Dan Randall
Western Thunderer
I’ve often wondered how the engineers of old, were able to divide 360 degrees into uneven amounts, before the days of electronic calculators and computers?…
Regards
Dan
7mm Mickoo's Commercial Workbench
- Thread starter mickoo
- Start date
Regards
Dan
OzzyO
Western Thunderer
Log table is your answer and slide rules. I did use log tables but I've not used them for 40+ years, a slide ruler never used one, I don't think that I would want to.
ATB
OzzyO.
MarkR
Western Thunderer
When I was an apprentice draughtsman, I used to draw slide rules!
timbowales
Western Thunderer
I've forgotten how to use both log tables and a slide rule, must be getting old 
mickoo
Western Thunderer
I used slide rules at school in tech drawing class and my apprenticeship along with Trig tables, not as a general means of education but as an alternative if you were out in the field (work, not school) and your calculator was naff. It was also a good way to discipline your math work flow and a good test of correlating several pieces of information to get an answer.
Back to wheels, it's simple really.
Princess Royal has 20, any other number is incorrect, whatever the source.
Princess Coronation has 21.
The one area you need to watch out for are the reinforcing webs, these were only applied to first few Princess Royals, not sure right now exactly which ones, but think it's limited to just the first three, after that webs were not fitted.
The wheels are interchangeable so the webbed wheels may have moved around but the first three lost them at some point quite early on for standard wheels.
Back to wheels, it's simple really.
Princess Royal has 20, any other number is incorrect, whatever the source.
Princess Coronation has 21.
The one area you need to watch out for are the reinforcing webs, these were only applied to first few Princess Royals, not sure right now exactly which ones, but think it's limited to just the first three, after that webs were not fitted.
The wheels are interchangeable so the webbed wheels may have moved around but the first three lost them at some point quite early on for standard wheels.
mickoo
Western Thunderer
I have a B12 in next years build queueCould really do with a B12 / D16 wheel as well
JB.
Rob R
Western Thunderer
That's 2 wheels 'cos they are different sizes.Could really do with a B12 / D16 wheel as well
JB.
Still only 1 rabbit hole though......
mickoo
Western Thunderer
Mid week update, quite a lot going on so first the Princess Royal.
Slow but steady progress, you spend hours doing bits and nothing changes, then suddenly it leaps forward.
I managed to salvage the boiler, I still need to take a bit off the firebox front plug so the boiler barrel sits tight up against the throat plate, but other than that no real dramas.
The kit middle cylinder cover is too narrow to fit between the frames, it's only 0.5 mm but it might as well be a mile, nothing for it but to scratch build a new one. What should have taken about 30 mins of decusping, forming, adding detail and fitting took rather much longer.
One thing to watch for is the two small handrails on the frames above the footplate, each side of the middle cylinder block, they were not there on roll out and appear to have been fitted a few weeks later, that means some wire plugs to fill the holes and dress smooth.
The white metal bogie bearing brackets/pedestals didn't survive the bogie pivot stay reworks, I'm kind of pleased about that as they were a bit naff and didn't fit into the frame recess very well at all. In hindsight I should never have fitted them as they let the side down badly; replacements are currently being fabricated, part metal for strength, part 3D for detail.
Part II is the arrival of some etch work, the Stanier high sided tender sides came back, pretty good all round so I can finish that off over the next few days and then start the chassis.
I did hedge my bets and two two sets of sides, one with half etched rivets and one full thickness with half etched rivet indents to punch out. Both came out fine but what I didn't spot until three days after the order was being processed are an extra line of rivets on the RH side.
These are for the fire iron tunnel which became evident when I found a really good clear image of the RH side, I'll just manually punch these out and then add the tunnel inside the coal space.
The other piece was a huge bridge for The Derby Line, the remit was just for the detail and fiddly bits, the plate work and big flanges will be cut by hand.
Quite a lot is back to back laminates, a, for strength and b, to add punched rivet detail; it'll be interesting to see Tony build this up and I'm half tempted to get one just to build myself, no need for it but it'd make a nice palette cleansing project.
Slow but steady progress, you spend hours doing bits and nothing changes, then suddenly it leaps forward.
I managed to salvage the boiler, I still need to take a bit off the firebox front plug so the boiler barrel sits tight up against the throat plate, but other than that no real dramas.
The kit middle cylinder cover is too narrow to fit between the frames, it's only 0.5 mm but it might as well be a mile, nothing for it but to scratch build a new one. What should have taken about 30 mins of decusping, forming, adding detail and fitting took rather much longer.
One thing to watch for is the two small handrails on the frames above the footplate, each side of the middle cylinder block, they were not there on roll out and appear to have been fitted a few weeks later, that means some wire plugs to fill the holes and dress smooth.
The white metal bogie bearing brackets/pedestals didn't survive the bogie pivot stay reworks, I'm kind of pleased about that as they were a bit naff and didn't fit into the frame recess very well at all. In hindsight I should never have fitted them as they let the side down badly; replacements are currently being fabricated, part metal for strength, part 3D for detail.
Part II is the arrival of some etch work, the Stanier high sided tender sides came back, pretty good all round so I can finish that off over the next few days and then start the chassis.
I did hedge my bets and two two sets of sides, one with half etched rivets and one full thickness with half etched rivet indents to punch out. Both came out fine but what I didn't spot until three days after the order was being processed are an extra line of rivets on the RH side.
These are for the fire iron tunnel which became evident when I found a really good clear image of the RH side, I'll just manually punch these out and then add the tunnel inside the coal space.
The other piece was a huge bridge for The Derby Line, the remit was just for the detail and fiddly bits, the plate work and big flanges will be cut by hand.
Quite a lot is back to back laminates, a, for strength and b, to add punched rivet detail; it'll be interesting to see Tony build this up and I'm half tempted to get one just to build myself, no need for it but it'd make a nice palette cleansing project.
Pencarrow
Western Thunderer
Thanks for the photo, I was wondering what all the diagonals were for.
mickoo
Western Thunderer
Not really an end of week update, sort of a stumble to the end of Friday sort of feeling. A lot of effort of little bits so little visual progress.
The cab roof took up most of the time and it's still not complete, the kit one is to wide, too long, marginally incorrect rear profile and has half etched raised bits for the reinforcing strip at the rear, gutter in the mid section and gutter at the eaves. The half etched rivets are more appropriate to armor plating studs on the Seigfried line..... it's just all the wrong trousers Grommit!.
The WIP roof is just plonked on, it still needs the reinforcing strip on the rear lip and center section gutter from 1x1 angle (I've run out). I also added the longitudinal angled supports underneath as they're visible through the open vent and I need to add them to the rear overhang in due course.
The chimney is also just plonked on, it's the wrong type; the first engines had a distinct parallel middle so the choice is try and modify this or 3D a new one.
The rest of the time was on the cab rear, floor, toolboxes, handrails, lamp irons, reach rods, yada yada yada...
I'm not overly happy with the smoke box front, it's a poor fit and even more energy expenditure isn't going to improve it much more, it's also a poor surface finish and the door is quite a poor fit. I'll ponder that on the 8 hr round trip to SVR tomorrow and suspect that the end result will be the bin a whole new 3D front end.
The cab roof took up most of the time and it's still not complete, the kit one is to wide, too long, marginally incorrect rear profile and has half etched raised bits for the reinforcing strip at the rear, gutter in the mid section and gutter at the eaves. The half etched rivets are more appropriate to armor plating studs on the Seigfried line..... it's just all the wrong trousers Grommit!.
The WIP roof is just plonked on, it still needs the reinforcing strip on the rear lip and center section gutter from 1x1 angle (I've run out). I also added the longitudinal angled supports underneath as they're visible through the open vent and I need to add them to the rear overhang in due course.
The chimney is also just plonked on, it's the wrong type; the first engines had a distinct parallel middle so the choice is try and modify this or 3D a new one.
The rest of the time was on the cab rear, floor, toolboxes, handrails, lamp irons, reach rods, yada yada yada...
I'm not overly happy with the smoke box front, it's a poor fit and even more energy expenditure isn't going to improve it much more, it's also a poor surface finish and the door is quite a poor fit. I'll ponder that on the 8 hr round trip to SVR tomorrow and suspect that the end result will be the bin a whole new 3D front end.
oldravendale
Western Thunderer
As ever, Mick, I appreciate your insistence on getting this just right.
mickoo
Western Thunderer
It's a Princess Royal, did you expect anything less
Problem is Brian, it's an ever deepening hole you dig......
Clarence3815
Western Thunderer
Pure craftmanship and knowledge of prototype.
Bernard
Bernard
Dave Holt
Western Thunderer
Very nice, indeed. There appears to be a large overhang of the smokebox forward of the saddle. Are you intending to represent the forward portion of saddle formed on top of the inside cylinder block? The flange to the smokebox was 2'-93/4" square, so well inside the frames, but it did have stiffening ribs to just below the top of the frame plates, so it was visible from the side.
Dave.
Dave.
mickoo
Western Thunderer
WIP, just basic bolt together for SVR show today.
timbowales
Western Thunderer
Work In Progress?
mickoo
Western Thunderer
Well, as they say around these parts, that was harder than it should have been and easier than it could have been.
I can't fit the front platform yet as it's a common user tender so need to build the engine and match the cab floor height, consequently the sides still need seam filleting in along the base and a few other gaps closing up. I also still need to add the internal support ribs, but only the tops as there will be a coal load in there to cover the bases up.
I can't fit the front platform yet as it's a common user tender so need to build the engine and match the cab floor height, consequently the sides still need seam filleting in along the base and a few other gaps closing up. I also still need to add the internal support ribs, but only the tops as there will be a coal load in there to cover the bases up.