Mickoo's BR modelling
- Thread starter mickoo
- Start date
mickoo
Western Thunderer
Well lets start with the class 40 this evening, sure enough there's not enugh rake on the windscreen, by a rough guess 1 - 1.5 mm.
It doesn't bother me enough yet (and may never do) but an option might be to use a thin slitting disc in a dremel and take a slice out and tilt the screen back. I think that might be preferable to trying to sand the screen back to a higher rake and keep the three faces flat and true.
Interestingly, the noses are all the same length, I'd have wagered the 40 was longer but I'm not quite sure which model has the correct sized bonnet doors, class 40, JLTRT 37 or Heljan 37 1st tooling.
Some highly scientific shots to show the difference.
It doesn't bother me enough yet (and may never do) but an option might be to use a thin slitting disc in a dremel and take a slice out and tilt the screen back. I think that might be preferable to trying to sand the screen back to a higher rake and keep the three faces flat and true.
Interestingly, the noses are all the same length, I'd have wagered the 40 was longer but I'm not quite sure which model has the correct sized bonnet doors, class 40, JLTRT 37 or Heljan 37 1st tooling.
Some highly scientific shots to show the difference.
timbowales
Western Thunderer
I'm actually not surprised that the noses are the same. From an engineering and production point of view it makes sense to maximise the use of standardised components. Swindon were doing it very successfully for years, until Collett came along 
mickoo
Western Thunderer
Now the 37 frames and fuel tanks, lots going on here, primarily due to a moving goal posts depending on which model you're making them for.
Before going further it's probably best to try and explain why I'm doing all this, I did write that earlier but several people off grid told me I was wasting my time, I did explain I'd written what the loose scheme of things was in my head....ohh I don't read the words, just look at the pictures
So in pictorial form it's here......
And here.
I've not decided which as yet, I never did Crimpsall but 10 shop I visited lots of times, just depends which new builds other stock I want to portray and which dates etc.
For the working models then a MPD somewhere is the plan; all pie in the sky no doubt, but dreams are free.
Before going further it's probably best to try and explain why I'm doing all this, I did write that earlier but several people off grid told me I was wasting my time, I did explain I'd written what the loose scheme of things was in my head....ohh I don't read the words, just look at the pictures
So in pictorial form it's here......
And here.
I've not decided which as yet, I never did Crimpsall but 10 shop I visited lots of times, just depends which new builds other stock I want to portray and which dates etc.
For the working models then a MPD somewhere is the plan; all pie in the sky no doubt, but dreams are free.
mickoo
Western Thunderer
Right class 37 tanks, first thing was to get a new chassis plate in so out with the Proxxon table saw, change of blade to mosnter eating metal one and calve off a big slab of 1.5 mm brass sheet. I've used the Heljan floor fixing screws and added long bolts in, by winding in and out I can level the floor where it needs to be.
The next item was the engine room floor block, this is screwed ( sub surface on the final run) to the brass chassis, it has a big hole in the middle, as will the brass plate so I can add the depressed engine section in as a 3D print when viewed from above. The primary object here is to get all the ribs, tanks and supports in the right places as well as the sand boxes.
I also need to remove the recessed plastic right that holds the skirts on the first tooling.....ro do I (more later). Once that ridge is removed then the ribs wiull be pulled out to the correct width and overlap the remaining shell edge.
It's not looking too bad and I need to cross reference the ribs with the bodyside features.....and here's where the
hits the fan, all three models are different 
It should be noted that the tanks are not identical lengths, the diesel tank is longer, they're not bowed on the model, that's just the wide angle lens on the camera., the biggest concern is the position of the sand boxes, the tanks are in the right place (the outer brackets are eqi distance from the buffer beams) and that defines where the sand boxes go, but on the real engines the fillers are almost directly over the outlets.....but! I need to cross reference it all with the SRPS detail photos to be sure.
Either way the RH one looks miles out, as do the RH steps, filler hatch ang grills. The three grills is a known 1st tooling issue, they're actually a fraction too long, Heljan corrected this on the second tooling but then made them a fraction too short. The longer grills are clearly pushing the access steps and filler hatch out as well, not really a lot you can do abut that.
At this point the JLTRT model was pulled out and a direct comparison made.
Yup RH sand filler hatch is bleedin miles out, note also water filler hatch moved left and lower step also, that's all good and dandy, however the three grills are in the wrong place, they're the right length but too far left, the LH edge should line up with the cant rail edge above and the RH edge should extend just past the cant rail grill support, ideally all three need moving right 1.0 mm and they'd be perfect.
For giggles I stacked the second tooling on top.
Good news, the sand filler is now in the right place but note the short triple grill set, the LH edge is perfect but the RH edge is also level with the cant rail support, it should extend slightly past. They have also moved the lower water filler access step into the right location.
I used the JLTRT real thing tanks to work from when drawing up the replacement 3D ones, they're pretty accurate but I think the fuel tank is a smidge too long, the brackets are each end are identical but on the JLTRT one the #1 end has been truncated a bit as well as the inter tank bracket not being assembled correctly on the model, it's about 50/50 root cause as to why the JLTRT one extends further.
Anyway, using the JLRTR tanks as abasis the first ones I printed were woefully narrow on the Heljan first tooling. I figured it was down to the JLTRT thicker cill or side material, how incorrect was that!
To compensate I widened the 3D tanks by 2 mm and the side lined up perfectly with the sides on the shell, brilliant, everything sorted then, not so. The above photo shows that both sets of tanks when viewed directly below have the same sort mof relation ship with the body behind, the side walls were the same thickness, the kick in of the cills the same so why was the Heljan one 2 mm wider.
Then I measured the bodies overall width, yes you guessed it, the Heljan first toolling is wider, not just abit but rather a lot (relative), 1.5 mm to be precise. The extra 0.5 mm I added was just counteracting the material thickness at the base of the cill.
I measured the second tooling and found it to be the same as the JLTRT, so, for future tank packs I need to do two sets, one for the correct second tooling and a wider set for the fisrt tooling.
Summary, if you're going to expose the tank suppoorts and engine chassis in a workshop type repair scenario then the best option is the Heljan second tooling.
The next step is to decide which workshop and then work out which body support stands they used, 3D some of those up and start making holes in the body to daylight the areas I want to detail out.
The first tooling body will get replacement metal skirts fitted back on, I'll probably ditch the engine room 3DP chassis and ribs etc, drop the floor down and just bolt the tanks to the brass bit, or maybe a facsimilie of the underside like JLTRT; then work out how to get some bogies and power it, probably as a dummy in MU with another.
The JLTRT needs some work as well, bought fully built and powered one of the cabs is not straight and there are some ugly joints that need tending to as well as the chassis sitting high at one end (due to the misplaced cab no doubt), it's also still got a boiler and steps so not a refurb but the buffer shrouds have been cut back and headcodes plated over (all give away refurb signs). My gut feeling is that it's got the wrong noses on but I'll ave a trawl and see if I can find a boiler fitted 37 with plated headcodes and shrouds cut back, possibly one of the 37/4 (were they dual ETH and boiler?) large logos in Scotland in the early 80's. That would be grand as I do like them and traveled on them on several trips.
Onward.
The next item was the engine room floor block, this is screwed ( sub surface on the final run) to the brass chassis, it has a big hole in the middle, as will the brass plate so I can add the depressed engine section in as a 3D print when viewed from above. The primary object here is to get all the ribs, tanks and supports in the right places as well as the sand boxes.
I also need to remove the recessed plastic right that holds the skirts on the first tooling.....ro do I (more later). Once that ridge is removed then the ribs wiull be pulled out to the correct width and overlap the remaining shell edge.
It's not looking too bad and I need to cross reference the ribs with the bodyside features.....and here's where the
hits the fan, all three models are different It should be noted that the tanks are not identical lengths, the diesel tank is longer, they're not bowed on the model, that's just the wide angle lens on the camera., the biggest concern is the position of the sand boxes, the tanks are in the right place (the outer brackets are eqi distance from the buffer beams) and that defines where the sand boxes go, but on the real engines the fillers are almost directly over the outlets.....but! I need to cross reference it all with the SRPS detail photos to be sure.
Either way the RH one looks miles out, as do the RH steps, filler hatch ang grills. The three grills is a known 1st tooling issue, they're actually a fraction too long, Heljan corrected this on the second tooling but then made them a fraction too short. The longer grills are clearly pushing the access steps and filler hatch out as well, not really a lot you can do abut that.
At this point the JLTRT model was pulled out and a direct comparison made.
Yup RH sand filler hatch is bleedin miles out, note also water filler hatch moved left and lower step also, that's all good and dandy, however the three grills are in the wrong place, they're the right length but too far left, the LH edge should line up with the cant rail edge above and the RH edge should extend just past the cant rail grill support, ideally all three need moving right 1.0 mm and they'd be perfect.
For giggles I stacked the second tooling on top.
Good news, the sand filler is now in the right place but note the short triple grill set, the LH edge is perfect but the RH edge is also level with the cant rail support, it should extend slightly past. They have also moved the lower water filler access step into the right location.
I used the JLTRT real thing tanks to work from when drawing up the replacement 3D ones, they're pretty accurate but I think the fuel tank is a smidge too long, the brackets are each end are identical but on the JLTRT one the #1 end has been truncated a bit as well as the inter tank bracket not being assembled correctly on the model, it's about 50/50 root cause as to why the JLTRT one extends further.
Anyway, using the JLRTR tanks as abasis the first ones I printed were woefully narrow on the Heljan first tooling. I figured it was down to the JLTRT thicker cill or side material, how incorrect was that!
To compensate I widened the 3D tanks by 2 mm and the side lined up perfectly with the sides on the shell, brilliant, everything sorted then, not so. The above photo shows that both sets of tanks when viewed directly below have the same sort mof relation ship with the body behind, the side walls were the same thickness, the kick in of the cills the same so why was the Heljan one 2 mm wider.
Then I measured the bodies overall width, yes you guessed it, the Heljan first toolling is wider, not just abit but rather a lot (relative), 1.5 mm to be precise. The extra 0.5 mm I added was just counteracting the material thickness at the base of the cill.
I measured the second tooling and found it to be the same as the JLTRT, so, for future tank packs I need to do two sets, one for the correct second tooling and a wider set for the fisrt tooling.
Summary, if you're going to expose the tank suppoorts and engine chassis in a workshop type repair scenario then the best option is the Heljan second tooling.
The next step is to decide which workshop and then work out which body support stands they used, 3D some of those up and start making holes in the body to daylight the areas I want to detail out.
The first tooling body will get replacement metal skirts fitted back on, I'll probably ditch the engine room 3DP chassis and ribs etc, drop the floor down and just bolt the tanks to the brass bit, or maybe a facsimilie of the underside like JLTRT; then work out how to get some bogies and power it, probably as a dummy in MU with another.
The JLTRT needs some work as well, bought fully built and powered one of the cabs is not straight and there are some ugly joints that need tending to as well as the chassis sitting high at one end (due to the misplaced cab no doubt), it's also still got a boiler and steps so not a refurb but the buffer shrouds have been cut back and headcodes plated over (all give away refurb signs). My gut feeling is that it's got the wrong noses on but I'll ave a trawl and see if I can find a boiler fitted 37 with plated headcodes and shrouds cut back, possibly one of the 37/4 (were they dual ETH and boiler?) large logos in Scotland in the early 80's. That would be grand as I do like them and traveled on them on several trips.
Onward.
mickoo
Western Thunderer
I agree, but if you write on social media they're all the same you're bound to get hammered for it, hence hedging my bets unless I know for sure, in this case I didn'tI'm actually not surprised that the noses are the same. From an engineering and production point of view it makes sense to maximise the use of standardised components. Swindon were doing it very successfully for years, until Collett came along
