Hornby R044 with CDU

[daniel11]

Hi,

 

I am just about to motorise the points on my layout. I have 17 individual points, 6 of which are paired into crossovers so will be operated simultaneously. I will never be operating more than two points at once. The thing is that I would like to use either Peco PL-26 levers or Hornby R044 levers wired through a CDU to Gaugemaster PM2s. However with that many points buying the levers new at over £5 each is not an option and finding Peco ones second hand at a good price is difficult. That leaves me with the option of Hornby R044 levers which I can get in bulk second hand quite easily.

 

But I have been reading that you cannot use these levers with a CDU without holding the lever for a second or so half way through the throw. Is there any possible way around this? I was thinking maybe of a larger CDU that didn't fully discharge with each throw maybe? Or do all CDUs fully discharge with each throw?

 

This one has 4 capacitors and recharges in 0.8 seconds. Would that overcome the issue and save me having to hold the lever in the middle? Would using a larger diameter wire speed it up?

 

Thanks in advance,

 

Daniel

[Brian]

I don't recommend R044 black levers with any CDU. The old fashioned design of the R044 causes the CDU to be discharged into the point motors coil which is in the position to be moved from. Then there isn't time for the CDU to reach a fully recharged state before the required move to needed position is reached. Resulting often in a fail to throw condition. As you state, the only way this can be overcome is to hold the R044 lever top centre for a second or so to allow the CDU to fully recharge, then continue the levers travel. A CDU will only recharge quickly if the power supply feeding it is able to supply the power needed. You can move a Hornby lever from one side to the other far faster than 0.8 second!

Use the R044 without a CDU operated from a 16v AC supply of 1.0Amp or 19 to 22 volts DC is fine.

 

The Peco PL26 lever is far a better design and can be used with a CDU. Alternatively use SPDT sprung to centre off toggle switches (On)-Off-(Off) type. Or two press to make non locking push buttons per point or even stud and probe selection.

 

Wiring throughout in 16/0.2mm equipment wire should be ok for most applications.

[daniel11]

I don't recommend R044 black levers with any CDU. The old fashioned design of the R044 causes the CDU to be discharged into the point motors coil which is in the position to be moved from. Then there isn't time for the CDU to reach a fully recharged state before the required move to needed position is reached. Resulting often in a fail to throw condition. As you state, the only way this can be overcome is to hold the R044 lever top centre for a second or so to allow the CDU to fully recharge, then continue the levers travel. A CDU will only recharge quickly if the power supply feeding it is able to supply the power needed. You can move a Hornby lever from one side to the other far faster than 0.8 second!

Use the R044 without a CDU operated from a 16v AC supply of 1.0Amp or 19 to 22 volts DC is fine.

 

The Peco PL26 lever is far a better design and can be used with a CDU. Alternatively use SPDT sprung to centre off toggle switches (On)-Off-(Off) type. Or two press to make non locking push buttons per point or even stud and probe selection.

 

Wiring throughout in 16/0.2mm equipment wire should be ok for most applications.

 

Ok. Thanks. I think I will just leave the CDU out then. I would love to use the Peco Pl-26 levers, but the cost would just be too much. As it happens I picked up 17 second hand Hornby switch on eBay last night for £22 posted!

[traction]

Good luck operating the point motors without a CDU!!

 

They can take up to 4amps each so a big decent power supply is a must if not using a CDU.

Trying to operate more than one point motor at a time as in a cross-over will prove even more challenging.

Using the push to make buttons or the spring loaded toggle switches would be much cheaper, the toggle switches not being too dissimilar to lever type switches as well.

 

Cheers

 

Ian

[BR60103]

I was wondering if you could do it using 2 CDUs -- one on the straight side and one on the curved. I'll have to ponder this.

[kevinlms]

Hi,

 

I am just about to motorise the points on my layout. I have 17 individual points, 6 of which are paired into crossovers so will be operated simultaneously. I will never be operating more than two points at once. The thing is that I would like to use either Peco PL-26 levers or Hornby R044 levers wired through a CDU to Gaugemaster PM2s. However with that many points buying the levers new at over £5 each is not an option and finding Peco ones second hand at a good price is difficult. That leaves me with the option of Hornby R044 levers which I can get in bulk second hand quite easily.

 

But I have been reading that you cannot use these levers with a CDU without holding the lever for a second or so half way through the throw. Is there any possible way around this? I was thinking maybe of a larger CDU that didn't fully discharge with each throw maybe? Or do all CDUs fully discharge with each throw?

 

This one has 4 capacitors and recharges in 0.8 seconds. Would that overcome the issue and save me having to hold the lever in the middle? Would using a larger diameter wire speed it up?

 

Thanks in advance,

 

Daniel

The CDU in question, isn't about the number of capacitors, its the total capacitance. The more capacitance you have, the more it will throw at once (think of a fiddle yard, where you want to throw multiple points at once, for a particular route).

The 0.8 seconds is due to the fact that the charge time is fast, as its transistor assisted.

[Pete the Elaner]

Hi,

 

I am just about to motorise the points on my layout. I have 17 individual points, 6 of which are paired into crossovers so will be operated simultaneously. I will never be operating more than two points at once. The thing is that I would like to use either Peco PL-26 levers or Hornby R044 levers wired through a CDU to Gaugemaster PM2s. However with that many points buying the levers new at over £5 each is not an option and finding Peco ones second hand at a good price is difficult. That leaves me with the option of Hornby R044 levers which I can get in bulk second hand quite easily.

 

But I have been reading that you cannot use these levers with a CDU without holding the lever for a second or so half way through the throw. Is there any possible way around this? I was thinking maybe of a larger CDU that didn't fully discharge with each throw maybe? Or do all CDUs fully discharge with each throw?

 

This one has 4 capacitors and recharges in 0.8 seconds. Would that overcome the issue and save me having to hold the lever in the middle? Would using a larger diameter wire speed it up?

 

Thanks in advance,

 

Daniel

A couple of points here:

 

Firstly, you want the CDU to discharge almost fully at each throw. If you don't you will still have current flowing through the motor when you open the switch again. The magnetic field will then collapse very rapidly which will produce an unwanted spark at the switch. This is one of the unwanted effects which a CDU eliminates.

 

You can also overload a point motor with a CDU which is too large. It is ok beefing it up if you are always going to throw several points at once but if not, then you don't want to the capacitance to be too big.

 

A larger wire will not charge the capacitor more quickly. The wire simply carries the current supplied by the power supply. The charging current is limited by a resistor on the input. I would not want to change this either. It makes the CDU a gentle load on the power supply & once the CDU is discharged, the charging current will still be flowing through the motor. You want this charging current to be as small as possible.

 

I remember Dagworth did something different. He used a circuit with a capacitor across ever motor coil. This would get around just about all your issues with 2 drawbacks: You would need to buy 34 capacitors & the circuit would only work for motors with separate returns for each coil...but the SEEP motors do have a common return.

 

As mentioned above, good luck to you if you want to run CDU-less. I temporarily wired up a friend's layout with SEEP motors, 16v AC PSU & no CDU. It was completely inadequate & the motors looked completely disinterested. Adding a CDU transformed things & they throw very reliably.

 

Have you considered about building a panel & ditching your switches altogether? With 17 points, I would find it much easier to locate them on a track diagram rather than if they were all connected in a line. You could then use stud & probe or push button switches. I have heard people frown on push buttons but it is the back spark which burns their contacts & your CDU prevents this.

[daniel11]

Just found some of these GEM levers for sale. They appear to be passing contact switches. Does anyone known if they are any good? How do they work and is that design any good for use with a CDU?

 

Thanks

 

gem.jpg gem 1.jpg

[Pete the Elaner]

They look similar in size & shape to Hornby ones & as you've described them as 'passing contact switches' I suspect they work in a similar way too.

I therefore doubt they are suitable.

 

Unless you use 2 switches for the same point; 1 for each direction?