What are they and do you really need them?

Hello again everyone,

Sorry to keep asking questions, (one day I'll be able to answer one!).  This time it's about point motors. I would like to fit them but I am unclear about how they are powered. I hope to have a DCC layout so do the points have their own power supply?  Also what is a capacitor discharge unit for and do you really need one?

It's this range of skills; modelling, carpentry electrics etc which make this such a great hobby! I just wish I was in possession of some of them!

Garry

Hi Garry,as far as dcc points motors are concerned i'm sure they get their power from the bus,others will be able to confirm this.i use a ac/dc power supply on mine although my layout will eventually dcc as well.the cdu gives a short sharp burst of power to throw the points.HTH.

Garry, there are two common types of point motor - solenoid and slow motion.

Peco and SEEP (others too I suppose) make the solenoid type.

For slow motion, Tortoise and Cobalt are the names I know.  Again there could be others.

To operate solenoid motors on DC or DCC, a separate power supply and CDU can be used (for a solenoid to move, it really does need a jolt of power as Alan has said. A CDU (or several if you have a lot of points that need to fire simultaneously) is strongly recommended.) 

This website has pretty comprehensive advice on wiring:  http://www.brian-lambert.co.uk/DCC.htm

Alternately, if you have DCC, stationary decoders can be used.  These are available from the likes of NCE and DCC Concepts (and others).

These don't require a separate power supply and use the DCC bus.

I prefer slow motion point motors which use a motor and gear train to change the point slowly and more realistically.  They also put less stress on the tie bar.  They move in one direction until they hit a stop in the motor and then stall out.  When polarity is changed they do the same in the other direction.  They are easier to set up in that you always get full throw.

For these, separate power supply and switching are an option. 

Again NCE and DCC Concepts (and others) do stationary decoders.

One big advantage of stationary decoders is that you don't necessarily need a control panel since point control can be done from your DCC throttle (I have the NCE Powercab).  The decoders that I have seen have an option to wire up to a control panel momentary switch.

Our club layout (see link below) uses SEEPs (nice because they have an integral switch for frog polarity switching) and CDU on the main circuit and Tortoise/Cobalt on the branchline.  Some of the SEEPs have stationary decoders.  We haven't got around to converting everything yet.  All the slow motion motors have stationary decoders that can be worked from the throttle or push buttons on the fascia.

Check the Forum Contents Index - you might find more info.

HTH

John

CDU's for solenoid motors give at least two advantages over normal AC input:-
1. it protects the coils from burning out as there is only a pulse of power even if you keep your finger on the button
2. the DC output from a CDU helps in route selection if using diode matrix http://rail.felgall.com/dm.htm


For DCC users wishing to operate solenoids from hand control, DCCconcepts have released a new CDU with decoders  for I think 8 points .

Thank you both for your replies. The Site you posted the link for, looks like it will save me a lot of head scratching John!  I'm inpatient to get on with things now, but I want to do it right and can see I still have a lot of research and learning to do before I can really get stuck in!

Thanks for your help Ron.  It takes time for the old grey matter to absorb things but I think I am getting there slowly!

[user=1487]GarryJ[/user] wrote:

………………………………………  It takes time for the old grey matter to absorb things but I think I am getting there slowly!

Join the club Garry. :cheers


No matter what it is that worries you, someone on here will always come up with the solution ……….:thumbs

[user=606]Sol[/user] wrote:

CDU's for solenoid motors give at least two advantages over normal AC input:-
1. it protects the coils from burning out as there is only a pulse of power even if you keep your finger on the button
2. the DC output from a CDU helps in route selection if using diode matrix http://rail.felgall.com/dm.htm


For DCC users wishing to operate solenoids from hand control, DCCconcepts have released a new CDU with decoders  for I think 8 points .

 The DCCconcepts DCC accessory decoder for solenoid type Point motors is the AD-S8.

 It can be op by DCC,  button control or both.

 AD-S8 has 8 separate decoders on the one board. Each decoder has it's own CDU and draws its power from the DCC  bus.

 The power draw to charge the CDU on each module is Milli amps and takes aprox 1 sec to recharge each time after firing.

 All my points are op thru DCC ( would not have it any other way) and up to now I have only used Lenz LS150 accessory decoders but since fitting an AD-S8 to my layout that will be my choice of accessory decoder in future.

 AD-S8 is just so easy to program for each separate point motor.

 It is also few dollars cheaper than the LS150 which only op 6 points.

 DCCconcepts also do an accessory decoder for op slow motion point motors.

 My only alliance with DCCconcepts is a satisfied customer.

 Cheers

 Ian

Am I right in thinking the AD -S8 won't work with slow motion motors Ian (the Tortoise, for example) :roll: ? 

Peter   AD1 & AD4
http://dccconcepts.com/index_files/DCCconcepts_accessory_Decoders.htm

The Traintech decoders control up to 4 points each and they do not need a CDU. You just wire the motor straight into the decoder.

Bob

[user=606]Sol[/user] wrote:

Peter   AD1 & AD4
http://dccconcepts.com/index_files/DCCconcepts_accessory_Decoders.htm

Interesting Sol. :roll::roll:

At 11 euros per point, still not cheap plus there's postage from Australia ……………..but still a cheaper option than the Lenz LS150.

These decoders make the original cost of the point almost a secondary factor …………… :???::???:

The Traintech option looks slightly cheaper but doesn't seem to cater for slow motion motors ………….

AD1 are available ex Hatton's 11 quid DCC Concepts DCP-AD1 Cobalt 1-way accessory decoder

Peter I use the Ad4 and Cobalt combination and I am quite satisfied with their operation.

Dcc concepts have released the Cobalt Digital which has the decoder and motor in one unit and runs off the dcc bus, you address each motor individually.

When considering point motors it really is best to work on a cost per point basis which includes motor and control system.

As for the original question things are moving on with solenoid point motors, the only reason I don't use them was they fired across alright but occasionally bounced back! So ended up with slow mo.

I'm sure these decoders work perfectly - it's more the cost I'm wondering about.

I can buy a "normal" Peco Code 100 point for £9.

I then spend £16 on a slo-mo motor to operate it, a further £10 on an accessory decoder and let's say £2 on wire, connectors and other "miscellaneous items".

That means each point has a standing cost of not too far short of £40 - a straight forward cross-over would cost nearly as much as a locomotive.  25 points would swallow up close to £1,000 !!!! :shock::shock::shock:

Maybe that "hand of God" isn't so unattractive after all ………………….:roll::roll:  Certainly I think some kind of manual control has it's place for "local"  point work.  I'd rather spend my budget on something more glamorous than a green or blue box under the baseboard !! :roll::roll::roll:

As an "average" guy with an "average" modelling budget, I think manufacturers need to be careful they don't price themselves out of their market.  They need to remember there's an economic squeeze at the moment.

Peter, because I have over 60 points, the large majority of those in stations are manual control.
Me, I am quite happy with standard solenoid motors.

I think I'm going to try some solenoids in my station area too Sol.

Am I right in thinking there's no need to bother about frog polarity with insulfrog points ?  Most of those in that area are older insulfrogs ……….:roll::roll:

Alternatively, a cheap micro switch might sort the polarity.:hmm

[user=6]Petermac[/user] wrote:

Am I right in thinking there's no need to bother about frog polarity with insulfrog points ?  Most of those in that area are older insulfrogs ……….:roll::roll:

.

Correct Peter but I suggest you bond the blades to their adjacent stock rails so you are not relying on blade contact and suggetion No 2 is to paint the frog tip with nail varnish or Supa Glue about 6mm longer to give a better insulation gap in case loco wheels bridge the two rails near the frog tip.

The nail varnish is a good idea Sol and, having asked about frog switching, I realise if I use SEEP motors, they already have a built-in polarity switch. :thumbs

I found a nice little circuit that allows you to use a switch with a direction indicator for the control board, in conjuction with a CDU.

Home built CDU's are really cheap, and you can even use them to drive relays if you want.

With the recent extensions , I will need to double up on these boards, at not much more than cost than a single commercial CDU.


Trouble is , I have to find the circuit diagram again .. DOH !!