Noisy Peco Point Motor

[noctilux2]

Has anyone come across & have a solution for a very loud Peco point motor. Oddly, it is only loud (very) when changed in one direction, the other is perfectly normal / acceptable. Thanks in advance for any help, PS: it does run through a CDU.

[kevinlms]

Has anyone come across & have a solution for a very loud Peco point motor. Oddly, it is only loud (very) when changed in one direction, the other is perfectly normal / acceptable. Thanks in advance for any help, PS: it does run through a CDU.

Is it aligned correctly & centred? My guess is that its slightly twisted, but not enough to prevent it working.

[DCB]

Does the CDU throw more than one point at the same time as this one?

[Gwiwer]

There is some information missing which high make diagnosis easier.

 

1.  What sort of point motor is this?  Is it the surface mount, the clip-in, clip in with extended pin or clip-in low voltage?

2.  Do you have a CDU (Capacitor Discharge Unit) wired into your points power circuit?

3.  Do any other motors display the same problem either all the time or just intermittently?

4.  Are you powering your points by AC or DC current?

5.  How do you control your points (lever, switch, stud contact, computer or something else)

 

Some thoughts.

 

If you are using the surface mounted motor which has a side-pull action these need to be perfectly aligned on the straight side of the point.  They also need to be positioned such that they pull / push perfectly flat (in other words the angle between the point tie-bar and the motor link-arm is exactly 180 degrees) and perfectly horizontal alongside the track (or, if your point is on a gradient, they must perfectly match the angle of gradient).   They are great little motors but don't have a lot of power.  

 

A surface-mounted motor may buzz for a number of reasons.  Typically it is meeting greater resistance in one direction than the other and is working much harder to throw the point which causes the buzz.  Try resettling the motor - sometimes the adjustment needed is less than 1mm to cure the problem.  If you are not using a CDU - and the jury is out on whether they really are essential or not - then the pulse of current to the motor alone might be causing the buzz.  In this case there may be no cure and the reason for it buzzing one way and not the other might lie within the electrickery.

 

A clip-in motor should be perfectly aligned if using Peco track since the locating lugs clip into rectangular slots on the point sleeper base.  It is still possible to fit them misaligned however and to cause them difficulty in throwing in one direction.  That again will cause a buzz.  Check the throw is immediate and smooth in both directions - if it isn't and there is hesitation one way (or even an incomplete throw) then refit the motor correctly as it is out of alignment.  That applies to all version of the underfloor motor but beware the long pin version which sits in its own baseplate.  The length of the pin means there can be a lot more play in the throw mechanism and therefore these motors are very tricky to fit in perfect alignment.  The cause and effect is the same as with the clip-in version; often a slight adjustment to the fitting is needed.

 

If you don't run a CDU then any point motor may buzz seemingly at random; including a CDU ensures a single high pulse of current is fed to the motor to throw the point rather than a longer feed of lower current which might be causing the buzzing.

[kevinlms]

There is some information missing which high make diagnosis easier.

 

1.  What sort of point motor is this?  Is it the surface mount, the clip-in, clip in with extended pin or clip-in low voltage?

2.  Do you have a CDU (Capacitor Discharge Unit) wired into your points power circuit?

3.  Do any other motors display the same problem either all the time or just intermittently?

4.  Are you powering your points by AC or DC current?

5.  How do you control your points (lever, switch, stud contact, computer or something else)

 

Some thoughts.

 

If you are using the surface mounted motor which has a side-pull action these need to be perfectly aligned on the straight side of the point.  They also need to be positioned such that they pull / push perfectly flat (in other words the angle between the point tie-bar and the motor link-arm is exactly 180 degrees) and perfectly horizontal alongside the track (or, if your point is on a gradient, they must perfectly match the angle of gradient).   They are great little motors but don't have a lot of power.  

 

A surface-mounted motor may buzz for a number of reasons.  Typically it is meeting greater resistance in one direction than the other and is working much harder to throw the point which causes the buzz.  Try resettling the motor - sometimes the adjustment needed is less than 1mm to cure the problem.  If you are not using a CDU - and the jury is out on whether they really are essential or not - then the pulse of current to the motor alone might be causing the buzz.  In this case there may be no cure and the reason for it buzzing one way and not the other might lie within the electrickery.

 

A clip-in motor should be perfectly aligned if using Peco track since the locating lugs clip into rectangular slots on the point sleeper base.  It is still possible to fit them misaligned however and to cause them difficulty in throwing in one direction.  That again will cause a buzz.  Check the throw is immediate and smooth in both directions - if it isn't and there is hesitation one way (or even an incomplete throw) then refit the motor correctly as it is out of alignment.  That applies to all version of the underfloor motor but beware the long pin version which sits in its own baseplate.  The length of the pin means there can be a lot more play in the throw mechanism and therefore these motors are very tricky to fit in perfect alignment.  The cause and effect is the same as with the clip-in version; often a slight adjustment to the fitting is needed.

 

If you don't run a CDU then any point motor may buzz seemingly at random; including a CDU ensures a single high pulse of current is fed to the motor to throw the point rather than a longer feed of lower current which might be causing the buzzing.

According to the original post, a CDU is in use.

[noctilux2]

Thanks to all who responded. Problem resolved by slightly realigning this under board Peco motor & connecting a CDU.

[dpgibbons]

Just to add to the knowledge stock - Peco code 55 turnouts; loud buzz in one direction, but eliminated when CDU installed.

 

Diagnosis: armature was not centred fore and aft on tiebar so unable to complete full motion in one direction; shorter impulse from CDU removes power (and hence buzz) before restraint occurs.