Chuffer Davies

8 hours ago, Barry O said:

But I find it sad to see items of interest on RMWeb  which are of great interest to me but... no contact details...

 

Baz

Hi Baz,

RM Web provides a private messaging service if you have the urge to contact a contributor directly.  To get to it click on the icon of the contributor to take you to their profile page and from there you can send them a message. 
Frank

6 hours ago, Jack P said:

Finally bit the bullet and started my two EM kits. 

Much to my surprise.. I also finished them!

 

 

Need to now go through and fix everything down (and swap out the slightly too short stock rail on the diamond). I was hugely impressed with the instructions, the bases print quality & the general approach to construction. I'm also amazed at the quality of the end result that I managed to produce. 

 

I had thought for a long time, that the cast common crossing was a godsend, but having built the diamond from all rail, I can see how much nicer they look, and not difficult either!

 

Wayne, could I just check, are the sleepers a specific spacing/width? I'm just comparing the turnout to my PECO EM flexitrack, and the timbers are thinner and differently spaced. I've got a junction to build, and so I'd love to make sure that things match up - should I be using C&L flexi instead? Definitely not a criticism as this is my first foray into 'proper' track construction!

 

 

Thanks in advance, and thank you for producing such an excellent product!!

Hi Jack,

sleeper spacing varies between plain track and points/crossings so they won’t match.  In fact sleeper spacing, length and cross section varied through time and across companies so it is quite difficult to ensure that your track work is definitely correct.  N.B. the sleeper spacing reduces as it approaches a rail joint to provide greater support and sleeper width whilst normally 10inch was 12inch for the sleepers either side of the fishplate. 
I think you are safe to stick with the EMGS plain track unless you are going to be pedantic about getting your track work absolutely correct for your company and period being modelled.

Frank

1 minute ago, MJI said:

 

 

Bought baseboards looking at over £1000.

 

So onto that website.

 

What thicknesses do you use?

We used 10mm on the sides and double thickness at the ends to avoid distortion when doing up the bolts to pull the boards together.  Alignment pins are to my mind essential to ensure reliable track alignment across board joints.  We also cross braced every 1ft approx but best to plan out where your point motors etc.  are going to be so that you don’t put a brace where a point/signal motor or uncoupling magnet needs to be sited. 

Frank

18 hours ago, Jol Wilkinson said:

The usual downside of laser cut baseboards is that you are restricted to the sizes and formats they produce, although some may produce custom sizes.

 

For example, several friends are jointly considering building a small display layout. They have identified a track plan and scenic layout, measuring 6' 6" by 1' 9" and incorporating a sector plate in one corner behind a scenic break. One requirement is that it comprises two baseboard units that can be fitted in the smallest car owned by one of them. That isn't possible using "standard" laser cut baseboard sizes. 

 

So, unless you opt to make your own baseboards, or commission custom made ones, your modelling will be constrained by what someone else produces. 

Rather than accept the extra cost of custom cut boards, as long as they come flat packed, you can purchase a standard size and just trim the width or length to suit your specific needs.  Still a lot less work than cutting your own.

For Clayton we chose to go to a timber merchants and got them to cut sheets of ply into standard strips of 100mm.  We then just needed to (carefully) cut these to length before assembling.  A bit like making our own flat pack board kits and much cheaper given there are 27  boards all in. 
Frank

Hi Alan,

I'm pleased to know that you are interested in my M-I-T system.  I will attempt to answer all your questions but inevitably some answers may trigger additional questions from you so feel free to keep asking them until you are satisfied.

I'll start by correcting a couple of points in your initial description of the system. 

I have to use a 1.5mm shaft in the tender and the Road Runner+ gear box because I was unable to source any ball races with a 4mm o/d and 2mm i/d.  The ball races I use are 4mm o/d and 1.5mm i/d meaning that I am then forced to use a 2mm o/d x 1.5mm i/d sleeve on the shaft to mount the High Level spur gears.  The ball races are needed because, as you have identified, the drive shaft rotates at the same speed as the motor and a brass bearing (unless it was sintered brass) would quickly overheat at that speed.

The socket of the ball and socket UJ is located in front of the loco's rear chassis spacer, not under the fall plate.  The N/Silver frame of the High Level gearbox is a replacement that I have designed (with the help of Chris Gibbon) to accept the ball races.  I don't think there is enough metal on Chris's  RRC+ gearbox frame to drill out a 4mm hole for the front ball race and the back hole may already be too big (not sure though).

Now to your specific questions:

End thrust: The ball races appear to be capable of accepting an amount of end thrust and so I have fitted sleeves fore and aft of the gearbox frame, and pushed up against the ball race at each end to absorb the end thrust.  This has not been a problem so far......   The ball of the UJ is located approximately half way into its socket and does not manage any end thrust.

Drive shaft:  The Markits UJ comes in 2 sizes: 1.5mm or 2mm.  This dimension only applies to the hole in the end of the socket but the ball always comes with a 1.5mm hole and a length of 1.5mm steel shaft.  The length supplied is only sufficient for the shaft between the two UJ's.  I have to purchase additional 1.5mm rod for the High Level gearbox and the spur gear's shaft.

Slotted Shaft: By this I assume you mean the socket of the ball and socket UJ.  This is part of the Markit's product.  It also has a grub screw to lock the socket onto the end of the gearbox's drive shaft.

The central part of the drive system between the UJ's is supported solely by the UJ's as it needs to move horizontally and vertically as the relative positions of the loco to the tender changes.

Mounting the Ball Races:  I use Loctite to secure them into the holes in their frames.  The ball races have a rim to one side to help their location and I always put this rim to the outside of the frame because the ball races have to absorb any end thrust.  

Draw Bar Mounting:  The majority of my models are permanently coupled but I have one model where it was easier to retain a draw bar pin which allows the tender to be quickly coupled/decoupled from the loco.  Either system works because the benefit of using a neoprene tube for the UJ in the tender is that this prevents the centre portion of the drive shaft (between the UJ's) from dropping to the floor when the tender and loco are separated. 

Wheel Diameters:  So far the biggest driving wheel diameter I have managed to model but still keep the drive under the fall plate was 5' 8" and this was the Great Western Mogul.  It all depends on how high the fall plate is located in relation to the diameter of the driving wheels.  So far I have been unable to come up with a gearbox design for loco's with larger diameter wheels which still allows the drive shaft to pass below the level of the footplate/fall plate.  As the loco's I'm building for Clayton will all have wheel diameters of 5' 2" or less I have not put any significant effort into designing a solution for models with larger diameter wheels.

Regards,

Frank

A bit more progress on the chassis for Guy's ROD.  I have now built the basic cylinder/slide bar assembly along with the crossheads and connecting rods. It all went together as designed but when attempting to install the assembly into the frames it became apparent that I am going to have problems fitting the front brake hangers because the rear cylinder covers are obstructing the space where I expected to install the hangers.  I'm not quite sure how this will be resolved but I'm sure I'll come up with something.

As with any typical eight coupled model with outside cylinders, where the connecting rods are attached to the 3rd axle, I had clearance issues between the back of the connecting rods and the crank pin nuts on the 2nd axle.  Bushing out the connecting rod sufficiently to clear the standard Ultrascale crank pin nut looked wrong.  Instead I decided to turn up some alternate (non-standard) crank pin bushes in the lathe and tapped 14BA, as per the attached photo. 

With these installed on the 2nd axle and a 0.4mm thick washer between the coupling and connecting rods on the 3rd axle, the connecting rods now clear the crank pins albeit by about 0.1mm.

I'm not quite on the home straight yet as I still have the leaf springs, brake gear and draw bar to install.  There is also the vexing question of what to do about the valve gear and associated eccentrics between the frames? 

Regards,

Frank         

30 minutes ago, New Haven Neil said:

 

This has always been the main reason.  It was more prevalent in the early days of DCC as it would appear more modern decoders are lees prone to this, but it would trigger from some other misdemeanour such as a momentary short.  I still do it just out of habit nowadays.

I did not know that so thank you for explaining the issue.  As it happens, because our layouts (Hungerford and Clayton) are both designed as analogue first and DCC second we still have all the normal isolation facilities you would expect of an analogue layout. As a result runaways could never actually happen except on my small test track, which may be why I’ve never experienced it.

Frank

1 hour ago, St Enodoc said:

Interesting. Most of us disable DC on our DCC-fitted locos to improve running. Perhaps he's reactivated it for his trip North.

I’ve never bothered disabling DC on my models, mainly because DCC has been fitted so that we can exploit the excellent control that it provides when shunting in the station yard.  Running on the mainline under DC is perfectly adequate.  I would be interested to hear your reasoning behind disabling DC and the benefit this provides you?

I can also hear Tony’s voice in my head telling us that his models run perfectly under DC control and he can’t see any reason for going DCC.  Tony we will have to agree to disagree because having extensive experience of operating the same models on Hungerford before and after converting to DCC, I can say with complete confidence that shunting under DCC is superior for two reasons:  Firstly enabling a degree of inertia avoids the less skilled operator from starting and stopping the shunting movement too aggressively, a common fault I have observed on exhibition layouts.  Secondly the 15volt constant current reduces the tendency of locos sticking as the track and wheels become increasingly contaminated from the atmosphere in the exhibition hall as the operating day progresses.  People following Grantham (a DC layout) this last weekend at Harrogate will have read the problems they had because of live steam models operating in the same exhibition hall.  It was our experience of  the exact same issue one time at Ally Pally that was the trigger to our investigating DCC originally.

1 hour ago, Enterprisingwestern said:

 

 

 

 

Pics as requested.

In the last shot there are four 3-2-1 blocks on it and still there's a slight curve at the outer ends.

I will leave them in the sun for a while to see if that does anything.

Thanks for all of your input.

 

Mike.

Hi Mike,

thanks for the pictures.  I wish we knew what the cause of the warping was.  I can’t immediately think what about the printing process could result in this given that the top and bottom of the sleeper are printed identically.  The top of the sleeper has apparently shrunk introducing the force that has curved the sleeper but why? Has it been subject to strong sun light perhaps?  
You will certainly need some strong adhesive to glue it flat and keep it so.  
I have a test track with three EM points.  These are glued down on a plywood base using UHU glue and after a couple of years there has been no movement.  They were installed almost as soon as I received them so they did not have time to warp. 
Please let us know (either way) how you get on.

Frank

On 04/03/2023 at 14:34, Enterprisingwestern said:

 

I've got badly bent timbering, (ooo err missus), too far gone to expect cork to hold it alignment once glued and ballasted.

Apologies if we've already been here, it's a long thread to wade through, I'm assuming the solution is a trip to the oven on a flat surface, but what sort of temperature, and with or without the rails in place?

 

Mike.

Hi Mike,

any chance you could take a picture to illustrate the problem?  When you say bent, do you actually mean bent or has it warped/curved? Do you have any idea what caused this deformation in the first place?  
Frank

5 minutes ago, Dave John said:

Then again Tony there are I think a good many modellers like myself who have gone in exactly the opposite direction by choosing to model subjects for which there is no rtr available. Why? Well, I wouldn't claim that my finished models could compare with the best of modern rtr but for me the pleasure of sitting down at the bench and making them far outweighs that of just opening a box and owning them.  It may be that you see less scratchbuilding because of the time taken to make things, but perhaps costs will swing the pendulum the other way. 

 

The bench this morning, not a box in sight;

 

 

 

 

Each to their own I suppose. 

Well said. I couldn’t agree more.

27 minutes ago, MJI said:

Not sure if I can get a disc in so will probably use the file, will try to remove another 0.5mm of backhead.

 

4-4-0 chassis

 

I am trying to avoid any waddle by not allowing side to side on the front bogie but plenty of sideplay on the rear axle.

 

If I was making my own chassis rather than a Comet kit I would have treated it like a Bo Bo.

 

It will be running mainly on straights but planning curves of around 1m radius.

 

Should this be enough?

You may struggle to get enough sideplay on the rear driven axle. My approach when building 4-4-0 or 4-4-2 chassis is to effectively build the 4-4 element of the chassis as a 2-6-0 by preventing sideplay in the rear bogie axle and the rear driven axle.  The front driven axle is given a small amount of sideplay and the front of the bogie acts as a pony truck pivoted around the pin locking the rear of the bogie.  A benefit of this is that there is no need to cut clearance holes in the frames for the passage of the rear bogie wheels much as would be the case on the prototype. 

1 minute ago, Tony Wright said:

When we were setting up LB, Geoff Helm (of Helsman controllers), knowing our requirements, recommended the employment of his controllers designed for O Gauge. These give a greater amperage than the OO ones and also, I believe, higher than 12 volts. Now, I was a bit of a duffer at physics, but greater amperage and higher voltage should result in more 'juice' to power the trains; that's certainly what's worked in practice.

 

Hi Tony,

Increasing the voltage supplied to a controller is fine as long as you don't then exceed the maximum voltage that a given motor can handle, which will occur when you wind the controller up to maximum.   Amperage by contrast doesn't work the same way.  The motor will attempt to draw as much current as it needs for a given train load and track voltage.  If the controller is not rated high enough (i.e. it can't supply enough amps) then the motor will be unable to draw the current it wants and will under perform, which is why using 'O' gauge controllers will almost certainly eliminate that particular constraint on the motor.

We use Gaugemaster 'O' gauge controllers on Hungerford for the same reason as you have stated for Little Bytham with the same result.

Frank

1 hour ago, Jesse Sim said:

I’ve had this issue as well, I think I could

be the only modeller thats contemplating switching back! to DC! 

Hi Jesse,

as a matter of curiosity can I ask what DCC control system you are using?  Whilst I have not noticed this issue myself, in theory at least   the top speed of a DCC loco will be constrained by 1 of 2 elements, the max voltage setting of the chip and the maximum voltage of the power supply, which ever is the lower.  Some systems allow the power supply voltage to be varied up to about 17volts I believe, but others do not. I’m using Lenz on Hungerford and a Digikeijs on Clayton both of which allow the track supply voltage to be set higher than 12 volts. It should also be realised that the decoder uses a bridge rectifier which typically drops the incoming voltage by 1.4 volts. The Vmax setting on the chip is an absolute voltage ( or at least it is on the Zimo chips I use). Therefore if you set Vmax to e.g. 140 (14 volts) and the supply voltage is e.g. 16 volts then there should be no loss of top speed over a DC motor being supplied with the typical 12volt max.  
This is my personal interpretation of what is happening on a DCC system unless anyone else on here knows better and can correct me?

9 hours ago, Chas Levin said:

 

.. but I still want to know why we have to do something like that and what's actually going on!

With a traditional drive system where the worm gear is mounted directly on the motor’s shaft then in the main the issue is caused by the thrust imposed on the motor’s bearings.  In one direction the forces will push the armature up against the rear bearing and in the other direction the front bearing.  The bearings at each end will typically be of different construction (blind at the rear and through at the front) and will therefore behave differently under force and this results in the different behaviour of the drive system.
 

In a Portescap with bevel gears the forces are the same in both directions and differences in directional performance (if any) cannot be explained in the same way.

19 hours ago, jrg1 said:

Very impressed with the model.  Can you describe how you clean it ultrasonically, and what you use for the bath, please?

Rather than fill up WW with the ins and outs of Ultrasonic cleaning I have documented my approach on my Chuffer's Workbench topic and for anyone who is interested please use the following link to jump to the item.

 Frank

I have been asked to describe the process for ultrasonically cleaning models prior to painting.  Ultrasonic baths are widely used commercially for cleaning jewellery, clock mechanisms, glasses and any number of other things.  These are now increasingly used domestically.  I purchased my ultrasonic bath from RS Components but I'm sure there are many other retailers from whom they can be purchased.

The first stage in the process is to strip the model down as far as possible and give it a clean with traditional cleaning methods.  In my case I use a baby's soft toothbrush and SIF cream cleaner. 

I fill the bath with 10/1 mix of warm water and specialist cleaning fluid, approx 1.1 litres is required to ensure that the various parts of the model are fully immersed.  Marigold (or equivalent) gloves are essential as the cleaning fluid must not come into contact with skin.

The bath comes with a plastic tray but apparently the tray reduces the power of the bath and so I choose to place the model in the bath without the tray.  Everything goes into the bath including the wheels (Gibson in this case) but not the motor or gearbox.  In operation the model will vibrate around the bottom of the bath.  This is probably a good thing because anything that is not properly attached will be shaken loose and drop to the bottom of the bath.  

I clean the model for two x 8 minute cycles.  As can be seen from the following picture It is surprising how much muck comes off in the bath despite having cleaned it with SIF before hand. 

On completion, and again wearing rubber gloves, I thoroughly rinse the cleaning fluid off the model with water and then after touch drying with kitchen towel I first dry the model as far as possible with a hairdryer before placing it in the airing cupboard for a minimum of 24hours to ensure that any water that might be trapped inside the boiler etc, is completely eliminated.   This is especially critical for any steel parts such as the tyres of the wheels and the axles to avoid them rusting.

The model is then ready for painting, or in my case, for sending off to be professionally painted.

16 minutes ago, chris p bacon said:

 

Does Youtube fight back when you use it...😀

Sorry, I try to keep my IT background in check but it still occasionally slips out. 
Old dogs as they say.

10 minutes ago, Dragonboy said:

I had the pleasure of seeing Retford at the beginning of the century, at I think a show in Watford iirc. I was amazed at the vast expanse of baseboards which were spread out in front of me.  It would be great to see some up to date video footage  of this wonderful layout. 
 

Brian

Hi Brian,

there are a number of Retford videos on YouTube. I used ‘Retford Model Railway’ as my search argument to find them.

Enjoy,

Frank