Film-Tech Forum ARCHIVE: Strong/Potts platter microswitch

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Posted by Jason Black (Member # 684) on 01-14-2004, 09:43 AM:

For some of you 'in the know' moreso than myself, I pose this quesion..

I called one of my suppliers this morning to find out if the 12 microswitches I rec'd this morning had the .1 or .5 oz spring in them. He stated that there shoudl not be a spirng in them at all, but he would call the manufacturer and check the specs.

This is the info printed on the switch in front of me...

A-20GV-B7-K (Made in Japan)
20A 120/250/480V
1HP.125VAC
2HP 250VAC
1/2A 125VDC
1/4A 250VDC

I hope that I'm not mistaken in the fact that this is suppposed to have a spring loaded return mechanism....

Anyone?

Posted by Ken Layton (Member # 133) on 01-14-2004, 09:59 AM:

You have the .5 switch. Be sure to pop the spring out from under the lever and discard the spring.

For everyone's info here is the switch cross reference from Grainger's:

Omron # A20GV-B7-K is Grainger # 6X289 (around $6.50)

Omron # Z15GW-B7-K is Grainger # 6X284 (around $6.25)

Posted by Jason Black (Member # 684) on 01-14-2004, 10:59 AM:

Ken,

Thanks for the info. From now on, I'll get these locally at Graingers. I'm paying $12.50/each right now from my vendor.

BTW,
Shoudl the spring be visible? I don't recall seeing a spring situated under the paddle/trigger mechanism...

Posted by Ken Layton (Member # 133) on 01-14-2004, 11:36 AM:

As they come new out of the box there is a spring under the lever. Maybe your vendor already removed the spring?

Posted by Jason Black (Member # 684) on 01-14-2004, 05:17 PM:

This could be the reason they stated that there was not supposed to be a spring in the first place.

His comment makes more sense now...

Thanks Ken!

Posted by Chris Hipp (Member # 1788) on 01-15-2004, 12:49 AM:

I might be sounding stupid here but which micro switches are you replacing? I have strong platters and in 2 years have not had one go out. The platters are about 6 years old.

Posted by Tom Wienholt (Member # 1510) on 01-15-2004, 01:22 AM:

The microswitch on the center-feed.

Posted by Michael Schaffer (Member # 1204) on 01-15-2004, 03:52 AM:

Chris - some of these control plates have an optical control unit which they call "phase control". You can see the LED, photocell and phase mask when you look inside the little black box. Maybe you have these.

Posted by Chris Hipp (Member # 1788) on 01-15-2004, 10:07 AM:

Yeah, I have the brains with the leds/solar cell

Posted by Robert D. LaValley (Member # 1867) on 01-18-2004, 06:36 PM:

Can you upgrade from micro-switches to leds and solarcells on potts platters?

Posted by Paul G. Thompson (Member # 655) on 01-18-2004, 06:40 PM:

Robert, I did.....I used a Phase control with the CFS (same as the older Potts) and it works great. However, you have to be very careful about platter timing if the other dishes are still on Micros.

Posted by Dustin Mitchell (Member # 372) on 01-18-2004, 10:38 PM:

Depending on the cost of the phase control boxes it seems it would make sense for those replacing micros every 18 months to upgrade. Not only are phase controls more reliable they also give a smoother payout.

Posted by Gordon McLeod (Member # 33) on 01-18-2004, 10:41 PM:

I prefer the micro switch to this day
less grief and fewer thrown prints

Posted by Ken Layton (Member # 133) on 01-18-2004, 10:43 PM:

Robert:

Yes, there is an upgrade kit to change the micro switch control plate to a phase control. It's part number 2430 (sells for around $120 list price) and it does one control plate. I would advise you to change all control plates on a platter over to phase control. Don't mix 'n match microswitch and phase control plates on the same platter system or you'll have motor timing problems. The kits can be purchased thru any Strong/Potts dealer.

Posted by Gordon McLeod (Member # 33) on 01-18-2004, 11:46 PM:

Also some of the motors have the diode in reverse polarity for use with the pahse control and then they will not work

Posted by Mark Gulbrandsen (Member # 72) on 01-19-2004, 11:44 PM:

I've always considered the Phase Control on the Potts or Strong a big time downgrade! The drive motors timming drifts around way to much for them to be very stable over the long haul. You will always be tweeking! Converting over to the micros with .5 oz tension is far more reliable and provides very smooth payout.
Mark @ CLACO

Posted by Dustin Mitchell (Member # 372) on 01-19-2004, 11:58 PM:

Thanks for the advice Mark. At $120 a pop for the phase control boxes its more economical to stick with microswitches too.

Posted by Mark Gulbrandsen (Member # 72) on 01-20-2004, 12:00 AM:

Yea, just be sure to replace them every 18 months to two years...even if they are still working. Those Honeywells are only good for so many clicks ya know. As I say the last click is it!
Mark

Posted by Michael Schaffer (Member # 1204) on 01-20-2004, 12:02 AM:

Do all motors generally have the diode in reverse for the phase control version? There seems to be a general consensus here (and how rare is that!) that the o.5 oz tension microswitch solution is the way to go. I have 2 locations with phase control (16 systems) and 2 with the microswitch (14 systems). Given the insubstantial costs for the microswitches, it seems like a good idea to convert them all.

Posted by Dustin Mitchell (Member # 372) on 01-20-2004, 12:51 AM:

Are you having problems with your phase controls? If not just leave them in there. The six platters I'm running with phase controls work just fine. Once and a while they will drift (rarely from what I've experienced) but unlike microswitches when something goes wrong its not catastrophic.

Posted by Michael Schaffer (Member # 1204) on 01-20-2004, 01:14 AM:

Hard to say. A lot of the brainwrap and throwing problems we had were because the platters hadn`t been timed in years, and because of operator carelessness. Timing and training the operators has gotten rid of the vast majority of these situations, but it seems to me that the microswitches - even though none of them has been changed in many years, I am sure - seem to be a little less problematic. I haven`t formed a definitive opinion yet, but I follow this discussion with great interest. Another factor is that we have tons of messed up brains (control plates) lying around in the parts rooms, and if it makes sense to standardize our brain situation along with repairing these, I would lean towards that solution.

Posted by Chris Hipp (Member # 1788) on 01-21-2004, 07:52 PM:

quote:
Thanks for the advice Mark. At $120 a pop for the phase control boxes its more economical to stick with microswitches too.

I would have to disagree with that. Let's say that you have twenty brains and you replace all twenty microswitches every two years for ten years. $6 x 2 brains x 5 years= $600 Vs a one time upgrade of $120.

I think it depends on how many platters you have and how long you plan to keep them.

In the past 3 years that I have been in booth I have never had a payout card go bad. Anyone have an idea of how long they generally last?

[ 01-21-2004, 11:35 PM: Message edited by: Chris Hipp ]

Posted by Jason Black (Member # 684) on 05-14-2004, 11:23 AM:

Just ordered replacement switches thru Grainger. I paid $4.27@ for 32 pieces.

I ordered Omron # Z15GW-B7-K is Grainger # 6X284. These required removing the spring. All seems well with regard to proper tensioning once installed.

These are FAR cheaper than the Strong units and are available to order at a local Grainger branch, or online.

Posted by John T. Hendrickson, Jr (Member # 849) on 05-14-2004, 05:30 PM:

Jason-

Would you happen to have that Grainger website address?

Posted by Steve Kraus (Member # 476) on 05-14-2004, 05:50 PM:

http://www.grainger.com/

Use the pulldown menu at top center to indicate you are searching by Grainger Item Number and plug 6X284 into the search field just to the right, then click Go.

Posted by Mark Gulbrandsen (Member # 72) on 05-14-2004, 06:48 PM:

Bong sounds......

Well thats the wrong microswitch!! The .98oz Omron switch would be the closest that Grainger sells to the original Microswitch. These are also inferior to the Microswitch version!! The Microswitch version is rated for twice the life span(or number of on-offs) of the Omron!! But if your a chaaepskate go ahead and get the Omrons, the Microstitch is only about 4 bucks give or take more from a wholesaler.

FYI: With the .5oz Microswitch version you can barely hear thre switch click when it turns on and you might mistale it for a bad switch. Contact your local Electrical Supplly that handles Microswitch as they will be able to get em for you..... At least in a while as Microswitch is now out of them as well.

Here is a link to the correct switch. Just remove the little spring under the bat for .5oz activation tension.

http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=basicswitches&PN=BZ-2RW84-A2

Mark @ CLACO

Posted by Matt Hefright (Member # 2470) on 06-21-2004, 11:48 PM:

so then the grainger switch #6X284 is the incorrect one. can that switch be modified without any problems to the show? where can the correct switch be purchased then? ( not the honeywell )

Posted by Paul G. Thompson (Member # 655) on 06-22-2004, 01:19 AM:

Maybe a conversion to a set of 1964 Dodge Dart modified breaker points would be in order. Those never failed.

The only thing that seemed to fail on those old Potts and CFS platters that used them was the ancillary stuff...

...namely that goofy sloppy hunk of plastic that was called a pay-out arm (which had a 1/4-inch allen screw that would practically electrocute the operator if he/she touched it) that would work correctly after it was firmly re-seated with smart blow from the heel of the operator's hand on a regular basis.

[puke]

You older fellows that ran those darned things know exactly what I am talking about. [Big Grin]

But all in all, just give me a good condition Strong A-3 with micros, and I know I can walk away from those things without fear of them tossing a print or grinding up film.

Posted by Jack Ondracek (Member # 1466) on 06-22-2004, 01:27 AM:

quote: Paul G. Thompson
Maybe a conversion to a set of 1964 Dodge Dart modified breaker points would be in order. Those never failed.

...works for me! [thumbsup]

Posted by Mike Babb (Member # 1379) on 08-16-2004, 07:34 PM:

Just shopping around online for these and I was wondering:

Ken's post in response to a question:
Omron # A20GV-B7-K is Grainger # 6X289 (around $6.50)
A-20GV-B7-K (Made in Japan)
20A 120/250/480V
1HP.125VAC
2HP 250VAC
1/2A 125VDC
1/4A 250VDC

From reading the posts it seems like this one is the right one. It says 2.5 oz operating force and .50 release. Does the 2.5 rating include the spring and without we're back to .50?

Also in Mark's posts, while he seems to prefer the honeywell brand, the grainger switch he recommends at .98 oz is a 3XG54, his .98 and me looking up and getting the grainger number based on that, I don't want to misquote him.

And finally, what is a 6X284 and how does it relate to this?

The photos on the grainger page all show the same numbers on the switches...

Thanks!

Posted by Mark Gulbrandsen (Member # 72) on 08-16-2004, 08:16 PM:

Ideally what you want is a micro with a .5 oz on force, even I'm not sure why I would reccomend a .98 oz force micro. The .5 oz works out better for estar base film and the film will not wrap back around the P.O.H. at all. In fact it feeds out so smoothly with the .5 oz switch that one would think its linear feed.

Here is a link to pretty much the switch we use although I'm not 100% sure this is the exact number. Just pop out the spring under the lever and you have a .5 oz actuation micro switch.

http://catalog.sensing.honeywell.com/datasheet.asp?PN=BZ-2RW8244-A2

Tommrrow when I'm at work I'll look at one for the exact Honeywell number and post it here. We get them in 100 quantity from a local Electrical Distributer thats the Honeywell Distributor for this area.

Mark @ CLACO

Posted by Ken Layton (Member # 133) on 08-16-2004, 11:11 PM:

The 6X284 is a 15 amp version of the 6X289. Specs are the same except for contact rating.

Posted by Mark Gulbrandsen (Member # 72) on 08-17-2004, 11:36 AM:

The Honeywell number for the switch is BZ-RW8435-A2 for those that are interested. Remove the spring under the lever before using them. Link to data sheet....
Link

Mark @ CLACO

[ 02-12-2007, 12:25 PM: Message edited by: Adam Martin ]

Posted by John A. Parker Jr. (Member # 1719) on 08-17-2004, 08:06 PM:

I ordered the exact switch from Newark. Their part no. is

23f2293. The cost per switch is 4.82 each.

Also if you put a 10 ohm 25 watt resistor across the switch,

It will last longer because of less inrush current.

John A. Parker Jr.

Posted by Mike Babb (Member # 1379) on 08-18-2004, 06:02 PM:

John, doing a little searching online I found the switch you mentioned isn't the same as Mark's switch. The contact rating is 4 amps.

The one Mark listed is in the Newark catalog as 23f4062. $14.37 and discounts in larger quantities.

Sorry to beat this topic to death, I just want to make sure I find the right one because we have these platters all over our area. We've used some Honeywells and some Omrons and I appreciate the feedback from everyone.

Posted by System Notices (Member # 2357) on 02-12-2007, 11:00 AM:

It has been 907 days since the last post.

Posted by Barry Floyd (Member # 385) on 02-12-2007, 11:00 AM:

I need to replace the microswitches on 2 of my Strong AP3 platter brains. Reading thru the posts above, the Grainger switch is "close" but not exact?

How hard are these to install?

Posted by Dennis Benjamin (Member # 1137) on 02-12-2007, 12:35 PM:

Not hard at all.....

Posted by Dustin Mitchell (Member # 372) on 02-12-2007, 12:41 PM:

If you buy a non-stock microswitch I believe you need to remove the spring, I am not sure though. That info is either in a post or Mark G. will be along shortly to let us know.

Anyhow, as Dennis said, very easy. Just put it back together the way you took it apart. You'll need to make sure the microswitch is aligned properly, so before you tighten it down you'll have to shift it around a bit. The right alignment will be when the blade 'clicks' to have the arm of the brain at the midpoint of its right-left travel.

Hope that made sense.

Posted by Louis Bornwasser (Member # 3063) on 02-12-2007, 01:26 PM:

Even with the spring removed, I have not found an "acceptable" replacement; too stiff. Louis

Posted by Mark Gulbrandsen (Member # 72) on 02-12-2007, 06:09 PM:

Louis,
There is a pretty acceptable switch made by Honeywell that I pointed out above that allows the platter to feed unbelievably smooth..at least this is as good as they get working from a stock switch. Lifespan has been about two years on them. It has about 1/4 the amount of spring tension as the normal switch from Strong, and about 1/4 the price in 100 quantity. My sucess with them has been 100%. The main thing though is that are these platters even acceptable at all [Wink]

????

Mark

Posted by Monte L Fullmer (Member # 2797) on 02-12-2007, 11:43 PM:

I must replace a good amount of switches each year since I've got 32 A(P)-3 units and 64 brains to tend to ...

..but, that's good to know about the surge resistor to put across so I can make these switches last longer

(dang, I know all about the ying and yang about phase control brains, but love them ten times better than microswitch brains any day of the week....)

Monte

Posted by Dustin Mitchell (Member # 372) on 02-13-2007, 10:10 AM:

I agree Monte, I know some here have had problem with phase controls but since replacing most of the carbon switches on my alpha platters almost 7 years ago I haven't had a single phase control fail. If I was buidling a new cinema and was going to use Strong platters (not a given mind you) I think I'd use phase controls despite the extra expense. Even with regular replacement you're going to have a microswitch fail early/get stuck and cause a brainwrap once in a while.

Posted by Marc Hansen (Member # 705) on 02-13-2007, 10:17 AM:

If you are running phase control platters and you have a phase control fail can you drop a microswitch payout in its place? Would you have to adjust/retime the platter?

Posted by Mark Gulbrandsen (Member # 72) on 02-13-2007, 12:23 PM:

quote: Marc Hansen
If you are running phase control platters and you have a phase control fail can you drop a microswitch payout in its place? Would you have to adjust/retime the platter?

Yes you can retrofit if you get the hardware kit to install the micros from Strong, part number is 3610. The hardware kit is very inexpensive. The Phase Control is one of the worst control devices anyone ever came up with excepting the carbon switch. I converted 6 platter systems to micro a couple of weeks ago. Time what.... if you time it today it will be different tommrrow. Thats the main reason the Phase Controls don't work well. I have weeded out most of the phase control modules in my service area and doing so has made my customers VERY happy.

Mark

Posted by Marc Hansen (Member # 705) on 02-13-2007, 04:33 PM:

Actually what I meant was if I had a phase control fail during a show could I drop in a microswitch payout and finish the show?
Marc

Posted by Mark Gulbrandsen (Member # 72) on 02-13-2007, 04:52 PM:

Yes. Its best to phase them out as they fail though.

Mark

Posted by Steve Guttag (Member # 268) on 02-13-2007, 06:20 PM:

We too are generally replacing phase controls with micros unless the customer insists on staying with the phase controls.

Posted by Monte L Fullmer (Member # 2797) on 02-13-2007, 09:05 PM:

(Sorry to make a small issue in standing up for the phase control brains is that you can tell that I'm seriously spoiled with platter that have continual rotation and smooth ramping payouts - like the SPECO LP-270s and the Christie AW series being the other two units that I've worked with - instead of the "OFF/ON" style of microswitched platters.)

Truthfully, the microswitched platters are more forgiving to current variances since all three platters depends on a simple variac to control the entire system, whereas the other makes have the independently controlled decks with more complicated electronics to operate such. Thus, the microswitch brain is actually the way to go for such current variances.

Bottom line is that if the STRONG decks are timed well with motors in an approx. line of speed, I'm not really complaining about using microswiched brains - as long I make sure that whoever works with these brains don't get finger happy and bending the tang on the switch when pulling the brain out of the center.

Posted by Ken Lackner (Member # 1002) on 04-19-2007, 06:15 PM:

What makes the Honeywell switch (BZ-RW8435-A2) so much better than the Omron (A20GV-B7-K)? The Honeywell switch at Newark is about 4 times the list price of the Omron at Grainger. Mark, which switch would be the "normal switch from Strong?"

Posted by Louis Bornwasser (Member # 3063) on 04-19-2007, 09:05 PM:

Remember the carbon piles? They were "less successful" than the phase controls. Louis

Posted by Mark Gulbrandsen (Member # 72) on 04-19-2007, 10:40 PM:

quote: Ken Lackner
Mark, which switch would be the "normal switch from Strong?"

The Hioneywell would be the normal one, they are more expensive cause they are still made in the gold ole USA.

I use BZ-RW8435-A2. Its suited better for ESTAR film.

Yea, those Carbon Piles... I just removed a set of those someplace within the last year but can't remember where... I was amazed they still did anything this late into life...

Mark

Posted by John T. Hendrickson, Jr (Member # 849) on 04-24-2007, 09:19 AM:

I have been ordering replacements from Allied Electronics. You can find this switch on pg 970 of their 2007 catalog. Price is up a little from last year. They go for $10.91 ea. in small quantities.

You may find better pricing if you want to take the time to shop around. When my inventory gets low, I just order them, since only 5 of my platters are microswitches.