A few good sessions at the bench over the last couple of days has seen the tender finished, aside from one remaining task. I have made the cross frames which fit between the wheels removable via some brass angle soldered to the inside of the outer frames. One of them needs to be cut to fit around the scoop operating mechanism.
Despite having built several Stanier tenders now, this one has been the most challenging to date. Some of that has been due to the large half etched panels and straightening out the bowing of them brought on by the etching process. The remaining fight has been with the fit of the coal space.
Not that clear in the photo below due to all parts being nickel, but in order to finish of the left side, I had to cut a triangular strip 3mm wide tapering to nothing over 55mm
Here we are with the axle box/spring castings just rested in place for the photos. They will be fixed in place after painting.
If you zoom into the photo below you can see that I did revisit the second feed pipe on the coal pusher mechanism.
I forgot to add that, for some reason probably oversight, there were no castings for the steam heat pipes. I had a look in the spares box but the casting that I had wasn’t very good so I made one up from rod, scrap etch and fine wire.
I also made the vacuum pipe removable (screwed on from underneath by a 10 ba screw) to ease painting.
Pretty much all of the external detailing is now complete. Studying the only photograph that I have of the rear of the tender (LMS Loco Profiles No4 Page 84) I noted that there was a small fitting with what initially looked like a single outlet pipe. Which is how I fitted the small casting, that I found tucked away in the corner of the castings bag.
However, having checked the Finney Duchess instructions and then looking at an a scanned and enlarged view of the fitting it seems that there is indeed a second pipe so I will need to revisit it and fit a second pipe if I can.
I have posted elsewhere of the lamp irons that I milled from recycled plug pins but I haven’t showed them fitted.
Next, I moved onto the springs and hangers. Several of the dampers had become detached from the springs. The white metal pins are the vulnerable parts so I decided to replace them.
First, I cut off all the dampers and pins from the springs. Next, I used a burr that came with a set of tools for the Dremel in the mill, to mill out the remains of the pin between the frame of the damper. I had to slow the mill down to 320 rpm in order not to over heat and melt the white metal.
I used a clothes peg to hold the springs to drill them again using the mill.
I cut lengths of brass rod to replace the white metal pins. I made a jig from a piece of ply with a blob of bluetac and a hand vice to help with soldering.
Not the prettiest of soldering but they look a lot better.
Although I haven’t posted for a while, the battle with the 4000 gallon tender has continued.
The biggest issue has been the coal space and getting it to fit. The instructions rather unhelpfully refer to fettling and filling gaps with coal. Fine if you are modelling a tender loaded with coal but not if you want to see the coal pusher.
The coal pusher castings are Finney 7 and as expected just come as a set of castings so I needed to make the push rods from strips of nickel cut with the guillotine.
Although a casting was provided in the set for the vent pipe arrangement Due to the laminated rear of the coal space being quite a chunk I didn’t trust that I could successfully solder it on without the risk of melting it so I filed up a replacement from some brass bar.
In order to get the coal chute to sit down properly I had to cut 2mm of the front edge.
Yesterday I had turned a spacer for the cross slide leadscrew which along with the extra backlash nut that I made earlier has removed all the backlash from the cross slide. This morning saw the final piece in the current puzzle, the replacement for the missing compound handle. Made from 8mm stainless I am really pleased with how much different the lathe performs now that I have made the improvements.
After spending most of the day trying different thicknesses of shims to get the most rigid, but sliding fit the carriage is back together. As I had hoped a 1/4 turn of the rear cap head screw locks the carriage.
I also cut a spacer/shim to fit on top of the feed nut to do away with the need for rocking about a grub screw. I have left the grub screw in place to stop the hole filling with swarf but it’s no longer functional.
This is the spacer in place before attaching the cross slide.
Next was reassembly of the apron, cross and compound slides ready for a test run. It all went back together nicely but getting the main lead screw cover in the right place for the power feed half nuts to engage/disengage properly was a right pain and took several adjustments before everything ran smoothly.
I still need to make a couple more spacers/shims to take more backlash from the cross slide but I needed the lathe back together to turn them.
A bit of a milestone reached this evening as it’s almost ready to reassemble. I just need to cut some lengths of M6 studding to fasten the bottom slide bars on with. Then once the basic carriage is reassembled and fitted on the ways, I need to mark out, drill and tap the carriage lock before reassembling the cross and compound slides.
There wasn’t a lot of depth and I wanted them countersunk to retain as much cross slide travel as i can also I doubt if these will ever get unscrewed again once finally fitted so I used M6 button headed cap screws instead of the usual deep headed type.
This is what it will look like when all fitted together.
The end support piece and the bottom of the carriage lock are made from the same piece of bar (eBay purchase) and must be free machining as recommended by Mike Evans, because they machined, drilled and tapped so much easier than the steel that I made the other parts from.
Next comes the most daunting part so far, machining the carriage casting to square up the cut outs in each side to take the extension pieces which will support the carriage stop.
Being a casting, the very nature of it is rounded corners and rough finish. At the very least the faces needed flattening to take the machined block which is to be let into each cut out. As I was studying the cut outs to determine how best to machine them, I noted that at the side where the inverted V was machined into the base there was a distinct slope to the edge of the cut out.
When I check this with a protractor it was almost 80 degrees. There wasn’t enough casting left to make this edge vertical without cutting into the inverted V so it made sense to machine this edge to 80 degrees. I reasoned that cutting the opposite edge to the same angle would also help relive any potential stresses on the M6 screws that I plan use to fasten these infill blocks to the carriage, when the lock is tightened down.
I then machined the ends of the infill blocks to suit the angled cut outs.
All this was made less stressful by the knowledge that a replacement carriage casting is only £23 plus P&P.
Although I have been waiting for delivery of various bits of metal and fixings which have been trickling in over the last few days (I have everything I need now, I think or should that be hope). I haven’t been idle.
I got the stainless steel lock nuts for tensioning the Gibs on the two slides and managed to get those ready to refit.
The last photos also show an anti backlash nut/block which I hope will take out the backlash from the cross slide lead screw. It’s an idea I got from the US YouTuber that I mentioned (username of Dr Jim) who made his from oil impregnated bearing bronze. I looked into getting some and nearly had a heart attack so settled for testing the concept in acrylic as I had seen another person do who had fitted anti backlash blocks to a home made CNC Mill.
Whilst making the anti backlash nut/block was quite simple. Finding out the thread size/pitch was a bit of a challenge and I am grateful to members of the Model Engineer forum who between a few relies gave me the information that I needed to work it out.
Why was it so difficult you might ask. Well, I have previously mentioned that the machine is imperial but fitted with Digital Read Outs on the cross slide. From what I have read, when fitting the DRO kit’s the lead screw is replaced as part of the upgrade. I rang Chronos who are the supplier of DRO kits in the UK who told me that the lead screws included in the kits are metric. On this basis it seemed logical that the cross slide leadscrew may in fact be metric.
As you might imagine a query on the ME forum elicited quite a few helpful answers and a few less than helpful ones thrown in for good measure. Ultimately I was pointed in the direct of a US site and advised that some of the machines actually came factory fitted with DRO’s and they retained imperial lead screws. With the help of replies that were specific with information I finally worked out that my cross slide leadscrew is a left hand thread 3/8″ 20TPI. Part of my difficulty was that I had no idea of how BSF threads were actually measured as I have never had cause to buy or measure any BSF fixings. All my experience has been in Metric or for modelling purposes, BA screws etc. Where we specify the whole thread length.
A set of taps was duly ordered from RDG engineering supplies (£10.96 inc. postage) and the job was done.
A friend who models in 4mm scale asked me if I would draw up some injectors for GNR tank engines (J52/53) so in between working on the lathe improvements while waiting for bits and pieces to arrive through the post I had a go.
He provided me with an annotated photo to work from which didn’t have every dimension on it so while I don’t think that it’s 100% accurate, it’s good enough for small scales.
Of course we need a handed pair which was the last job.
For my birthday/Christmas present from my Son last year, I received a Stuart Models 10 V Stationary Steam engine Kit. Although I knew it was coming they didn’t get to visit us until yesterday so I have only just got my hands on it.
Saying it’s a kit is stretching it a bit in terms of the kits that I am used to in 7mm modelling but I don’t know how else to describe it.
Here is what you get in the box
Last but not least the hardware and sundries in the form of nuts and bolts, gaskets etc.
I had a first go at Fly cutting with the mill last night. The pieces of bar in the last post are what’s known as hot rolled steel. Hit rolled steel is the cheapest way to buy steel but you do get an outer coating of oxidisation and the edges are far from flat/square
For the two larger pieces I needed to square up the edges and then flatten one face. I had two options use an end mill or fly cut them. I used an end mill on the edges bt for the larger area it would have taken a fair amount of time to flatten it with my largest end mill with is 10mm. With a fly cutter I could do the whole area in one or two passes at each cutting depth. The other thing that appeals to me about fly cutting is that it uses a piece of tool steel similar to a lathe tool and is something that I can confidently re-sharpen in the workshop on the grinder. I have no means of re-sharpening end mills so they become quite expensive consumables.
This is the fly cutter in action, it was spinning at 740 rpm and I was taking off 0.04mm per pass