fire etc... (camera itself be damned)

 

..aaaand back on topic remember that when its upside down that the top teeth are now the bottom ones - :P

[Guy Bodart]

Hello;

 

I bought a basically unused bolex H16 Serial number 67068, it

still has the warranty card in the case and no scratches anywhere.

 

It is 2 perf,

I need to grind off sprocket teeth.

 

Are the teeth to be removed the ones near the base of the sprockets, or at the end away from the mount ?

 

 

I found the set screws on the sides of the sprockets and was able to loosen them, but this

doesn't release the sprocket, unless something else is holding it in there

that I don't see. IS it just friction on the spindle?

 

Does someone know of a manual PDF that instructs how to get them off put them back on?

 

Is there a failsafe key for replacement so they go back at the right rotation or

to you have to do some kind of fine tuning synch?

 

Thanks.

 

 

Hi

Do not try anything stupid. You will never get a good result. THe film will be scratched and you will be out of sync when you will put back the sprocket wheels

Send the camera to guy@cameraspro.com and it will do the job for $20.00. He can even convert your camera to Super or Ultra 16mm

[Chris Millar]

Hi

Do not try anything stupid. You will never get a good result. THe film will be scratched and you will be out of sync when you will put back the sprocket wheels

 

I agree with you that stupidity will lead to bad results - however I have outlined easy methods to do this work without losing sprocket to pull down registration.

 

Forgive me for pointing this out but it would seem that either you haven't read the thread fully or you are implying my suggestions are stupid.

;)

[Jean-Louis Seguin]

Hi

Do not try anything stupid. You will never get a good result. THe film will be scratched and you will be out of sync when you will put back the sprocket wheels

Send the camera to guy@cameraspro.com and it will do the job for $20.00. He can even convert your camera to Super or Ultra 16mm

 

 

Mr. Bodart,

 

Perhaps it is your lack of mastery of the English language, but why are you referring to yourself in the third person when you are obvious making a blatant attempt at promoting your own company and services. This is not the purpose of this forum. Take out a banner ad if you want to advertise.

 

Jean-Louis Seguin