Model Railway Forum banner
1 - 17 of 17 Posts

·
Registered
Joined
·
551 Posts
Discussion Starter · #1 ·
I've built myself a very small shunting layout with 5 Peco small radius electrofrog points. The purpose behind the layout was to practise with DCC wiring and accessories etc before building my big loft layout. It's about 4' x 18".

I have bought myself a Hornby R8247 Accessory Decoder to power the point motors to work with my Elite. It's just a start into the world of DCC operation.

So I laid the track and started fitting a Peco point motor mounted on PL12 mount with the centre spring removed, and I dug out of my spares box a couple of the Hornby new style (like the Peco PL-10) motors and their respective surface mounted plate with the Bothy to cover the motor. I had to enlarge the hole on the arm of the Hornby surface mount to get it to go over the Peco points tiebar. I also had bought a Peco side surface mounted Point motor PL11 to try out also. This point motor was wired in parallel with another point motor to operate as part of a cross over.

The Hornby point motor mounts do not have a spring in them.

I fitted the mounts to the board making sure everything was parallel and in line with the action of the point tie bar, wired it all up and went to operate the points with my Elite.

Hmm, only one of the Hornby motors on its mount would change the point and the PL11 would change it's respective point but the other two Hornby point motors did nothing but buzz when operated. The Peco PL10 on its PL12 base was also reluctant to operate.

I thought at first that there wasn't enough power from the Accessory Decoder so I altered the relevant CVs to lengthen the time the current to each output is on for to the maximum recomended time (by Hornby for solenoid type point motors) to 0.8 seconds. This helped a bit but still not great performance.

To me there seems quite a bit of resistance in these surface mounted bases that has to be overcome by the solenoid action, but I can't see how I can reduce this.

So.....

I then mounted a PL10 directly to the underside of a point and this operated fine with a 0.8 second burst of power from my Accessory Decoder.

I am now of the thnking that surface mounted point motors on bases is not the way to go. The first part of my big layout to be laid will be my fiddle yard and I was hoping to use surface mounted PL10s to save making holes in my baseboard but after my trial I'm not convinced by surface mounted point motors (PL10s on PL12s) is the way to go.

Can anyone provide any advice on how to get surface mounted PL10s on PL12s to work?

I haven't tried them the old fashioned way with a passing contact switch direct from a 16V AC supply. This will probably supply current for longer than 0.8 seconds but not much longer I wouldn't have thought.

Can I up the length if time the current is on from the Accessory Decoder without fear of burning the point motor out?

I've got enough PL10 motors to do my layout so I'm keen to use them.

Any thoughts would be appreciated.

Andrew
 

·
Registered
Joined
·
984 Posts
The PL12 does add a bit of resistance but you should be able to get it working. You have to make sure that everything is lined up nicely and probably need to lubricate the motor (and perhaps the point too).

You may find benefit in using the spring in the PL12 rather than in the point.

I find I have a lot less trouble with the PL10s on the top of the baseboard because they are easier to line up accurately!

As an example I have fitted a PL10 with a PL13 switch to a PL9 under the baseboard actuating a PL12 (with spring) above the baseboard to drive a point which still had its spring fitted via the extension bar. This lot all worked from straight regulated 12V DC. I think that is probably a worse case scenario (and I don't intend putting in a point that inaccessible again!). Your Hornby accessory decoder should be providing better drive than straight 12V DC.
 

·
Registered
Joined
·
2,150 Posts
The one thing I would add is to make sure that the wire you use is sufficient for the job. Solenoid point motors do need quite a whack to move them.
If the point is enough near enough you may get away with 16/0.2 but I would always suggest 32/0.2 if possible for anything over a few inches.
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #4 ·
Thanks guys, everything was lined up straight and true as I made sure of that.

I agree with you Suzi, having it on top of the board is going to be so much easier in terms of lining it up but...not in my case.

I tried lubrication also, point blades just like in the 12" to 1' scale, no effect.

Wire size is 7/0.2. It is only about 3 feet max length. I've used 7/0.2 at 12 feet long to power point motors with no issues.

I've wired my towbar electrics in my car (fused at 15 amps at 12 - 14v DC) with thinner wire (to BMWs specifications) than 32/0.2. 32/0.2 wire in automobile set ups would be good for about 30 amps at 12v DC, that's a bit overkill for point motors, no?

I will double check the connections on the Hornby point motors as they have mibbie got a bit strained from feeding thru the small hole in the mounting plate.

The Peco point motor was soldered to wire which was then led straight to the Accessory Decoder.

I'll have another fiddle and see what I can get to work and keep you posted.

Thanks again

Andrew
 

·
Registered
Joined
·
197 Posts
Are you using the PL10e motors that Peco recommend for DCC? I'm not sure if the Hornby motors are like these or the old "10" which need heavier current to throw them.

While the motors may be lined up straight to the tie bar, are they level with it? When I put the first one or two surface mounted motors on my rebuilt layout (though not DCC), I had similar problems and eventually realised that the motors are designed for use without underlay! Putting a packing piece under the mount cured the problem!

If you are using very short wire runs, I wouldn't expect there to be much of a voltage drop; though when using them in a long run on your main layout, there will be a significant drop (there's a lot of current flowing through a relatively high resistance); so thick wire is a must in that situation.
 

·
Premium Member
Joined
·
531 Posts
It could also be that your Peco points are too stiff for the point motors to throw.

Between the point blades there's a movable spring cover. Slid it towards the end of the points to make the blades move more freely.

K9-70
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #7 ·
Thanks again guys for the comments.

I tried again last night, I fixed a Peco point to a board and got a Peco mount and screwed it down directly to the board. Thus the underside of the mount is level with the underside of the point.

I fitted a motor and it didn't really work very well. I slackened off one of the mounting screws and that appeared to help significantly but now the whole motor and baseplate jumps when the point motor is operated. There is plenty of slack in terms of levels of the point tie bar the operating arm and the how the arm fits over the tie bar. Once I had waited for the capaciter discharge unit to charge up again within the Accessory Decoder it worked maybe 6-7 times out of 10 which is not enough in my opinion.

I then fitted a PL13 switch to the top of the motor and it then just simply refused to work in either direction. Just not enough current/power etc to make it work.

I then fitted a motor and PL13 directly to the underside of the point and it worked satisfactorily.

I have wondered about the PL10E, I'm thinking there isn't quite the oomph in the DCC system I've got to give the point motors the kick they need.

I'll buy a couple and see how I get on.

I'll keep you posted.

Thanks again

Andrew
 

·
Just another modeller
Joined
·
9,983 Posts
*** No and No.

Given that you asked for help, and your problem is getting enough energy to the motor to make it work properly, Tony's wire comment is a strange bit of advice to reject as its absolutley valid.

You are forgetting (or don't realise) that the point motor draws a momentary 4 amps and its voltage drop under load that is the issue, not the current carrying power of the wire.

You are way undersize at 7x.2 and Tony is right, 32x.2 will let the whole of the drive voltage/energy actually get to the point motor.

Richard

QUOTE (Andrew Rolland @ 5 Apr 2011, 02:28) <{POST_SNAPBACK}><snip>
Wire size is 7/0.2. It is only about 3 feet max length. I've used 7/0.2 at 12 feet long to power point motors with no issues.

<Snip>
that's a bit overkill for point motors, no?

Andrew
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #10 ·
Richard

I never said I was ignoring or rejecting the advice given previously, hence the word 'no' and the question mark at the end of my sentence regarding overkill.

I have some 16/0.2 wire that I'll try, if that fails then I'll dig out some wire at 32/0.2 that I've used on the car and try that too.

But why then previously with no CDU, I was operating two parallel wired PL10s with 12 feet of 7/0.2 straight from the 16V AC output of a Gaugemaster without fault using a Hornby passing contact switch?

Is it that the switch was making contact for longer than the 0.8secs that I have the Deocder set too thus more power was going where it was needed?

In my current set up...Is it that the Decoder is using a lower voltage than my Gaugemaster was putting out and combined with the power lost in my thin wires there isn't enough oomph to drive the point motor on its base with a switch fitted?

That's why I was initially querying the size of the wire needed no probs previsouly, now problems.........

I am quite prepared to accept the need for thicker wire as I understand the physics and Ohms law/power loss etc and the fact that these motors do need a reasonable amount of current to make them work. That's why I have made up the small layout to try it out in the first place and by asking questions on this forum hopefully I'll get the thing working. If you don't ask questions and listen to/read the responses you will never learn.

So why do Peco and Hornby supply wire at 7/0.2 if it is way undersized for the job then? Typical manufaturers penny pinching?

Andrew
 

·
Premium Member
Joined
·
497 Posts
does this relate to your other post re. r8247 ?

you problem is that the hornby decoder pulls its power straight off the dcc bus and the peco points do like there power, 0.2-0.4 all you should need to throw a solnoid if you have enough current

imo 16/0.2 is just about right for the peco solenoid try and keep the wire runs as short as poss also soldering the wires direct rather than using the peco looms to avoid any other problems
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #12 ·
Thanks

It is related, but I thought best to post seperately?

Using 6" lengths of 16/0.2 I conencted the PL10 to the Decoder and using 12" lengths of 16/0.2 I connected the Decoder to my Elite. No bus used. All connections soldered.

The results were better 19 out of 20 throws successful, so I'm quite happy to accept that I needed thicker wires. Although you won't be able to connect 32/0.2 into a Hornby Accessory Decoder as the terminals aren't big enough.

I think I do need to wait for the internal CDU to charge up before throwing the point again. If I tried to throw again quickly it refused. Mibbie I need thicker wire between the Elite and Decoder

It still refused to throw the motor on a PL12 base when using a PL13, I think there is just too much resistance when all added together. When fitted directly to the underside of the point the PL10 could throw the point and the PL13.

The PL13 which is split new does feel really stiff to operate. Probably not the best solution, although I'll need to have a think as I'm keen to use a point motor driven switch to alter frog polarity to improve running.

But then this is it. If I need a point motor (~£5), a motor operated switch (~£2.50) and then an Accessory Decoder (albiet 1/4 of ~£30 as you can drive 4 points from it) the costs add up and would I be better to invest in some other form of combined decoder/point motor/switch? .... Now what copy of Model Rail did the point motor review.... Hmm I'll mibbie do some more homework before building my layout.

Thanks again for all your help guys.

Andrew
 

·
Just another modeller
Joined
·
9,983 Posts
*** A that final cost you should think about Cobalt plus the AD4 accessory decoders... dead reliable and low current need - plus you can also have a panel switch (single pushbutton) plus panel lights and spare switching also on cobalt for other things... as well as just about the simplest wiring possible (and light wire if fine all round as current draw is so low)

regards

Richard
 

·
Registered
Joined
·
551 Posts
Discussion Starter · #15 ·
Carried out another little experiment.

I connected up a PL10 on PL12 base using a Hornby Passing contact level switch, using 16/0.2 wire all plumbed into the 16V AC outlet of a Gaugemaster. No CDU.
Thwack, thwack, thwack. 100% reliable point switching. Loads of grunt. But of course not very digital!
Then added a PL13 to the equation, thwack, thwack thwack again 100% reliable switching.
Added a second PL13 and only then did the PL10 begin to refuse.

I then repeated the experiment with the power source being a 15V DC outlet on the back of my Elite and the PL10 struggled when sat on a PL12 with no PL13s attached.

So the higher the voltage the better the performance with the PL10s. I'm still doing my homework on the best point motors to use with DCC when mounted above the boards.
 

·
Registered
Joined
·
1 Posts
It could also be that your Peco points are too stiff for the point motors to throw.

Between the point blades there's a movable spring cover. Slid it towards the end of the points to make the blades move more freely.

K9-70
I know you wrote this ten-odd years ago, but I chanced up on it tonight when setting up a peco surface-mount motor that wouldn't move the point, and your tip was the solution!
 

·
Registered
Joined
·
984 Posts
I know you wrote this ten-odd years ago, but I chanced up on it tonight when setting up a peco surface-mount motor that wouldn't move the point, and your tip was the solution!
If using the PL12 base with a spring in it you can remove the spring in the point completely.
 
1 - 17 of 17 Posts
Top