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Offline Vaji2021  
#1 Posted : 15 August 2021 15:37:40(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
One of the curved circuit tracks [24194] on my layout is getting stuck and I am wondering if anyone has attempted a repair. The actuator lever gets stuck in one direction but works fine in the opposite direction. Peeking in to the electro mechanical device underneath the track does not show a spring or cam that brings the actuator to it's neutral position. Any one has experience with fixing a circuit track? Please help.

Thanks.

Vaji Nasoordeen.
Offline Mman  
#2 Posted : 15 August 2021 17:59:57(UTC)
Mman

United Kingdom   
Joined: 23/05/2021(UTC)
Posts: 247
Location: England, Guildford
I look forward to seeing any solution to your problem as I have a Z gauge one doing the same thing.
I thought of using a drop of watch oil where the actuator touches the spring contacts but that might just make it stickier.
With Z I fear that simply replacing them is the solution for defective circuit tracks and uncouplers but with HO there should be room for adjustment.
ChrisG
Offline Vaji2021  
#3 Posted : 16 August 2021 01:46:01(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
Chris,

I toyed with the oil idea and abandoned it for the same reason as you. The 24194 will be replaced in due course but till I get a replacement I am trying to keep the layout operational. Let's hope someone on the forum may have attempted a fix and would share their experience.

Vaji.
Offline rhfil  
#4 Posted : 16 August 2021 16:04:50(UTC)
rhfil

United States   
Joined: 05/09/2014(UTC)
Posts: 422
Location: NEW HAMPSHIRE, Somersworth
I worked in hardware retail sales for a number of years and am fairly familiar with the range of lubricants that are available. There are a number of dry spray lubricants that are available that have teflon or graphite. I have recently purchased a teflon one but it still seems to leave an oily film. I have dry graphite that is available in a tube but that can be messy. There is a graphite spray available but I have yet to try it. It is hard to find these days.
The teflon spray I tried is Blaster Chan and Cable Lubrcant. I believe they are also the one that makes the graphite spray.
Any good hardware or building material store should have both of them and the dry graphite. It comes in a small tube and is the recommended lubricant for cylinder locks because it is dry and does not collect dirt.
Offline Vaji2021  
#5 Posted : 16 August 2021 18:06:14(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
rhfil,

In my case, it appears that the sticking in one direction is mechanical in nature in that the actuator does not return to the neutral position. A teflon based lubricant may be a solution but I would hesitate in using graphite as it may cause some conductive spots in a space that one could not get easy access to clean up. I have been experimenting with cut pieces of rubber band inserted into the spaces on each side of the actuator from the bottom and it seems promising. It creates a springy effect and the actuator 'bar' bounces back to it's neutral position. Still in test mode and will post pics once I have got good results. Looking at using a soft eraser to get the right thickness to squeeze into the spaces. Chris may try it on the small Z track item because a simple rubber band may be thick enough to wedge in the spaces on opposite sides of the actuator 'bar' at the bottom.

Vaji.
Offline Mman  
#6 Posted : 17 August 2021 19:34:30(UTC)
Mman

United Kingdom   
Joined: 23/05/2021(UTC)
Posts: 247
Location: England, Guildford
I’v dug out my C track to examine my circuit tracks and whilst the 24994 and 24194 work perfectly the 24294 2nd radius one sticks in one direction.
These HO circuit track pieces are radically different from the Z ones, not just the size but also the contact composition.
The Z ones have exposed contacts with cams on the actuator bar acting to push the appropriate contact closed when a loco travels over. Only locos have the ability to operate them and at crawl speed they will often stop the loco when it touches the actuator. The springyness of the contact returns the actuator bar to the central position when the loco has gone. Sadly my defective Z one seems to have a distorted actuator bar - dimensionally unstable plastic? I’ve already had one of these where the bar simply broke in two where it had become brittle.

The HO ones have sealed micro switches against which a cam on the actuator bar act when a slider goes over the fork piece attached to the bar and the micro switches internal spring provides the impetus to return the actuator to its central position.
As far as I can see - it is not possible to dismantle the HO ones without breaking off two pieces of plastic holding the circuit board in place. The micro switches are mounted under this board. On my defective one the actuator bar is free to move but one of the micro switches seems to have lost its spring pressure.
Micro switches usually last a few million operations but apparently not these ones.
Since I have nothing to lose I will dismantle the defective HO one and report back.
ChrisG
Offline Vaji2021  
#7 Posted : 18 August 2021 02:19:04(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
Hi Chris,

The opening under the 24194 is quite small and I am glad you have been able to peek inside. If you are planning to dismantle it, note that the actuator bar is mounted on a shaft that goes through the two pieces of plastic which acts as the mount and pivot point. The other end of those two mounting plastic pieces seem to be integral with the bottom of the rail bed although I cannot see enough to be sure. So prying it out may ruin the piece. In my case, I am seeking a non-destructive solution till I get a replacement for the 24194. The rubber band strips are about 50% efficient thus far so I am continuing my efforts and will report once I reach the sweet spot.

Regards.

Vaji.
Offline JohnjeanB  
#8 Posted : 18 August 2021 15:17:36(UTC)
JohnjeanB

France   
Joined: 04/02/2011(UTC)
Posts: 3,084
Location: Paris, France
Originally Posted by: Vaji2021 Go to Quoted Post
One of the curved circuit tracks [24194] on my layout is getting stuck and I am wondering if anyone has attempted a repair. The actuator lever gets stuck in one direction but works fine in the opposite direction. Peeking in to the electro mechanical device underneath the track does not show a spring or cam that brings the actuator to it's neutral position. Any one has experience with fixing a circuit track? Please help.

Thanks.

Vaji Nasoordeen.

Hi Vaji

Yes you can open them and fix the delicate mechanism:
- unplug the blue spade female connector
- unscrew the PCB which holds the 2 microswitches
- check / remove the mobile plastic fork that is feeling the slider, it must rotate very freely and not touch the center stud rail
- check the microswitches for any arm molding error or weak force (They are providing the force to return to central position.

NOTES:
- dont do this too often as the two plastic bridges to hold the fork feeler may not stay in place
- when sliders are normally adjusted (pushing not too strong) the slider may take off when coming in contact with the fork feeler

Cheers
Jean
Offline Vaji2021  
#9 Posted : 18 August 2021 15:45:29(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
Thanks Jean for the instructions.

My unit does not have any screws holding the PCB down to the track. I don't see any plastic pins either where the PCB could be press fitted to the track. The two blue female spade connectors seem to be soldered to the underside of the PCB. Shall poke around some more. It is still integral to my layout so progress is slow on a fix. Those plastic bridges look pretty delicate.

Best regards,

Vaji.
Offline Mman  
#10 Posted : 18 August 2021 16:25:48(UTC)
Mman

United Kingdom   
Joined: 23/05/2021(UTC)
Posts: 247
Location: England, Guildford
image.jpgMy C track circuit tracks don’t have screws holding the circuit board in place either. Two plastic bridges hold the circuit board down and they also form part of the pivot holes for the actuator bar. My C track is at least 20 years old, perhaps later examples are different.
ChrisG
Offline JohnjeanB  
#11 Posted : 18 August 2021 22:08:10(UTC)
JohnjeanB

France   
Joined: 04/02/2011(UTC)
Posts: 3,084
Location: Paris, France
Hi
My mistake
My units are also exactly like Chris' picture thanks for this).
So unplug the spade connector
pull gently the PCB out.
Doing this will pull out the 2 brown plastic holding both the PCB and the fork feeler
When putting the PCB back, don't use brute force but instead move the fork feeler back and forth so it will engage properly with the switch levers
So no screws there Sorry
Cheers
Jean
Offline Vaji2021  
#12 Posted : 19 August 2021 15:22:19(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
Thanks Chris and Jean.
I was wanting to post a picture myself but did not know how to do that in a 'quick reply' mode. Anyway, Chris your picture is worth a thousand words! My trial fix involves placing a piece of a rubber band folded into a u-shape and wedged in the right upper most corner of the rectangular cutout on the PCB [my contact functions well on one side, so the rubber 'spring' is placed on the other side]. It is not a stable solution but it is responding with about 50% success. I want to try it with a soft foam that will go as a square block into that space and give a gentle spring effect so as not to make it hard on the locomotive to traverse over the contact lever.

Regards Jeans suggestion, I cannot see how the PCB is held down to the track bottom other than the two plastic bridges that house the mechanism. Marklin normally provides plastic spigots to mount their decoders etc. but in this case I do not see any. The three small holes and the two large holes on opposite ends of the PCB do not give up any clue of how one could get under that PCB. They may be a part of the electronics.

Anyway, this is just a hobby and till I get a replacement, I will play with it!
Offline Vaji2021  
#13 Posted : 22 August 2021 18:48:42(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
I have to report success in my efforts to fix the sticky 24194 in a non destructive manner. I have a picture which I do not know how to attach to this note. Basically I inserted small pieces of rubber band at two locations of the sticking side. If I use Chris's picture to describe, the rubber pieces went into the left side of the 'pivot bar' on the lower left and middle left spaces. This gives it a fair bounce back and after running a lok over it many times, I get about 80% returns to neutral position. So I can live with that and some tweaking on actions connected to this circuit track.

Hope someone can improve on this further. Not a substitute for a replacement but serves the immediate operating needs of the layout.

Thanks for all the suggestions.

Vaji.
Offline river6109  
#14 Posted : 23 August 2021 07:00:25(UTC)
river6109

Australia   
Joined: 22/01/2009(UTC)
Posts: 14,636
Location: On 1965 Märklin Boulevard just around from Roco Square
I've fixed quite a few of them but its an art work to repair them or to align them correctly, the best way of doint it, you have to take the the 2 tongues out and lokking at the angle they are in but you have to have one that is working correctly, by comparing them you than have to adjust the angle and put them back together.
Unfortunately with these tongues its no good just aligning one of them as you will find the other one will not work properly.
On my layout there are only 8 left and most probably I will replace them to with opto couplers, I couldn't afford it on my layout for these contact tracks not to work 100 % os in due course I've taken them all out and I'm quite happy with the optocouplers I've introduced and they fit nicely between sleepers and work only with a maximum hight of 8mm and are activted via the slider.
the newer ones with micro switches, its the same dilemma, the switches who ever solderd the wire onto it, used a soldering iron with a to high temperature and this in turn weakend the inside copper contact and therfore the plastic lever doesn't return to its supposed to be position., you can buy these switches and I've replaced them and they're working fine now kepping in mind not to have a soldering iron with its temerature to high

both designs have design faults.

John
https://www.youtube.com/river6109
https://www.youtube.com/6109river
5 years in Destruction mode
50 years in Repairing mode
Offline Vaji2021  
#15 Posted : 23 August 2021 18:22:39(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
20210820_143605.jpg

Please note that the circuit track is functioning close to 100% after several runs over it. The rubber bands will stay in place for a long time as they cannot drop out or deteriorate in a hurry.

Vaji.
Offline Vaji2021  
#16 Posted : 29 August 2021 02:09:30(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
Just a follow up report on the rubber band fix. The 24194 has been working flawlessly for more than a week of operations. So I think the fix can be confirmed as being successful.

Regards.

Vaji.
thanks 2 users liked this useful post by Vaji2021
Offline river6109  
#17 Posted : 29 August 2021 10:11:46(UTC)
river6109

Australia   
Joined: 22/01/2009(UTC)
Posts: 14,636
Location: On 1965 Märklin Boulevard just around from Roco Square
Although you may have fixed the problems I don't think Märklin will supply an extra 2 rubber bands to overcome a faulty switching track., the money we pay for it should be fault free.

Märklin seems to design a module or part that hasn't been fully tested or being approved by an expert, we had several different version of a soleniod motor with very little success d everytime the use these micro switches they create another problem for themselves and all their customers.

by the way it is not a circuit track but a switching track

John
https://www.youtube.com/river6109
https://www.youtube.com/6109river
5 years in Destruction mode
50 years in Repairing mode
Offline Mman  
#18 Posted : 29 August 2021 10:42:23(UTC)
Mman

United Kingdom   
Joined: 23/05/2021(UTC)
Posts: 247
Location: England, Guildford
Originally Posted by: river6109 Go to Quoted Post
Although you may have fixed the problems I don't think Märklin will supply an extra 2 rubber bands to overcome a faulty switching track., the money we pay for it should be fault free.

Märklin seems to design a module or part that hasn't been fully tested or being approved by an expert, we had several different version of a soleniod motor with very little success d everytime the use these micro switches they create another problem for themselves and all their customers.

by the way it is not a circuit traclk but a switching track

John


Strange that Märklin translated ‘Schalt’ as ‘circuit’ since the literal translation is ‘switch’.
The French description on the box translates as ‘(straight) remote control track/rail’.
Usually their English translations are good (but US English).
ChrisG
Offline river6109  
#19 Posted : 29 August 2021 10:57:52(UTC)
river6109

Australia   
Joined: 22/01/2009(UTC)
Posts: 14,636
Location: On 1965 Märklin Boulevard just around from Roco Square
Originally Posted by: Mman Go to Quoted Post
Originally Posted by: river6109 Go to Quoted Post
Although you may have fixed the problems I don't think Märklin will supply an extra 2 rubber bands to overcome a faulty switching track., the money we pay for it should be fault free.

Märklin seems to design a module or part that hasn't been fully tested or being approved by an expert, we had several different version of a soleniod motor with very little success d everytime the use these micro switches they create another problem for themselves and all their customers.

by the way it is not a circuit traclk but a switching track

John


Strange that Märklin translated ‘Schalt’ as ‘circuit’ since the literal translation is ‘switch’.
The French description on the box translates as ‘(straight) remote control track/rail’.
Usually their English translations are good (but US English).
ChrisG


Google translate: Schaltgleis = Switching track,

US English= anything could happen

https://www.youtube.com/river6109
https://www.youtube.com/6109river
5 years in Destruction mode
50 years in Repairing mode
Offline Vaji2021  
#20 Posted : 30 August 2021 03:02:57(UTC)
Vaji2021

Sri Lanka   
Joined: 18/02/2021(UTC)
Posts: 17
Location: Western Province, Colombo
John, All,

I think M knows that as hobbyists, we enjoy tinkering with their products. So they may be introducing some weak design aspects to let us entertain ourselves <in jest!>. One day I am hoping that I can meet their design engineers and offer some suggestions of how to make robust products. Their strong suit is their locomotive design but they can improve in their accessories department.

Regards.

Vaji.
thanks 2 users liked this useful post by Vaji2021
Offline hxmiesa  
#21 Posted : 30 August 2021 07:20:34(UTC)
hxmiesa

Spain   
Joined: 15/12/2005(UTC)
Posts: 3,519
Location: Spain
Brown rubber bands turn to glue/goo in some years. I´m not sure this is a good solution. Sorry.
Best regards
Henrik Hoexbroe ("The Dane In Spain")
http://hoexbroe.tripod.com
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