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  • 2 weeks later...

Just a short interlude:

 

Hedging

 

The other day I found a short and simple recipe to make Hedges – the result being really convincing.

 

It’s a matter of personal taste, I know, but I do not like trees which look like a trunk with dumplings above nor do I like bushes resembling lumps. From my window I have a tree in view and can see the sky between the leaves. Every day! No clumping of green.

 

 

Therefore I was keen to try out the idea I saw in www.Stummiforum.de: get a stripboard (may well be used), cut a row and thread short pieces of 0.3mm wire through the holes.

 

Spray with glue, add the well known filter fibres (or some other better suited stuff*)). Spray grey (real bark very seldom is brown), spray glue again, then leaves to taste. Embed.

 

 

The result can be partly be seen through (depending on the amount of glue and leaves in the last step, of course) – and that’s what I prefer:

 

post-12822-0-04478300-1445024571.jpg

 

post-12822-0-83641300-1445024588.jpg

 

post-12822-0-94941300-1445024602.jpg

 

post-12822-0-94399900-1445024625.jpg

 

Armin

 

 

*) my “invention” are cocos or sisal fibres (Aldi & others sell doormats made of these) instead of the usual filter fibres. I cut these to various lengths (max 1cm) and sprinkle them onto the wires. My preferred method when I make trees – looks like that then:

 

post-12822-0-70541000-1445024661.jpg

 

Much less tendency to clump…

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Playing around

 

In post #97 above I pondered about trying out a proposal for powering a MONORAIL loco – see Stubby’s thread.

After a longer think I decided to give my idea a try and searched my boxes for the needed parts. There’s not so much needed: a decent piece standard track, several reed switches, a latching relay, a LED, two batteries and an otherwise idle wagon.

After the missing parts had been ordered and arrived, I learned how to wire a latching DPDT relay and bodged my test rig (Heath Robinson type) together.

 

It is not the real thing (i.e. a monorail loco driven by a real prime mover), rather just a manually pushed wagon with a LED that proves the constant flow of current. Also, I use not a real single rail, but one rail of normal track (the other rail has the wagon upright and is unpowered).

 

The concept is that the rail is sectioned and that near each gap is a reed switch (closing type) located; under the wagon bottom there is a magnet. The reeds are wired in parallel and – by closing a circuit – send a pulse to the relay. Thus each of these pulses switches a second circuit powering the monorail sections. The trick is that I use a DPDT latching relay.
The power is transferred to the motor/LED through the leading and the trailing wheel; these must always have contact to two subsequent rail sections.

 

One could also simplify things by using DPDT reeds and power the monorail sections directly through these. Of course this would employ a really simple circuit: no more than an ladder of reeds wired in parallel: 

 

post-12822-0-20068100-1445619695.gif

 

    

However, the devil is in the detail: reed switches are prone to arcing and welding if currents as normal with O scale locos (Stu in the meantime has decided to go to 1:35!) are involved. High current reeds can be bought but are expensive… In addition such reeds must switch simultaneously with the travelling of the wheels over the section gaps. Bad alignment here would result in series of short circuits…

The use of a relay allows much higher currents and eliminates any problems with simultaneity.

That is the circuit I designed:

 

post-12822-0-18450900-1445619736.gif

 

 

This all looks rather complicated, but ImhO it isn’t:
– a row of several cheap reed switches,
– two buses instead of one
– plus a latching relay.

The additional cost of the latter is much less than the cost of many DPST reeds.

Oh, nearly forgot that this requires a proprietary power source for the reed bus – a 4.5V battery will do and that's what the reed contacts prefer (instead of ~1A track current).

 

To make the whole thing work, some measuring is required: the length of the sections must equal the wheel base (in my case it’s 40mm); the same is valid for the distance between the reed switches. An important point, precision is needed!

Now to the “laboratory”. This is the track – cut into six sections and already wired to its bus:

 

post-12822-0-20230900-1445619877_thumb.gif

 

 

And this is the row of reed switches – glued to a strip of card and wired to the relay with connection to the battery pack:

 

post-12822-0-75942200-1445619908_thumb.gif

 

 

The card strip maintains the distance of the reeds (40mm) and allows subtle shifting of the row of reeds in order to align them with the section gaps.

 

All together now – the card strip with reeds is positioned under the sleepers (therefore the two white foamcore strips):

 

post-12822-0-28681700-1445619942_thumb.gif

 

 

The LED can be seen in the following short (15sec) video clip. To attach it (the LED, of course :stinker: ) and to ensure contact I found a surprisingly simple way: drilled two small holes into the bottom, pushed the leads through and – alas! – they were quite near the wheel tires… No additional wipers needed! A bit CA glue, a bit bending and we have another example of Heath Robinsoning…  :boast:  :boast: 

 

An interesting point: as I did the first trial runs the LED was alight only as long as the wheel(s) had travelled some 2mm into the following section. I fiddled around quite some time with the magnet (round neo type), added more etc. Until I replaced it with a smaller magnet – now it works as wanted! The old strong magnet tripped the reeds several times – how, I don’t know…

 

The wagon I used was of uncertain pedigree and had well (??) wheathered wheels. I tried to make the tires shiny, not yet really successful. Therefore the flickering of the LED in the following video:  

 

https://youtu.be/th00VOto4ck

 

It shows that the LED is supplied with current while being pushed over the six rail sections.

 

Relief!   :sungum:  :boast:  :sungum: :boast:   :sungum: :boast:   :sungum: 

 

Your comments are welcome.

 

 

And now – finally – back to the topic of this thread: the Port layout…

 

  Armin

 

 

PS: no, not yet back to the layout. First (Saterday) I must visit the US-Modellbahn Convention in Nieder-Roden. 

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  • RMweb Gold

Many thanks for all of this - very humbling anyone would take so much effort on a theory for someone else's mad idea !

 

If I understand this correctly - alternate sections of track are fed from opposite polarity - but the polarity itself is switched (the whole of the track) alternately between Positive and Negative.

 

So section 1 is +'ve, section 2 -'ve, section 3 +'ve, and so on

 

Then the relay is triggered (via the reed switch and the magnet) and all sections change their polarity

 

So S1 is now -'ve, S2 is +'ve, etc

 

Provided the gaps in the track are the same distance apart, the wheels will swap sections at the same time the polarity is switched.  Any momentary short as the wheel touches both sections is counteracted by the velocity of the vehicle and the momentum from a flywheel.

 

I think I understand everything so far.

 

But.....

 

I'm intending to use more than one wheel for each pole (two under the loco and two under the coach), to provide a more certain current collection.  How will this circuit cope if the wheel set for the loco straddles the section break between the track ? 

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The wheelbase of the coach must be identical to the wheelbase of the loco. The distance between the loco trailing axle and the coach leading axle must match this too. On the bright side, with this arrangement there will always be two wheels collecting current and two wheels returning current, except at the rail breaks. It is important to never bring the train to a halt on the rail breaks. Both loco and coach can have extra wheels for show, but they would probably have to be compensated so the pick-ups keep working on any uneven points or changes in gradient.

 

The whole thing seems a brilliant way to get into "finescale" without all the worry of choosing between 00-SF and EM and P4 :-)

 

- Richard.

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Many thanks for all of this - very humbling anyone would take so much effort on a theory for someone else's mad idea !

 

Just because it's fun – to me!

 

If I understand this correctly - alternate sections of track are fed from opposite polarity - but the polarity itself is switched (the whole of the track) alternately between Positive and Negative.

 

So section 1 is +'ve, section 2 -'ve, section 3 +'ve, and so on

 

Correct!

 

Then the relay is triggered (via the reed switch and the magnet) and all sections change their polarity

 

So S1 is now -'ve, S2 is +'ve, etc

 

Provided the gaps in the track are the same distance apart, the wheels will swap sections at the same time the polarity is switched.  Any momentary short as the wheel touches both sections is counteracted by the velocity of the vehicle and the momentum from a flywheel.

 

Perfect – see the second drawing there.

 

I think I understand everything so far.

 

You do.

 

But.....

 

I'm intending to use more than one wheel for each pole (two under the loco and two under the coach), to provide a more certain current collection.  How will this circuit cope if the wheel set for the loco straddles the section break between the track ? 

 

Then we have a problem.

Wait a bit – must (!) first visit the US-Convention in Nieder-Roden…

Will revert later this evening.

  Armin

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  • RMweb Gold

Things might be a little smoother, and allow multi wheel pickup with more sections. In my imagination, I want two (or more) sections with one polarity, then an unconnected section, followed by two of the opposite polarity. As long as the leading and trailing pickup spans are shorter than the powered sections and the inter pickup gap is longer than one section, current flow should be continuous. It also means that the individual sections don't have to be precisely the same. I think...

 

Will do diagrams if needed!

 

Thanks

 

Dave

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But.....

 

I'm intending to use more than one wheel for each pole (two under the loco and two under the coach), to provide a more certain current collection.  How will this circuit cope if the wheel set for the loco straddles the section break between the track ? 

 

I admit that I never touched anything larger than H0,

But I imagine that a 1:35 loco should have enough weight to go with one-wheel pickup?

Fly wheel, KA capacitor and/or - last but not least - ATF may be of help.

 

 

 

But now the latest news:

 

 

Surrender!

 

The K.I.S.S. gang wins!

 

No moving parts, just two cheap Bridge Rectifiers… Brilliant!

 

That’s my view of the thing: as the train rushes (or trundles) over the track sections it “senses” nothing than an Alternating Current – regardless where its wheels touch the rail. This AC is rectified. Period.

 

Taking my hat off to… the noname problem solver (need not subscribe to that ominous school!)

 

Regards

   Armin

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  • RMweb Gold

My turn to apologise for a thread hijack.

 

This project may be 1:35 scale, but the prototype loco's wheelbase is only 3'11", which equates to a scale length 34mm. This makes the loco no longer than a 3F or Pannier.

 

Therefore there will be little natural weight in the loco or the coach. Plus the more wheels the merrier.

 

I'm now musing over how to insulate the wheels & connecting rods...

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A small thread hijack re making papier-mache from toilet paper - Many years ago I successfully dropped a toilet roll into the porcelain receptacle (which was unused at that point, fortunately) and decided that rather than throw it away, I would dry it out in a microwave - PLEASE DO NOT DO THIS! - the roll heats from the most dense bit outwards as I found out, and starts to burn from the tube in the middle - I got it outside. and dumped it in the metal dustbin, and then we popped out to the local shop  but it sat and smouldered on a fine, sunny summers afternoon, for around three-quarters of an hour - needless to say the smell of charring wood (which is what it is!) spread all down the street - it was a hot day, and everyones windows were open................

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Jack , maybe a hijack, but good advice. I have tried using microwave on some of my mashed paper models, but found it was not drying faster so gave up. Best way is to leave in nice warm room. Airing cupboards are very useful, but planning around long dry times is best approach. Put it to one side, forget about it, do something else and the job gets done without any worry.

On the subject of drying out a sodden toilet roll, again the airing cupboard is best place. One reason I kept conventional hot water tank was for the lost heat I could use, and although most of the space is used for cottons etc, there is a nice but small space next to the tank.

 

I have tried using a hot air gun to speed dry some models. It does actually work, but you have to keep an eye on it as bits will suddenly start to burn when they get dry enough. Have not set off smoke alarm, yet!

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  • 2 weeks later...

Sorry for the delay in writing this up…

 

Already a fortnight ago I visited the US-Modellbahn Convention in Nieder-Roden (not far from Frankfurt am Main).

 

There I took several photos (posted there) and checked the offers of the various vendors. Had to keep my wallet tight, very tight!

 

So I secured just a few little things – not so much, ‘cause there’s not much room on my small layouts.

 

Here we are:


post-12822-0-23149600-1446831067_thumb.jpg

 

 

 

The Oil Tank is the first plastic kit I will try my luck at – wish me all the best…

 

Again I welcome any comments. Thanks everyone.

 

  Armin

 

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Depending on your era / local laws, the oil tank may need a bund - a surrounding water tight enclosure big enough to contain the entire contents of the tank, should it develop a leak.

 

....usually built of bricks & about 2-3ft high, (from my experience).

 

Calm down, gentlemen, calm down…

 

Already in the pipeline, this thing.

Must just find the proper brick paper…

 

But many thanks for your interest!

 

Regards

  Armin

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Quayside Oil Tank

 

 

Wasn’t soo difficult!

The five elements were quickly MEKed together, then sprayed dark green. Also, the piping was a simple thing. Here mocked up on a scrap piece of MDF:
 

post-12822-0-57888400-1447274136_thumb.jpg

 

 

As I was told, a Bund Wall is needed to confine possibly spilled oil; would otherwise contaminate the soil and – much more problematic – the nearby water. Well, here are the needed parts (foamcore + 4x card):

 

post-12822-0-84554200-1447273734_thumb.jpg

 

 

All glued together, duly covered with fitting paper (concrete slabs & brick), coping added. Tank weathered and put at its place, gives this picture:
 

post-12822-0-83504100-1447274190_thumb.jpg

 

 

Easy peasy. I like it… You too?

 

Always grateful for comments.

 

  Armin

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In my job, I test software. I have to think, if it does this, what else is affected ? If that happens, what happens next ?

 

Without trying, I find myself applying this thought process to modelling.

 

So, an oil tank, it needs a bund wall, which needs a way in. It will also need pipes, and valves. Are the valves electric, if so, where is the control box, how does the box get power ? Cable, or overhead supply ? If the vales are manual, where do the operators stand - on the ground ( on what - gravel, brick, concrete ?) or on a raised platform ?

Will the tank be used at night, so does it need lights ?

 

Yes, these are details, which may not be necessary, but if all of the expected items are there, the picture looks right without you realising why.

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  • RMweb Premium
This is an attractive model and I might end up with something similar on my own layout - a tank and pump for loco refuelling up together.
 
I have a feeling, the control and pump box should be outside the bund, for ease of maintenance and for protection in case of a spillage. Access to the tank would only be needed for periodic inspections and maintenance, so Stu's steps could be temporary or portable.
 
The model reminds me of a small tank for heating oil at a museum near me:
post-14389-0-06641500-1447412962.jpg
 
Inlet
post-14389-0-51784500-1447413005.jpg
 
Outlet
post-14389-0-06249200-1447413025.jpg
 
I hope this is helpful and not critical.
 
I didn't see a No Smoking sign anywhere :-)
 
- Richard.

 

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