14 January 2015.
- Text related to using wire handrails and etched ladders added to first paragraph.
- Comment related to 3D printed counterweight levers on signals removed. These are no longer printed on signals.
- Extra information about the use of glues added.
- Painting and lighting of signals sections amended.
- Instructions on how to cut the detail parts away from the sprues.
- Extra instructions when drilling the counterweight lever arm to stop the arm from bending and possibly breaking.
- Replaced photo of bracket signal rodding order.
- Added some references to HO Fine Detail signals, ladders and safety handrails, wire and drill sizes for 7 mm Scale.
Introduction
It is advised that the following construction details are followed particularly in relation to the installation of the various wire operating rods.
The bracket signals are of the type that have bellcranks not wheels to transmit the action to the signal arm and of course this is usually achieved with wire not rods. Wire though is not really possible in HO scale due to the lack of weight of the counterweight to hold the wire taut.
These instructions are based around a bracket signal as this is the most complicated signal. The same processes are to be followed for the simpler signals.
If you wish to have finer handrails and ladder they may be cut away with transistor cutters after the existing printed handrails have been used as a guide to bend up some wire handrails. The post and the landings could be drilled at the printed attachment points to accept the wire. For HO use some of the 0.15" (0.032" for 7 mm Scale) phosphor bronze wire listed below. Etched ladders are available from several sources.
Tools and Other Materials Required
The following tools and other items are required to complete the signal:- 2-56 x 1/2” black acetal plastic or metal screws available from Kadee are required for the operating mechanism adjusting screws, alternatively 8 BA x ½” screws can be used. These screws (or some other equivalent) must be used as a small head is required to clear the adjacent screw(s) on multiple arm signals.
- #4 x 6 mm self-tapping screw available from Jaycar (HP0550) for attaching the main crank to the mechanism mounting.
- 3 mm M3 washers available from Jaycar (HP0431) or 1/8” similar washers to hold the cranks on.
- HO - The signal operating rods are 0.015” Tichy Train Group Phosphor Bronze wire (Part No. #1102 - 12 x 200 mm lengths in a pack).
- 7 mm Scale - The signal operating rods for are 0.032” Tichy Train Group Phosphor Bronze wire (Part No. #1105 - 12 x 200 mm lengths in a pack).
- Below baseboard operating rods are 0.032” Tichy Train Group Phosphor Bronze wire (Part No. #1105 – 12 x 200 mm lengths in a pack).
- 0.4 mm or a No. 78 drill bit for wire operating rod holes in the parts on the Fine Ultra Details sprue.
- HO and 7 mm Scale - 0.45 mm or No.77 for White Strong Flexible main operating crank.
- HO - 1 mm or alternatively a No. 60 or 61 drill bit is required to clean out HO signal arm pivot hole on post and to drill the hole in the bottom of the main below baseboard crank for the operating rod to the servo or other mechanism (relay, push rod, bowden cable or other arrangement including manual).
- 2 mm or 5/64” drill bit used to clear screw holes in main operating mechanism of remaining nylon powder from printing process.
- A pair of transistor nippers (side cutters).
- A selection of small and very small paint brushes are required, e.g. 1, 0, 00 and 000.
- Various paints listed below
Signal Arms and other small parts are best painted (at least partly) while still on the sprue. The undersides of the signal arms can be painted after they have been removed from the sprue and the support is cut away from the black band area on the back of the arm.
Please note that the finials and other small parts will detach very easily so it is probably best to remove these and put them aside before too much handling of the sprues. The finials will be painted later once glued to the post top.
The cast iron support for the bracket signal is separate so that the detail can be appreciated and so that the inner parts of the beams and bottom of the slatted timber deck can be painted cream. The cast iron support can be painted cream before gluing it in place but don’t paint the edge that will be glued to the post or the top of the small brackets on the outer end which will also be glued to the underside of the beams.
Spray the signals with white acrylic matt paint to seal the surface of the White Strong and Flexible particularly where other colour paints will be as the sintered nylon powder of the model is absorbent and the black paint for instance will seep into the signal and spread away from the part being painted. The white acrylic sealing coat prevents this. Several coats may help but only use one coat on areas that glue will be applied to such as the post top (finial) and on the post for the cast iron bracket support.
Interestingly, once sealed, the rough surface seems to help with controlling the application of the various colours, that is, it doesn’t flow everywhere.
It is best to use only matt (flat) paints as the rough surface of the signal will be pronounced with a shiny surface.
The suggested colours for painting are:
Primer seal coat – Brushed or sprayed matt white acrylic (your choice of brand)
Light Stone for decks – Humbrol 103 Matt Cream or Humbrol 148 Matt Radome Tan
Black trim – Brushed matt acrylic (your choice of brand)
Red for signal arms – Humbrol 60 Matt Scarlet
Photos can be used as reference for painting the signal arms.The signal lenses can be made by using Krystal Clear or probably PVA glue and wiping into the lens area with a toothpick until it covers the lens hole . After drying clear the lenses can be coloured using Tamiya X-27 Clear Red and X-23 Clear Blue. The 'green' lens of a signal was actually blue glass as the yellow light from the kerosene lamp when viewed through the blue lens produced green.
If the signal is to be lit the Tamiya X25 Green Clear is best used as the LED is not yellow enough to show through the blue clear as green.
If the signal is to be lit then the areas of the post around the signal lamp need to be painted black then painted white as required for the post. This is to stop light transmission through the post from the LED (see photo of effect).
Some light will still be reflected back from the signal lens and this might be reduced by using matt clear on the rear of the lens (see photo).
 |
| Lamps showing in 'daylight' - 1K Ohm resistor |
The lamps on the signals have a slot in front and back. The rear is to allow the wires to come out and the front is a slot as the minimum wall thicknesses make it difficult to have a lens or hole.
The 0.8 mm SMD LED will be a slight push fit into the hole in the top of the lamp and the square LED sticking out of the front of the tiny circuit board will fit into the slot.
The 0.8 mm
SMD LEDs are to be gently pushed vertically into the body of the lamp. I found
that I had to use my finger nail to push it in but a toothpick would also work.
Don't use a metal object to push the LED home as damage may be done to the fine
wire on the top end. The other wire is at the bottom of the LED. Ensure that
the wires align with the slot at the rear of the signal as it is pushed into
place.
The wires
from the small outrigger dolly post of the bracket signal were threaded under
the landing and then through the angled bracket supports under the rear of
the landing and then down the main post.
The wires
from the lamp on the main post were run down the back of the post around the
end of the landing and then down the back of the post.
Glue the
wires to the signal with Super Glue progressively stopping at each change of
direction.
A small 2
pin plug and socket is made by cutting up an integrated circuit socket. solder
the long pins of one half to each side of the circuit board as shown on the
diagram and photo below. Solder the wire from the LED to the two connections at
the other end of the circuit board. The longer wire of the LED goes to the +ve
terminal and the shorter wire of course goes to the -ve terminal. I have used a
1K Ohm 1/2 Watt resistor so that the light shows through the spectacle plate of
the arm during daylight but any value from 1K Ohm to 10K Ohms could be used,
your choice. 10K Ohm will probably not show during 'daylight' (room lights on).
Glue the
circuit board to the signal where shown in the photo below and tuck the excess
wires of the LEDs out of the way up in between the two halves of the mechanism.The wires on the male plug are soldered across the two holes rather than into the holes, this is needed from clearance from the main operating crank of the signal (see photo).
Preparation of Signal Post and Various Parts
A number of holes need to be drilled before assembly can begin.
For HO a 1 mm or alternatively a No. 60 or 61 (7 mm Scale - 2 mm drill bit) drill should be used in a pin vise to clear out the signal arm pivot on the post of any unfused nylon powder remaining from the printing. For the Frosted Ultra Detail signal posts the signal pivot hole should be cleared with smaller drill bits leading to the final 1 mm drill bit. Check that the pivot rod of the signal arm fits into the hole and rotates easily. The HO signal arm pivot rod may be slightly out of round from the printing process and if this is the case then use a fine jewelers file and gently file the rod round until it fits and rotates nicely, there should not be much slop in this fit. Be careful as the rod could be easily broken. If the rod does break then the signal arm can be drilled from the front through the pivot centre with a 1 mm or alternatively a No. 60 or 61 drill bit in a pin vise and a short length of Tichy Train Group 0.040” phosphor bronze rod Part #1107) can be glued in place prior to fitting the signal arm into the post.
Similarly, there is a 1 mm hole in the top of the signal post for the finial that needs to be cleared of unfused nylon powder. This hole is only about 1 mm deep as the post on the finial is very short.The 7 mm Scale signals have the finial printed as part of the post.
Drill a 1.0 mm (alternatively a No. 60 or 61) hole in the long arm of the main operating crank at the centre point of the curved end. If the starter holes have not printed then use a scriber point to make a hole to start the drill.
NOTE:
For signals with two or more signal arms such as a Home and Distant Signal and Bracket Signals stagger these holes. The outer main crank is drilled 1.0 mm (alternatively a No. 60 or 61) in the location as above and the inner main crank is drilled 1.0 mm (alternatively a No. 60 or 61) two or three starter holes higher (about 2 mm) to eliminate any interference with each other’s servo operating rod or similar rod. Do not drill the holes at the same spot on the cranks as they will interfere with each other during operation.
Care needs to be taken when drilling the White Strong and Flexible material with a 0.45 mm (or No. 77) drill bit as the nylon seems to grab the drill bit. Drill only with a pin vise, going slowly, backing the drill out occasionally. There is a risk of breaking the 0.45 mm (or No.77) drill bit if too much pressure is used.
For HO a 0.45 mm or No. 77 (0.8 mm for 7 mm Scale) hole needs to be drilled in the Main Operating Crank short arm which will be below the operating rod from the signal above, at the starter hole at the centre point of the curved end. If the starter holes have not printed then use a scriber point to make a hole to start the drill.Bellcrank and Counterweight Brackets on the Post(s)
Again for HO use a 0.45 mm or No. 77 (0.8 mm for 7 mm Scale) to drill through the small bellcrank brackets and into the post and beam on a bracket signal. Repeat for the counterweight brackets.
Place a rectangular cross section toothpick or piece of scale timber into the slot of the brackets for the counter weight lever and the small bellcranks as a drilling support then drill for HO 0.45 mm or No.77 (0.8 mm for 7 mm Scale). There is a very small dimple in the brackets where the hole is to be drilled, take care when drilling these holes and keep the hole at right angles to the post in both the vertical and horizontal planes.
The Signal Parts on the Frosted Ultra Detail Sprue
The detail parts should be removed with a pair of transistor nippers and the fine sprue should be cut away from the thick sprue where it attaches to the sprue. The remaining piece of fine sprue can then be trimmed from the detail part. If the fine sprue is cut away from the detail part first before being cut from the thick sprue there is a risk that the item may break particularly the counterbalance lever which has two fine sprues.
The Frosted Ultra Detail resin drills nicely but care should be taken to find the small pilot starter holes marked on the counterweight lever and the bellcranks.
Note the change in drill bit size.
For HO a 0.4 mm or No. 78 (0.8 mm for 7 mm Scale) hole, needs to be drilled in the operating hole of the signal arm, a small starter hole can be found on the back of the signal arm near the boss of the arm pivot point.
For HO three 0.4 mm or No. 78 (0.8 mm for 7 mm Scale) holes need to be drilled in the arm of the counterweight lever, remove from the sprue before drilling. When drilling the holes the circular weight on the arm needs to be placed into a small hole on a piece of wood so that the counterweight balance arm is flat to the wood otherwise the arm may break where the drilling is being done, particularly on the hole nearest the weight.
For HO three 0.4 mm or No. 78 (0.8 mm for 7 mm Scale) holes need to be drilled in the arms and angle of the small bellcranks, remove from the sprue before drilling. These small bell cranks are only used on bracket signals.
Fitting the Signal Operating Rods
A normal Home, Starter or Distant style signal only requires two rods to be made, one from the signal arm to the counterweight lever and the second from the counterweight lever to the operating crank below the baseboard.
A signal with two arms such as one with a Home and Distant arm on the same post is the same apart from having two counterweight levers and double the rods.
A bracket signal however is much more complicated so it will be used as an assembly example.The arm on the bracket main post is as normal with just the two rods.
The signal arm on the small post (called a dolly) is a lot more complicated. It has two small bell cranks, one at the top of the main rod from below and a second to get the rods out and up to the counterweight lever and then to the signal arm. As a result there are four rods involved and this requires some accurate bending of the rods as well as assembly in the right order.
The photo below shows the installation sequence for the rods, counterweight levers and signal arms.
Rod 1 from signal arm to counterweight lever
Temporarily fit the signal arm into the pivot on the post and the counterweight lever into the pivot on the bottom end of the small signal dolly. With the signal arm and the counterweight lever in the middle of their potential travel, measure the distance from the hole in the signal arm to the outer hole near the counterweight on the counterweight lever and record it. For HO cut and bend a piece of 0.015” (0.032" for 7 mm Scale) wire rod making the bent part on each end at least 2 mm long (the 90 degree bends on both ends go the same way). Fit the rod into the signal arm from the rear leaving about 2 mm sticking out the front of the arm, this will be trimmed later when the signal is operating satisfactorily. Now slide the rod into the hole nearest to the counterweight on the counterweight lever, slide the signal arm pivot rod into the mounting hole on the post and at the same time swing the counterweight lever into the pivot on the small dolly post. Now for HO using a short piece of 0.015” (0.032" for 7 mm Scale) wire rod with a right angle bend of 1-2 mm on its outer end (to protect your finger tip), push the wire rod through the outer pivot hole, through the counterweight lever and then into the hole in the post. Once again leave 2 mm sticking out for later trimming.
Rod 2 from End of Counterweight lever to Outer Bellcrank
Temporarily fit the outer bellcrank into the pivot on the bracket beam below the small signal dolly post with another piece of wire rod (bent on outer end to protect your finger tip). Ensure that the counterweight lever and the bell crank are in the middle of their potential travel. Measure from the hole in the outer end of the counterweight lever to the hole in the outer end of the bellcrank and record it. For HO bend a piece of 0.015” (0.032" for 7 mm Scale) wire rod to this length making one bent end piece go one way and the other bent end piece go the other way (a right angle Z shape).
Rod 3 from Outer Bellcrank to Bellcrank on Main Post
For HO, now the 0.015” ((0.032" for 7 mm Scale)) wire rod from the outer bellcrank to the bellcrank on the main post must be made. Temporarily fit the bellcrank to the pivot on the main post using another piece of wire rod bent on the end to protect your fingertip. With both bellcranks in the middle of their travel, measure from the top hole in the bellcrank on the main post to the outer bellcrank lower hole and record it. Make a wire rod to this length with the right angle bent ends being the same way and at least 2 mm long.
Remove the main post bellcrank pivot rod and attach the wire rod that runs between the two bellcranks from the top hole on the main post bellcrank to the bottom hole on the outer bellcrank.
With the previously made Z shaped wire rod held horizontal, slip one end into the hole in the outer end of the counterweight lever, remove the pivot rod from the bellcrank pivot, slide the bellcrank onto the wire rod, swing it down to the bellcrank pivot and push the wire pivot rod back through the pivot bracket and into the post.
Rod 4 from Main Post Bellcrank to the Main Operating Crank Mechanism
Now, measure, cut, bend and attach the wire rod from the main post bellcrank lower hole (insert wire rod from the rear of the bellcrank) to the operating crank below the baseboard. Leave the lower end of this wire rod long enough to go past the under baseboard crank and do not bend or fit it to the crank at this stage. Swing the main post bellcrank into position in the main post pivot and fit the pivot pin into the pivot and the post.
If all has gone well each wire rod will be held in place by other wire rods and parts of the signal itself.
If you gently pull and push the long operating rod from near the operating crank below, the small dolly post signal arm should work.
This long rod may want to flex away from the post and not fully transmit the movement. I have found that a small ‘U’ shaped wire staple of the 0.015” wire can be inserted into 0.4mm holes drilled into the post just below the horizontal ladder supports part way up the post to minimise this flexing (see photo below). Make one side of the ‘U’ longer and insert this into a single hole as it is easier.
If the arm doesn’t move properly then you have to look at each wire rod that you have made and adjust accordingly.
Rods 5 and 6
The rodding for the signal arm on the main post can now be done similarly to fitting the small dolly signal arm operating rod to the counterweight lever above and then the operating rod down to the main crank can be fitted. Slide the rod behind Rod 3 which will trap it in place.
Note that all bent rod ends face to the front of the signal except for the Z shaped rod that has the upper bend facing to the rear.
Unfortunately I can’t give any help on the length of the various rods as the adjustments involved for each rod length can be quite small. Persevere and it should work.
I found that using a Keiran Ryan Models etched brass hand rail bending jig beneficial.
http://www.krmodels.com.au/krm_misc_001_page.html
Final Fitting and Adjustment of Signal Operation
If the signal arms work nicely then the rear light shield can be glued onto each signal arm shaft where it exits the signal post pivot. This will keep the signal arm in place. Care needs to be taken here so that the glue doesn’t go through the hole in the light shield pivot boss into the post pivot hole and glue the arm to the post. It is suggested that a thick glue or contact cement be used and only on the rear of the light shield pivot boss, DO NOT USE SUPER GLUE (ACC).
At this point the excess signal arm shaft can be trimmed with a pair of transistor nippers.
Now the long vertical operating rod down to the main operating crank can be bent and fitted as follows:
Fit the main crank to the mounting with a #2 x 6mm self-tapping screw and a 3mm or 1/8” washer as shown in the photo below.
Screw the 2-56 or 8BA adjusting screws into the 2mm holes in the mechanism so that their ends meet the bottom of the main operating crank at each side making the ends of main operating crank level. Do not pre-tap the holes it is much better if they aren’t tapped as the grip on the screw thread is important to maintain the adjustment of the throw of the main operating crank and hence the signal arm, it must not be able to unscrew of its own accord.
Place the signal arm and the main operating crank in the middle of their range of movement (the main operating crank should be vertical) and mark the operating rod with a very fine marking pen where the vertical operating rod is opposite the 0.4mm hole in the main operating crank. Bend the operating rod from the signal above at this point to enable it to go through the main crank 0.4mm hole and so that the bend is such that the operating rod will be trapped between the mounting and the main operating crank, i.e. the end of the rod is pointing outwards and the bend is between the mounting and the main operating crank. Undo the #2 x 6mm screw and remove the main operating crank from the mechanism, slide it onto the operating rod and screw it back onto the mechanism.
Adjust the 2-56 or 8BA screws below the main operating crank by screwing them out to control the range of the signal arm.
Attaching the last Detail Parts
Finally, glue the previously painted cast iron support to the post and the underside of the bracket beams. If Super Glue (ACC) is used then it may require several applications as the glue will be absorbed into the surface. Alternatively a Super Glue accelerator may be used, apply the glue then immediately apply the accelerator to set the glue before it is absorbed.
Glue the finial to the top of the post.
Glue the small round tops of the signal lamps in place, I would suggest a small spot of PVA or contact cement if you might decide to add LED lighting at a later stage.
NOTE:
HO Fine Detail and 7mm Scale ladders and safety handrails are to be supplied by the purchaser which will produce a finer result. Etched brass HO and 7mm Scale ladder kits can be obtained from Keiran Ryan Models. 7mm Scale safety handrails can be made from strip brass section and HO from brass wire or fine strip brass section.
Operating Methods
The signal may be operated by several methods:- Servo control such as Tam Valley Singlet
- Relay using a wire mounted to the ‘clapper’ of the relay
- A ‘push/pull’ rod from the edge of the layout including bellcranks as required.
- Working signal levers can be obtained from the following suppliers:
Modratec - http://www.modratec.com/
McKenzie in H.O.Lland - http://www.mckenzies.net.au/index.htm
- A ‘wire in tube’ (Bowden cable style) from the edge of the layout. Modratec (above) sells wire in tube systems.
- Using linen thread, fishing line or similar through screw eyelets with a lead fishing sinker attached below the short arm on the opposite side of the main crank as a counterweight.
- Muscle wire (SMA – Shape memory Alloy) – You will have to work this one out. Anton’s Train did sell muscle wire actuators.
It is easier to attach any operating rod or thread, etc. to the hole in the bottom of the main crank before mounting the signal so that the rod/thread can be lowered through the mounting hole in the baseboard. This is much easier than trying to attach it under the layout.
Using Tam Valley Singlet Servos
If using a servo then the servo arm can also be attached to the servo operating rod (but not to the servo) before lowering the mechanism into the baseboard hole. Ensure that the main crank of the signal mechanism is centred and that the servo arm will be in the middle of the servo throw. Tam Valley sell a small circuit that will centre the servo throw although this can be achieved by gently moving the servo arm to one end of its movement then to the other, noting where the centre is and mark it on the servo with a fine point marker. Attach some double sided tape to the base of the servo mounting, screw the servo arm to the servo shaft at the previously marked centre point. Swing the servo up to the baseboard and push in place. If the underside of the baseboard is rough and the double sided tape will not stick then just place the servo by eye ensuring that everything is centred for the throw and screw in place; this should be fine as the servo has a long throw and the signal only needs a short throw.Program the servo for the movement end points following the Tam Valley procedure. If you used double sided tape and you are happy with the operation screw the servo mounting in place.
I have designed suitable layout fascia mountings for the Tam Valley Singlet control circuit. These are available in White Strong and Flexible in white, polished white, black and dark green. The fascia mountings allow the push buttons and LEDs to be recessed into the fascia so that they can’t be pushed accidentally or be caught on clothing. The fascia mount has been designed to fit into a 30mm circular hole in the layout fascia.
Mounting the Signal
The normal signals have been designed to be mounted in a 20mm diameter hole in the layout baseboard.
Although the common spade drill bit is 19mm, 20mm spade drill bits are available. The baseplate of the signal is 22mm wide so a 22mm spade bit could be used but beware of the closeness of the two mounting holes to the mechanism hole. The 20mm size was chosen to give sufficient room to design the mechanism particularly for the two operating main cranks of the two arm signals.
A 22mm hole should be cut for the bracket and multiple arm signals.
Use two #2 x 12mm screws to attach the signal to the baseboard, a screw driver with a long shaft will be needed so that the signal is not damaged while screwing it down.
Problems with Printing Your Order
Although I haven’t ordered a test print for each signal type, the signals are designed in the same way and are drawn using various standard 3D components.
Each time Shapeways prints an item it goes through a manual check.
I have heard that because of this manual check, sometimes when you order a print Shapeways may fail it, even though it has been printed previously. I believe that the person reviewing the model probably misinterprets parts of the model against the design rule minimums.
If this happens you will get an email from Shapeways saying that the item you ordered can't be printed, I will also get a notification email from Shapeways with your contact email.
If this happens I know that this would be aggravating to you as it would be to me.
When I am notified of a problem I will review the design, correct the problem (if it even exists), then upload a corrected version of the item. I will attempt to do this quickly and then notify you that the model has been corrected.
At this stage you can make another order then contact the Shapeways Service Team and request that the new order by sent with the first order to save on the shipping cost for one item. Shapeways have done this previously so there should not be a problem but do it quickly while the first order is still being printed.
At this stage you can make another order then contact the Shapeways Service Team and request that the new order by sent with the first order to save on the shipping cost for one item. Shapeways have done this previously so there should not be a problem but do it quickly while the first order is still being printed.
When a new version of an item is uploaded to Shapeways the print history is reset even if the update is small. Because of this you may find that an item is marked as “First to Try”, if this is the case you should be quite safe in ordering it even though it may look like it has never been printed before.
If you receive an order that has not been printed correctly you have to contact the Shapeways Service Team by email and deal with them as I am ‘out of the loop’ in this situation.
The signal designs have been through a number of print iterations so hopefully there won’t be any issues.
No comments:
Post a Comment