Speed Dial Question

[Andrew Glenn Miller]

Hello, just wondering if anybody has the same sort of thing going on with their bolex systems.

 

I got an earlier model rex-5 system. The speed dial is nice and tight but there might be a concern. The marker reaches a few millimeters short from the 12 f.ps. line. Just for further information, the speed dial ends above the six on the 64 f.p.s.

 

I should run a test with a timer to see where my actual fps markers are. It might be difficult getting it precise, I'm still deciding what the bets plan is to do so.

 

In the meanwhile is this an issue? Why is it almost a full centimeter off from the 12 fps and not the 64 fps as well.

Edited October 3, 2011 by Andrew Glenn Miller

[Chris Millar]

If I recall the plate with the numbers on it can revolve independently of the knob - yours has just moved ...

 

You should still have the full range on the governor - but don't take the numbers as gospel (you shouldn't with an old camera anyway).

 

To fix, take it off and figure it out - I don't have one here to remind myself, but its not too hard if you have the right tools

[Andrew Glenn Miller]

I should really invest in a digital camera of some sort..

 

 

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I apologize.

[Andrew Glenn Miller]

If I recall the plate with the numbers on it can revolve independently of the knob - yours has just moved ...

 

You should still have the full range on the governor - but don't take the numbers as gospel (you shouldn't with an old camera anyway).

 

To fix, take it off and figure it out - I don't have one here to remind myself, but its not too hard if you have the right tools

 

 

Alrighty then, I see two screws that seem to attach the independent slate with the numbers. Maybe I should pass it along to a professional, not sure what will happen if I start unscrewing these.

Edited October 3, 2011 by Andrew Glenn Miller

[Jean-Louis Seguin]

Hi Andrew,

 

On cameras that have some wear or that ran improperly lubricated for a certain length of time, the parts associated with the speed governor wear down a little increasing all the running speeds throughout the whole range. Without replacing any parts, it is possible to readjust the speeds by shifting the knob position. If you adjust the knob for a perfect 24fps let's say, the low and high limits will also shift and the selector knob may stop short or overshoot the 12 or 64 fps marks.

 

Cheers,

Jean-Louis

[Chris Millar]

Alrighty then, I see two screws that seem to attach the independent slate with the numbers. Maybe I should pass it along to a professional, not sure what will happen if I start unscrewing these.

 

If you unscrew them, they will come off - then you can put them back on

 

The trick is to find the correct placement for the witness dial, but without any testing gear and since its wrong already so you're not going to to make it any worse by eyeballing it - set the governor at the lowest speed, then set the witness dial at 12 ... Done.

 

The proper way maybe would be to get a tachometer on it then set 24fps as centre - even when doing that you'll notice that 64 and 12 are off - and it's a question of what do you line up with what anyway.

 

I say go for it yourself - it really is simple stuff.

[Chris Millar]

yes

 

... what Jean-Louis is saying is if you make the assumption it was done intentionally then don't move it.

If you have a digital multimeter with a frequency setting you can appropriately fix a bit of wire on the 1:1 shaft, send a voltage through the camera body and pick up the frequency that the shaft is rotating kinda like a weed whacker - it tends to work even without the extra voltage, at least on my cheapo DMM.

[Andrew Glenn Miller]

Thanks for the information, I did a little basic math and timing to see what I came up with on the 24 fps interval.

 

10 second duration

 

245 = 10.208 sec

238 = 9.916

 

recrank

 

237 = 9.875 sec

231 = 9.625

 

recrank

 

237 = 9.875 sec

228 = 9.5

 

recrank

 

237 = 9.875 sec

228 = 9.5

 

20 second durations

 

458 = 19.083 sec

recrank

454 = 18.916 sec

recrank

460 = 19.166 sec

 

 

I know it's not precise, but it gives me an idea. My camera seems to hold pretty decent times via the crank up method, so the marker seems to be doing just fine where it is atm.