Grasshopper goes Large 7mm DA 'Black 5'

[Grasshopper John]

Cheers Tim, I have had advice on the way, but I have managed to assemble inside out, upside down, and in the wrong place I have a habit of Thinking I know what goes where great experience for recovery though. Here is another one.

 

I was working on the reverse levers this morning getting them in place was an effort using wire so I used a 12ba nut and CH bolt. Then I noticed the expansion link had a hole mid way down, then the penny dropped I had connected the radius rod through the link to the support bar, Wrong, the radius rod should have been in the hole that had nothing in it.

 

So another dismantle of all and a refit. Now its much better and everything that should move does

 

 

 

Glad the motion bracket is re moveable as things would have been a bit harder than I already made things for myself. 

 

Just the eccentric rods to concentrate on then start on the final wheel assembly.

[Grasshopper John]

I'm not happy with the way the reverse leaver is attached I've left too much movement, whats needed is a couple of washers between the support bracket and the lever to stop sideways movement, so another re jig I just have to remove the 12ba nut and start again.

 

One thing about re doing things is you know at the second attempt it's 100 % correct or in some cases some are even an improvement

 

Grasshopper on way to WB.

[Grasshopper John]

This is how the reverse levers were assembled, as I said I wasn't too happy.

 

 

and after with the washers in place

 

 

Looks a lot better. I used felt tip on the inner washer and separated them with a rizla, worked a treat nice movement up and down none to the side.

 

Next and last job for now on the cylinders was the eccentric rods, I soldered the caps on the end and drilled a hole for the return crank, they are fixed with a 14ba bolt no nut or washer needed as it just took a dab of solder on the expansion link at the back then I just filed away the slot in the head.

 

 

 

Now the coupling rods, I've already assembled them but a bit ( quite a bit ) of fettling needs to be done on the crank bushes before they can be fitted.

 

Grasshopper.

[3 link]

 it just took a dab of solder on the expansion link at the back then I just filed away the slot in the head.

 

 

 

Grasshopper.

 

It sounds like you have got to grips with the black art of soldering  .

 

Martyn.

[Grasshopper John]

Spent the last few days on the final pieces of the valve gear, you assemble one thing and have to redo or adapt another. What i thought would be easy was far from it, the return crank, getting it in the right position took ages as the slightest movement of the bush would throw it out and had to start again.

 

This is the final assembly but I have a small tight spot and its where the eccentric rod joins the return crank on the LH side so another disassemble.

 

 

 

I'm not happy with the width of the expansion link, even though I've moved it as far as it will go outwards the conn rod still catches the eccentric rod, so still some fettling to be done, Have run it at speed using a brush on mini drill and she runs ok but at slower speed thats where I have the small bit of binding.

 

Grasshopper

[3 link]

Hi John,

 

What you need is a test track, I use to have two Peco points set as a crossover with a couple of lengths of track each side. It is alright sorting out any tight spots in a straight line, but the real test is if the loco can go through a 6ft radius without any binding of wheels against the frames or brake shoes and also valve gear.

 

Martyn.

[Pete Harvey]

Nice work John you will be giving OzzyO a run for his money soon (he could do with some exercise )

 

Pete 

[david.hill64]

Well done that man! Looking really good.

[Dave Holt]

Your chassis build looks to be coming along nicely. However, the hole you have used to fix the radius rod to the expansion link is too far from the expansion link pivot, even for full forward gear, and results in the lifting arms sloping down too steeply. The hole you've used was used in the prototype to insert the radius rod die-block pin and was deliberately placed beyond the maximum travel of the reversing mechanism to avoid any chance of the pin working out and getting jammed in the hole! If it's not too late, I'd create a new hole in the expansion link, say half way between the pivot and the existing (pin insertion) hole and attach the radius rod using that. The lifting links will then be in a more realistic position.

Dave.

[Tim2014]

Great work John - much faster than me too

I rather like your front crank bushes - how did you do them?

[dikitriki]

Hi Tim. John,

 

For totally recessed crankpin nuts, which as LMS enthusiasts you will appreciate the need for, see post 9 here;

 

http://www.rmweb.co.uk/community/index.php?/topic/7367-dikitrikis-7mm-workbench-scratchbuilt-wagon/

 

Richard

[Grasshopper John]

Your chassis build looks to be coming along nicely. However, the hole you have used to fix the radius rod to the expansion link is too far from the expansion link pivot, even for full forward gear, and results in the lifting arms sloping down too steeply. The hole you've used was used in the prototype to insert the radius rod die-block pin and was deliberately placed beyond the maximum travel of the reversing mechanism to avoid any chance of the pin working out and getting jammed in the hole! If it's not too late, I'd create a new hole in the expansion link, say half way between the pivot and the existing (pin insertion) hole and attach the radius rod using that. The lifting links will then be in a more realistic position.

Dave.

Thanks Dave that makes a lot of sense as my connecting rod has a tendency to hit the eccentric rod, I should be OK to change the position of the hole as the motion bracket is removable, I've had it on and off so many times I've lost count.

 

Great work John - much faster than me too

I rather like your front crank bushes - how did you do them?

It's just an ordinary top hat bush but reversed so the head of the top hat is outwards, this gives a lot better clearance when you fit the conn rod. hope that helps Tim.

[Grasshopper John]

Hi Tim. John,

 

For totally recessed crankpin nuts, which as LMS enthusiasts you will appreciate the need for, see post 9 here;

 

http://www.rmweb.co.uk/community/index.php?/topic/7367-dikitrikis-7mm-workbench-scratchbuilt-wagon/

 

Richard

Thanks Richard, lovely work I wondered from the photo OzzyO showed me how you did that.

 

Regards

John.

[Grasshopper John]

Well it took a bit longer than expected but worth it although I still have a very slight catch on the rear  of the expansion link, not much though the completed valves run on a plastic tray with only a slight incline.

 

So I had to strip the eccentric rod, and expansion link drill some holes and re-assemble, I forgot I broke one of the expansion links by trying to form it a few  times and it decided to part company again. It was more hassle to solder it back than re-assembling the valve gear.

 

 

I re did it using 188dg solder soit wont happen again (he says )

 

So all done now with I hope Dave, the radius rod is now sufficiently higher, the lower hole which would have been visible I just filled with solder and filed it smooth.

 

 

 

Now a little bit of work on the correct locking nuts for the rear crankpins and get rid of the 10ba ones which were only temporary.

 

Grasshopper

[dikitriki]

 the radius rod is now sufficiently higher, the lower hole which would have been visible I just filled with solder and filed it smooth.

 

Grasshopper

 

Hi

 

The valve gear looks much better. But the lower hole in the expansion link should still be there.

 

Richard

[Dave Holt]

Hi

 

The valve gear looks much better. But the lower hole in the expansion link should still be there.

 

Richard

Absolutely! Agree on both counts. I have personal experience of using these holes. Hours of endless fun driving the die-block pin in and out of the radius rod, through the expansion link, trying to get the taper pin slot in the pin to align with the holes in the rod on three sets of valve-gear (rebuilt MN, but the arrangement is identical to a Black Five).

Dave.

[Grasshopper John]

Thanks Richard / Dave, Thankfully it's only solder so a bit softer than the NS I had to drill yesterday

 

Grasshopper.

[ozzyo]

That is looking very good John.

 

OzzyO.

[Grasshopper John]

It's not looking so good at the moment OzzyO, I drilled the holes as advised then a little bit of fettling on the expansion link to give a bit more clearance, then I drilled and taped a couple of retaining nuts for the rear drivers, it was going OK then I noticed that a return crank was out of place probably because of the different position of the radius rod.

 

The return crank was also catching at the bottom, I worked out it needed a couple of bends, In trying to achieve them which I did I squashed the top hat as now it won't go home properly, so this morning I have to replace the offending top hat and re-assemble.

[Grasshopper John]

A very small error meant I had to strip down the body which has given me the chance to get those springs sorted out, I've been meaning to do this so out with various files I set about getting rid of excess solder and the cusps ( Thanks Martyn ) .

 

So nearly 5 hours of filing I think they look a whole lot better.

 

 

 

My fingers and thumbs are numb I just hope I can hold a pint.

 

Grasshopper.

[Grasshopper John]

Well after a major setback I've finally got the valve gear finished, It runs beautifully now, for some reason I couldn't get the right side to work as well as the left, so thinking cap on and another strip down I realised  the return crank was wrong I made the left with two bends but the right only one.

 

So after dismantling the radius rod ( again ) from the return crank I put it in the vice and gave it the tweak at the lower end to stop the conn rod fouling the radius rod.

 

 

 

I admit I had a few problems with the cylinder wrappers but I can get over that later on.

 

Few pieces left to attach to the frames and then it will be a strip down and a coat of black etch primer, will do the Tender at the same time.

 

Not sure if 7mm makes a diff from 4mm but the difference in the running is very noticeable.

 

Grasshopper

[Pete Harvey]

Jon

 

I would not be bothered about the wrappers as they were never mirror finish and the metal would warp after a few hours of use.

 

The build looks great.

 

Pete

[Grasshopper John]

Understood Pete, I will think about that I like building as the real thing would look, a bit battered

 

Just last pieces now fitted to frames before a coat of primer, exhaust injector and pipes the lever mounts and the drop grate bracket.

 

 

 

The exhaust pipe is on it's way, was pleased with the way I soldered the WM to the pipes and frame, getting a bit more confident now.

 

Grasshopper.

[Grasshopper John]

Most of this build is new territory for me so the exhaust pipe is no different, It's a strange arrangement as the injector is at an angle so the pipe has to have two bends quite close to each other.

 

Took a few attempts as I've never had to bend copper tube before but got there in the end, I made up the brackets from copper wire and used low melt for the join into the injector.

 

 

Just hope I've done it correctly as it was all guesswork.

 

Grasshopper.

[Dave Holt]

It's really not a good idea to do modelling of this standard by "guesswork". Proper sources of information are fundamental. I've attached a part copy of the pipe & rod drawing for a late Black V. I can recommend the Wild Swan series of loco studies as a good source for this type of information.

To be specific, there's no double bend in the steam supply pipe to the exhaust steam injector. Hopefully, you will be able to make out the pipe run in both planes.

 

 

Here's also a photo of the underside of my 4 mm Black V, to help clarify the arrangement shown in the drawing.

 

 

Dave.