Welcome to the forum   
Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Share
Options
View
Go to last post in this topic Go to first unread post in this topic
Offline C Ridout  
#1 Posted : 17 March 2018 18:43:26(UTC)
C Ridout

United Kingdom   
Joined: 10/03/2018(UTC)
Posts: 9
Location: England, Yateley
My 37020 BR53 is jamming with every revolution of the drive wheels. The rear 2 wheels get jammed at the same point in every revolution. I have taken the body off and tried to work out what is causing the problem but it is not immediately obvious.

The miniature cogs between the driving wheels are what I suspect is the problem but I cannot be sure. It's almost as if the rear miniature cog is locking the 2 rear drive wheels. Something is perhaps not aligned properly, although it looks ok. Has anybody else had this problem? If so, what was the fix.

The motor is spinning freely and appears to be ok.

I may send it back to M if I cannot get it working properly and freely.
Offline franciscohg  
#2 Posted : 17 March 2018 19:22:10(UTC)
franciscohg

Chile   
Joined: 10/07/2002(UTC)
Posts: 3,265
Location: Patagonia
It might be a quartering problem with the drive wheels.
Although it can be fixed at home, it is not very easy.
Regards
UserPostedImage German trains era I-II and selected III, era depends on the mood, mostly Maerklin but i can be heretic if needed XD, heresy is no longer an issue.. LOL
thanks 2 users liked this useful post by franciscohg
Offline Webmaster  
#3 Posted : 17 March 2018 19:51:28(UTC)
Webmaster


Joined: 25/07/2001(UTC)
Posts: 11,161
I had something similar on my BR45, every turn of the main wheels there was a jam... And a barely audible "click" when it got loose again..

In my case, it was valve gear rods touching each other on one side and a small bend adjustment of the offending rod fixed the problem.
Juhan - "Webmaster", at your service...
He who asks a question is a fool for five minutes. He who does not ask a question remains a fool forever. [Old Chinese Proverb]
Offline C Ridout  
#4 Posted : 17 March 2018 20:37:36(UTC)
C Ridout

United Kingdom   
Joined: 10/03/2018(UTC)
Posts: 9
Location: England, Yateley
Originally Posted by: franciscohg Go to Quoted Post
It might be a quartering problem with the drive wheels.
Although it can be fixed at home, it is not very easy.
Regards


I think you may be right. I have taken apart the connecting rods on both sides and the wheels are turning and running smoothly without the connecting rods. I have discovered that on the 4th wheel the alignment is not quite correct. One of the wheels is a few degrees out of alignment and I am hoping that this is the cause.

It won't be easy to fix as the wheel needs to move on the axle a few degrees.

Many thanks.
Offline C Ridout  
#5 Posted : 17 March 2018 20:39:30(UTC)
C Ridout

United Kingdom   
Joined: 10/03/2018(UTC)
Posts: 9
Location: England, Yateley
Originally Posted by: Webmaster Go to Quoted Post
I had something similar on my BR45, every turn of the main wheels there was a jam... And a barely audible "click" when it got loose again..

In my case, it was valve gear rods touching each other on one side and a small bend adjustment of the offending rod fixed the problem.


The valve gear rods have been disconnected so I could eliminate them as the cause. I just have to make sure that they go back in the right order.

Thanks.
thanks 2 users liked this useful post by C Ridout
Offline Webmaster  
#6 Posted : 17 March 2018 22:24:16(UTC)
Webmaster


Joined: 25/07/2001(UTC)
Posts: 11,161
Could be as simple as some grit in the gears?
Juhan - "Webmaster", at your service...
He who asks a question is a fool for five minutes. He who does not ask a question remains a fool forever. [Old Chinese Proverb]
Offline jvuye  
#7 Posted : 17 March 2018 23:05:08(UTC)
jvuye

Belgium   
Joined: 01/03/2008(UTC)
Posts: 2,881
Location: South Western France
I've seen a lot of these in my (long) Märklin repairman career. Wink
People try to turn the wheel by pushing them with a finger, and they get out of square.
That simple!

It almost always happens on the last driving axle, the one with the rubber tyres.

One should **never** do that , unless he removes the brushes first to free up the mechanism.

There is only one durable solution: have a new wheel properly installed using a quartering tool and a wheel press.

Alternatively when proper new wheels were no longer available, I'd remove the off-sync one from the axle (with a wheel puller) and I'd lightly knurl the axle (on a lathe) to give it a new "grip"
Works well and is as good as new...until someone repeats the wrong handlingRollEyes Wink

But you can try the following, since you've taken the rods off already:

1° remove the brushes
2° check , with the position of the counterweight which driver is off and in what direction
3° try to twist the offending wheel (probably on the side without the gears) back into sync with the other 3.
4° If the wheel is not too loose and stays in place, reassemble the rods and test

Good luck

Jacques
Jacques Vuye aka Dr.Eisenbahn
Once a vandal, learned to be better and had great success!
thanks 2 users liked this useful post by jvuye
Offline C Ridout  
#8 Posted : 17 March 2018 23:38:33(UTC)
C Ridout

United Kingdom   
Joined: 10/03/2018(UTC)
Posts: 9
Location: England, Yateley
You are right. It was the last driving axle with rubber tyres which was slightly out of alignment.

It is now running much better although still not perfect, especially in reverse.
Offline C Ridout  
#9 Posted : 18 March 2018 11:06:05(UTC)
C Ridout

United Kingdom   
Joined: 10/03/2018(UTC)
Posts: 9
Location: England, Yateley
Originally Posted by: jvuye Go to Quoted Post
I've seen a lot of these in my (long) Märklin repairman career. Wink
People try to turn the wheel by pushing them with a finger, and they get out of square.
That simple!

It almost always happens on the last driving axle, the one with the rubber tyres.

One should **never** do that , unless he removes the brushes first to free up the mechanism.

There is only one durable solution: have a new wheel properly installed using a quartering tool and a wheel press.

Alternatively when proper new wheels were no longer available, I'd remove the off-sync one from the axle (with a wheel puller) and I'd lightly knurl the axle (on a lathe) to give it a new "grip"
Works well and is as good as new...until someone repeats the wrong handlingRollEyes Wink

But you can try the following, since you've taken the rods off already:

1° remove the brushes
2° check , with the position of the counterweight which driver is off and in what direction
3° try to twist the offending wheel (probably on the side without the gears) back into sync with the other 3.
4° If the wheel is not too loose and stays in place, reassemble the rods and test

Good luck

Jacques


You are very knowledgeable about this topic and it has has been a great help.

I see that you remove the motor brushes as well when testing. Why do you do this?
Would you ever put Loctite onto an axle to hold the wheel in the correct position?

I use adhesives for quite a few engineering applications in the aviation industry and this is a similar.

Thanks.
Offline jvuye  
#10 Posted : 18 March 2018 17:19:30(UTC)
jvuye

Belgium   
Joined: 01/03/2008(UTC)
Posts: 2,881
Location: South Western France
Originally Posted by: C Ridout Go to Quoted Post

You are very knowledgeable about this topic and it has has been a great help.

I see that you remove the motor brushes as well when testing. Why do you do this?
Would you ever put Loctite onto an axle to hold the wheel in the correct position?

I use adhesives for quite a few engineering applications in the aviation industry and this is a similar.

Thanks.


Hi
The brushes exercise quite a lot of friction on the motor, which with the the demultiplication brings a considerable resistance if you try to turn the mechanism pushing on the wheels.
The force can be too much for the wheels/axle pressfit assembly, and this is why your wheel is probably out of quarter.

If you still wnat or need to do this, at least try on the gear's side, but only if the gear is an integral part of the wheel;
But older locos had wheels without integrated gear and separate gear mounted on the axle, and you should never really try to turn the wheels without first removing the brushes.

As for loctite, I tried it in the early days but it doesn't hold.
I don't see how it can be applied in a way that will guarantee durable assembly.
(But if I don't see it, doesn't really mean it can't be done. I just don't know how!Wink Smile )

As I said knurling of the axle or new parts are the only durable solutions I personally recommend

Hope this helps

Jacques Vuye aka Dr.Eisenbahn
Once a vandal, learned to be better and had great success!
thanks 1 user liked this useful post by jvuye
Users browsing this topic
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

| Powered by YAF.NET | YAF.NET © 2003-2024, Yet Another Forum.NET
This page was generated in 0.574 seconds.