Jon Fitness' average 7mm signals workbench.

[Jon Fitness]

Wasn't sure whether to blog or thread this, but I'll start with a thread and see how we go. I've built a few 7mm signals for a mates (sadly now defunct) garden railway and they were mostly operated by solenoid point motors. As we've moved the signals to the new indoor layout I've thought about maybe powering them with micro servos and to this end I've got some bits from MERG http://www.merg.org.uk/ and I'm giving it a go. So...this is the first signal. It's a scratchbuilt ex LMS upper quadrant 3 doll bracket thats now a gantry (er...don't ask..yet.)

This is one of the servos (digital prodder thing to show size)

This is the kit of bits that will be a driver unit for up to 4 servos (If I can fathom it out)

And this is a box of bits that will program the servo driver to do as it's told. (How much travel and how fast or slow etc) If I don't fry the contents with the soldering iron that is...

I'll update with words and pics as I progress. Feel free to comment/help/laugh as required.

More Soon

JF

Edited June 23, 2016 by Jon Fitness

[Jon Fitness]

Well........this is my first attempt at assembling a circuit board. It is the driver board for the servos for the signal.
made one mistake which has probably totalled the big capacitors (got them the wrong way round then tested the board..they got a little warm )
It still went through the circuit tests as per instructions but I won't know for sure whether it works until I've made the programming box and can couple up a servo.

Still, if I have knackered it, £4 for a learning curve isn't too bad

Edited June 23, 2016 by Jon Fitness

[Ressaldar]

Hi Jon,

 

great to hear from you. This could be the start of some interesting ideas and photos. I look forward to the next episode.

 

regards

 

Mike

 

 

[dikitriki]

Hi Jon

 

This is very timely.

 

With some 20 plus signals to build for Heyside, all servo controlled, I'm looking forward to lots of good ideas. I am very envious of your speed of construction, and how fast Saltney has risen from the ashes.

 

Regards

 

Richard

[Jon Fitness]

Hi Mike and Richard,

As this electronics lark will be a steep learning curve, I'll try not to mislead everyone with my relative incompetence!

I think I've already fried the capacitors by putting them the wrong way round

[beast66606]

Hi Mike and Richard,

As this electronics lark will be a steep learning curve, I'll try not to mislead everyone with my relative incompetence!

I think I've already fried the capacitors by putting them the wrong way round

 

If it passed the tests they should be fine ...

[Jon Fitness]

If it passed the tests they should be fine ...

 

Fingers and eyes crossed!

I'll be starting the programming box tomorrow but theres a lot of prep work to do before I get to the circuit boards.

[Jon Fitness]

Done some work on the programming box for the servos.
The case has to be prepared to accept the switches, buttons and 9way D connector. Overlays are provided to help you do this and also for the mounting board that holds all the "gubbins" inside.



3 resistors have to be soldered to each rotary switch and a bit of pre-wiring done to the pot.



After struggling to understand most of the simplest instructions, all thoughts of neatness went out the window and I just wired it up literally using the diagram....which (as I see it) doesn't quite agree with the markings on the circuit board. Some re-wiring to do then

More Soon

JF

Edited June 23, 2016 by Jon Fitness

[signaller]

Jon, if all else fails, I have a programming box that you are welcome to borrow.

 

Cheers

Roger

[Jon Fitness]

Jon, if all else fails, I have a programming box that you are welcome to borrow.

 

Cheers

Roger

 

I may well have to!

Jon F.

[Jon Fitness]

Right-oh.....
Had a big session with the soldering iron and after lots of muttering, burnt fingers, reversing 10 wires and repairing pcb tracks, I was sort of ready for a test.
This lash up, believe it or not, when connected to a 9v battery actually worked





I had a play with all the buttons and the servo did pretty much what it was told to do so after disconnecting everything, I boxed it up and away we go on the next stage.





Which is mounting 4 servos under the signal

Edited June 23, 2016 by Jon Fitness

[beast66606]

Its a lot easier with an NX panel

[Jon Fitness]

Its a lot easier with an NX panel

Not if Chester S&T are looking after it......

[Guest Digital]

Superb work John and some nice soldering.

 

I powered mine with some modified Tortoise point motors Signal Demo video at bottom of page.

John

[Jon Fitness]

Nice little demo there John. Hope to get back to this project when I've finished the goods shed for the layout.

JF

[arff999]

Hi Jon

Have you ever made them in 4 mm if so you fancy making some more, im in need of some for my layout, im not bad with a soldering iron but i dont fancy making these they look pretty hard.

 

JOHN.

[Jon Fitness]

Hi Jon

Have you ever made them in 4 mm if so you fancy making some more, im in need of some for my layout, im not bad with a soldering iron but i dont fancy making these they look pretty hard.

 

JOHN.

Hi John,

4mm scale? Way too small for me I'm afraid. My "sausage fingers" can only just manage 7mm scale

Jon F.

[-missy-]

Hello Jon

 

I am following this with interest. The most recent photos all look a bit fimilar to me as I have just been doing exactly the same thing on my layout although for point control right now, the signals will come soon. The MERG servo stuff is very useful and so adjustable, I dont know about you but I am very happy with the results.

 

Missy

[Jon Fitness]

Hi Missy,

Good to know you're having success with the MERG stuff B) I may be asking for advice soon . I've come to a temporary stop on this project due to other jobs taking preference but I'm getting "itchy signal fingers" so I'll be back into it shortly

Cheers

Jon F.

[Jon Fitness]

An average 7mm scale signal.

Haven't had any time to get stuck into the servo operated gantry recently, but as I have been asked to build a couple of simple signals for another layout, I decided to photograph each step as I built one. I've also been asked how to add lights to a signal so I'll combine the 2 jobs!

It's not an attempt to win any prizes (I'm not that good) and I realise there are many ways to do this but it's a basic guide to building a simple workable LMS/BR(M) tubular post upper quadrant stop signal from brass etc.

I'm doing it with the intention of showing people who maybe haven't attempted a signal but fancy trying one.

Please bear with me while I go through the basics. (And feel free to add comments, good or bad!)

The build process will have photos of 2 signals but they are both basically the same.

Here goes then.

Your typical average 20' tall tubular post signal can be made either from a kit from one of the suppliers such as Model Signal Engineering or Scale Signal Supply or you can scratch-build one using a mix of readily available brass tube and parts from the aforementioned suppliers, or even a few home produced bits as I do.

The tubes for this signal post are from the K&S range. The upper part of the post is from K&S No 127 which is 3.2mm diameter and is a sliding fit into the lower part (K&S No128) which is 4mm diameter. These equate to a scale 5.5 and 6.5 inches and are pretty close to scale size. The tube for the arm pivot needs to be 1.5mm with an internal diameter of 1mm.

There is a basic rule for the dimensions of the posts; For signals up to a total of 22 foot tall the lower part of the post is a scale 7' 3'' from ground level to the change of diameter and 11'' for signals 22-30 feet (after 1944 this was increased to 35').

The tubes can be cut with a good substantial craft knife by rolling the tube back and forth under the blade. Use a firm pressure and keep the blade square to the tube ensuring you have a single cut mark. Do not attempt to cut right through, just leave a good clean score mark. The tube can then be snapped cleanly. This works like a plumber's pipe cutter but without crushing the tube!





You can use this method to cut the upper/lower post tubes, allowing about 7mm extra on the thinner tube to slide into the wider portion. The wider tube needs to be chamfered around its circumference where it will meet the thinner tube. Rotate the tube between finger and thumb whilst holding the file against the edge


At the same time cut an 8mm length of the 1.5mm/1mm tube for the arm pivot.


A baseplate can be cut from brass strip. K&S make a suitable size which is 25mm wide. Mark off a 40mm length using a square and scriber and cut this off with tin snips. I also cut off the corners with a view to rounding them off later! (Doesn't always get done!)





Scribe a line up the middle and mark a cross about 7mm in from one end.


As my drilling abilities are a bit dodgy I usually drill a 3.5mm hole at his point then carefully widen it out with a tapered broach so the wider part of the post is a tight fit on the hole. This will help later when soldering the post vertically in the hole (Every bit of support helps!)



You now have your basic components for the signal post. The small component in the picture marked "concrete" base, is meant to represent the concrete foundations that the post was set in when planted in the ground. I find that this tends to disappear under ballast on a layout so my preference is to omit it..


Now all the bits are prepared, clean up the brass ready for soldering. The labels that K&S apply leave glue behind; this can be wiped off with a bit of white spirit and the metal burnished with a glassfibre brush.

More soon.
Jon F




 

Edited June 23, 2016 by Jon Fitness

[Jon Fitness]

Now you have your basic signal post bits, it's time to join them together.

Time to fire up the soldering iron!



First, coat the end of the thinner post tube (about 7mm will do) with a thin layer of solder. I have used a liquid flux and Carr's 188° solder and a 25watt iron.




Apply more flux to the end of the tube and insert into the wider one and lay it down on a piece of scrap wood. Check the alignment by rolling the tubes back and forth a little. Clean the tip of the iron and apply to the joint until the solder runs. Re-check alignment. If it's moved, re-heat and re-set until correct.


Set the baseplate on your piece of wood and see if the post will stand unaided in the hole. (Hopefully it will!) If you are using one, slide the little "concrete" base ring (yes I know it's brass!) down the post on to the base plate.

Some of you may have an eye for vertical but I still have a check with the engineers square before I solder the post up. In this case use of the square is made a bit awkward by the base ring but it looks pretty much ok.



Apply plenty of flux, a hot iron and some solder to the joint. You may have to be patient while everything warms up but once the solder flows then cools you will have a strong joint. Re- check for correct alignment. If it's not right, re-heat, adjust and allow to cool





When the post assembly has cooled you can now fit the pivot tube for the arm.

Mark a point about 7mm from the top of the post, bearing in mind the orientation of the pivot to the baseplate (don't laugh, I still get wrong sometimes!) Looking head on at the signal it's on the left side and in line with the baseplate.



Prepare the short length of pivot tube by applying a little solder to it. You can keep the tube still by having a piece of wire through it and holding it down on your piece of wood. Try not to solder the tube to the wire (yes I still manage to do that as well..)



Set the post assembly down on the wood with the baseplate facing longside left (try it you'll see what I mean) and apply some flux to the area where the mark is for the pivot. With the wire still in the pivot tube, place it on the post at the mark as in the pic and apply the soldering iron to it. Once the solder has flowed remove the iron and allow to cool. The joint should be as in the picture.




Time for a signal arm to hang on your post but that's for next time..

More soon..

JF.




 

Edited June 23, 2016 by Jon Fitness

[darren01]

HI

This top work ,as i am about to start building my first MES signal,so will follow this with Interest

All the best

Darren

[Jon Fitness]

HI

This top work ,as i am about to start building my first MES signal,so will follow this with Interest

All the best

Darren

Hi Darren,

 

Building an MSE kit is much the same (without all the hassle of cutting things to size) so I hope this helps. Good luck fella

 

 

 

 

[Jon Fitness]

OK, lets put an arm on this signal.

Although I use my own cast whitemetal arms, the methods for etched brass arms are much the same.

Choose your arm and solder a spindle to it I have a preference for using 14BA bolts as spindles as you can lock everything up with a nut on the back while you fix everything else on to the post that needs aligning with the arm. One of the advantages of a whitemetal arm is that I can screw the bolt into it and undo it anytime should I need to.




Set the arm to the On or Danger position (horizontal) and make a mark on the post, just above the little operating arm. This will be for the arm stop, so that the arm cannot droop below horizontal. (Nowt worse than a bit of droop!.)





Drill a 0.8mm hole right through the post and insert a length of 0.8mm wire through just far enough so that the signal arm rests against it in the correct "on"position. Remove the arm from the signal, snip the excess wire off the back of the post, and solder both sides using a lower temperature solder such as Carrs 145°. This should avoid melting the solder on the pivot tube (hopefully!)




When cooled, clean up excess solder, stand the post up, place the arm in the pivot and you should have the startings of a presentable signal.




Lamp, LED and associated wiring next.



More soon..

JF.

Edited June 23, 2016 by Jon Fitness

[Jon Fitness]

With an arm now on the signal, you'll be needing a lamp behind it. I like to have working lamps in my signals and I have had a request to show how I fit these so here goes.

I use my own cast whitemetal combined lamp/bracket that has a 3mm hole for an LED to be fitted from the back but similar products are available from MSE or SSS. Some of these are designed to have a bulb fitted from underneath but the basic idea is the same.

Looking at the back of the lamp casting, drill a 0.8mm through hole in the lower left corner.



Bend the shorter leg of the LED (the "negative" terminal) back on itself as per the photo and thread it through the drilled hole. The body of the LED should locate in the larger hole (DO not glue it in!)

Where the short leg fits in the little hole, apply a bit of flux and secure it with a quick dab of 145°solder. This will be enough to hold it in position and enable you to change the LED should it ever fail without destroying the lamp casting. At this stage, trim the protruding leg of the LED from the front of the lamp case but leave the other one until the wire is attached later. Keep the cut off LED leg as you can use it as a ladder stay later!






With the arm in position, make a mark on the back of the post just below arm level and drill a 0.8 mm hole in the post. This is for the lamp wire. I use some very fine equipment wire I got from All Components which is thin enough not to show up too much but strong enough for the job.



With the signal post secured so it won't move (in a vice preferably) and the arm set to danger, offer up the lamp case to the post and align the LED with the arm. This the fiddly bit! Apply a bit of liquid flux to the joint and while holding the lamp case in correct alignment, carefully solder it to the post with 145° solder. I use a 13watt Antex soldering iron for this job. When cooled, check that the arm clears the lamp when it swings up and down and the LED aligns correctly with spectacle holes on the signal in both positions.




Cut a length of wire off about 3" longer than the signal and bare about 7mm off one end. Thread the plain end into the hole in the post until it appears at the 'ole at the bottom. Pull it through, leaving just enough to allow you to solder the wire to the long leg of the LED. Wrap the bared section around the long leg, tuck it as close to the back of the LED as possible and check it's not touching the other leg. Carefully solder this on with electricians solder.




Trim the long leg off the LED as close to the wire as you dare and retain the offcut. These make useful ladder stays!



To complete the electrical circuit, solder an earth or negative wire to any convenient metal part (I usually drill a hole in the baseplate near the bottom of the post and fasten the bared end of the earth wire to it ) so that it will run next to the live wire from the LED. These 2 wires can then be taped together o run a sleeve of heatshrink tube over them.

Solder a 1000 ohm resistor to the positive lead, bare a little bit of the earth wire and you are ready to test the lamp.




The 1000 ohm (1k) resistor enables you to connect up 12v dc from your model railway supply or even a 9v battery.



Let there be light!

More soon

Jon F.

 

Edited June 23, 2016 by Jon Fitness