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Re: Tim V's workbench

Posted: Wed Sep 19, 2012 5:31 pm
by Brinkly
Hi Tim,

Yes please I would certainly like to see it.

Regards,

Nick

Re: Tim V's workbench

Posted: Wed Sep 19, 2012 7:16 pm
by Tim V
OK, I'll try and remember to bring it!

Re: Tim V's workbench - pinned axles

Posted: Sun Oct 21, 2012 3:41 pm
by Tim V
Following comments on breaking drills, here's how I drill the pin holes in axles.

Check, this looks about 0.125"
IMG_4173.JPG

Put into a machine vice
IMG_4175.JPG

File a flat using my steel file. Don't forget to keep files for steel and brass separate, once used on steel, files are blunted for brass.
IMG_4176.JPG

Using a centre to form the drilling point, otherwise the drill will wander, and break
IMG_4180.JPG

final drilling through - no breakages.
IMG_4181.JPG

Re: Tim V's workbench - Class 4 Tank

Posted: Wed Nov 14, 2012 9:50 pm
by Tim V
Here is the latest project on my workbench. Now a class 4 tank never ran through Clutton (to my knowledge), but it's my train set! Also I think I was nearly run over by one of these on the S&D, and I had a Hornby Dublo one in my first electric train set. So when I spotted a Bachman body on a stand, well there you go.

Ingredients are: A Comet chassis, a High Level gearbox, and I did plan to use the Gibson brass centred wheels, but they're not out yet, so I'm using the ordinary plastic centred ones. Usual specification, sprung, split axles etc.
IMG_4249.JPG

Mix them all together and see what turns up!

Re: Tim V's workbench - Class 4 Tank

Posted: Thu Nov 15, 2012 3:02 am
by DougN
Sounds really nice Tim. As you say it is your train set and you can run what you like. :thumb I too have a hankering for strange locos for my train sets but so far i have resisted.... probably would help if I had them half as finished as yours.

Re: Tim V's workbench - Class 4 Tank

Posted: Thu Nov 15, 2012 6:11 pm
by Mike Garwood
Tim

Lovely engines! How are you going to tackle the rear bogie?

Mike

Re: Tim V's workbench - Class 4 Tank

Posted: Thu Nov 15, 2012 6:21 pm
by Tim V
Give us a chance Mike, the project is fairly low on my list of priorities :P

Re: Tim V's workbench - pinned axles

Posted: Fri Nov 16, 2012 9:50 am
by Paul Townsend
Tim V wrote:Following comments on breaking drills, here's how I drill the pin holes in axles.



I made the jig to Tim's design and had no troubles except at break-through when drilling the easily available 1/8th Silver steel axle material, and could only succeed by increasing pin from .5 to .7mm. When I discussed this with Tim he said he had a stash of ground MS in 1/8" so I have been seeking a supply for two years and could only find industrial quantities from USA.

All known to me ME stockists in UK didn't go below 1/4".

Now that Ultrascale are selling their GMS it should be problem solved....too busy with other projects right now, but I received an instant supply from U'scale so will try .5mm again asap on my next chassis.

Re: Tim V's workbench - DCC couplings

Posted: Sun Jun 02, 2013 5:42 pm
by Tim V
Currently working on DCC couplings, following an idea from Jim Smith-Wright.

Experiments with Dingham couplings led me to believe they were worth pursuit. It is much easier to have on-board control than any other coupling I have tried. Here I'm trying a electro magnet in a pannier tank. It fits!
IMG_4943.JPG

OK long way to go yet....

Re: Tim V's workbench - DCC couplings

Posted: Sun Jun 02, 2013 7:23 pm
by nigelcliffe
Having been here before, some years ago, the field strength you get from a coil is a lot more useful if you can put the moving armature inside the coil, or at least across the open end of it. And an armature which is a permanent magnet is much more powerful than just an iron rod.

A lot of the design of an electromagnetic based mechanism comes down to making a link from the armature near or inside the coil and the actual coupling.

The highest point of friction I found was starting the coupling from rest. Therefore the magnetic field needs to be maximum strength for this action, which tends to mean permanent magnet in/near coil and repulsion from the field in the energised coil. Return to rest can be by gravity.


http://www.2mm.org.uk/articles/dcc_couplings/index.html
And also in 4mm scale if you do some searching onto the first "older postings" page.
http://www.nigelcliffe.blogspot.co.uk/


- Nigel

Re: Tim V's workbench - DCC couplings

Posted: Sun Jun 02, 2013 8:33 pm
by martin goodall
Forgive me if I 'rain on your parade', but it has always struck me that the weakness of any vehicle-mounted uncoupling system is that you may wish to uncouple between various different vehicles in a train when shunting (especially if you are dealing with a freight train).

If you simply mount the on-board uncoupling mechanism on the loco or on a particular vehicle, this does not assist if or when you wish to uncouple between two other vehicles in the train, as you may well wish to do in quite a few cases. The alternative is to mount on-board uncoupling mechanisms on several vehicles to give the required operational flexibility, but this would be both time consuming and expensive.

It is this factor that convinces me that track-mounted magnets (permanent or electro-magnets, according to preference) will give significantly greater flexibility in operation, without the added complexity of on-baord coils or other vehicle-mounted operating mechanisms.

Re: Tim V's workbench - DCC couplings

Posted: Sun Jun 02, 2013 9:27 pm
by nigelcliffe
martin goodall wrote:Forgive me if I 'rain on your parade', but it has always struck me that the weakness of any vehicle-mounted uncoupling system is that you may wish to uncouple between various different vehicles in a train when shunting (especially if you are dealing with a freight train).

If you simply mount the on-board uncoupling mechanism on the loco or on a particular vehicle, this does not assist if or when you wish to uncouple between two other vehicles in the train, as you may well wish to do in quite a few cases. The alternative is to mount on-board uncoupling mechanisms on several vehicles to give the required operational flexibility, but this would be both time consuming and expensive.

It is this factor that convinces me that track-mounted magnets (permanent or electro-magnets, according to preference) will give significantly greater flexibility in operation, without the added complexity of on-baord coils or other vehicle-mounted operating mechanisms.


As I own a modest fleet of locos with DCC controlled AJ couplings on them, and have been using them for a few years, I can speak from some experience.

Having the coupling on the loco saves thinking about where to stop to run-round a train. No longer does a short train have to pull all the way to the end of the run-round loop and then play "hunt the magnet" or "reverse back to find the magnet". This is THE biggest gain. It is an amazing improvement in operating a layout compared to being tied to base-board (electro)magnets.


BUT, I completely agree that under-baseboard magnets are still required. Propelling a train up a siding and operating the uncoupler coil as a wagon passes over is much more sensible than fitting coupling mechanisms to lots of wagons (not to mention having to come up with a sane control mechanism).


I see it as an improvement to existing under-baseboard magnet systems, not a replacement.


- Nigel

Re: Tim V's workbench - DCC couplings

Posted: Mon Jun 03, 2013 3:57 pm
by Tim V
Unfortunately, you are both seeing the problem from a "model train" perspective.

I am trying to emulate the shunting that was carried on in goods yard all over the country, that is not reflected in our models - the practice of loose shunting. Motorised wagons and onboard couplings are the way forward. Replicating wagons being knocked into sidings is what I am trying to achieve.

The benefits of onboard uncouplers have been commented on by Nigel. It must also be remembered that on Clutton, the shunting is carried on at some distance from the driver and shunter. It isn't possible to line up the couplings over magnets in the track.

Costs are pretty low, as having used DCC for some time, I have a collection of older/inferior decoders ideally suited to the task.

Re: Tim V's workbench - DCC couplings

Posted: Wed Jun 05, 2013 6:15 am
by Dave K
Tim V wrote:I am trying to emulate the shunting that was carried on in goods yard all over the country, that is not reflected in our models - the practice of loose shunting. Motorised wagons and onboard couplings are the way forward. Replicating wagons being knocked into sidings is what I am trying to achieve.

The benefits of onboard uncouplers have been commented on by Nigel. It must also be remembered that on Clutton, the shunting is carried on at some distance from the driver and shunter. It isn't possible to line up the couplings over magnets in the track.


Tim,

I seem to remember seeing, at either Wells or S4urm, David Nicholson on the ZTC stand showing a wagon fitted with a AJ uncoupling decoder. The decoder took up most of the area between the solebars.

I wounder if this was passed on or has 'withered on the vine'

Re: Tim V's workbench - DCC couplings

Posted: Wed Jun 05, 2013 4:24 pm
by Tim V
I actually built such a wagon, using a similar modified relay some time ago.

I went on to discard that idea!

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 11:42 am
by billbedford
Tim V wrote:I am trying to emulate the shunting that was carried on in goods yard all over the country, that is not reflected in our models - the practice of loose shunting. Motorised wagons and onboard couplings are the way forward. Replicating wagons being knocked into sidings is what I am trying to achieve.


I once suggested to the guys in the Newport Club a prototype for a layout that would have been prefect for this sort of thing -- Branches Fork. But they were not convinced and went off muttering about 1:80 gradients and not being able to keep the wagons on the layout………

The easy way to arrange a siding loose shunting is to arrange so that the most of the length of the siding is lower than the point where uncoupling magnet is. The slope into the siding won't have to be very steep -- just enough for a free running wagon to roll away from the uncoupling point.

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 11:46 am
by Tim V
OK in principle Bill, but the real thing had brakes. The shunter would walk alongside the wagon(s), ready to pin down the brake at the required spot. Using gradients for this sort of thing, the wagons would possibly accelerate down the slope, destroying the illusion.

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 11:57 am
by grovenor-2685
When I used to watch, many years ago, the shunting in our local coal yard, I never saw the shunters running alongside, they would set the road, uncouple and the engine would give the train a kick so the wagon or wagons rolled into the siding and would then bounce off any wagons already there in turn setting them in motion, rather on the billiards principle. I think they just left it to the coal merchants to put the brakes on when they were ready to unload. Choregraphing all this with decoders and motorised wagons would be quite some excercise.

At Railex one of the layouts was using motorised vans to demonstrate capstan shunting but it was all very unconvincing, to me anyway, in the complete absence of any ropes from the capstans.
Regards
Keith

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 12:41 pm
by allanferguson
On Burntisland we use real capstans with real ropes to shunt the wagons onto the tipplers. It has to be said it's not very convincing, since the ropes have to be hooked / unhooked using 1:1 fingers. But it does demonstrate to a younger audience just how such things were done, and that end of the layout usually attracts largish crowds. And I can most certainly sympathise with what Tim V is trying to achieve. The trouble, you really need the noise of the loco accelerating, the screech of brakes, the chunk of couplings tightening, and the crash as buffers meet. I used to watch this at Buchanan Street goods a long time ago. The crashing of buffers took place inside the goods shed, so out of sight. Would this be an idea?

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 12:51 pm
by Natalie Graham
grovenor-2685 wrote: I never saw the shunters running alongside,


My Uncle was a shunter. I can't imagine him running anywhere. :D Pity he isn't still alive, I could have asked him.

To replicate this kind of shunting though would it not be more reaslitc if, in the absense of an automated railway worker carrying a shunting pole, the wagons had DCC controlled brakes rather than couplings? Then the wagon could be pushed by the loco and stopped by the operator in lieu of the shunter. I can't see motorised wagons as a realaistic option unless you can get them running in tandem with the loco then stop the loco and leave the wagon moving. For a wagon to set off by itself before coming to stop elsewhere in the yard would be an odd sight, especially when accompanied with the whirring of an electrical motor.

How would motorised wagons work anyway? Wouldn't it need a means of disconneting the drive or would you have to try and match the speed of the motorised wagons to the rest of the train?

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 2:08 pm
by Tim V
The motorised wagon runs in a consist!

I said walk - not run by the way. The shunting I remember was done at walking pace.

There is video of shunting on Youtube.

Re: Tim V's workbench - DCC couplings

Posted: Thu Jun 06, 2013 2:17 pm
by Noel
Country goods yards, unlike many busier town or city goods yards, would never normally have seen a shunter. Shunting would have been done by the guard [or possibly one of the yard staff]. In either case, whatever happened to relatively robust traffic like coal, much traffic would have been rather more fragile and/or needing to be placed at an exact location relative to the facilities needed for unloading [bank, shed, crane, etc.] Books by former railwaymen show that such traffic was normally either placed by the engine or given a gentle nudge and walked in [see Tim's post below], with whoever was shunting having a hand on the lever ready to apply the brakes. The wagon stayed under control and the loco crew didn't have to waste time retrieving it because it wasn't quite in the right place for unloading. Also higher authority [the stationmaster at a country station] may have been present or close by...

Sorting yards also had shunters, and whether gravity fed because it was a hump yard or on a gradient, or loose shunted with a loco, the cut would be moving quite fast when it was detached. Then the shunters [sometimes literally called 'wagon chasers'] would definitely have to run, both to reach the cut and then alongside it to get it under control, particularly with a multiple wagon cut, where several brake levers would need to be pinned down or handwheels turned. Doing this while crossing diverging pointwork to other roads and avoiding other moving vehicles was difficult and dangerous, and serious or fatal accidents were not that uncommon. Modern day H & S would not be impressed. Misjudgements of speed were also not unknown, and the resulting impacts as a cut hit standing stock could be messy, expensive and complicated to sort out, and might lead to disciplinary action against members of staff involved. This was one factor in the introduction of shock wagons and vans.

Re: Tim V's workbench - DCC couplings

Posted: Fri Jun 07, 2013 8:07 am
by jim s-w
Tim V wrote:The motorised wagon runs in a consist!

I said walk - not run by the way. The shunting I remember was done at walking pace.

There is video of shunting on Youtube.


I dunno if this is the one you meant Tim (it's a bit modern)

http://www.youtube.com/watch?v=mwJvFfZa ... ata_player

But as you say it's walking pace and the wagons don't seem to change speed much once they are set free. It's interesting to see some that are marked up no loose shunting to be loose shunted!

Cheers

Jim

Re: Tim V's workbench - DCC couplings

Posted: Fri Jun 07, 2013 9:33 am
by billbedford
Tim V wrote:OK in principle Bill, but the real thing had brakes. The shunter would walk alongside the wagon(s), ready to pin down the brake at the required spot. Using gradients for this sort of thing, the wagons would possibly accelerate down the slope, destroying the illusion.

I'm sure, Tim, even you could do subtle slopes if you really tried……..

Re: Tim V's workbench - DCC couplings

Posted: Fri Jun 07, 2013 10:04 am
by Noel
Yes Bill, but could he [or any of us] get his wagons all to accelerate and decelerate at virtually identical rates? If not, then wagons will either stop too soon or too late.

Noel