Building a G.W.R. Castle + more in 7mm OF from a JLTRT kit restarts on P.88 by OzzyO,

[Horsetan]

Horsetan already has the Portescap motor strategic reserve under his bed.. There was one on eBay over the weekend, £50 last time I looked.

 

Yes, but eventually the strategic reserve will run out, and then I'll be needing a credible alternative that can do all the things the RG4 drivetrain can do, won't I, Craig?

 

I'm sure there must be helical cut gears you could fit in a 4mm model available somewhere. ...

 

I suppose I can always ask Ultrascale what they think of an ABC-style multi-start worm-plus-helical, even if it's going to be a "no" vote from them.

[ozzyo]

I suppose I can always ask Ultrascale what they think of an ABC-style multi-start worm-plus-helical, even if it's going to be a "no" vote from them.

 

 

Hello H/T,

 

what about the people that do the Porter's Cap gearbox (High Level?).

I think that the gears are pretty well standard so getting the helices should not be to much of a problem.

 

OzzyO.

[Horsetan]

Hello H/T,

 

what about the people that do the Porter's Cap gearbox (High Level?).

I think that the gears are pretty well standard ....

 

Not quite standard, unfortunately. Most gear makers in 4mm make single-start worms (which I loathe), but not multi-starts, which I think would need matching helicals. You can't use the helical gearwheel from a single-start to be driven by a multi-start, as far as I know.

 

And the reason for going for a multi-start is, as Sid Stubbs wrote in MRJ 42, because it can be back-driven just like bevel gears or contrate-and-pinions, i.e. the geartrain won't "lock-up".

[ozzyo]

Hello H/T,

 

what about the people that do the Porter's Cap gearbox (High Level?).

I think that the gears are pretty well standard so getting the helices should not be to much of a problem.

 

OzzyO.

 

 

Hello H/T,

 

when I said that the gears were standard, I meant that they were an industry standard. Probable cut by Murforts (not sure on the spelling) or some such co.

 

First time I've used one of my own mess. as a quote.

 

OzzyO.

[Horsetan]

....Probable cut by Murforts (not sure on the spelling) ....

 

Biddle & Mumford?

[ozzyo]

Biddle & Mumford?

 

 

That sound about right.

[Engineer_London]

Apologies for slight further diversion of the topic onto helical gears. I have a preference for worm-free drives, too, where space in the model allows.

 

I bought a few sets of small helical gears from HPC a while ago, and began the development of an EMU bogie drive for 4mm with these gears [1.7:1] as the final stage. I've also started on trial fitment of a Slaters helical gearbox [2.9:1] into a 4mm steam loco chassis. Both projects have been started but slowed down by work and life matters, though.

[Horsetan]

....I bought a few sets of small helical gears from HPC a while ago, and began the development of an EMU bogie drive for 4mm with these gears [1.7:1] as the final stage.

 

Which ones? Any particular reference number?

 

I've also started on trial fitment of a Slaters helical gearbox [2.9:1] into a 4mm steam loco chassis.

 

I've seen that one. Struck me as being a little on the large size for 4mm.

[Engineer_London]

Still a bit off topic - note to Horsetan

 

HPC part numbers were: PH0.4-10/RH and PH0.4-17/RH. Both described as HELICAL GEAR - CROSSED AXIS PLAIN

 

These were 0.4 module, 10 and 17 tooth for 2mm shaft, definitely not in the fine pitch league, unlike the Slaters or the other brands of railway gear packages. They were small enough for bogies of 12mm wheel diameter, 28mm wheelbase. Steel gears purchased as this is only an experiment in feasibility, which about describes the very occasional modelling I can do at the moment. If the overall solution shows promise, I'd probably look for alternatives in gear material and pitch, aware of the consequences for cost, of course.

[ozzyo]

Hello all,

 

I've opened a thread in motor and drive systems about gearboxes that will drive back in OO (4mm) as I think that we may get more replies in that section than we will in this thread.

 

Well the Loctight should have set now so on with some more running in.

 

OzzyO.

[Horsetan]

Hello all,

 

I've opened a thread in motor and drive systems about gearboxes that will drive back in OO (4mm) as I think that we may get more replies in that section than we will in this thread.....

 

Thanks!

[ozzyo]

Hello all,

 

well the motor & gearbox question thread seems to have gone down well,

 

In a previous post I mentioned about the intermediate shafts slipping in the bearings, this was how I checked for that , The two purple lines on the shaft and inner race should line up

 

My lash up highly sophisticated set up for running in gearboxes

 

Boiler band tided up and rivet replaced, 4405 is the only member of the class that I have seen photos of with this pipe running from the super heater cover

 

Cover plate fitted to the drivers side & fireman's side

 

Two general views showing that most of the front end fittings are in place

 

A closer view of the front end, a bit of tiding up still to do

 

Getting ready to fix the valance overlays in place. I was going to fit the rear overlays that butts up to the rear buffer beam first but I would have lost some of the rivets on the centre section of the overlays. The dots on the tank side are to remind me of the position of the rivets that hold on the sandbox supports

 

OzzyO.

[ozzyo]

Hello all,

 

just about to start fitting the injectors, now if we thought that the mud hole & washout plugs were fun try these.

 

Over flow pipe straight down, over flow exit under the step near the front of the step

 

Over flow pipe coming out from the injector at 90deg. and under the step with the over flow exit at the rear of the step

 

Over flow pipe coming straight out of the injector and then turning through an approx 45deg. bend and then being fastened to the rear of the step plate with no visible sign of the over flow exit

 

Over flow pipe coming straight out of the injector and under the step with the over flow exit at the rear of the step

 

And you thought that the G.W.R. was a railway that standardised on there locos!!!

 

OzzyO.

[ozzyo]

Hello all,

 

if anyone would like a copy of how an injector works, please PM me and I'll send you a copy of how it works.

 

OzzyO.

[buffalo]

Those injector photos remind me of earlier saddle tank and pannier conversions where many of the saddles had the overflow pipe passing straight down through the running plate but on the panniers there was often a right angle union (as in your second photo) and the pipe went out over the plate and down the outside.

 

As you say, standardisation, but the standard parts could be assembled in different ways

 

Nick

[ozzyo]

As you say, standardisation, but the standard parts could be assembled in different ways

 

Nick

 

 

That is very true.!!!!!!!!!!!!

 

OzzyO.

[craigwelsh]

I think this sums up standards http://xkcd.com/927/ .

 

Interesting check for slippage, some sort of thing for tyre slippage on the prototype, planes as well as trains.

 

I hadn't realised there were those cover plates between boiler and tanks, they cover over that i'd thought was a weak point with the boiler on top of the tanks.

[Blandford1969]

I think this sums up standards http://xkcd.com/927/ .

 

Interesting check for slippage, some sort of thing for tyre slippage on the prototype, planes as well as trains.

 

I hadn't realised there were those cover plates between boiler and tanks, they cover over that i'd thought was a weak point with the boiler on top of the tanks.

 

More to the point they deflect water hopefully to run down the drain on the tank top so it does not flood all over the motion. Loveley model, your thread really helps us to understand how these kits go together and gives lots of ideas.

[ozzyo]

Hello all,

 

Craig, the tanks were held together by a strap that went over the boiler at the front end of the tanks as seen in the following photo, the strap is held to the tanks by the four bolts in front of the water filler. Different railway Cos. had other means of doing this the L.M.S. for example normally used straps that were welded (riveted) to the boiler and came out through the cladding.

I have used this method for checking for slip for more year than I care to remember.

 

Blandford, I think that you summed up what the cover plates were for better than I could have done!

 

Anyway back on to the build.

The front steps in place, I've been thinking (that's bad for me) about adding some form of strengthening to these. All I can come up with is a U shaped length of wire soldered to the back of them. Other ideas welcome.

 

cab steps in place showing the strengthening strip down the back

 

Cab step treads in place

 

Rear buffer beam and buffer body's in place, I've still got to fill in the slots for the steps on the bunker back

 

The injectors as supplied

 

The first set of modifications, overflow pipe removed and drilled 1mm and delivery pipe bent back

 

New stubs for the overflow pipes added (bottom) and steam feed pipes added (top)

 

First fit to the loco body using the feed water pipe, overflow stubs still to be trimmed

 

Overflow stubs trimmed, in these two photos you can see the join between the centre and rear valance overlays

 

Overflow pipe in place (1.5mm tube). I went for the front edge of the step type for this. This cant have been very footplate crew friendly!

 

OzzyO.

[ozzyo]

Hello all,

 

I was working on the vacuum pipes yesterday and low and behold more changes to the normal. On most locos the vac. pipe is to the left of the coupling hook when viewed head on. On the front buffer plank this is the case, but on the rear buffer plank it's on the R/H side of the coupling hook. But at some time it change sides.

I have also had a problem with the lengths of the valances, More on that later when I've got it sorted out.

 

OzzyO.

[ozzyo]

Hello all,

 

as I mentioned in my last post, I found an problem with the length of the valances.

The rear buffer beam as first fitted, as you can see the rear overhang is quit long. When I checked the length between the buffer beams they were about 2mm to close together

 

So off it came

 

So first part of the fix, a length of 2mm L angle, I also filed two slots in it for the frames to fit in

 

Buffer beam refitted, you can see the difference in the overhang. IIRC this took the distance between the buffer beam to 31' 10"

 

The rear of the valance refitted the gap between the rear and centre valance sections still to be sorted out

 

The gap now filled in

 

Rear vac. pipe fitted, I've also filled in the slots for the steps

 

The steam heat cock as supplied

 

and as modified, to do this I drilled a 1mm hole through the handle into the body, then cut the handle off and turned it round and soldered it back in place with a short length of brass wire in the hole

 

Now in place on the rear buffer beam

 

The front buffer beam, I've still got to straighten out the vac. pipe. on the front buffer beam it looks like there are two types of vac. pipe used, this type and the type that has the bag end next to the buffer body

 

OzzyO.

[ozzyo]

Hello all,

 

well it's been a while but we're back on with the frames.

Going back a bit you will remember that I fitted spacer SB in place but did not solder it in place

 

Well I decided that it would have to go, 1] it would make soldering the cylinders in place hard work, 2] getting the fixing screw in would be damned near imposable. You can see one of the spacers that I have soldered to the frames inside of the cylinders, this is 1.5mm I really needed 1.75mm but I will just use some shim while I solder the cylinders in place

 

Cylinders in place from below and above

 

The front valve chests in place, I will leave the cleaning up until I have fitted the cylinder wrappers

 

OzzyO.

[ozzyo]

Hello all,

 

two posts in one day,

The first fit of the body to the frames. Hope you like the background

 

One of the top hats that I'm using for the mounting screws from below, I have seen some builders put these in from the top. But when you do this the forces from the screw will try to pull them from the soldered joint. That is one reason that I do it this way

 

The other reason that I do it this way is that I can have the end of the top hat go all the way to the body, this will stop any chance of the spacer being bent

 

The valve spindles as first soldered up and after a quick grit blast

 

Now this is where the fun starts. Does the pump arm go in front of the valve gear or behind it.? I think that it should be in front of it, so I will have to do some work on the motion bracket to make sure that the pump arm will clear it

 

If anyone can help me with photos of this I would much appreciate seeing them.

 

OzzyO.

[Mike]

Check out figure 358 in Russells "Pictorial Record of Great Western Engines" the arm comes off the back of the cross head and through the top rear of the motion bracket, so it's behind the connecting rod and misses the coupling rod..

[ozzyo]

Check out figure 358 in Russells "Pictorial Record of Great Western Engines" the arm comes off the back of the cross head and through the top rear of the motion bracket, so it's behind the connecting rod and misses the coupling rod..

 

 

Thanks for that Mike,

I don't know how I missed that photo. So a bit of work to be done on the motion bracket and to bend the arm outwards to miss the valve gear should sort it out. Sound so easy when it's in print.

 

OzzyO.