7mm Mickoo's Commercial Workbench

[7mmMick]

JB,
Some shots of that area and other ashpan bits would be very useful. Also the area around the the back of the driver's side steps and the injector on that side, if they haven't moved it forward. By chance I am working on the replacement chassis for the Hall.
Thanks
Simon

Yes please JB, what Mr Thompson said

 

[mickoo]

The next change I needed to do for a late Lot built Hall is the fire iron tunnel, I will own up to being asleep at the back of the class when making the splashers earlier and not realizing the two rear LH ones are wider.

In reality it didn't make things overly difficult, which ever way you cut this square in half you'll end up with two equal rectangles. Some parts would have been easier pre-assembly, others easier after assembly as you have fixed datum points to work from/fix to.

The first image is for engines without the tunnel, the second with (obviously Sherlock ), I salvaged the splasher faces and rear splasher top sheet. A new tunnel side sheet was added to the outside of the remaining fold up splasher supports; the kit has fold up splasher faces from the footplate below with a detail overlay on the outside.

Next step was to grind off the riveted angle plate around the base of the old splashers as the new ones are wider. The salvaged splasher faces were then fitted at the new wider location and the rear cover trimmed to width and refitted.
A new middle splasher cover was made up with beading and fitted in place; then new riveted angle strips made up to fit around the base of each splasher. An etch here would have been really really helpful , but it was out with the fret saw and files, those two parts took longer than the rest of the works combined.

Finally the new tunnel top was added and the flat filling/blanking plate behind, that'll need trimming to allow the firebox to sit down in there when we get to that point. The tunnel end joint with the splasher top will be covered by the middle nameplate bracket to neaten things up a little. I also now need to re-drill the clack pipe feed hole in the new location further forward.

 

[mickoo]

Apparently I’m straightening out buckled damper doors on Pitchford on Saturday so let me know if you need undercarriage shots.

JB.

Late to the party, there is but I wouldn't know what I needed, until I saw it sort of thing, if that makes any sense

 

[mickoo]

The last change to make a later Hall is to add the ATC/AWC bracket and housing to the front axle boxes.

Engines up to 5920 had the traditional bracket mounted behind the buffer beam. From 5921 onward the design changed, the big bracket was removed and a cranked stay added to the front of the axle boxes. The stay cannot be rigid as the axle boxes need to move independently, therefore a large bearing and securing nut holds each end of the stay to each axle box.

The housing does not look like a typical ATC unit and I cannot find any reference to the striker underneath, I don't think it's AWS either as the installation started way back in 1933 when the engines were built.

You also need to change the front inverted V brace, the originals terminated in a small plate fixed to the side of the bogie frame and have a shallower angle. The later ones go right to the base between the side frame and lower flange, this gives clearance to extract the stay pins/bearings. I've no information about the rear so have left as original, there being no stay back there so it is logical that inverted V brace remained as original.

The print encompasses the axle boxes which fit over the top hat bearings and hold it all in place. The enlargement shows I need to really clean up before taking photos

 

[BrushType4]

Apart from the skill of a superb build, the photography and cleanliness of the work is to behold too.

 

[mickoo]

Apart from the skill of a superb build, the photography and cleanliness of the work is to behold too.

Thanks but it really isn't that clean, Malcolm Mitchell just put a picture up on Facebook of his Grange build, it makes my work look like a right dogs dinner

 

[7mmMick]

The last change to make a later Hall is to add the ATC/AWC bracket and housing to the front axle boxes.

Engines up to 5920 had the traditional bracket mounted behind the buffer beam. From 5921 onward the design changed, the big bracket was removed and a cranked stay added to the front of the axle boxes. The stay cannot be rigid as the axle boxes need to move independently, therefore a large bearing and securing nut holds each end of the stay to each axle box.

The housing does not look like a typical ATC unit and I cannot find any reference to the striker underneath, I don't think it's AWS either as the installation started way back in 1933 when the engines were built.

You also need to change the front inverted V brace, the originals terminated in a small plate fixed to the side of the bogie frame and have a shallower angle. The later ones go right to the base between the side frame and lower flange, this gives clearance to extract the stay pins/bearings. I've no information about the rear so have left as original, there being no stay back there so it is logical that inverted V brace remained as original.

The print encompasses the axle boxes which fit over the top hat bearings and hold it all in place. The enlargement shows I need to really clean up before taking photos

View attachment 155844

View attachment 155845

Lovely that mate. Can I have one for 5999 please I’m guessing it would have been so fitted by 1959 and I’m just on with the bogie

 

[mickoo]

Lovely that mate. Can I have one for 5999 please I’m guessing it would have been so fitted by 1959 and I’m just on with the bogie

Yeah I'll whizz one up for you, it fits over the small 5/32" axle top hats, do you have those?

If not I need the OD of the top hat bearing that pokes through the frames and the inside distance between the frames, these frames have been modified from the kit as the wide spacers were too wide and for S7 and the intermediates to narrow and left a big gap between the wheel inside face and the frame side.

I took the wider stays and cut them in half and butt joined them back together to get a width more visually pleasing, that width will not be anywhere near what you have.

 

[mickoo]

Regarding the fitting and the said item, some Google surfing has turned up some lovely information, Justin Newitt on RMWeb posted a link to a pdf about GWR ATC https://www.rmweb.co.uk/community/index.php?/topic/158771-gwrwr-automatic-train-control-equipment/

In a nut shell they revised the installation with a smaller head and sprung shoe on a cam. I've attached a crop of the relevant page that shows one style of drawing for the smaller revised unit, there are several other designs but all on the same principle. This unit appears to be mounted directly on the axle with a torsion bar to prevent rotation, maybe a trial installation. Nearly all the others I've seen are on the stay between the axle boxes or bespoke brackets under the bogie.



These revised units also found there way under other classes, prairie tanks have been mentioned.

 

[simond]

I guess mounting it directly on the axle, (or axleboxes) of a wheelset without brakes, means that it is going to be very accurately the same height for a very long time.

No suspension movement to consider, & very little wheel wear...

 

[mickoo]

I thought it was about time I did a general update on progress so far for the Finney7 Hall.

A good day at the bench produced the firebox and finishing off the boiler and smoke box units built the other day. The bonnet and chimney are just for visuals, they need the mould lines removing and cleaning up before fitting.

The firebox is now secure with the cab, the boiler and smoke box are bolted together and to the footplate through the saddle, there's a couple of high points on the boiler that's stopping the joints being nice and tight.

Normally I'd leave be and low melt solder the gaps but I'd prefer a better mechanical joint and if possible no solder at all.

The firebox wrapper has been cut to fit over the fire iron tunnel inner closure plate, the other option would have been to trim the closure plate to the firebox side profile. Cutting the wrapper resulted in one simple flat cut to match the flat top, rather than a tapered cut in the closure plate to match the wrapper.

 

[Scale7JB]

Got photos of the Hall, will hopefully upload tomorrow. Can you PM me email addresses for a full size transfer?

JB.

 

[mickoo]

Got photos of the Hall, will hopefully upload tomorrow. Can you PM me email addresses for a full size transfer?

JB.

Mailed

 

[SimonT]

From you to me!

 

[Dan Randall]

The firebox wrapper has been cut to fit over the fire iron tunnel inner closure plate, the other option would have been to trim the closure plate to the firebox side profile. Cutting the wrapper resulted in one simple flat cut to match the flat top, rather than a tapered cut in the closure plate to match the wrapper.

Doh! Wish I'd thought of that, when I was faffing around with the fire iron tunnel on my "Castle"...

Regards

Dan

 

[LarryG]

Lovely platework. Your locos bring to mind the old Murray Mint TV ad..."Murray mint, Murry mint, too good to hurry mint", or in your case, ..."Mickoo brass, mickoo brass, too good to paint alas.

 

[mickoo]

From you to me!

It shall be so

 

[mickoo]

Just a quick end of week update on the Finney7 Hall, tender and engine upper works all complete. Cylinders, motion and injectors tomorrow to finish it off whence I shall do some final decent shots all around.

The outside steam pipes were fit for purpose but too long, not much but enough to have to faff around and shorten and get the angles right between the pipe and footplate. I could foresee one of those shortening the stool legs episodes looming.
I already had a 3D one drawn up for the 47xx, so it was much easier to just adjust the length and print a new set out.

Big To Malcom Mitchell who expedited a set of his stamped mud hole covers yesterday at short notice, after I suddenly realised I only had two of the four needed.

The final alteration for a late Lot hall was to move the top lamp iron to the smoke box door which is easy to do. Whistle and safety valves will be fitted after paint.

 

[mickoo]

Way back at the tail end of 2019 I had a Bulleid Light Pacific (BLP) on the books and the track view through that big 'ole at the front was disturbing. To that end I knocked up a smoke box chamber which required the builder to cut and fold a shaped brass shell (an etch was considered if there had been more interest) and attach the 3D print, the associated pipes also needed adding.

Whilst it is pretty dark in there the blastpipe can be seen and once painted with a little weathering and highlighting is a whole lot better than the track view.

Fast forward almost exactly two years and another BLP has been added to the schedule, since increased to two and it was time to think about resurrecting the smoke box chamber module. That seed sat dormant until this week when someone required two more, they were happy to cut the metal and proceed as before, I being time short was not.

Long story short and several trial prints has seen the unit evolve into a virtual stand alone item, one only needs add the two blast pipe area pipes which are to small to support themselves printed, those being the blower ring pipework and vacuum ejector pipe.

The new unit has all the walls (whilst the rear wall top end cannot be seen, it does set the correct height of the unit and stabilise it in the casing) and floor added as one unit, simply paint, flip the casing upside down, drop in and glue; I also added a few more details which had since come to light. The unit is designed specifically for the Finney7 casing and to fit within the inner taper, though I'm sure it'll fit other models with a bit of adjustment.

The walls and floors do use more resin (expense) and increase the print time from 2 to 9 hours, but the time saved not having to cut out the metal shell or the expense of an etched shell then I think is worth it.

There is a slight error with the new unit shown, the floor over the middle cylinder has been accidentally raised, it should be lower and show the two longitudinal ribs in there as seen on the original design. That has been rectified and the first two production units have just finished in the printer as I write this.

 

[Scale7JB]

Lovely bit of cad work, and probably took less time than knocking it up in brass?!

JB.