7mm Finney Battle of Britain
- Thread starter mickoo
- Start date
Yorkshire Dave
Western Thunderer
Afterward a clean in hot water with Bicarbonate Soda, no idea of mixture, probably too much, but it seems to come up nice and spangly, making photography a tad tricky
Glad to see it worked - good old NaHCO3. In early days it was used as a toothpaste! It is also used to neutralise acid/base spills in chemical labs inter alia.
And it's cheap to buy at around £5 /kg
Steph Dale
Western Thunderer
Useful stuff to have on the workbench for all sorts of reasons; good metal polish, superglue accelerator, etc...
Steph
Steph
mickoo
Western Thunderer
Hmm only paid 67p /Kg and I wouldn't want to brush my teeth in this stuff.
Me thinks I've got something different as checking the lable small print it's not Bicarbonate Soda but Sodium Carbonate, that which is used to clean dishwashers and washing machines and it's granular not a liquid.
Google is your friend, they are the same but different, seems Sodium Carbonate is a bit more aggressive, seems to work so far.
MD
Me thinks I've got something different as checking the lable small print it's not Bicarbonate Soda but Sodium Carbonate, that which is used to clean dishwashers and washing machines and it's granular not a liquid.
Google is your friend, they are the same but different, seems Sodium Carbonate is a bit more aggressive, seems to work so far.
MD
Last edited:
Yorkshire Dave
Western Thunderer
No problem as it still neutralises acid. It's chemical formula is Na2CO3, pH value 11.6 compared with Bicarbonate of Soda pH value of 8.4.
I only used Bicarbonate of Soda as it is one of the many cooking ingredients in my kitchen.
oldravendale
Western Thunderer
I've used washing soda and a hot water bath overnight for final cleaning. Been doing it for years and it seems to be an effective cleaner before painting - as long as you get the white deposit out of all the nooks and crannies!
B
B
mickoo
Western Thunderer
Brian, I think the white powder residue is a reaction to the solder, I did get some only an hour or so after cleaning but it comes off easily with a soft fibre brush, removing the solder and another wash seems to have stopped that trait, mind I haven't left it to soak overnight as yet so the results might be different.
Anyway, onward. The only big change to the kit is the installation of insulated fully sprung horn blocks, nothing new or ground breaking just rehashing something done hundreds of times before by a great many people, but here's how I did it.
I'll detail the horn guide modifications later just for the sake of completeness.
So first step is to fit the first horn guide, the model is designed around a compensation beam set up, as such there's a large and important stretcher over the first axle, we can't get rid of it, nor is it easily modified so we have to work with what we have. The horn guide units are from the Martin Finney range and designed for the model, they are designed with the guides to be fitted outside to replicate the real engine 50/50 installation. I.E the horn guides are half outside the frames and half inside, as opposed to 100% on the inside like virtually all the rest of steam engines.
However, we need to add a leveling screw to the top of the guide etch work, which means we need to flip the assembly around and as such we do not have a ready guide for placement.
Step one is to get one of the assemblies soldered into place.
In this case the far one, I've used a standard brass bearing and one of the etched horn plates as a back stop for the spring. The insulated bearing has been turned around and pushes the assembly against the frames. To ensure the right height I have packed some wood and etch under the assembly, you know that as soon as you touch this with the iron it's going to move down, so the packing is there to stop that.
Having made sure the guide is the right height flip over the model and check the longitudinal position.
Luckily the slot and tab fixing of the horn guides can be easily seen and it's pretty easy to get the assembly in the middle of the opening. For the record the horn guide was soldered in with copious amounts of 188°C solder and then cleaned up.
To solder the assembly into place, take one big iron at 400°C and a dab of 145°C solder and simply apply to the base of each side of the joint, with luck the solder will flash up the joint far enough so that you do not need to try and get near the top, if not then a dab of 145°C at the top of the opening will fix it nice and strong.
Ok having got one in the right place we have to get the other in, same height and square with the frames, normally you'd have one of the other axles still as a rigid set up, but I decided to cut out all of the bearing openings whilst the frames were flat and straight, I've not had much luck making neat square openings on frames already assembled.
Using the chassis jig we can over come this.
Here I've used axles one and five and extended them a set distance from the jig, one has to assume the jig is square and all axles are at right angles with the jig and parallel with each other. Anyway the two axles are set 18.00 mm from the jig which means that none of the frame empennages touch or interfere with the set up. Now we know the frames are parallel with the jig, and by deduction that any axle rods will be square in the frames.
I've had to pack out the frames to the right height and again placed packing pieces under the horn guide I'm going to solder, like previously, a big dab of 145°C solder at high temp fixes the horn guide into place.
Next we need to add the leveling screws, but the limited access caused by the frame stretcher means that we have to extend the screws above that, a simple 2.0 mm clearance hole (wiggle factor) is more than enough for the 12BA screw.
Finally check that the horn block slides freely in the guide.
Adding the spring and setting up comes later once the keeps are in place.
The one downside of flipping the horn guide around is that it increases side play and makes the insulated bearing flush with the frames, excellent if you are modeling normal locos, even better in S7, however the Bulleid pacifics are narrow framed with the 50/50 bearings so even in O fine we will need to add spacers or washers to limit side play, ideally a thin inverted U strip to represent the real engine would be added, but Bulleid wheels are solid near the hub so such exercise is pointless.
The real deal.
Enjoy
Mick D
Anyway, onward. The only big change to the kit is the installation of insulated fully sprung horn blocks, nothing new or ground breaking just rehashing something done hundreds of times before by a great many people, but here's how I did it.
I'll detail the horn guide modifications later just for the sake of completeness.
So first step is to fit the first horn guide, the model is designed around a compensation beam set up, as such there's a large and important stretcher over the first axle, we can't get rid of it, nor is it easily modified so we have to work with what we have. The horn guide units are from the Martin Finney range and designed for the model, they are designed with the guides to be fitted outside to replicate the real engine 50/50 installation. I.E the horn guides are half outside the frames and half inside, as opposed to 100% on the inside like virtually all the rest of steam engines.
However, we need to add a leveling screw to the top of the guide etch work, which means we need to flip the assembly around and as such we do not have a ready guide for placement.
Step one is to get one of the assemblies soldered into place.
In this case the far one, I've used a standard brass bearing and one of the etched horn plates as a back stop for the spring. The insulated bearing has been turned around and pushes the assembly against the frames. To ensure the right height I have packed some wood and etch under the assembly, you know that as soon as you touch this with the iron it's going to move down, so the packing is there to stop that.
Having made sure the guide is the right height flip over the model and check the longitudinal position.
Luckily the slot and tab fixing of the horn guides can be easily seen and it's pretty easy to get the assembly in the middle of the opening. For the record the horn guide was soldered in with copious amounts of 188°C solder and then cleaned up.
To solder the assembly into place, take one big iron at 400°C and a dab of 145°C solder and simply apply to the base of each side of the joint, with luck the solder will flash up the joint far enough so that you do not need to try and get near the top, if not then a dab of 145°C at the top of the opening will fix it nice and strong.
Ok having got one in the right place we have to get the other in, same height and square with the frames, normally you'd have one of the other axles still as a rigid set up, but I decided to cut out all of the bearing openings whilst the frames were flat and straight, I've not had much luck making neat square openings on frames already assembled.
Using the chassis jig we can over come this.
Here I've used axles one and five and extended them a set distance from the jig, one has to assume the jig is square and all axles are at right angles with the jig and parallel with each other. Anyway the two axles are set 18.00 mm from the jig which means that none of the frame empennages touch or interfere with the set up. Now we know the frames are parallel with the jig, and by deduction that any axle rods will be square in the frames.
I've had to pack out the frames to the right height and again placed packing pieces under the horn guide I'm going to solder, like previously, a big dab of 145°C solder at high temp fixes the horn guide into place.
Next we need to add the leveling screws, but the limited access caused by the frame stretcher means that we have to extend the screws above that, a simple 2.0 mm clearance hole (wiggle factor) is more than enough for the 12BA screw.
Finally check that the horn block slides freely in the guide.
Adding the spring and setting up comes later once the keeps are in place.
The one downside of flipping the horn guide around is that it increases side play and makes the insulated bearing flush with the frames, excellent if you are modeling normal locos, even better in S7, however the Bulleid pacifics are narrow framed with the 50/50 bearings so even in O fine we will need to add spacers or washers to limit side play, ideally a thin inverted U strip to represent the real engine would be added, but Bulleid wheels are solid near the hub so such exercise is pointless.
The real deal.
Enjoy
Mick D
mickoo
Western Thunderer
Short update this evening, before progressing I wanted to make sure my method of bearing retention would work, it would of been nice if the etched horn guides had a little fold out toe with a hole that could be tapped and used as a fixing for the retaining strap, sadly that's not the case so some other form of fixing is required.
Trying to solder little pads for the fixings was quite beyond my skill set so I decided to make one long strap, solder into place and then cut the middle out.
In the front is the Mk1, I used the outside edge of the frames as a target line and then forgot all about the raised edge on the bearing, which then required the pads to have a notch cut out, no great shakes but work that wasn't required.
At back is a complete strap fixed into position and I've used the rear edge of the frames as a line up, next step is to cut the middle out and dress the edges to allow the bearing to slide in and out.
MkII worked better and the rest will follow suit, I may take off the MkI and remake, but in all honesty this will all be hidden by the actual retention strap and again, is work not really required, but it'll probably niggle me enough for me to redo it like the others.
The actual retention straps will be a little wider and will have the etched springs attached to them so that the whole lot comes off for wheel dropping.
Retention screws are 12BA.
Right time to fettle some coupling rods so that the other horn guides can be fitted, luckily the kit provides two types of coupling rod, knuckle forward or knuckle rearward, which means one set is sacrificial and can be soldered solid to align the axles with.
Mick D
Trying to solder little pads for the fixings was quite beyond my skill set so I decided to make one long strap, solder into place and then cut the middle out.
In the front is the Mk1, I used the outside edge of the frames as a target line and then forgot all about the raised edge on the bearing, which then required the pads to have a notch cut out, no great shakes but work that wasn't required.
At back is a complete strap fixed into position and I've used the rear edge of the frames as a line up, next step is to cut the middle out and dress the edges to allow the bearing to slide in and out.
MkII worked better and the rest will follow suit, I may take off the MkI and remake, but in all honesty this will all be hidden by the actual retention strap and again, is work not really required, but it'll probably niggle me enough for me to redo it like the others.
The actual retention straps will be a little wider and will have the etched springs attached to them so that the whole lot comes off for wheel dropping.
Retention screws are 12BA.
Right time to fettle some coupling rods so that the other horn guides can be fitted, luckily the kit provides two types of coupling rod, knuckle forward or knuckle rearward, which means one set is sacrificial and can be soldered solid to align the axles with.
Mick D
Yorkshire Dave
Western Thunderer
Not ever having seen the fret is this something which could be re-designed into new BoB kits?
mickoo
Western Thunderer
Absolutely, in fact you could also add an extra horn guide part to the outside to push the bearing out a mm or so, it'd take up some of the side play and visually look more like the real thing.
To be fair, Martins existing etch is perfectly designed for the application in mind, brass bearings in a compensation beam chassis.
The issues are my own in converting it to accept nylon insulated axle boxes, in which case, rather than change the original it would be better to develop a new one tailored to fit the Slaters nylon insulated axle boxes.
Mick D
Tim Humphreys ex Mudhen
Western Thunderer
Mick,
Why are you using the nylon insulated axle boxes?
Tim
Why are you using the nylon insulated axle boxes?
Tim
mickoo
Western Thunderer
Tim,
Because the owner is using split axles, so we had two choices, metal horn guides and nylon axle boxes, or nylon horn guides and brass axle boxes. I have little faith in my ability to fix nylon guides to metal frames, except maybe to add additional mechanical fixings, which is such a faff and makes a non prototypical installation look even worse. At least this way it sort of looks like the real thing.
This method was the easiest for me to fabricate, within my comfort zone and uses metal to metal construction as much as possible.
It also fitted in the etched cut out slots on the kit (9.50 mm). Fitting nylon horn guides requires the slots to all be opened out to 10.60mm or greater to allow for alignment.
It basically means you have to file each side of the gap in the frame accurately +o.40mm to ensure everything lines up with the brake hangers and other empennages, just seemed like a lot of hard work when a simpler solution was available.
We did toy with another idea in that we used the etched guides with the brass axle box but the guide was separated from the frames with 0.25- 0.50mm copper clad board.
Mick D
mickoo
Western Thunderer
Right O, finally sorted the keep plate and springs, it'd been niggling me how best to do it, but in the end it was just a case of JFDI and see what comes out of the oven.
The springs come as three etches and by natty design slot in between the J hangers and axle box, which in a nut shell means they can only befitted from inside the frames and pushed outward, this kind of complicates the fixings.
The spring assembly was attached to the keep plate and all dressed up nice and clean, i do need to go back and give it a little extra clean here and there where the solder has left some little gaps in the lamination's. Front and back view are fine but the edges are a little tardy in places.
Because the spring and keeper plate can only be fitted from the inside and slid into place the fixing screws need to be fiendishly short, I did toy with the idea of slotting the keeper plate and the MkI was just that, but it looked naff so a solid MkII was made instead.
The problem is that the spring lamination just covers the fixing screw, but only just, an own goal of course because I put them there in the first place A long screw finds the head catching the spring and it's a tight squeeze to get past, tight enough to damage the thread or strip the screw slot.
From directly above you can just see the marginal overlap. The screw heads as 2.30 mm in dia and I reckon if I skim them to 2.00 mm that will fit past the spring and the normal longer screws can be used.
Of course the lower MkI fixing pads stand no chance of getting a screw in as they are closer still to the frame edge, so they'll be off shortly and made like the other five.
Overall from the outside, the side you cannot see due to the near solid BFB wheels, it passes muster, just another five to do and then back to the rest of the normal construction.
I may as yet add a thin 1.00 x 1.00 mm strip along the top of the keep plate to close the gap between it and the frames.
MD
The springs come as three etches and by natty design slot in between the J hangers and axle box, which in a nut shell means they can only befitted from inside the frames and pushed outward, this kind of complicates the fixings.
The spring assembly was attached to the keep plate and all dressed up nice and clean, i do need to go back and give it a little extra clean here and there where the solder has left some little gaps in the lamination's. Front and back view are fine but the edges are a little tardy in places.
Because the spring and keeper plate can only be fitted from the inside and slid into place the fixing screws need to be fiendishly short, I did toy with the idea of slotting the keeper plate and the MkI was just that, but it looked naff so a solid MkII was made instead.
The problem is that the spring lamination just covers the fixing screw, but only just, an own goal of course because I put them there in the first place
A long screw finds the head catching the spring and it's a tight squeeze to get past, tight enough to damage the thread or strip the screw slot.From directly above you can just see the marginal overlap. The screw heads as 2.30 mm in dia and I reckon if I skim them to 2.00 mm that will fit past the spring and the normal longer screws can be used.
Of course the lower MkI fixing pads stand no chance of getting a screw in as they are closer still to the frame edge, so they'll be off shortly and made like the other five.
Overall from the outside, the side you cannot see due to the near solid BFB wheels, it passes muster, just another five to do and then back to the rest of the normal construction.
I may as yet add a thin 1.00 x 1.00 mm strip along the top of the keep plate to close the gap between it and the frames.
MD
mickoo
Western Thunderer
Right, having completed all of the keep plates it was time to move on with other aspects, the remaining spring assemblies I'll pick off one at a time as and when the mood takes me.
A general view from the front end as of this evening, apart from the bogie wheel splashers, most of the work has been at the rear end.
The drag beam assembly has taken some time as it's quite complex but it all goes together, just like it says on the tin, no hidden nasties and it all just fits, the time is taken up with the complex fiddly bits.
On the driver's side is the steam generator, a lovely casting in it's own right and a couple of other bits, nothing too daunting here. I've not added any pipework yet, the instructions give you the option to do it now or wait until more of the body work is in place. I've opted for the later as I've left the top part of the drag beam removable for the time being, it's held in place with the draw bar screw which I changed from the kits pin arrangement. Once you add the pipework it kind of all becomes fixed here and I'm not sure you can effectively paint inside this area once it's all fixed together. So I may mask off and waft a bit of black etch primer in there before boxing it all up.
The firemans side is a little more exciting with the two injectors.
I have to confess I struggled to get my mind around the lovely 2D drawings in the instructions and work out which bit went where and after a rummage through my photo archives found an image or two in 3D, after that it was game set and match. I did find in my research that there appears to be two types of injector fitting, as well as two types of drain cock fitting, now these are preserved engines so I'm not sure if this is a preservation change or a change on the real engines in service, for completeness I need to dig around the working engine images I have and see if these changes existed back then.
Final view of the firemans side, next step will be the ashpan hoppers, these, like the injectors are quite complex, but the effort is certainly worth it. I am tempted to add an extra stretcher under the foundation ring assembly to secure it and make it removable for painting, the ashpan hoppers will be attached to that assembly as well. We'll see, not decided on that yet and am keen not to divert too far from the instructions, deadlines kind of keep you focused and the W1 needs a bit more work this week to keep that pot simmering.
Mick D
A general view from the front end as of this evening, apart from the bogie wheel splashers, most of the work has been at the rear end.
The drag beam assembly has taken some time as it's quite complex but it all goes together, just like it says on the tin, no hidden nasties and it all just fits, the time is taken up with the complex fiddly bits.
On the driver's side is the steam generator, a lovely casting in it's own right and a couple of other bits, nothing too daunting here. I've not added any pipework yet, the instructions give you the option to do it now or wait until more of the body work is in place. I've opted for the later as I've left the top part of the drag beam removable for the time being, it's held in place with the draw bar screw which I changed from the kits pin arrangement. Once you add the pipework it kind of all becomes fixed here and I'm not sure you can effectively paint inside this area once it's all fixed together. So I may mask off and waft a bit of black etch primer in there before boxing it all up.
The firemans side is a little more exciting with the two injectors.
I have to confess I struggled to get my mind around the lovely 2D drawings in the instructions and work out which bit went where and after a rummage through my photo archives found an image or two in 3D, after that it was game set and match. I did find in my research that there appears to be two types of injector fitting, as well as two types of drain cock fitting, now these are preserved engines so I'm not sure if this is a preservation change or a change on the real engines in service, for completeness I need to dig around the working engine images I have and see if these changes existed back then.
Final view of the firemans side, next step will be the ashpan hoppers, these, like the injectors are quite complex, but the effort is certainly worth it. I am tempted to add an extra stretcher under the foundation ring assembly to secure it and make it removable for painting, the ashpan hoppers will be attached to that assembly as well. We'll see, not decided on that yet and am keen not to divert too far from the instructions, deadlines kind of keep you focused and the W1 needs a bit more work this week to keep that pot simmering.
Mick D
mickoo
Western Thunderer
One of the additional task with this build are some detailed photos for the instructions. That's no reflection on the current rendition of the instructions, which are very nicely detailed. However, and this may just be me but I find it easier to visualize items in 3D, especially if someone else has designed it, it's not so hard if you designed it yourself as you know how it all breaks down.
The images will go into the instructions as supplements to the existing drawings where required, and I understand high quality ones will eventually be available on the site as downloads, though don't hold me to that. They are there to help people if they need it, nothing more, nothing less. Maybe give people a better idea of what's in the box or if it meets their expectations.
I'll probably be on spud duty for the rest of the week for showing these
but I think y'all like to see views behind the scenes now and again. The final version may not look exactly like this, but you'll get the general gist of where we're hoping to go.
I always scour the web for other peoples build photos to help me, so maybe these will help others in the future.
A couple from Section 6: Frame Brackets.
Section 11: BR Ashpan.
Section 12: Injectors and Generator.
Enjoy.
MD
The images will go into the instructions as supplements to the existing drawings where required, and I understand high quality ones will eventually be available on the site as downloads, though don't hold me to that. They are there to help people if they need it, nothing more, nothing less. Maybe give people a better idea of what's in the box or if it meets their expectations.
I'll probably be on spud duty for the rest of the week for showing these
but I think y'all like to see views behind the scenes now and again. The final version may not look exactly like this, but you'll get the general gist of where we're hoping to go.I always scour the web for other peoples build photos to help me, so maybe these will help others in the future.
A couple from Section 6: Frame Brackets.
Section 11: BR Ashpan.
Section 12: Injectors and Generator.
Enjoy.
MD
Heather Kay
Western Thunderer
Good clear annotated photos of complex areas in a kit will generally trump a drawing for me. It really helps to see the parts in relation to each other.
mickoo
Western Thunderer
They also show all your mistakes and poor workmanship if your not careful, good job PSP has a clone brush
Sad as it is, the next section I'm going to try and complete with latex gloves on, primarily to stop finger prints and the every increasingly annoying task of getting them off the work piece for decent photos.
MD