Aristocraft No 6 swtch/point problem - momentary pause as locos traverse the switch/point

[beavercreek]

Don't know if anyone has had this prob. Installed a no 6 (#6) switch/point on the layout and it has the Aristocraft live frog microswitch control to change polarity when a loco runs over it. It is causing the loco to pause momentarily as it traverses it (using either branch but worse on the main path). Have checked all the connections, current path etc but cannot come up with the reason. It happens with any length loco and any species but is markedly more noticable with shorter locos due to the pickup having a shorter wheelbase and the momentum not being as much. When at very slow speeds it is really a problem, sometimes even 'stalling' the smaller locos. The only thing that I can think is that the microswitch has become 'lazy'.
Any similar experiences would help to fathom out what is going on here.

 

[minimans]

I think it more likely the micro switch has dirty contacts, they don't make clean contact but enough that your multimeter shows voltage but when you apply a load ie. A loco it will not allow any amps, therefore stops the loco the heavy current draw will then burn through the dirt makes a contact and off it goes....................
On my Rolls-Royce advanced electrical course it was made clear that you should always check volts and amps with the expected draw applied as without load all sorts of erronious figures can appear!

 

[beavercreek]

Many thanks Paul. I thought it might be the microswitch. The only prob is that I have to take up a lot of track to check it out!

 

[minimans]

Many thanks Paul. I thought it might be the microswitch. The only prob is that I have to take up a lot of track to check it out!

You could check the switches in the ground I would have thought? if you have a fairly decent multimeter you could check voltages at each rail section as the Loco passes and see which section is going dead? and if it comes back to life on it's own after a pause?

I forgot to mention make sure the switch is flat, i have had problems with a couple of LGB 1600 switches bowing because the wood underlay warped twisting the switches as well, this would cause no end of trouble with certain Loco's but some would sail through!!

 

[beavercreek]

Hi Paul
Its the frog that goes dead momentarily so it must be the microswitch being gummed up or being 'slow'. I am assuming that the Aristo switch is supposed to detect a loco and arrange polarity of the frog as the loco enters the switch. It will be easier in the long run if I lift the point to check underneath anyway, just in case.

 

[Neil Robinson]

It will be easier in the long run if I lift the point to check underneath anyway, just in case.

I respectfully suggest that you consider using railclamps on the pointwork when you relay it. I find it then becomes much easier to lift for maintenance without disturbance to adjacent trackwork.

 

[beavercreek]

Thanks Neil for the pearls of wisdom
I usually do but in this instance the point is situated under a natural 'bush' tunnel and for speed (and probably laziness) I laid it with ordinary joiners with over-joiner clamps on top!
Hindsight eh?

 

[ntpntpntp]

... I am assuming that the Aristo switch is supposed to detect a loco and arrange polarity of the frog as the loco enters the switch. ...

No "loco detection" as such. The normal arrangement for a live frog point has the frog polarity switch working in association with the point blade tie-bar: ie. whichever way the point is set throws the microswitch (or whatever is used) so that the frog has the correct polarity for that route.

When you check the frog continuity with your meter, do you get open circuit or is it the wrong polarity compared to the plain rail after the frog? Would be unusual for a factory-fitted microswitch to be wired wrongly but.... ?

 

[GrahamMills]

I must admit that when I bought an Aristocraft #6 switch and found that the instructions effectively said "Not suitable for use outside" because of the microswitch, I did wonder what surreal world Aristocraft were living in.

Has anyone here got a USA Trains #6 switch and do they have the same problem with microswitches?

 

[spike]

I must admit that when I bought an Aristocraft #6 switch and found that the instructions effectively said "Not suitable for use outside" because of the microswitch, I did wonder what surreal world Aristocraft were living in.

Has anyone here got a USA Trains #6 switch and do they have the same problem with microswitches?

The USAT #6 has a rather naff little microswitch inside the switch unit.
IMO the unit is not really suitable for outside, it fills with water to easily and the armature
of the large coils rusts quickly.
I dead frogged all my #6s and added better links.
All my locos from Annies to Dash9s run over the frogs with no noticable hesitation.

Pic of the dead frogging.
1st pic shows where I isolated the frog.

2nd pic is the added links to feed the rails
All other USAT links were removed.