Posted in Controlling Interests, Fisherton Sarum, General, HW&DMRS, tagged Fisherton Sarum, High Wycombe and District MRS, HWDMRS, Merg turntable controller, model electronic railway group, Southern, Southern Railway on May 16, 2013 | 2 Comments »
My recent Controlling Interests #5 recent modifications completed…and working post included an update on the Model Railway Electronic Group (MERG) turntable control unit that with the grateful help of fellow HWDMRS member Mark Riddoch I am now using to drive the turntable on Fisherton Sarum.
The purpose of this #5-xtra post is to demonstrate how the operation now looks via the short video I have put together below, enjoy:
Posted in Controlling Interests, Exhibitions, Fisherton Sarum, General, HW&DMRS, tagged Fisherton Sarum, High Wycombe and District MRS, Hornby Magazine, Merg, Merg turntable controller, Model Railway Electronic Group, Model Signal Engineering, Southern, Southern Railway on May 15, 2013 | 5 Comments »
In my previous Controlling Interest posts I have discussed changes being made to a number of layout control items on Fisherton Sarum. For the last number of weeks the layout has been set up in its entirety at my local Model Railway Society , the High Wycombe and District MRS (whom have a nice new website also worth taking a look at..) initially to enable a photoshoot for a future magazine article to take place along with preparation for its planned appearance at the Basingstoke show. Unfortunately, due to ill health I was unable to attend this show (but is now booked to attend next years show instead) and the layout has stayed at the Society Rooms enabling it to be running at this Saturday’s HWDMRS open day and also means it can fully prepared before its visit to the Hornby magazine exhibition at Hartlepool in July.
This prolonged period of having the layout set up has enable a number of items of work to be carried including:
Signals
There are two working LSWR lattice post signals on Fisherton Sarum, built from Model Signal Engineering components, based on two actual signals at Salisbury. These will be the subject of a View from the line post in the future, but I have recently repaired the east end bracket signal that was damaged at the last show and both have had their paintwork touched up.
Remote Signal Operation
Before the last show I attended I added a third controller to the set up so that each fiddle yard operator can now drive trains towards them, whilst the third controller allows shunting the shed area to be carried out. This balances the workload between each yard operator, and to enhance this further I have now added a remote signal switch to each of the fiddle yard indicator panels to allow them to operate the approach signal at their end without having to move across to the main control panel. This is controlled by a ‘Local/Remote’ switch on the main panel, this provides an interlock to ensure that only the panel or fiddle yard switches can operate the signals at any one time. After a bit of head scratching and the addition of a couple of diodes in the circuit this is now fully functional.
Turntable
As per my Controlling Interest#2 Turning Tables post with the grateful help of fellow HWDMRS member Mark Riddoch the Turntable is now controlled by a Model Railway Electronic Group (MERG) turntable control unit. After initial installation there appeared to have been an issue with the counter clockwise alignment (to take up any slack when turning counter clockwise the MERG unit is designed to rotate past the selected track and then move clockwise back for final alignment) this has now been identified as being due to a small amount of slip in the connector joining the turntable drive shaft and the output shaft from the gearbox and this has now revised and I am pleased to say the turntable rotation and alignment is now quiet smooth and accurate in both directions.
In addition to the above I have also carried out a general touch up of the scenery in some places and paid attention to some of the track joins to improve running.
Posted in Controlling Interests, Fisherton Sarum, tagged Cobalt Point Motors, Cobalt slow acting turnout motors, Fisherton Sarum, Improviong Peco Points.improving Peco tunouts, Peco, slow acting turnout motors, Southern, Southern Railway on June 3, 2012 | Leave a Comment »
One the benefits of recently changing to slow acting ‘stall’ type point motors as per my Controlling Interests #3 post, where I describe my fitting of DCC Concepts Cobalt slow acting motors, is that the unprototypical spring and spring housing in the middle of the Peco turnout is no longer needed, removal of this certainly improves the look of the turnout.
A Peco Turnout as previously Installed still with spring and spring housing
There are a number of simple improvements that can be made to the Peco turnouts even when using solenoid type motors that still require the spring to be in place. These include firstly removing the lugs at each end of the tiebar, that are designed for hand operation. Secondly, and if the motor is not being mounted directly under the turnout but under the baseboard, shortening the sleepers either side of the tiebar that have the slots in them for the Peco point motor fixing tabs.
Spring, spring housing and spring housing sleeper base removed
I had already done these modifications on Fisherton Sarum’s turnouts and now have been able to go a step further by removing the spring, spring housing, the spring housing sleeper base and trimming back the spring location moulding on the tiebar. The spring is easily removed along with the spring housing by simply bending back the metal clips on either side of the housing and removing complete with the spring. This then exposes the moulded sleeper base under where the housing was and this can be simply cut away along the edge of the neighbouring sleeper.
New sleeper and ballast added and lightly weathered to match the original
I then filled the resulting space with a sleeper, from a spare piece of plain Peco track, cut to length and glued into position. Ballast was then also glued between the sleepers, and the whole lot weathered to match the original turnout and ballast.
All of the above modifications would of course be easier to do before the turnout was installed on the layout, in which case I would suggest replacing sleepers either side of the tiebar with copper clad sleepers soldered into to position but as this is retrospective modification I decided on the process above.
Posted in Controlling Interests, Fisherton Sarum, tagged Cobalt Point Motors, Cobalt slow acting turnout motors, Fisherton Sarum, point control, SEEP point motors, slow acting turnout motors, Southern, Southern Railway, turnout operation on May 14, 2012 | 2 Comments »
When I first built Fisherton Sarum I made the decision to use SEEP solenoid point motors to control the turnouts, this was partly due to being familiar with solenoid motors at the time and partially due to cost. In hindsight from both a visual and reliability perspective a mistake. It has become apparent after a number of exhibitions that reliability of the SEEP motors is questionable, even when used with a Capacitor Discharge Unit (CDU), and most frustrating issue has been the inconsistent operation of the built in microswitch.
The first two Cobalt motors in place.
Originally I used the built in switch of the The SEEP PM1 motor for changing the turnout frog polarity and had glued a Peco PL-13 Accessory switch to the underside of the motor to provide switching for point direction indications on the control panel. As time has passed where the built in switch has proved inconstant or unreliable I have swapped the duty of the two switches over so that the Peco Accessory switch is doing the more critical role of switching the frog polarity.
I have now decided to replace all the point motors with the slow acting type and have chosen the DCC Concepts Cobalt slow acting motor (note I have not gone DCC control, I am still of the analogue camp). I choose this over the other slow acting motors on the market due to it being slightly smaller than its competition, recommendations from other users and experienced gained with them on Ashland, one of the Hornby Magazine layouts I helped build.
There is always an awkward one, the clearance under the main baseboard L Girder is not enough for the Cobalt to be directly installed. I will install it to the side and operate the Turnout via a crank and probably leave the unpowered SEEP in place here to act as part of the crank.
Installation of the motors on the whole is quite simple with the exception of one location where the motor needed to be installed to the side (where I plan to keep the unpowered Seep motor in place as part of the crank arrangement).
I am utilising the existing wiring and control panel push buttons, but as the Cobalts require a polarity change and a constant supply, I have turned once again to my friend, fellow Fisherton Sarum operator and electronics wizard Mark Riddoch who is building for me some cleaver circuitry to take the push button inputs to and turn it into the constant feed required by the motor. Being operated from a 12VDC supply I am retaining a diode matrix system to operate a number of motors from one button when required such as on the ladder of turnouts in front of the shed.
This weekend has seen the first 4 motors (6 to go) changed and wired up.
Update 20th May: All 10 motors have now been changed to Cobalts. Next step will be the changes to the control panel to power them.
Posted in Controlling Interests, Fisherton Sarum, HW&DMRS, tagged Fisherton Sarum, Merg, Merg turntable controller, model electronic railway group, Peco turntable, Salisbury, Southern, Southern Railway, Turntable, turntable indexing on May 8, 2012 | 6 Comments »
In my controlling interest #1 post I mentioned the change of turntable control system to the Model Railway Electronic Group (MERG) turntable control unit. Since I first built Fisherton Sarum the turntable was powered via a Frixinghall motor and gearbox that did not have any form of automatic indexing. This meant that the rotational speed of the table was not easy to control and track alignment had to be done by eye (sometimes hitting the mark easier than at othertimes) via a toggle switch.
The turntable on Fisherton Sarum is very much the focal point of the layout.
Friend and regular operator of Fisherton Sarum, fellow High Wycombe and District MRS member and electronics wizard Mark Riddoch has very kindly built for me a MERG turntable control kit which drives a stepper motor and gearbox.
This clever bit of electronics can give up to 63 different positions (I only need 8 i.e. each end of 4 roads, on Fisherton Sarum) to an amazing precision of 0.03 degrees.
The stepper motor and gearbox installed on a new cross member on the underside of the turntable well
The turntable is simply operated from the panel via a rotary switch (a binary hex coded switch, for those that understand such things) to select the desired road and then pressing the start button. The controller then automatically works out the shortest distance to the desired alignment. When turning clockwise the deck is stopped automatically at the correct place or if turning anti-clockwise it over runs slightly before stepping back clockwise to the correct position ensuring any slack in the gearbox is taken up. The controller has a learn mode to allow the desired positions to be accurately set up which it then remembers.
The Meccano shaft locked in position with a brass pin through the boss and shaft. (apologies for the poor image)
The typical bank holiday weekend weather, just passed, encouraged working inside rather than other pursuits so the installation was completed. Installation has required a few slight changes to the control panel: firstly to incorporate the rotary switch, mounting inside the control panel the controller PCB card and changes to the wiring harness to get the required five wires to the stepper motor and gearbox that is being mounted directly under the turntable itself, replacing the previously installed traditional motor, gearbox and worm and wheel drive.
It is imperative that the link between the gearbox outlet and the table deck is positive and has no possibility of slip. The Peco deck is designed to be an interference fit on to a Meccano shaft so to ensure no unwanted movement is possible I have drilled through the boss and the shaft at 90 degrees and pinned it with a short section of Brass wire.
A close up of the motor, gearbox and drive coupling arrangement.
This shaft matching the gearbox output shaft has had a flat filed onto it and a brass collar joins to the two with grub screws ensuring a positive connection.
Programming the turntable in learn mode has not gone 100% to plan and I did not yesterday manage to get it working correctly, so need to some additional advice. Once I have mastered the programming I will upload a video of the turntable under its new control in action, so watch this space.
I am once again indebted to Mark, and offer my my sincere thanks for his time and assistance with this addition to the control of Fisherton Sarum which should, when fully up and running, improve the operation and visual effect no end.
Posted in Controlling Interests, Fisherton Sarum, HW&DMRS, tagged Doncaster Festival of Railway Modelling, Fisherton Sarum, High Wycombe and District MRS, Merg, Merg turntable controller, model electronic railway group, Southern, Southern Railway on April 9, 2012 | 3 Comments »
Although Fisherton Sarum is not currently set up, I am using the time between shows to make a few changes and additions to the operating system. These modifications include: the addition of a third controller for main line operation (see below), the installation of a Model Electronic Railway Group (MERG) turntable control unit with stepper motor, moving of the signal control to the fiddle yard panels and changing all the point motors to slow acting Cobalt types. The other modifications will form the subject of future posts so to coin a phrase watch or follow this space.
N1 Class No 1822 trundles west with a rake of dia 1774 40T ballast hoppers. In the new scheme of things this will be driven by, and towards, the west end fiddle yard operator, with the signal operated from a remote switch on the fiddle yard indicator panel.
Whilst operating the layout at the Doncaster Festival of British Model Railways my fellow operators from the High Wycombe and District MRS, naming no names (Roger and Mark) hatched a plan for improved operation of the main running lines. Currently the layout has two Gaugemaster ‘W’ handheld controllers for traditional DC Cab control allowing either controller to control any section of the layout.
Our default operation is one controller for the shed area and one for the main lines. This does mean that only one of the fiddle operators actually drives the main line trains and does so in both directions. The suggestion was to add a third controller so that two can be used on the main lines, i.e. one up and one down, allowing each fiddle yard operator to drive the trains towards their end. This will also increase the likelihood of trains passing on the main too (already possible but meaning the shed movements having to stop). The plan also includes the addition of remote signal controls to the fiddle yard indicator panels to ease operation too.
Time has been spent this weekend modifying the control panel wiring for the new controller, along with the installation of the new Turntable controller (but more of this soon). The final part of the controller installation will be the wiring on the west end baseboard to a socket for the new controller (the wiring harness is already in place with suitable spare cores). Fisherton Sarum’s first outing with the new operation will be Tring and District MRC show 13th October 2012.
