Primrose No2 in 7mm

[doilum]

Not sure if this is the best place to start a build blog but here goes!

Why Primrose No2? Area 8 had but three 16" Hunslets as opposed to around nine or ten of the 15" type. Primrose No2, Beatrice at Ackton Hall and Glasshoughton No 4. I had already scratch built the latter two as, at the time, the 7mm 16" appeared to be quite low on Mike Edge's "to do" list. I did my own drawings from photos and measurements taken from my 15" models. In the end my footplate is 1mm short, and my tank about 2mm too long with a reverse discrepancy in the cab. The chassis is spot on. So when one of Mike's 16" kits appeared on the bay of E with a few bits missing I had to have a cheeky bid and won.

[doilum]

I am still trying to figure out how to continue with text after including an image.

Primrose No2 is Hunslet 3715 of 1952. New to Primrose Hill colliery in Swillington she moved on to Micklefield when it closed and from there to preservation at Embsay. In her working days she appears to be very camera shy so if anyone can help with photos of the steps and handrails I will be most grateful.

This is in no way a review of the Judith Edge kit, just an account of how I used the parts to build third 16"" Hunslet and perhaps encourage someone else to have a go.

Normally I would always start with the coupling rods and frames but whilst Slater's sort out some wheels and pick ups I thought I would make a start on the saddle tank. There are a few photos of my basic tools. My preferred method of removing items from the fret is an old blade in an Exacto #2 cutting into the grain of a plywood offcutt.

Before starting to bend the wrapper, I scribed aline down the dead centre on the inside face and created a tiny notch with the piercing saw at each end. I also labelled front and rear as the tank is not reversable. Likewise the formers have a tiny notch cut at TDC. This greatly simplifies lining it up later.

The tank wrapper, like the rest of the kit is 0.022" brass ( if scratch building I might use 0.016") but it started to take a curve in mother's old mangle and then rolled nicely under a heavy copper tube. The formers could then be tacked into place noting which was front and rear. I like to set them back about 0.5mm to allow a little wiggle room during final fitting. The tank front is only fitted when the rest of the work is satisfactorily completed. Don't forget to tap out the rivets first!

At first, all seemed to be going almost too well, but as I attempted to complete the bottom of the curve and create the fold over metal memory kept causing the soldered joint to break. I began to wish I had annealed the wrapper first which might have killed the memory. One option might have been the big iron send "real" electricians solder but in the end I applied a generous dollop of 145 solder and flux to the inside, dug out the RSU, set it to 11 and won.

[doilum]

OK. Not sure what happened there. Not the sequence of images intended. But that was day one.

A few intended photos are missing. So here they are:

Edited July 26, 2021 by doilum

[Barclay]

16 hours ago, doilum said:

I am still trying to figure out how to continue with text after including an image.

 

Hi click to the right of your image and then press return. The cursor should then move underneath the pic.

[doilum]

1 hour ago, Barclay said:

Hi click to the right of your image and then press return. The cursor should then move underneath the pic.

Thanks. Perhaps the problem is that I tend to work from a tablet. I will ask clever daughter to have a look.

[Michael Edge]

The tank would probably be better in thinner material but we try to keep the whole kit on one sheet, annealing is definitely recommended. 

[doilum]

7 minutes ago, Michael Edge said:

The tank would probably be better in thinner material but we try to keep the whole kit on one sheet, annealing is definitely recommended. 

Thanks. The thicker brass is the better choice for everything else. Controlling costs is critical in this type of kit. I hadn't had a problem with the 15" kit and thought I would get away with it!

[doilum]

Day 2: The footplate.

I had just an odd hour or so to spare today. The first step was to identify the front and rear buffer beams and pop the rivet detail. Then, starting at the front use tiny blobs of solder to tack the front buffer beam into the etched recess provided. Once satisfied that all is straight, square and the correct way up, complete the seam. Add the valances and then the rear buffer. The work is carried out on a jig I made many years ago to facilitate building Mr Kirk's coaches. All work today courtesy of my ever so cheap and cheerful Chinese iron.

My final task is to cut a block of straight flat wood to fit exactly inside the valances. This will keep everything true and flat as the build progresses.

[doilum]

There was actually a little more time than expected so I set about replacing the missing boiler etch. Rather than try and replicate Mike's clever piece of brass origami, I simply rolled a full boiler from some 0.009" (0.21mm) K&S tinplate I have had for years. The boiler bands came from the scrap etch alongside the frames. There was exactly just enough!

The former is a length of broom handle that is adjusted with extra layers of masking tape. Jubilee clips keep everything in place. Whilst this is a job that can be performed with a conventional iron, the RSU makes it almost a doddle.

Edited July 27, 2021 by doilum
Additional information

[doilum]

Gardening was rained off so I put a bit more effort into finding a good monochrome image of Primrose No2 in action. A search under" Peckfield colliery Primrose No2" resulted in an excellent image from 1971. The tank footstep and grab rail are on the right (off) side. Question is: were they duplicated on the left?  There are no front steps and the cab steps are not boxed in. I know that the livery was red but it is unlined and the top of the tank is red too. I assume the cab roof maybe black.

Still raining so I added the right hand tank grab rail and step. No doubt a definitive photo of the left hand side will turn up just as the paint is drying!

Edited July 28, 2021 by doilum

[Michael Edge]

Primrose No2 had a step on the LH side in 1974 at least - I think the photo (taken at High Dyke/Sewstern) I have may have come from Dave Ford's collection on here. Most of these had a step on the RH side, some on LH but I'm not sure if these were instead or as well. The top of the tank was painted red in preservation at least although normal HE practice was to paint it black, cab roof definitely black.

[doilum]

19 hours ago, Michael Edge said:

Primrose No2 had a step on the LH side in 1974 at least - I think the photo (taken at High Dyke/Sewstern) I have may have come from Dave Ford's collection on here. Most of these had a step on the RH side, some on LH but I'm not sure if these were instead or as well. The top of the tank was painted red in preservation at least although normal HE practice was to paint it black, cab roof definitely black.

Many thanks for the break through! Somehow the High Dyke scheme had completely passed me by.  I think, given the 1974 date, we can be confident that she is in pretty much her final working condition. There are foot step and grab rails on both sides of the tank. I cannot be sure if just the dome has been painted black, or if a narrow Hunsletesque black strip has been painted along the tank top. 

The plain red livery is typical of the final Allerton area workshop rebuilds. A few years earlier they would have had the full lining and gloss finish.

I have just found for a photo from 1991 taken at Embsay where she is resplendent in a fully lined livery with a black top to the tank between the handrails. It was good to see she had been refinished with NCB and S121.

Edited July 29, 2021 by doilum

[doilum]

Day three: the smoke box.

First step: make sure the base is the correct way round. Pop out the rivets and solder the front to the base taking time to ensure this is dead square. The outer wrapper has been etched down to around 0.016" and is easy to work without annealing. The inner face of the front can now be tinned with a generous application of flux before and after. The main thing is to get one bottom edge of the wrapper absolutely level with the base and flush with the front. After lots of checking it is a matter of working your way round frequently stopping to check that it is still flush with the front and therefore square. The plywood is flat and the aluminum offcutt provide a much needed  third hand.

[5050]

Neat idea the aluminium 'clamp'.  Might try that as my board is plenty big enough to fit one.  Do you tighten the screws each time to secure the workpiece or just have it at a 'useful' clearance all the time?

[doilum]

22 minutes ago, 5050 said:

Neat idea the aluminium 'clamp'.  Might try that as my board is plenty big enough to fit one.  Do you tighten the screws each time to secure the workpiece or just have it at a 'useful' clearance all the time?

I tend to tighten it gently each time. I have found that time spent knocking up a jig is repaid very quickly and avoids much frustration, burnt fingers and lost components.

[doilum]

Still awaiting the wheels so I decided to have a go at the idiosyncratic area 8 chimney. Beatrice has a neat cast example but I cannot remember where I bought it from.

There are some good photos in the Martin Bane article regarding the modification of locomotives using the Porta system and all my Austerities have scratch built attempts to represent them. The 15 and 16" locos have a stumpy stove pipe affair that tapers slightly. I did think of filing the top lip off the resin casting provided, but felt that it was too skinny and best left for the spares box. This left me looking for bits of concentric brass tube. Slitting with the Dremel creates the taper and the chimney is anchored by a central blast pipe. Finally the triangular gussets are added. Once in primer any remaining imperfections can be dealt with by brush application of a filler primer or cellulose stopper.

Back to the prototype. Primrose No2 was slightly unusual for area 8 in that throughout her working life she had standard 16" buffers. By the time she gets the full repaint in preservation she has a DIY extensions welded on to take them to 22".

Edited August 1, 2021 by doilum

[doilum]

[doilum]

The wheels and pick ups arrived today so I managed an hour after tea marking out the frames and drilling a 1mm pilot hole for each pick up. I normally place them behind the front and rear axles and ahead of the middle axle but, because of the positioning of the cross members, I have placed the front ones ahead of the axle too. Tomorrow I will carefully open out the holes until they are a perfect fit on the plastic trumpets. Too big and the pickups can slop around and will need securing with epoxy, too tight and they impede the smooth operation of the plungers. 

I have prepared the plunger units in advance. Firstly, the plunger must move totally free in the trumpet. Four of the six were fine, the other two needed just a little broddle with the 1mm drill. I like to solder the tag directly to the plunger. The photo shows a pair of pliers being used as a heat sink. Without this there is every chance that the trumpet will melt internally, and yes, I destroyed the first one. Fortunately I found a recycled trumpet in the spares box. The choice of wire is important too. It must be multistrand and as light as possible if the plungers are to dance freely. In a perfect world they would be black and almost black but red and orange were the best i could find in the scrap box.

Slater's pickups get a poor press in some quarters but installed carefully I am confident these will be trouble free and totally reliable.

[doilum]

[doilum]

I managed a full afternoon. First task was to fit the 10 BA crankpins and tap the Slater's bushes to suit. Then on to the frames. The half etch slots make assembly a breeze. As is usual, the axle holes needed a gentle touch with a file and the centre holes were extended vertically by 0.5mm. Wheels on and first whizz test. All fine.

On to the coupling rods. I decided to split these on the centre crankpin. All went well until.............

I need to find a fail safe way of opening up the holes! 

I learned a long time ago that the pillar drill is to be avoided at all costs. Gently twiddling with a drill in the pinvice takes for ever...... A drop of WD-40 helps...... The rat tailed file will upset engineers but actually works.

[doilum]

Oddly enough I didn't swear or throw anything. The damaged part of the laminate was cut and unsoldered. A fresh piece of the waste etch soldered in place and the joint reconstructed using the good one as a pattern. Despite the fading light ( I only work in enhanced natural daylight) I simply HAD to know. Coupling rods on, bushes screwed on and.........Whizz zzz. Absolutely no fettling at all. This is unheard of. Pack up whilst you are winning.

[Ruston]

13 hours ago, doilum said:

I need to find a fail safe way of opening up the holes! 

Broaches. https://www.eileensemporium.com/index.php?option=com_hikashop&view=product&layout=show&product_id=1288

[doilum]

1 hour ago, Ruston said:

Broaches. https://www.eileensemporium.com/index.php?option=com_hikashop&view=product&layout=show&product_id=1288

Maybe time to bite the bullet. Might need the next sizes up though.

Finished the chassis this morning now ready for primer. Then organise a new rattle can of NCB red.

[doilum]

Quote

And at the end of the day:

 

Not sure if it shows but the paint has a definite bloom. Probably the result of only just letting the etch primer dry, or maybe the very high humidity as the storm broke overhead, or perhaps it was the final gasp of the old rattle can????

Thing is, it captures exactly the look of these late Allerton rebuilds that didn't get the lining or laquer finish. Now, what's the chance of replicating it on the body?

Edited August 6, 2021 by doilum
Additional information

[doilum]

Spent the afternoon putting the bits together. First of all the pickups and then a full build and test run before trimming the crankpins and loctiting the bushes.