Burton-on-Trent South - Adding Buildings

[ISW]

On 04/09/2020 at 18:23, 47137 said:

Ian, I am installing my point servos in similar 15 mm U-section aluminium, and having a terrible time trying to set them up to drive the points.

 

My main problem is, there is far too much up-and-down movement of the piano wire. If the wire is long enough to go through the tie-bar in the neutral position, the wire extends 4 mm or so above the tie bar at the end stops - enough to foul a Kadee coupler.

 

I have a 6 mm ply track bed and I am suspecting the fulcrum in the aluminium is simply too close to the tie bar. Does this sound likely? I am feeling a sense of exasperation coming on.

 

- Richard.

Richard,

 

I'm sure this is something you'll be able to overcome, after all I managed it and I'm a total novice!

 

To help, here is a photo of one of my servo installations:

 

As you can see, I'm using the 2nd hole from the servo axle thus the up/down movement is quite limited. I'm guessing you're using a hole nearer the end of the servo arm?

 

My baseboard is 12mm (on the Lower Levels, the Upper Level is 9mm) and I'm getting ample lateral movement of the piano wire at the turnout. In fact I'm getting too much really.

 

Now, you have 6mm baseboards so I'm guessing you had to use an outer servo arm hole to get enough lateral movement at the turnout (because the lever-arm at the servo side is longer than that at the turnout side of the pivot point). Hence a lot of up/down movement of the piano wire.

 

My suggested solution is to move the piano wire onto a hole in the servo arm closer to the servo axle to limit the up/down movement. If this results in inadequate lateral movement of the piano wire at the turnout then you'll have to add a ~5mm packer between the underside of your baseboard and the aluminium U-channel holding the servo. Given you are using 6mm plywood a few offcuts will do nicely as the packer. It doesn't need to be an exact size / position, just be large enough for the screwholes of the U-channel. I'd probably pva-glue the packer in position. Yes, that means you'll need a longer piano wire. Sorry.

 

Does the above make sense? Let me know how you get on. At least you only have a few turnouts ...

 

Ian

Edited March 31, 2022 by ISW
photos re-uploaded

[47137]

12 minutes ago, ISW said:

....

 

Does the above make sense? Let me know how you get on. At least you only have a few turnouts ...

 

Ian

 

Ian it makes complete sense. You mentioned underlay a while back, and I'll guess this is 3 mm thick, in addition to your 9 and 12 mm baseboards. So 12 to 15 mm thickness in all.

 

I have bonded two offcuts of 4 mm ply together, the glue will be set tomorrow. This will give me 4 + 4 + 6 = 14 mm, and I will indeed try the holes in the servo arm nearer to the drive shaft.

 

If 8 mm packing is too much, I'll try 4 mm. I'd like to keep my spare 6 mm ply for something better if I can. I will report back. I am cursing myself at the moment simply because I installed five servos before I realised what was happening! I will run out of 0.6 mm piano wire but I have some 0.5 mm to try.

 

- Richard.

[ISW]

10 minutes ago, 47137 said:

Ian it makes complete sense. You mentioned underlay a while back, and I'll guess this is 3 mm thick, in addition to your 9 and 12 mm baseboards. So 12 to 15 mm thickness in all.

That's correct, I'm using floorboard underlay which, to my eyes, is exactly the same as the expensive stuff from Woodlands Scenics(?).

 

11 minutes ago, 47137 said:

I have bonded two offcuts of 4 mm ply together, the glue will be set tomorrow. This will give me 4 + 4 + 6 = 14 mm, and I will indeed try the holes in the servo arm nearer to the drive shaft.

What size hole are you drilling for the piano wire? I used 8mm and it was 'just' enough. It needed accurate positioning or else I had to elongate the holes a bit. But the smaller the hole the easier it should be to avoid ballast dropping into the hole. The foam type underlay helps with this as it sort of 'seals' the hole up.

 

11 minutes ago, 47137 said:

If 8 mm packing is too much, I'll try 4 mm. I'd like to keep my spare 6 mm ply for something better if I can. I will report back. I am cursing myself at the moment simply because I installed five servos before I realised what was happening!

Been there, done that, know the feeling!

 

Ian

 

[47137]

It's funny how a night's sleep sorts things out.

 

1. The tip of the piano wire must stay below the tops of the rails, to clear the trip pin on a Kadee coupler.

 

2. The piano wire must be long enough to stay in the tiebar when the servo moves through its neutral point (and not drop out).

 

3. Ideally, the mechanism will work well using the default throw of the servo, as provided by the MegaPoints servo controller with its factory settings.

 

The only way I can do items 1. and 2. is to use the hole in the servo horn nearest to the servo drive shaft.

 

This leaves the controller settings (end stop adjustments) and the thickness of the baseboard to achieve item 3.

 

The default throw is about 90 degrees, i.e. 45 degrees each side of the neutral point ...

 

 

For me, x = 4.5 mm; this is the smallest throw available.

 

With a throw of 45 degrees each side, the dimension x' = 4.5 / sqrt(2) = 3.2 mm.

 

So the piano wire is shuffling up and down by about 4.5 - 3.2 = 1.3 mm and the only way to reduce this is to reduce the movement of the servo.

 

And so, the only way to get enough movement on the tiebar is to shim the servo downwards. Arguably, I am in an ideal position with a 6 mm thick track bed. I can shim downwards not upwards.

 

A 4 mm shim is not enough. 5.5 mm is about right, and I am hoping 6 mm is spot-on. 8 mm will be too much. I am writing out this while the glue sets to hold a 6 mm shim onto the baseboard 

 

- Richard.

[ISW]

1 hour ago, 47137 said:

The default throw is about 90 degrees, i.e. 45 degrees each side of the neutral point ...

Richard,

 

You can 'adjust' the end-stops (movement) of the servo with the MegaPoints servo controller board, and this allows for a much larger angle than 90-deg, nearer 135-deg I think.

 

I went and checked the vertical movement of the piano wires on one of my turnouts, something I'd not bothered doing before. The result was a vertical movement of ~1.5mm (visibly), in line with your calculations, although my angle of movement is closer to 135-deg. I have the piano wire cut roughly level with rail top and, although the piano wire does go below the top of the stretcher bar during movement, it's still in contact with the sides of the hole in the stretcher bar. In this arrangement I've encountered no operational problems.

 

Ian

 

[young37215]

Guys

 

Dave Fenton's videos on Youtube have been a constant source of reference for me and I find them an invaluable resource when faced with a problem. My experience is that it takes a while but once you find a way that works, you should keep using it.

 

In my case my baseboard is 12mm thick chipboard.  With the point in situ I mark the centre point of the tie/stretcher bar hole. The point is then removed and a 2mm hole drilled. The actuating piano wire is threaded through the baseboard from underneath and the bracket is screwed in place and then removed again to allow for a larger 6mm hole to be drilled. The bracket is reattached using the same screw holes which should align the actuating wire in the correct place to pass through the tie bar. There is sufficent flexibility from the 0.6mm piano wire I use as an actuator for less than perfect alignment. Once secured I adjust the rotation of the servo using my Megapoints controller which reduces the angle of movement but still changes the point. I use the 4th hole down on the servo arm for the piano wire which I cut to 90mm lengths. When I am happy that all is well I trim back the piano wire to avoid contact with coupling/loco undersides etc. 

 

Bottom line in my opinion for Richard's issue is twofold:

 

1. you need to adjust/reduce the range of servo motion to stop the piano wire protruding higher than the rail head. 

2. You need the to increase the distance between point and servo bracket to the 12 to 15mm range as you describe

 

Good luck!

Rob

 

[47137]

I made a few changes to my first mechanism and eventually ended up with something able to work perfectly every time. Then it was like shelling peas to do the other seven.

 

In essence:

• I settled on 0.5 mm piano wire. The 0.4 mm I began with was too soft, and I ran out of 0.6 mm. The 0.5 mm bends easily at the servo end stops, but holds the point blades firmly against the stock rail.
• I put a 6.3 mm plywood shim under the baseboard. This doubles the distance between tie bar and U-channel and takes this up to 12.6 mm.
• I set the MegaPoints servo controller to give the maximum throw on the servo (I guess about 130 degrees).
• I moved the piano wire to the second hole on the servo horn, so the throw is now 6 mm not 4.5 mm.

And, when I trim the piano wire flush with the tops of the rails, the tip of the piano wire dips below the top of the tie bar during servo operation but stays engaged in the tie bar and does not drop out.

 

This is a huge relief. It was frustrating when I could see my first versions could never work, and I suggest, 12 mm is the minimum workable distance below the tie bar. On the strength of this experience I believe the YouTube demonstration of an installation using a 6 mm baseboard is flawed; the piano wire would foul a coupler and the builder never ran a train across it. I'll drop a friendly note to Dave, I have found most of his videos informative and rather better than his handbooks, but this one video sent me astray at the beginning.

 

I suppose it is a shame I have had to alter the factory settings on the servo controller, but I am pleased every servo is using the same settings. There is no custom set-up for individual servos, and if the board ever fails it will be straightforward to configure a new board.

 

- Richard.

 

Examples:

Edited September 7, 2020 by 47137
Added photo.

[ISW]

10 hours ago, 47137 said:

And, when I trim the piano wire flush with the tops of the rails, the tip of the piano wire dips below the top of the tie bar during servo operation but stays engaged in the tie bar and does not drop out

Richard,

 

That sound exactly like the arrangement I have on my layout. It'll be 'interesting' when I do the my Upper Level baseboards, as those are 9mm not 12mm plywood. I'm not expecting any issues though.

 

That's a very tidy installation in the photo.

 

10 hours ago, 47137 said:

I set the MegaPoints servo controller to give the maximum throw on the servo (I guess about 130 degrees).

Just be aware that there have been 'circumstances' where a servo has been incorrectly 'commanded' by the controller to do full deflection, and this results in the pivot arm effectively 'levering' the servo out of the aluminium U-channel. I know @young37215 has experienced this issue, and has posted a photo of the resulting piano wires sticking well above rail level. Thankfully, it's not happened to me, yet (!?). It's therefore recommended to cut the sides of the U-channel away at the pivot arm to alleviate this issue, something I can't do as I have a microswitch in the way. What I did instead was to put 2x M3 nut/bolt though the sides of the U-channel to 'clamp' the servo in place, hoping this will help. Fingers well crossed ...

 

Ian

 

[47137]

I have had my first of these "circumstances"!

 

One of my Peco points is very close to a baseboard support so I hit on the idea of trimming the little pip from the end of the tiebar and using the hole underneath. Very neat:

 

The idea here was to show the use of this little hole as a location where the up and down shuffle of the piano wire doesn't matter so much.

 

A few hours later, this servo threw a wobbly - I have no idea why - and ripped the piano wire out of the tie bar:

 

So - don't be tempted to use the holes in the ends of a Peco tiebar. They may be perfect for gentle little wire-in-tube applications, but not with servos.

 

Slots in the aluminium U-section would be a good idea but it is a bit late for me. All of my servos are fixed into their channels (I think!), with the U-channel squeezed tight and gap-filling cyano between the servos and their mounts. The slots would be sensible for the next layout, or I if need to renew a servo.

 

- Richard.

[ISW]

5 hours ago, 47137 said:

with the U-channel squeezed tight and gap-filling cyano between the servos and their mounts

Richard,

 

That's probably a lot easier to do than my M3 nuts & bolts, although my solution is easier to undo. Horses, courses, and all that ...

 

5 hours ago, 47137 said:

A few hours later, this servo threw a wobbly - I have no idea why - and ripped the piano wire out of the tie bar:

Did this cause any 'damage' to the servo installation? I've heard that it can 'lift' the servo out of the U-channel.

 

Ian

[47137]

No damage to the servo installation.

 

Fortunately I had had the presence of mind to drill a hole below the centre of the tiebar before laying the turnout. I was thinking of a remote linkage at the time.

 

I reworked the servo bracket to fit into the space. Functional if not pretty:

 

I wonder if there is a case for using Velcro to attach these brackets to the baseboard? Better an errant mechanism to fail by detaching itself in one piece than rip up the tiebar or strip the servo gears.

 

- Richard.

[ISW]

1 hour ago, 47137 said:

I reworked the servo bracket to fit into the space. Functional if not pretty:

Richard,

 

Blimey, that looks tight for space. You'll only get ~90-deg throw out of that servo, so I'm surprised that's enough to move the turnout. Just shows I'm using way more servo movement than is really necessary.

 

1 hour ago, 47137 said:

Fortunately I had had the presence of mind to drill a hole below the centre of the tiebar before laying the turnout.

I managed to miss the hole on a couple of turnouts, a double-slip if I remember correctly. I had to drill a pilot hole from above through the tiebar, and then, carefully, drill the 8mm hole from below. I did cause a 'little' damage to the sleepers, but nothing that shows from above. Lesson learnt, as they say.

 

Ian

[47137]

4 hours ago, ISW said:

Richard,

 

Blimey, that looks tight for space. You'll only get ~90-deg throw out of that servo, so I'm surprised that's enough to move the turnout. Just shows I'm using way more servo movement than is really necessary.

 

Ian, in fact the servo does manage its full range. My photo is misleading. I can take a better photo tomorrow.

 

This is a rather confined location under the baseboard and there is some distortion from the wide-angle lens. Here are two fresh shots, I think the throw is most of 120 degrees:

 

 

 

Anyway, it works.

 

I think I would need much a thicker road bed - perhaps 18 mm instead of 12 mm - to get enough tiebar movement from a 90 degree throw.

 

- Richard.

Edited September 8, 2020 by 47137
Added photos.

[young37215]

11 hours ago, 47137 said:

I think I would need much a thicker road bed - perhaps 18 mm instead of 12 mm - to get enough tiebar movement from a 90 degree throw.

 

Alternatively you could use one of the lower holes on the servo arm which would widen the arc of the throw. I spent yesterday fitting 8 servos all of which have the wire attached to the 4th hole down from the top. I reduce the range of servo movement to just a little more than the minimum required to change the point using a Megapoints Controller. 

[47137]

11 hours ago, young37215 said:

 

Alternatively you could use one of the lower holes on the servo arm which would widen the arc of the throw. I spent yesterday fitting 8 servos all of which have the wire attached to the 4th hole down from the top. I reduce the range of servo movement to just a little more than the minimum required to change the point using a Megapoints Controller. 

 

Do let us know how you get on, because when I used a longer throw the piano wire shuffled up and down too far and would foul a coupler. See this post and the ones before it going back to 4 September.

 

If all is well, then the root of all of my problems - and they caused a fair amount of grief - were the use of a 6 mm baseboard thickness. 

 

- Richard.

 

Edited September 9, 2020 by 47137

[ISW]

MegaPoints Controllers - A Power Supply

 

For my 12v power supply for the MegaPoints controller boards I have been using the recommended (well, it was in 2016) PS-101 power supply. This works just fine, but the noise from the cooling fan is just irritating. Maybe that's why MegaPoints themselves now sell a fanless power supply.

 

While on the hunt for a 12v replacement power supply, I discovered that the one used by old Microsoft Xbox 360s is a 12v supply. So I managed to pick one up for a ridiculously low price of £1.

 

The plug is proprietary in the extreme with 2-pins over 3-pins over 3-pins. A simple Google brings up the pinouts, which are essentially; 2-pins (on / standby), 3-pins (12v) 3-pins (ground).

 

Now I could have simply hacked the plug off, but it seemed a shame to ruin a perfectly good (if very cheap) power supply. So, I went onto eBay and bought a 'transfer' cable that plugs onto the end of the power supply. I then 'hacked' off the plug from the 'transfer' cable:

 

 

I soldered on a simple 4-pin socket, to which I could insert a 4-pin screw plug. The plug has the top 2-pins shorted (I could have added a switch) and this tells the power supply to be 'on' (& not standby). The other 2-pins provide the 12v.

 

Result, a nice cheap and decent power supply, capable of 14.2amps! Obviously, the MegaPoints controller will never draw anything like that (and my cabling wouldn't take it either), but it shows that the Xbox power supply will never get stressed.

 

Edited March 31, 2022 by ISW
photos re-uploaded

[ISW]

Lower Level Baseboards - Lighting

 

Having now installed the Upper Level baseboards, the Lower Level and the Ramps are a bit 'in the dark'. This situation cannot be allowed to remain as I will need at least some access to the Lower Level and Ramp tracks for routine maintenance, fixing derailments, and general viewing access for normal train running.

 

To alleviate this situation, the plan is to install LED strip lighting along the underside of the Upper Level baseboards. This will comprise short lengths of LEDs on both the front and back frames of the Upper Level baseboards. I did consider using the 'ends' of the Upper Level baseboards instead, to avoid having the rear lighting facing straight at me, but the Ramp tracks will probably cast too much of a shadow on the Lower Level tracks.

 

As usual, I'm doing this 'on the cheap' with some rolls of LED strip off theBay and a 12v DC power supply from a Car Boot! Yes, I know the Xbox power supply mentioned in a previous posting is probably more than capable of driving the MegaPoints controllers AND the lighting (and probably some more as well ...), but it's just feels more logical (and safer?) to keep the lighting entirely separate.

 

Here are the various bits powered up:

 

As with the Xbox power supply, I resisted the temptation to 'lop off' the plug, and used a socket with a short length of cable. The chocolate block connector is only temporary. Once installed, each length of LED will be run off a 12v bus cable looped around the underside of the Upper Level baseboards. That's another bus cable to install.

 

Edited March 31, 2022 by ISW
photos re-uploaded

[ISW]

Upper Level Baseboards - Tracklaying

 

And so, after quite a hiatus tracklaying has finally commenced on the Upper Level Baseboards. As I hadn't done any for quite a while I thought I'd be a little 'rusty' and so am continuing with one of the Ramp Tracks, specifically the 2-Track ramp.

 

The 2-track Ramp had previously 'ended' on Baseboard G. I've managed to extend these Ramp Tracks across the Ramp Baseboard H curve (Connection 2a), where it finally connects with an Upper Level Baseboard, Baseboard I. Tracklaying continued of these 2-tracks across Baseboard I, then J, round the curves of Baseboard A, and onto Baseboard B. If all this is the proverbial gobbly-goop, then the following Plan should help: 

 

I've currently reached the 2 turnouts at the top-right of Baseboard B.

 

It was certainly a good idea to use these tracks (which are effectively hidden in the final scheme of things) as a bit of a 'refresher' as my skills had, indeed, become a bit rusty! However, by Baseboard A I was getting back into the swing of things.

 

 

Edited March 31, 2022 by ISW
photos re-uploaded

[ISW]

Upper Level Baseboards - Turnout Installation

 

I am, to a large extent, repeating what I did on the Lower Level Baseboards but with a few tweaks. 

 

Tweaks - Definition: Fixing the glaring errors you made previously

 

This time I'm removing the stretcher bar overspring. It's not necessary with servo operation, and the 'click' of operation can get a little tiresome.

 

I would go back to the Lower Level turnouts and remove the spring, but levering up the small metal 'tabs' to remove / replace the cover is impossible with a foam underlay.

 

The crossing (frog) is electrically isolated by removing the 2 pre-soldered-on jumper wires, and the tongue rails electrically connected to the stock rails by adding new jumper wires. These also act as the power feeds for the turnout.

 

The crossing feed wire, pre-installed by Peco flops around a bit too much, and foam underlay doesn't 'clamp' it into any particular fixed position either. To fix this problem I simply superglue the wire in place and add some 'granular' powder to strengthen the glue (baking powder also works). 

 

I'll also be 'beautifying' the turnouts in the scenic areas by removing all superfluous plastic mouldings around the switch toe.

 

One key advantage of a foam type underlay (as apposed to cork or no underlay at all) is that there is no need to remove the sleepers at fishplated joints. All that is required is to cut away the rail fastening, to allow the fishplate to slide through. The sleeper is 'pushed down' very slightly, but this is easily accommodated by the foam underlay.

 

Edited March 31, 2022 by ISW
photos re-uploaded

[young37215]

56 minutes ago, ISW said:

the 'click' of operation can get a little tiresome.

 

I agree with the sentiment but the click is a useful audible check that the servo has actually changed the direction of the point! I speak from experience when I say the servos (or more probably the servo controller) can change their range of movement without any apparent intervention on the users part. I value the click because it reduces my chances of derailments. 

[ISW]

33 minutes ago, young37215 said:

 

I agree with the sentiment but the click is a useful audible check that the servo has actually changed the direction of the point! I speak from experience when I say the servos (or more probably the servo controller) can change their range of movement without any apparent intervention on the users part. I value the click because it reduces my chances of derailments. 

Rob,

 

Indeed a valid point, however the 'click' somehow seems to detract from the 'realism', whereas the whirr of the servo feels right.

 

Fingers crossed it'll work correctly as I really don't fancy retro-fitting the springs; if I can even find them on the carpet where they tend to 'ping' to on removal!

 

Ian

[ISW]

Upper Level Baseboards - Tracklaying

 

With the 2-Track ramp now extended up onto the Upper Level baseboards, it was time to tackle the 3-Track ramp connection to the Upper Level baseboards. This occurs at the junction between Baseboards B and C (see previous posting for 'map').

 

As the whole layout has been drawn up in software and printed out (boy, did that take a lot of paper, and a lot of tape to join it all together), I have a printout for each Baseboard. I transfer the layout from paper to the Baseboards by the simple expedite of prodding a bodger (sharp nail with handle) through the paper on the track centrelines at regular intervals. I then, err, join the dots using a 1m straight edge and, for the curves, my box of railway curves (very handy).

 

Here is a view looking along Baseboard B, with Baseboard C in the background. Salient 'features' have been annotated for your ease of understanding:

 

If we now move to the Baseboard B/C interface, you can see the 3-Track ramp appearing Top-Right in the view below:

 

In both views, Upper Level Baseboards C & D are removed to gain suitable access for marking out and subsequent tracklaying. You can see the advantages of having the layout in removable sections.

 

It's nice to be making some progress again, although the lack of some turnouts (despite being on order since mid-July) is going to hamper things somewhat.

 

Ian

 

Edited March 31, 2022 by ISW
photos re-uploaded

[saxokid]

Some very nice work here Ian.

 

 

cheers neil

[ISW]

10 hours ago, saxokid said:

Some very nice work here Ian.

 

 

cheers neil

Neil,

 

Thanks for the compliments. I hope you find something useful in my ramblings and/or learn from my mistakes.

 

Ian

[47137]

On 01/10/2020 at 15:42, ISW said:

This time I'm removing the stretcher bar overspring. It's not necessary with servo operation, and the 'click' of operation can get a little tiresome.

 

I would go back to the Lower Level turnouts and remove the spring, but levering up the small metal 'tabs' to remove / replace the cover is impossible with a foam underlay.

 

Ian, you should be able to open up the little metal tabs with a jeweller's screwdriver. Having done this, you can discard the cover and cut the tabs off flush with a cutting-off disc in the mini drill. (I find myself with my eyes very close to the action doing this, and eye protection really is a must).

 

I decided to remove the springs, but I then put the little covers back, and I'm now thinking the turnouts look better without the covers.

 

- Richard.