Film-Tech Forum ARCHIVE: Kelmar Series IV Automation cam timer sticking

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Posted by Stephen Frazza (Member # 2320) on 11-07-2004, 02:18 AM:

I have a Kelmar Series IV Automation that's cam timer is getting stuck. It will pick up and see the signals from the cue detector but ignores them because the timer(it's red and plastic) hasn't fully finished it's rotation.All the lifts and drops happen at the right time ,I took it off and rotated it by hand. and they match the manual but it is getting stuck or stopping and not finishing its cycle, and it ignores the lights up and end of show cues when its stuck.

I'm thinking it might be the motor attached to it but i'm not sure. I can't see any thing else happening that would cause this So I was hoping someone might have some experience with this problem or any other thoughts on what I could look at.

Posted by Steve Kraus (Member # 476) on 11-07-2004, 10:38 AM:

Where does it get stuck? In general on cam timer automations there should be two dwell periods where the motor is stopped. One is the between shows and one is during the show. One of the cams is responsible for powering the motor so that when push of the start button (or an end cue) starts it moving it will continue to turn until it gets to the next dwell period.

If the cam assembly is stopping some place other than these two dwell periods you will need to test to see if it is receiving power in which case the motor could have failed, the internal gears jammed or something is stuck amidst the cam assembly. If it's not getting power then you need to check that cam & switch that is there to power it. If it is rotating properly and stopping only as it should (where the cam that powers it has the notches) then there is some other issue other than what you have described.

These comments are about purely mechanical cam timer automations in general; someone else can address yours more specifically.

Posted by Tim Reed (Member # 137) on 11-07-2004, 12:21 PM:

Here's the problem. The #1 and/or #2 microswitch (nearest the motor) is/are bad. The #1 switch is the one that maintains power to the cam motor (later in the cycle), and it stops the device on the mark at the end of the rotation. The #2 switch (and this is the one that gets most people) is the hold circuit switch. This can make the motor stop prematurely by breaking the start circuit before the #1 switch has a chance to "take over".

I've found that 90% of the time, however, it's the #2 switch. But it's just as well to change them both, since the unit has to be disassembled to get to them. A good indication of #2 switch failure is the projector and lamp will start, but the c/o never opens...

EDIT: I'm questioning my memory, so check the schematic to verify that #2 is the hold circuit switch and not #3 instead... sorry, can't remember for sure - I'm getting to be a few years out of the biz now.

Posted by Mark Gulbrandsen (Member # 72) on 11-07-2004, 05:24 PM:

quote: Steve Kraus
In general on cam timer automations there should be two dwell periods where the motor is stopped.

Definately not true on all automations.... even of the same manufacturer. This sort of function all depends on the model you have... in fact the majority of cam timers make a full 360 degrees then shut off with each activation in 30 seconds.

Tim is right about the motor run switch possibly being bad and the best way to tell of its that is to hold the start buttom down and watch the cam timer run. If it runs then stops randomly while the button is held down then the motor is bad..... If you hold it down for 2 seconds to get the motor going and then release the start switch and the motor stops then the motor run switch os bad. Consult your model numbers manual or trace the wires back from switch 1 or 2 to find the right one and then replace it.

Mark @ CLACO

Posted by Stephen Frazza (Member # 2320) on 11-11-2004, 01:02 AM:

Well I took it out and took it apart. I tested the microswitches with a multimeter and the # 2 is shot. So Tim was right.

I looked in Grainger's catalog and i don't think they have this microswitch. So any suggestions as to where as i could pick this up. I searched for it and i could order it online but i was hopeing for somewhere i could just go pick it up at. Thanks guys.

Posted by System Notices (Member # 2357) on 12-12-2006, 05:51 PM:

It has been 761 days since the last post.

Posted by Frank Dubrois (Member # 3042) on 12-12-2006, 05:51 PM:

I have the same issue with a Kelmar Series IV automation. I pulled the automation out, but didnt take the cam out. It sounds like the same problem, so I was wondering, before I take the cam out, where is the motor run switch located? I can't seem to find really good documentation on it and I don't even know what the switch looks like. Thanks!

Posted by Tim Reed (Member # 137) on 12-12-2006, 06:32 PM:

The number 1 microswitch is nearest the cam timer motor. Although, as noted above, the number 2 switch (the hold circuit) is often the culprit.

Posted by Frank Dubrois (Member # 3042) on 12-12-2006, 06:52 PM:

It sounds like the #2 switch. If you hold in the start button, the sound switches, the changeover opens etc...if you just hit the start button, the projector starts, but the cam doesnt move. Where would the #2 switch be? And what exactly am I looking for? Im not real good at reading schematics, but if it is listed there, perhaps I could find it. Like I said, I never removed the cam, so if the switch is hidden under the cam or somewhere unseen, I'll have to look for the switch the day I goto repair it. I assume its a solder job?

Posted by Mark Gulbrandsen (Member # 72) on 12-12-2006, 09:05 PM:

Yuuuuuup! You definately have a bad motor run microswitch. Very common problem with those units. The micros that are made today are just not near the quality they were in the old Xetron units. Those micros last a very long time. Today you're lucky to get 5 years.

Careful there takin that thingy apart. Don't get the cams mixed up and be sure not to accidentally re-adjust the cams and screw up the timming.

The wires to that switch should be part of a nylon plug that just pulls off. Makes it real easy to repair. Number the plugs so you get em back on the correct switches. Check your local electrical supply that stocks Microswitch Brand(made in Fleaport, IL and they will probably have the switch U need.
Mark

Posted by Frank Dubrois (Member # 3042) on 12-12-2006, 10:00 PM:

Well, im a little confused. There are like 6 nylon plugs that plug into the cam, and one going from the motor to the circuit board. I thought there were only 2 switches...since I have 6 (or so) plugs, are there more? The plugs look like they plug into the cam (I only have a front view at this time since I didnt remove it. From the discussion in this topic, I assumed there were 2 switches. Sorry to sound so stupid, but like I said, I havent taken it apart yet simply because I dont have the replacement switch, so I didnt wanna waste the time. I will have order the switch from our distributor since I will need to install it right away and wont have time to go shopping...besides, I dont even know what kind of switch it is. I know I can replace it...not a problem, but finding it is my worry right now.

Thanks for the tips on the plugs..I'll number them before I remove them.

Posted by Louis Bornwasser (Member # 3063) on 12-12-2006, 10:34 PM:

Your dealer can get this quickly. We stock them by the hundreds. Louis

Posted by Frank Dubrois (Member # 3042) on 12-12-2006, 11:02 PM:

Do you have a photo of what one looks like? I just would like to know what I'm looking for.

Posted by Tim Reed (Member # 137) on 12-13-2006, 06:05 AM:

Frank, we're only talking about the switches that control the rotation of the cam timer motor, since that is the problem. Just call Louis and he will send you what you need.

The cam timer unit consists of about 6 or 8 microswitches. The plugs you see in a nice, neat row down the length of the unit are the actual switch connections. Maybe needless to say, but they all have to go back on in the right order. [Wink]

The switches are counted from the motor out. #1 is next to the motor, as mentioned above. #2 is next to #1, and so on.

If you have to hold the start button for a few seconds to get the motor to run by itself, then the #2 switch is likely bad. If the motor does start for a moment when you press the start button, but shortly stops, then it is the #1 switch.

Regardless, it is always best to just replace both of these switches, while you have the unit apart.

Note that dis-assembling a cam timer is not for the faint of heart; there are lots of little pieces and they all have to go back together in exactly the right order. It takes a measure of finesse.

I clear off a large space on a table, to give myself plenty of room to work and stay organized, and get all the new replacement switches together. Start by removing the nuts and the rods that hold the timer together. Begin sliding the cam and switch assemblies apart and set them aside on the table in sequential order. Do not get lost! To keep the whole shooting match from collapsing in your hands, though, I only slide the rods out a little at a time, so I only remove one switch/cam section at a time (or, just start on the end closest to the switch you need to replace, and keep the remaining sections together on the rods).

Once you get the first section off, you will see how the switches are mounted. They just lie in place, really.

Pick a time to do this when you can finish the task at one sitting, without being called away in the middle of the work. Since you have not done this before, I would allot at least an hour, to an hour and a half -- including removal and reinstallation in the automation.

Posted by Frank Dubrois (Member # 3042) on 12-13-2006, 09:41 AM:

Ugh. I didn't know I have to actually take the cam apart to get to each switch. I will replace switch 1 and 2 just to be safe. I appreciate the detailed replacement instructions. Anything else I should be careful of? I want to make sure it goes together ok.

thanks again!

Posted by Mark Gulbrandsen (Member # 72) on 12-13-2006, 10:14 AM:

quote: Louis Bornwasser
Your dealer can get this quickly. We stock them by the hundreds.

I agree its nice to support your dealer but a repair of this nature is important to good presentation and expediting the repair of the cam timer should be done. If a tech were making a call to do this and didn't have the switch in his van then hopefully he'd do the same thing so the customer woudn't have to bear another call expense. The switches are very easy to find locally.

The cams are keyed so they only go together one way. You can use a felt tip pen to number them. For black cams use a grease pencil or white paint pen. Just take your time and don't rush. Its alot easier than it actually looks.

Mark

Posted by Steve Guttag (Member # 268) on 12-13-2006, 10:39 AM:

Take a straight edge as long as the stack of timers are....

Take a Sharpie...hold the straight edge along the timers and mark a continious line so that all of the timer placements are now identified. When you reassemble...so long as you reform your line...all will once again be in time.

Posted by Frank Dubrois (Member # 3042) on 12-13-2006, 10:46 AM:

I think I'll number them and use the straight edge trick. Thanks, that will definately help [thumbsup]

Posted by Mark Gulbrandsen (Member # 72) on 12-13-2006, 11:42 AM:

Good point Steve! That will assure you that none of the timming adjustments are thrown off during repair of the assy.

Posted by Frank Dubrois (Member # 3042) on 12-17-2006, 06:48 PM:

Does anyone know if this automation has to be taken out in order to remove the cam? I am trying to budget time for this repair, and when I looked at it, I remember being able to pull it about 3/4 or so of the way out. I noticed I couldn't quite see how to remove the cam from that postiion. It would be so nice and easy to be able to take the cam out without removing the entire automation. Am I able to do that? I haven't been back there since my first post, so I don't have the luxury of looking it over before I return.

Thanks!!

Posted by Mark Gulbrandsen (Member # 72) on 12-17-2006, 07:27 PM:

Wall mount... No, Console mount... hopefully no if it was installed correctly.

Mark

Posted by Frank Dubrois (Member # 3042) on 12-17-2006, 08:20 PM:

Its a console mount and when I pulled it out, it came out about 3/4 of the way. I couldnt quite see how to get the cam out since it was kind of half in the console, half out. I assume it is held in by screws, and thats what has to be unscrewed..in which case, I'd have to take out the whole automation. Can a board be taken out that brings the cam with it? If not, this is gonna suck.

Posted by Gordon McLeod (Member # 33) on 12-17-2006, 08:32 PM:

Often the wireing harness is tie wrapped without a proper service loop and that can stop things sliding out

Posted by Frank Dubrois (Member # 3042) on 12-17-2006, 10:03 PM:

Everything went very smooth. I appreciate the tips for keeping things in order when taking the cam apart, it certainly helped!! It was switch #2 that was bad. Thanks again!!!

[ 12-19-2006, 02:31 PM: Message edited by: Frank Dubrois ]