R8247 not powerful enough to change my points...

[toolongtoremember]

Hi there, 

 

As the title suggests, I have invested in five hornby points decoders and one elink module. 

 

The point decoders dont have enough power to flick my points, does anybody have any fixes for this problem? 

 

The layout is N gauge, using peco track, peco PL11 surface mounted point motors and the peco motors that go underneath as well.

 

Many thanks. 

[Chrissaf]

You've noticed then....that the R8247s are gutless.

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The Peco point motors that go underneath are they PL10 or PL10W motors?

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All my point motors were the PL10W variety (they have higher resistance solenoid coils than the normal PL10 versions). My R8247's just didn't want to know with my PL10W point motors. I ended up using my R8247s to fire a relay. The relay contacts then operated the points via a traditional CDU / separate DC power supply arrangement. It was a lot of additional cost, but was the only solution that I could get working that still used the R8247s. I couldn't send the R8247's back for a refund as I had bought them more than a year earlier and had been unused in boxed storage. Some other brands of point decoders can be more powerful and easier to configure and set up.

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With regard the PL11 surface mount decoders. These should work with the R8247, as many on here do use that combination and report that they work. The main thing is NOT to overtighten the PL11 mounting screws. There should be a slight amount of play. If the PL11 is too firmly screwed down, the case flexes and the internal solenoid slug can stick. The other thing to note with all types of solenoid point motors, the alignment must be 100%. The slightest level of misalignment can cause the points not to throw properly.

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Now for the most likely reason for why your points are not working. Peco use a different point motor wiring colour scheme to Hornby. Both Hornby AND Peco use the SAME three colours - Black, Red & Green. But Hornby use the BLACK as the common return. That is the one in Hornby world that connects to the R8247 C terminal. Peco use the GREEN as the common return. So in Peco world, it is the Green point motor wire that connects to the Hornby R8247 C (common) terminal and the Red and Black wires are used to turn Right and turn Left.

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Double check to make sure that you have wired the point motors up correctly. They also need to use reasonably thick wires (typically 32/0.2mm** wires, with a minimum 24/0.2mm** wires if over a shorter run length). The solenoids draw a lot of current and wires that are too thin can restrict free current flow.

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Note** 32 or 24 strands of individual wire, each 0.2mm diameter contained in a common PVC sheath.

 

[Fishmanoz]

My tongue is only slightly in my cheek when I say put the 8247s on eBay and buy some real point decoders instead.  

 

Yes, the 8247s are real but a very old design, marginal on operating current despite having internal CDUs, have to be programmed on a programming track unlike most more modern designs, and prone to resetting their addresses to default 1-4 after short circuits, requiring return to the programming track to re-address and sometimes first resetting. 

 

You should also check mechanical issues issues around your points including motor alignment that might be making it harder to throw the points in the first place.

 

Also if you persist with the 8247s, don’t have any of them set on addresses 1-4 to avoid other points on the end of an 8247 that has reset being changed at the same time as you try to change the real 1-4s. 

 

PS.  Posted at the same time Chris was replying. 

[toolongtoremember]

Thank you so much for your input, both of you. 

 

I have them wired correctly, with the correct wires sizes. I found them very easy to program and set up, some throw points just about (both ways) and some just dont have the guts to do so. I have the PL10E point motors and they just refuse to work with them even though I have them 100 percent lined up with the points. 

 

I bought the decoders from Hattons just under a week ago without thinking they would be sub quality because of the hornby name, I will certainly return them and perhaps go with some other brand ones. Not sure I've done the right thing going with e-link/railmaster at this point either. 

 

Many thanks! 

[Yelrow]

I thought this was a hornby forum, where we support the products. To that end, i  totally disagree with fishy comment about the quality, and following comment about hattons selling sub quality products. Mine work perfectly, as i am sure do hundreds of other  peoples.  Chris, has it right, about not screwing motors down too tight. When i fit mine, i manually check the point changes. I dont find them at all gutless. May be, the fault lies with the peco PL 10E. Have you thought about returning those.  As for Elink/ railmaster. thats down to personal choice. However, your elink comes with a 1 amp Transformer, which many have upgrade to a 4 amp one, which is far more powerful.  Had you an Elite, in conjunction with your Railmaster, which is for many, the preferred choice, i think you could well find your problems are solved.  It is a known fact that  the one amp supplied, does not cope well , with  several points. Changing the decoders, may well, not solve the problem.

[96RAF]

I support John’s comments.

I have had several very old R8247s and an even older R8216 acc decoder in use without any problems.

Mine are on a separate bus so unaffected by any derail spikes which can upset them if on the same bus. They may be a pest to program but its dead easy using RM and usually once set they are left like that forever.

There are other make acc decoders as Fishy says which are self learning but if you trawl the forums you can find adverse comment about those also.

Rob

[Yelrow]

The more I think about it the more I am convinced, it’s the 1 amp supply.  Nothing  wrong with the point decoders, just lack of grunt.Does not apply with the Elite, as comes with 4 amp supply.

[Fishmanoz]

Well, that worked a treat, after a fashion ......... say something negative about a Hornby product and the supporters come flying in from all over Europe!  It would be sad if everyone on here had the same view of everything.   I’m glad some find the product perfectly adequate but I have said nothing about the 8247 that hasn’t been said on here many times before over the years. 

 

Also, if I might recall the situation with these from a number of years back.  The product was off the shelves for well more than 12 months and people had no choice but to buy accessory decoders from other manufacturers.  My view at the time was that the high level of faulty 8247s being replaced by Hornby prior to this meant that they had at least a production problem if not design issues too.  But maybe I’m wrong, maybe it was just a stock issue.  During the time I was hopeful that Hornby would come back on line with a better and more up-to-date offering, but they didn’t.

 

Just on Hattons, they are one of my more-preferred suppliers, but they fell short when the 8247 was off their shelves. They marketed a supposed equivalent at the time.  The only thing equivalent about it was that it was an accessory decoder. In its way, it was a very capable product, so capable in fact with so many options that an advanced certificate in electronic engineering was the minimum needed to interpret the manual and set it up correctly.  And it had the shortcoming in design in that it didn’t contain a CDU so was very particular about the supply you could connect it to for reliable operation, it couldn’t be expected to work connected to a DCC track, it needed a separate supply, one of the many reasons it was not a direct equivalent of the 8247.

 

Which brings me to John’s suggestion on the possible need for the 4 Amp supply. He may well be right, but if he is, that is a shortcoming of the 8247 design. The 8247 contains a CDU and CDUs are designed to store sufficient energy to throw a point, usually 2 at the same time, independent of their supply current.  Then they recharge slowly at a low current before the next operation.  Consequently, all 5 of TLTR’s 8247s should be able to recharge together without overloading the eLink standard 1 Amp supply (note he/she hasn’t reported overloads).  And when throwing points, the energy should come from the CDU and not be affected by what supply current they are connected to.

 

 

 

[toolongtoremember]

Thanks everybody for your replies, the suggestion a 4amp power supply shouldn't affect it as the points fire from the internal CDU in each unit (which isnt great as each unit between four points only contains one CDU!)

 

The main probelm I found is that then you have to wait for a duration to then throw the next point from the same decoder, up to three times as they are four point decoders. This will be an exhibition layout so I can't use those. 

 

The units also drained the DCC bus if I threw the points on each of the units when they all went to recharge at the same time, killing the e-link so I will have to upgrade the power supply to that too for any set of decoders so it seems - but shouldnt this of been ready to use out of the box with just a few decoders present?. 

[Yelrow]

I know nothing about peco points, as i have none. What i do have are 15, hornby points, working perfectly from hornby point decoder, with a 4 amp supply. I  dont have time to search all the old posts, but i copy bits i want from them, and it was a Hornby  suggestion that the points would perform better, with a 4 amp transformer. Which was why i bought one, to run with my Elink. The result, was immediate, perfection.  The tech guys, will know if there is a difference between peco and hornby points, but i would a euro, being a risky guy, that if poster, connects to a 4 amp supply, his probs, will disappear, happen both types,   alike.

[ronbram]

I run a LGB layout. The LGB point motors can easily fry the output stage of nay -regardless of brand- decoder. So from day one onwards I run a 16 V AC line from  a 2*5A torrodial transformer along the layout. I use the output of the decoder to drive a small relay, which  on its turn sends the 16 V AC to the point motor. This ensures sufficient power for the point motor and save the DCC power for where it is most needed, to drive trains.

[96RAF]

More or less exactly what I do Ronald...

 

The pulsed port output from my ACC decoder pulls in a relay coil just long enough for the main contacts to pass the oomph from a proper CDU powered by an old analogue controller Aux AC output to the solenoids.

 

This method also allows you to put a switch in the CDU side to operate the points manually as well as by DCC.

Rob

[ronbram]

I even went as far as building a very cheap booster using a LM18200 h-bridge chip. All stationary decoders are run from that decoder so they don't influence the main DCC signal for the trains.

Details to the design:

link

[toolongtoremember]

For completion of the thread, I swapped the honby point decoders for DCC Concepts ADS-8SX. So far I have two  of those units (16 points total so far) wired up to the standard e-link, and I have to say it's a massive improvement, every point fires first time every time with no waiting around now. 

 

[Yelrow]

I have those as ewll, but find little difference between them and the hornby ones. Mind you, i am only running  a single point x 4 on the hornby ones. Do not agree they are gutless.