Film-Tech Forum ARCHIVE: AW3 Speed Problem

This is topic AW3 Speed Problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Manuel Francisco Valencia (Member # 710) on 11-12-2003, 06:23 PM:

I am having a problem with my platters on one tree. I can't get the low speed slow enough. I did have the old power supplies in but recently I upgraded them with the IR Kit,however, the problem was present before. My low pot setting on the cards is as low as it can go and my filter alignment is correct. I haven't checked the resistance on the resistance card yet since it is set at factory but I am going to check that anyway. I do not think that would be a problem anyway because the problem was present with the old card set at 25 at max. Has anyone had this problem before?

Posted by Brad Miller (Member # 2) on 11-12-2003, 07:18 PM:

Did you change out the light filter, or just the IR led and led card?

Posted by Manuel Francisco Valencia (Member # 710) on 11-12-2003, 09:26 PM:

The filters are changed.

Posted by Michael Rourke (Member # 1142) on 11-13-2003, 02:57 AM:

I have been told (by Christie) that the LO adjustment is not critical for proper payout or take up.

I have had that problem before, when there isn't enough travel in the pot to slow it down to a crawl, and it can be corrected by changing the sensor (you already did that..to the IR diode) or the motor control card. I used to increase the resistance of the sensor to 100 Kohms at 70 degrees to keep the platter slow at 20 degrees, but was informed that 70 Kohms was imperative for proper payout and take-up.

Posted by Brad Miller (Member # 2) on 11-13-2003, 05:24 AM:

quote:
I have been told (by Christie) that the LO adjustment is not critical for proper payout or take up.

The hell it isn't! Damn I wish Christie knew how to time their platters. [Roll Eyes]

If you don't have the low set properly, you can have an oscillating takeup, most easily seen near the end of long movies. That can cause the takeup arm to bounce and crash into the motor, especially on 70mm.

Michael, with the new IR led, the new led card and both the HI and LO pots set to minimum, does the platter still creep? Are you certain that no light is leaking into the arm?

Posted by John Westlund (Member # 913) on 11-13-2003, 02:06 PM:

Brad is right about the LO adjustment being critical. I have had a deck that the LO setting was too fast on and never noticed it until the credits of Lord of the Rings. During the credits the takeup was oscillating and the arm slammed into the motor causing the film to jump off the takeup arm roller.

Posted by Ken McFall (Member # 845) on 11-20-2003, 02:23 PM:

Here's something that is really pissing me off with the AW3's.

I have a couple that are oscillating quite badly. So did the usual start from scratch setup etc. No joy... so decided to change the motor card with one of the new spares I have. Guess what... the new cards fit in fine but don't make contact and are so loose they would fall out if I closed the flap! Have they changed the design of the connector?

I have three new connectors.... but they came with no contacts, possibly my fault as the manual does not make it clear that you order them separatly. So until I can get some I'm stuck.

To do a complete strip down and reset return spring tension etc is quite a big job, especially as I have nine screens to consider.

One other thing that happened is that I found a module that would not lock in place. Ah I thought just the keyway come out. But when I tried to lift the plate off the keyway was stopping the plate from coming off! At this point I noticed a small hole had been drilled in the plate at an angle towards the bearing. With a bit of trial and error I was able to tap the keyway in far enough to allow the plate to lift off. Is this a known problem, clearly its happend here before hence the hole. But I would have though it ws a design fault if the keyway can come loose and prevent you from removeing the platter.

I have a few happy mornings work to look forward to setting everything up [Roll Eyes]

Posted by Aaron Sisemore (Member # 145) on 11-20-2003, 03:03 PM:

Oscillation in AW3s after doing a proper calibration is almost always caused by a dying LED/photocell unit (the device under the brain that the gradient filter moves between). Replacing this should cure the problem.

-Aaron

Posted by Ken McFall (Member # 845) on 11-20-2003, 03:20 PM:

Hi Aaron,

yeah that's my next thing to do when I have a morning to play with, I have a couple of spares. I'm just concerned with LOTR starting soon as I don't want any problems with a full plate of film bouncing all over the place!

What's this upgrade I've seen mentioned.... changing the LED and control card.

Posted by Manuel Francisco Valencia (Member # 710) on 12-09-2003, 12:44 AM:

Does anyone know what these "set" resistance cards are set at? For some reason I could not get a reading.

Posted by Brad Miller (Member # 2) on 12-09-2003, 12:53 AM:

The IR kit is a joke. You really should send it back to Christie and demand a visible led assembly.

BTW, you never answered my timing question above.

Posted by Manuel Francisco Valencia (Member # 710) on 12-11-2003, 03:45 PM:

Brad

I am sorry but I wasn't to specific above and I threw you guys off. My platters do NOT creep. The low speed is just really fast. Last night I changed the settings on the pots a bit and this is how it is acting. With my high pot adjusted for 25RPM and my low pot turned as low as possible the platter will only spin as slow as 5RPM. At 20 degrees it spins at 15RPM. At about 35 degrees it spins at 20RPM. In other words it goes to 20 RPMS in about 35 degrees and slowly accelerates to 25RPM in the next 65 degrees. There is no light leaking into the arm and I checked my filter alignment I don't know how many times. I am new to these IR kits so what experiences have you had with them Brad. I have some more on order but it isn't to late to cancel if they are terrible.

Posted by Brad Miller (Member # 2) on 12-11-2003, 03:47 PM:

Sounds like you got a defective kit.

Seriously, I would return those and demand Christie send you the visible leds and use your existing filter and led control card.

Posted by Manuel Francisco Valencia (Member # 710) on 12-11-2003, 04:07 PM:

I had this problem before I installed the kit. At first I thought it was just the resistance card so I figured the IR kit would solve it.

Posted by Brad Miller (Member # 2) on 12-11-2003, 04:13 PM:

Stick a business card in between the filter and led to block the light. Does it stop?

Posted by Manuel Francisco Valencia (Member # 710) on 12-11-2003, 04:19 PM:

Heading to work now. Will give it a try.

Posted by Manuel Francisco Valencia (Member # 710) on 12-13-2003, 06:27 PM:

Damn that was a long shift! Anyways, the platter motor did not even hum with the card in place.