Film-Tech Forum ARCHIVE: How do I time the Christie AW3 Platter without a rpm meter

This is topic How do I time the Christie AW3 Platter without a rpm meter in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Michael Dolan (Member # 4808) on 05-27-2008, 06:15 PM:

I was told in order to properly time the Christie AW3 platter system you had to have an RPM meter I was wondering if anybody new of another way to do it.

Posted by Monte L Fullmer (Member # 2797) on 05-27-2008, 06:25 PM:

You can print this Manual out on the AW3 for your reference.

20+1 Rpm is factory norm. 5 rev per 15 seconds is close enough. Put a mark on the deck and begin counting.

good luck

Posted by Galen Murphy-Fahlgren (Member # 4535) on 05-27-2008, 06:32 PM:

I use two Christie P/N 196363s (Bevan-Poo, I believe they call it) and my wristwatch. Put one Bevan-Poo closer to the middle to avoid it being thrown, and stick another in the brain to hold the arm at the proper position.

Posted by Brad Miller (Member # 2) on 05-27-2008, 06:43 PM:

here

Posted by Sean McKinnon (Member # 612) on 05-28-2008, 10:52 AM:

I use the RPM meter religously. I have not seen a Christie platter timed as perfect without using it. It is really worth it in my opinion, I wouldn't time a Christie platter without it!

Posted by Mike Olpin (Member # 1115) on 05-28-2008, 08:09 PM:

The timing is easy to achieve with just a piece of tape placed at the edge of the deck and a stop watch. Simply count the number of times the tape passes the mast in a given duration. Does not have to be perfect to the mark, just fairly close. I'm good to about a quarter of a revolution.

The timing suggested on Brad's link yields excellent results, especially if you find your platter acts a little "jumpy" when calibrated to Christie's specifications.

Posted by Joe Redifer (Member # 3) on 05-28-2008, 08:15 PM:

Just buy a Film-Tech Platter Safety Ring and crank both the High and Low trimpots up to 100%! [Wink]

Posted by Mark Gulbrandsen (Member # 72) on 05-29-2008, 11:25 AM:

quote: Sean McKinnon
I use the RPM meter religously.

I do too, especially in a complex full of AW-3's. My boss prefers a digital tach but I can get through timming three platter systems by the time he's done farting with the first one. Although the Christie Tach has a fairly high end Stewart Warner movement I still double check the calibration on mine(against his digital readout one) every couple of months just to be sure its correct.

Posted by Tristan Lane (Member # 1169) on 05-30-2008, 04:10 AM:

Grainger Tach

Even thought the tach has a "Westward" brand name, it was assured to me by a grainger rep that it was in fact, made by SW and is the exact same animal that Christie minus the branding.

You can order the tach from Grainger, and then give Jim Graton a call at Christie to get the drive wheel and bushing part#'s for the tach. I've had to call him a couple of times about this part number (I wish I'd written it down somewhere)

Posted by Mark Gulbrandsen (Member # 72) on 05-30-2008, 07:42 AM:

But does it have the correct diameter rubber contact wheel on it's input shaft?

Mark

Posted by Sean McKinnon (Member # 612) on 05-30-2008, 05:22 PM:

quote: Tristan Lane
and then give Jim Graton a call at Christie to get the drive wheel and bushing part#'s for the tach

Posted by Monte L Fullmer (Member # 2797) on 05-31-2008, 01:46 AM:

Christie Taco-meters cost less than these Grainger units and include a real time wheel, or the two times rpm wheel.

Posted by Tristan Lane (Member # 1169) on 05-31-2008, 04:19 AM:

Monte, I'm not sure that's correct. Last time I price them, the Christie tach was priced at over double the grainger tach (drive wheel included)

Posted by Ken Lackner (Member # 1002) on 05-31-2008, 08:05 AM:

What is a Taco meter? Do they make a Burrito meter as well?

Posted by Sean McKinnon (Member # 612) on 05-31-2008, 09:21 AM:

Also just FYI the meter I used to have which I think was from Grainger required that you multiply the reading by 2 to get an accurate RPM reading for the AW3, If it said ten RPM, that was really 20 RPM.

Posted by Monte L Fullmer (Member # 2797) on 05-31-2008, 12:58 PM:

( [Big Grin]

- love to pick-on words there...) When I got my tach a few years ago, I only paid $110 for it from a local dealer.. but, I guess with everything else, price increases have made its mark in this area.

Posted by Tristan Lane (Member # 1169) on 05-31-2008, 03:09 PM:

quote: Sean McKinnon
Also just FYI the meter I used to have which I think was from Grainger required that you multiply the reading by 2 to get an accurate RPM reading for the AW3, If it said ten RPM, that was really 20 RPM.

The same method is required for the tach that is purchased from Christie.

Posted by Sean McKinnon (Member # 612) on 06-01-2008, 10:16 AM:

good to know. I did not buy the tach I was issued I guess I just assumed it was third party because you had to multiply the results.

Posted by Brad Miller (Member # 2) on 06-01-2008, 02:41 PM:

Who cares what the tach says??? Just get a platter timed perfectly, and take readings using whatever tach you want and mark it. Geez [Roll Eyes]

Posted by Galen Murphy-Fahlgren (Member # 4535) on 06-01-2008, 04:08 PM:

While we are on the topic of AW3s, when setting the LED potentiometer, I set it to 70k ohms at 70 as normal, but when I crank it open to full throttle, the resistance is dropping to 26k ohms, whereas the Christie manual gives the extraordinarily vague figure of "less than 40 kilo ohms." Is this no big deal? My platters may never have been timed to spec before, and I am trying to get a stable system with uniform timing so I can have my spare cards close to plug and play.

Posted by Sean McKinnon (Member # 612) on 06-01-2008, 04:34 PM:

When you "Crank it open" the resistance is supposed to drop. To be honest I never bothered to leave the meter on and move to actuator around.

Posted by Sean McKinnon (Member # 612) on 06-02-2008, 07:23 AM:

Unfortunately Brad, when you are servicing 120+ screens it is must easier to know how to read your meters properly than to make guesses through trial and error to find a measurement that you can repeat.

Posted by Brad Miller (Member # 2) on 06-02-2008, 08:00 AM:

Sean, you mark the tach ONE TIME. From that point on you know to set the speed to your marks. Besides, I have 2 tachs from Christie and both are slightly different anyway.

Posted by Mark Gulbrandsen (Member # 72) on 06-02-2008, 08:07 AM:

This thread shouda been titled... "From Which Angle Do I Pick My Nose?"

[Roll Eyes]

Posted by Sam D. Chavez (Member # 1841) on 06-02-2008, 10:22 AM:

I agree with mark.

I piece of tape and a second hand on the watch is all you really need with the newer LED kits. A platter is a self regulating device given any kind of chance.

Posted by Kenneth Wuepper (Member # 1174) on 06-02-2008, 10:58 AM:

As with all self regulating devices, these machines need to have the limits preset so that the automatic control will operate properly.

Like the cruise control on your car that it will not operate below a certain speed: the platter system is calibrated in the opposite way, using the maximum or other known speed as a limit.

Calibrating the payout sensor sets the linearity of control and the limit sets a range over which it will operate.

KEN

Posted by Michael Dolan (Member # 4808) on 06-02-2008, 11:00 AM:

Well before everyone picks there nose let me say thank you for all tyhe advice I have been able to get most of my platters timed pretty nicely and running smoothly. Now I can sit back and pick my nose!! [Razz]

Posted by Sean McKinnon (Member # 612) on 06-02-2008, 11:52 AM:

quote: Brad Miller
Sean, you mark the tach ONE TIME. From that point on you know to set the speed to your marks.

Right, but you still need to time the first system properly in order to repeat the results. Even if you put a mark on your tach you need to know how to read it the first time. Tape also dries out and falls off, and even permanent marker will wear over time. Also, you could be in a situation where your tach breaks or your traveling and forgot to pack it and have to borrow one from another tech.

It's like drawing the ISO 2969 curve on your RTA, it's a handy shortcut but you still need to know how to read the RTA.

Posted by Sam D. Chavez (Member # 1841) on 06-02-2008, 03:06 PM:

Kenneth,

I totally agree with you as well about the linearity. I worked endlessly on AW2's in the '70's and learned a thing or two about what was needed. I never could understand the requirement for something like 32 to 36 RPM max payout speed on a gear motor that would take off on a dime and fling a print without hesitation. Of course the print could only go so far on the AW2 as the payout would keep it from falling all the way off but I had one diasterous show where the outside of a long print unraveled and got under the platter until it came to a stop.

Posted by Brad Miller (Member # 2) on 06-02-2008, 10:33 PM:

quote: Sean McKinnon
Right, but you still need to time the first system properly in order to repeat the results. Even if you put a mark on your tach you need to know how to read it the first time. Tape also dries out and falls off, and even permanent marker will wear over time. Also, you could be in a situation where your tach breaks or your traveling and forgot to pack it and have to borrow one from another tech.

You know Sean, I timed platters with a piece of masking tape temporarily stuck to the top edge of the platter deck for well over 10 years before I picked up a tach. I never had any problem with it, and if you read the tips section that is the procedure I found works best to get the smoothest operation (and coincidentally that was written before I got a tach).

Posted by Tim Reed (Member # 137) on 06-02-2008, 11:01 PM:

I LOVE my tach! I just wish I'd gotten one years ago. [Roll Eyes]

But I did the same thing as you, Brad. I timed one the "old-fashioned" way and got it perfect, then put the tach on it to see what it read.

Posted by Sean McKinnon (Member # 612) on 06-03-2008, 11:43 AM:

Ok, to each thier own. Everyone is different and has different methods that work best for them. I am sure that you are more skilled at timing these platters than I am as you have been doing it a lot longer than I. Personally I find that I get much better results using the Tach but I will be the first to admit I was never good at doing it the old fashioned way. [beer]