Richards Workbench, Heljan 31s and JLTRT Class 40s

[richard carr]

Having finally got the Heljan 31s to run properly its time to do a bit upgrading.
To the only really glaring error is the roof line by the headcode box, its too sharp, here's a photo that shows what I mean.








The defined line is just too sharp so I took a big file to mine to make it look like this.







I think this looks a lot better. It took just a few gentle strokes of a big file then a small file then some wet and dry paper ending up with 400 grit. If I polished it a bit more you would hard pressed to tell it had been done at all.
I have started to weather this one and the weathering will cover up the roof as that part will be oily black. I have also painted the handrails yellow as they should be. I have done the same on the green one but here it removes the grey roof to reveal the green below it.





As you can tell I'm not the best in the world at putting numbers on !
That might need doing again.

 

[richard carr]

The other thing I have on the go is a pair of JLTRT class 40s. The one thing I don't like about the kit is the bogie chassis its solid except for sprung radial truck that doesn't work that well from what I have seen of others. So on my first 2 40s I designed a new chassis with 3 beam compensation, here it is fitted to my MMP one.



It works well, in a straight line or gentle curve, but this one won't go round the 10 foot radius curves of Croscombe and there is no rocking of the axles as they held in the original bearings that cannot rock. My first JLTRT 40 has different version the Mk 3 (Mk 1 never got off the drawing board) it does go round the main curves on croscombe but not the tight ones.
So now I have the Mark 4 version, here's the etch





It still has 3 beam compensation but now includes a radial truck for the pony wheel.

The first thing to do is build up the bearings for the wheels



To do this I have taped the chassis to a block of wood and have started drilling out the alignment holes, I tried using a 0.7mm drill with 0.7mm wire, that didn't work as the wire did not want to go in the holes it was all too tight, so now I'm using a 0.8 mm drill with 0.7mm wire that works fine.

 

[SimonT]

Richard,
excellent stuff. I look forward to watching this build; I should do something to improve the Peak lash-up. Do you think that the 40 will manage 75" corners?

The 31 looks spot on - temptation, even if they weren't seen up my hill.

Simon

 

[richard carr]

Simon

75 inches is getting a bit tight but we have some that tight so once its built I will let you know. What wheels did you use in your peak ? I'm using home made ones here that are only 3.15 mm thick, slater's are quite a bit thicker than that and all the front boss needs to come off too.

The 31s look good as they are but once they get the weathering on the cab fronts to highlight the doors and foot steps etc they will look really good.

Richard

 

[SimonT]

Richard,
I used the normal Slaters loco wheels for the main wheel sets and wagon wheels the the pony trucks; I read somewhere that the prototype used wagons wheels. There is no side play on the driven (rear) axle. The centre axle is undriven and has enough end float to be limited by the outer frame walls. The leading driven axle has something like 20thou end float. The pony wheel can touch the outer frames where a piece of 5 thou plastic sheet ensured electrical peace.

Not sure that I can justify a 31 when there is the 9F to purchase this year!

Simon

 

[iploffy]

I am watching this with interest as I have a very poor riding JLTRT 40 it doesn't like curves full stop. One of the major issues with it is that the spring in the truck is so strong it pushes the first set of drivers off the rails.

 

[SimonT]

One thing to remember with class 40 and Peak frames, they are jogged outward a few inches to give the pony wheel more space to swing.

None of which is mentioned in the NQ destructions. Mine are soldered solid but I might build it in when I do a rebuild. Currently two of the axles are compensated and the pony truck does its own thing under the influence of a lot of lead. Trimming the back of the bogie frames by ablout .5mm helps clear the pipe work around the tanks.

Richard, will we be able to see this at Brightwell?

Simon

 

[richard carr]

Simon

Unfortunately I'm on holiday in St Lucia then so I won't be able to make it.

The good news is that I have put it ogether and it runs easily through a B6, both my other forties won't get anywhere near that. I need to add the outside frames which I will do tomorrow and post photos of everything too.

Richard

 

[Cliff Williams]

On the JLTRT CLass 40 front I weight them up, to be honest I weight them all now.
More recently I do the weighting at the start. a sheet of lead flashing is tailored to line the insides of the vertical walls, one thickness, both sides.
I have been known to push it to three thicknesses for one loco, but it needed some significant chassis strengthening.



Then you need to modify the bogie pivot, you cannot have screws on the end so close to the rear wheels, it acts as a lethal short and dcc chip fryer!
Its rod telescoping inside tube and anchored with a grub screw:


Modifications complete it was time to certify the loco on the weighbridge!


I also made up some floating axle springing too and it works well!

 

[iploffy]

I strikes me as something Mr Waterman should have looked at before he released the kit don't you think. The real life 40's were buggers to keep on the track in yards and were banned from Humps due too the length of the bogie and it's notorious ability to find it's way onto the dirt. How some were converted into snow ploughs is beyond me did they make the plough the same weight as the 40 to keep it on the rails or add a more (what's the word I am looking for) get the suspension to work right when they removed the pony truck. I personally love the peaks and the 40's their sheer presence and size but they had their failings as well. I hope the offering from Heljan solves the problem.

 

[Steph Dale]

Ian,
The main problem they had was a total lack of secondary suspension, so the bogie couldn't pitch or yaw. Both classes have a fairly lengthy wheelbase, and with only axlebox springs to take up any track irregularity they have some problems! There's no doubt that Bulleid and Raworth came up with a very stable design, but it has its limitations.
In the case of the ploughs the problem is less obvious; shorter wheelbase y'see.
Steph

 

[Cliff Williams]

OT Richard : You can order a BR9F in scale seven from Lee Marsh and it is no extra for the S7 conversion at this stage.

 

[richard carr]

OT Richard : You can order a BR9F in scale seven from Lee Marsh and it is no extra for the S7 conversion at this stage.

Thanks Cliff I'll give him a call.

Richard

 

[richard carr]

I am watching this with interest as I have a very poor riding JLTRT 40 it doesn't like curves full stop. One of the major issues with it is that the spring in the truck is so strong it pushes the first set of drivers off the rails.

Cliff is right you need plenty of weight in all the JLTRT diesels, especially the forty mine weighs in at 2.4kg or just over 5lbs, cliff's is even heavier. I also think its important where the weight goes, you need to put plenty in each nose, without it mine didn't run that well, it made a big difference once I had filled each nose with lead.

Richard

 

[richard carr]

Work has been progressing on the 40. Here is the main chassis now with the bearing made up



I have used 0.7mm wire passed through holes drilled with a 0.8mm drill which worked well.

The file is the big one I used to reshape the Heljan 31 roof.

So this is the chassis removed from the wood, a craft knife blade helps lift it up, you then need to cut off all the spare wire and file them flush on both sides.



I folded it up by hand and then started filing out the bearings so that the wheels were a nice easy fit



Next I started on the radial truck in the same way as I did the chassis.





Then once excess wire is cut and filed flush it just folds up.

 

[richard carr]

The next step was to attach the radial truck to the chassis, I used 2 10ba nuts and bolts to do this, the slots jut need a small tweak with a file to get things moving nicely. Here it is going through a B6 point.










Here we have the side attachments, these are to replicate how the jlrtr outer frames fit to their chassis so that mine works in the same way. The larger piece is for strengthening the chassis, you can put where ever you feel its needed to add some extra stiffness.



Here we have the JLTRT outer frames, I have cut a slot (with a drill and craft knife) where the main beam support passes through the chassis, you could file this flush but its easier to get a good soldered joint if you don't and miles easier to remove if you ever need to.

 

[Cliff Williams]

Pity you never had that drawn for normal O Gauge Richard!

 

[richard carr]

Cliff

The chassis is 26.5mm wide, the JLTRT resin chassis is 25.6mm wide so I would have thought it would probably work.

I need to make a few minor changes to the etch then I will get a batch done and send you one to try.

Richard

 

[Cliff Williams]

Yes that will work! Superb. I look forward to that immensely!
Let me know the cost in due course please.
Here is my last JLTRT Class 40 in action at John's layout:

 

[richard carr]

I managed to do some more over the weekend.

I put together a JLTRT outside frames for the bogie to test that through a B6



It clips over the chassis very neatly . There is just enough sideplay to push it through the B6 once you have thinned the sides a fair bit with a big file. The next view looking down shows how much movement there is.







I have now started to add the motor and the delrin cogs. I hate trying to add the cogs as a force fit so I ream them out with a 3/16th reamer then drill and taper pin them in place.



There is enough room to get the motor, beams and delrin cog in fairly easily between the frames.