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Seeking Information on Dan Norris and Norris Film Products


Gareth North

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Hi Matthew.

 

I thought I had replied to your 24th of August post while at work but looks like i probably got distracted and forgot to hit Post. I get what your on about now the Nylon point is your drive shaft bit of white plastic that drives the camera from the motor. To ensure that the motor drive did not damage the camera if it tried to turn the camera when it was not set to turn I.E. it was attached wrongly or camera incorrectly configured Dan made it of plastic so the plastic drive pin would break and not the actual camera or motor. Most of the Bolex motors seem to be missing this white drive pin plastic when they come up on ebay. This was explained to me by another shooter who used the Bolex setup in the 90's and made sence. According to this guy Dan supplied two plastic pins as Bolex did a redesign on the drive shaft socket on there cameras this is discussed earlier in the thread. But in effect you can make yourself a new drive shaft pin using some particular type of strong but malable plastic and fashion a drive pin maybe even 3d print it? Will take some times to get right length and mimick the tooths on the end of the plastic to attach correctly to your camera but you should be able to do it!
But then you have issue No2 which looks like what I had which is the motor is not bringing the shutter fully closed over the film in a consistent manner (according to your tests). I did some shots in 2016 with the LPC-90 controller meter and motor. The meter meters the scene adjusting the shutter speed to get consistent exposure, I shot a days worth of timelpase only to discover great footage but mared by a white angle of over exposure because the motor was not comming to a stop properly so the shutter was not fully closed over the entire frame when stopped between frames. This is I guess what you think your getting. The motor needs to hit a certain angle of rotation to fully close and your guessing seing as you have not attached the motor to the camera yet that it is not doing this.
I got very dissapointred by this at the time and shelved my kit and started searching ebay for other motors assuming it was the motor that was bad very few have come up and each time I have been outbid. I have no idea what make and model the actual internal motor is so as to replace it so was stuck. I knew that this might be a tall order to get working and was happy to accept the risk. £400 in customs and postages seems quiet a lot though. How much was the motor itself? Did you buy it from Calvolsky?
Anyhow Michael Bober reactived this thread with his post and I was intrugued to dig all my kit out again and test and I found that bizarely it was all working when I tested a few weeks back. However the reason I think why mine might have started working correctly now is that i did something fancy in 2016 I had x2 12v batteries in series to get 24v and then added x2 6v batteries in parellel to increase ampage. I never tested in any other arrangement. Now I just have x2 12v batterys in series and it seems to be consistnetly hitting the same spot. Maybe you are not suppliying correct voltage / ampage so motor is sloppy in its rotations? How are you powering it? Michael Bober had it doing the same thing when it was powered with just 12v but when on 24v it hits its spot correctly!! Maybe its a power issue? Have you got your multimeter out :)
I still need to fully test mine at the fastest motor speed to see if it really is consistent across its range of speeds mine might still have an issue I know I fully put it through its paces that one day in 2016. I need to find the time to test throughly. Anyhow i Hope this splurge of text might help you.
Best Regards
Gareth North
bolexh16user.net
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Hi Gareth,

 

Thanks very much for your very detailed reply.

 

In actual fact the nylon point is not part of the drive shaft coupling, it is a totally separate part which is positioned on a relative arc to the motor drive shaft; it is adjustable and turns the motor body on its own axis. I can see from your photo that this part is not included in the Bolex motor drive, hence your confusion.

 

It is disappointing to find out you had the same fatal error of inconsistent motor stopping positions, but very interesting that your experiments with increased ampage seemed to help the issue.

 

In my case I am already powering the units from my Arri SR3 24v battery, but it could be an issue of under current supply, so this is definitely worth exploring.

 

My own thoughts were that maybe the driver transistors and related capacitors have degraded in time, so I am replacing all the key components in the motor circuit. I received the parts form Mouser today.

 

I will report back when I've finished the work and tests.

 

The whole kit including capping shutter was £860 plus postage and customs on top, bought on ebay from a reputable cine company in the States. They did offer a refund but I would lose the £400.

 

Best regards,

 

Matthew

Edited by matthew roberts
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Hi Matthew,

 

I have a pair of Yuasa NP7-12 12v 7ah Batteries to make 24 volts up and it seemed to be working correctly but i had not attached the motor to the camera thinking about it so that might apply some resistance. Either way I need to fully test it this weekend at all shutter speeds and attach to the camera and see if it does actually work properly.

 

This Arri version of the Norris does seem like quiet a fiddly setup can't quiet get my head around how its actually supposed to operate based on your description probably need to see it in action to 'get it'. The capping shutter seems like an extra layer of problems. I never saw.

 

I think I got lucky on the customs I think I paid around $900 for the motor and didnt really pay any customs. Yes let me know how it goes would like to see you get it all working.

 

Best Regards

 

Gareth North

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Hi Gareth,

 

The battery set up you have looks good, certainly provides a lot more juice than one arri onboard battery - I think they are rated at 1-2 amps.

 

Looking again at the Arri inching knob rotation cycles I think I am making a mistake by referencing one exact whole rotation when checking the Norris - the Arri inching knob does not complete an exact cycle of open/close shutter for one rotation of the inching knob, it is the intervals that I would need to measure.

 

I will have to wait till I can make up a better test coupler adapter, I have ordered a piece of acetal which I will drill to an exact (as I can) fit. I have a stencil cutter which is computer controlled which could help in marking it out.

 

Today I finished replacing the key components on the motor board - driver transistors, 2 electrolytic caps and 4 IC's. The motor definitely runs a lot quieter now which can only be a good thing.

 

Best regards,

 

Matthew

Edited by matthew roberts
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H Matthew,

 

The Norris motor I have attaches to the Bolex camera's 1:1 drive shaft so one motor rotation is one complete loop of the shutter. Is Arri's drive shaft a 1:1 shaft or maybe 1:2 or higher value? I'm sure that should be easy for you to find out! That will make your guesses a bit more tricky if its doing multiple motor rotations to fully rotate the shutter once to know if its hitting its mark or not!

 

Wow I'm impressed with all your electronics efforts. I did do a degree in electronics but found resoldering and fault finding to component level really tedious. I suppose if you can replace all the components thats a good idea as they will all be rather cheap but often caps or others are sometimes burned up or marked so you cannot see what value they were to replace them you must of got lucky if you could identify eveything. Thats great if its working better.Maybe you can make a niche little venture of fixing this stuff for people going forwards!

 

By the way I think you've answered a question i had but never asked! I need to fashion a new plastic drive shaft pin as mine has a crack developing in it. I was unsure what I should be ordering and from where but just done a google search for Acetal Plastic that you mentioned and immeditaly found plastic rods that look like they coud do the job so looks like I know what I need to get so Thanks for that!

 

Let me know how it goes! I think your getting somewhere! If your creative and technical your unstoppable as Robert Rodriquez used to say!

 

Best Regards

 

Gareth

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Hi Gareth,


I had a look inside the motor box while it was running, the motor itself completes one half rotation for open and one half rotation for close shutter, it is geared to turn the camera inching knob 9 times in just less than a full rotation.


I have run into a problem with the motor circuit and wondered if you could help - I managed to burn out 2 resistors on the DC input to the board just after a IN4004 diode. I guessed the value and tried 22ohms which definitely seems wrong, but think it may be 2.2k. I wondered if you could check your circuit board to verify the value of these 2.


I have attached an image with the 2 resistors circled (2.2k but I thought they must be wrong so took them out).


Obviously only if and when you have some time.


Best regards,


Matthew

post-74116-0-36850900-1535652483_thumb.jpg

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Hi Matthew,


Yes I can have a look at that for you. I have x2 controllers the LPC-90 and another one either the MMC 350 or the SCC 300 not sure which until i get home. I'll have a look tonight and see which one it is if its the SCC300 one I'll take the front off and let you know.


Best Regards


Gareth North
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Hi Gareth,

 

That's most kind of you, but it's not the controller I'm referring to (SCC300 or LPC-90) but the motor circuit board as per your picture earlier in this thread.

 

It looks like the circuit board is exposed on one side with the Bolex version - the side of the board in the image I have posted will be on the inside of your motor box (unfortunately).

 

I'm pretty sure the correct value is 2.2K, but a partially broken wire on the motor tachometer which I did not see caused confusion on my part.

 

Thanks very much.

 

Best regards,

 

Matthew

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Hi Matthew,

 

Sorry for the delay spent the wekend away from home. Had a look at it this morning and I have removed with a little Allen key the screw holding the heatsink down via a rod to the main metal shell everything is built into. I thought this would be wnough to loose it and be able to remove it but its not buding and I can see no other area to unscrew unless its the ny holding the other heatsink in place??

 

Any ideas? What did you loose to remove it?

 

Best Regards

 

Gareth

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Hi Gareth,

 

Thanks so much for taking the time to have a look for me, are there a couple of push switches (inch and reset) on the fascia? if so you need to undo a couple of nuts securing them to the casing.

 

If that doesn't do it then not to worry, I wouldn't want you to compromise your unit in any way.

 

Best regards,

 

Matthew

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  • 2 weeks later...
  • 2 weeks later...

Hi Matthew,

 

Sorry for going quiet on you! Got inivited last minute to a festival as someone dropped out. One you could still exchange tickets I.E. No photo idea and then went away on holiday for a bit and then returned to a computer that was dead. Have you totally given up?

 

I will try and see if i can prise my board open if it might still help you knowing those resistor values? Or have you just had enough?

 

Best Regards

 

Gareth

 

bolexh16user.net

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Hi Gareth,

 

Sorry for the late reply.

 

Not to worry about opening your motor controller I have found a resistor value that seems to work ok. My main problem is consistent shutter position at each motor start stop actuation.

 

I have replaced the grub screw on a slipping drive coupler and cleaned all the bearings and gears, but it is still not that accurate, even though I have eliminated all slippage between the coupler and the Arri inching knob.

 

It is also problematic winding new film on and then synching the Norris drive to a closed shutter position - I don't trust the Norris inching mechanism to do that job, the Arri electronic inching is 100% reliable and accurate. In addition the Norris shutter closed/open positions change when film is loaded.

 

Best regards,

 

Matthew

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  • 3 years later...

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