7mm Mickoo's Commercial Workbench
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mickoo
Western Thunderer
More JLTRT 4F, I've built three of these 4F's from three different kits, each has their strong points, each their faults, the ideal model would be the best of all three.
All my previous JLTRT builds with resin boilers also had the etch work for the metal one but missing any castings used on the resin moulding, the 4F broke that duck and this is about as far as it goes with the kit metal work once you take the resin boiler out.
The smokebox will be a 3D replacement with door and chimney as one unit for strength, the rest will be scratch built so out with the crayons and scissors tomorrow.
Other than the cab the rest of the etch work was just fine, just over a day (a long day admittedly) to do the rolling chassis, rods and footplate shell, the rest of today was on the cab.
The cab comes in three pieces, why I have no idea but the joint in the roof section isn't anywhere near any guttering (which by the way varies a lot over the class) so you end up with a butt joint and endless filling to smooth off. Luckily the material is quite thick (0.5mm) so there's plenty of meat there so you can attack it with big files.
Not with standing the three pieces the joint is close to the cant rail bend, which makes it awkward to grip/hold the roof section to form the bend. In the end I soldered two slabs of sheet metal on (show as a red overlay in one photo), one covering the opening in the side sheet to stop the small top rear extension distorting and one on the roof section to extend it as a hand hold for bending.
The cab floor also needs some work and the square boxes are a little long and stick out the back so need shortening. The floor has a piece missing where the drivers side box goes, the instructions do note this (thumbs up for noting and advising) so that's easy to add, but, there are no sides where the floor extends past the side sheets, those'll need adding from scrap etch.
Finally you can line the tender up and see that the floor is much too high, which is why I hadn't fitted it previously. This is quite common for tenders that are multi class, the floor section will be for the highest foot plated engine it was attached to, in this case I believe it was the Royal Scot class.
On the chassis I added the obligatory Lego sand boxes, hornguides/springs and ashpan. One thing none of the three kits model is the extended bracket for the leading sand boxes, this pushes the box out and wraps around the leading brake hangers.
All my previous JLTRT builds with resin boilers also had the etch work for the metal one but missing any castings used on the resin moulding, the 4F broke that duck and this is about as far as it goes with the kit metal work once you take the resin boiler out.
The smokebox will be a 3D replacement with door and chimney as one unit for strength, the rest will be scratch built so out with the crayons and scissors tomorrow.
Other than the cab the rest of the etch work was just fine, just over a day (a long day admittedly) to do the rolling chassis, rods and footplate shell, the rest of today was on the cab.
The cab comes in three pieces, why I have no idea but the joint in the roof section isn't anywhere near any guttering (which by the way varies a lot over the class) so you end up with a butt joint and endless filling to smooth off. Luckily the material is quite thick (0.5mm) so there's plenty of meat there so you can attack it with big files.
Not with standing the three pieces the joint is close to the cant rail bend, which makes it awkward to grip/hold the roof section to form the bend. In the end I soldered two slabs of sheet metal on (show as a red overlay in one photo), one covering the opening in the side sheet to stop the small top rear extension distorting and one on the roof section to extend it as a hand hold for bending.
The cab floor also needs some work and the square boxes are a little long and stick out the back so need shortening. The floor has a piece missing where the drivers side box goes, the instructions do note this (thumbs up for noting and advising) so that's easy to add, but, there are no sides where the floor extends past the side sheets, those'll need adding from scrap etch.
Finally you can line the tender up and see that the floor is much too high, which is why I hadn't fitted it previously. This is quite common for tenders that are multi class, the floor section will be for the highest foot plated engine it was attached to, in this case I believe it was the Royal Scot class.
On the chassis I added the obligatory Lego sand boxes, hornguides/springs and ashpan. One thing none of the three kits model is the extended bracket for the leading sand boxes, this pushes the box out and wraps around the leading brake hangers.
dibateg
Western Thunderer
Yes - I remember I had a job with that turn in at the top of the cab side. For a kit that was 'supposedly easy to build'! How a beginner would have coped I don't know. Nice work with the extra prints for the frames.
14 years ago, apologies for the poor photo quality:-
14 years ago, apologies for the poor photo quality:-
Yorkshire Dave
Western Thunderer
Although this is rather academic now, surely this appears to be a design flaw in the kit (or in kits) where wrap-over cab roofs are involved.
Using tony's photo as an illustration the logical solution would have been to have the first lower third of the cab roof as part of the cab side etch (red area) with central section as a separate etch (yellow area). This would allow the cabsides at roof level to be pre-formed using the cab front as a guide whilst all as separate parts before being soldered together. The green outlines are my interpretation of your description of the current kit parts.
mickoo
Western Thunderer
That's pretty much sums it up.
Three pieces, the sides and part of the roof and a central roof section, the problem is the small part of the roof that is attached top the side is too close to the bend to allow you to form it neatly and the joint between side and roof is not near a covering gutter.
In red the kit centre section, in green the kit side plus a small section of the roof (green arrow) shows the small area of roof you have to form the cant rail bend, it's 100% of naff all.
What they should have done, as you note, (if they persisted in having three pieces....why
) is extend the side pieces up to a new smaller (blue) centre roof section, this gives you more material (blue arrow) to aid forming the cant rail bend and with the added bonus that the joint is now covered (80%) by a gutter (yellow outline) that a majority of engines have on top.
I have no idea why it's three pieces, their math and artwork is spot on and all three pieces fitted perfectly with no gaps or edges to cut back, so it could easily have been one piece, it's not as though there are alternative roofs or sides to swap in and out. They've basically turned a 10 min fold and solder job into a 2 hr mess of solder, cutting back and dressing smooth.
There will still be a small witness mark once painted so it'll need further work in the paint shop sanding ultra smooth, if not you'll end up with a kink or witness mark in about the worst place possible (viewing angles), any imperfections in this area will show up like sore thumb as the light catches it.
mickoo
Western Thunderer
Brief update on the JLTRT 4F, it's nice when the test print first first time and is fault free, doesn't always happen like that truth be told. I decided to leave the chimney off the smokebox module for a couple of reasons.
A: Other people might want this and there are several types of chimney so it's better to design as a pick and mix.
B: The lip would need supporting and those supports are best placed on the top of the firebox, so they'd need extra work cleaning off and surface preparation. The less work you have to do in high visual areas on surface prep, the better.
C: The larger hole allows a screwdriver to wiggle in and tighten up the screws that bolt it to the footplate.
The rear end has a socket that encloses the valve chest on the cylinder block, on the 4F they're way up high above the frames, I wanted to keep all the motion as part of the chassis so it's a split design and with a fair wind the joint is marginal.
Having done all that really smart stuff I then had to balance the world order and do something dumb, secured the tender footplate without the scoop and handbrake stands in place, they pass up through the hole from below . Not to worry, I'll split the stands (they're 3D) and hide the joint where the floor is or at the flanged base (which is the bit that can't pass through the hole in the footplate. I've added a picture of the Crab tender I did recently that was the test bed for this approach.
Finally more bits added to the cab leaving only the gutters to graft on and the splashers, these are white metal, quite thick and shorted on the wheel rims, I contemplated all new brass fronts and tops but really didn't fancy all that cutting out and faffing around, luckily I managed to thin the top curved plate from below with a mini sanding drum to give enough clearance, they still have some surface defects that'll get filled with Milliput before paint.
Next up, sanding pipes, remaining brake linkages and cylinder and inside motion.
A: Other people might want this and there are several types of chimney so it's better to design as a pick and mix.
B: The lip would need supporting and those supports are best placed on the top of the firebox, so they'd need extra work cleaning off and surface preparation. The less work you have to do in high visual areas on surface prep, the better.
C: The larger hole allows a screwdriver to wiggle in and tighten up the screws that bolt it to the footplate.
The rear end has a socket that encloses the valve chest on the cylinder block, on the 4F they're way up high above the frames, I wanted to keep all the motion as part of the chassis so it's a split design and with a fair wind the joint is marginal.
Having done all that really smart stuff I then had to balance the world order and do something dumb, secured the tender footplate without the scoop and handbrake stands in place, they pass up through the hole from below . Not to worry, I'll split the stands (they're 3D) and hide the joint where the floor is or at the flanged base (which is the bit that can't pass through the hole in the footplate. I've added a picture of the Crab tender I did recently that was the test bed for this approach.
Finally more bits added to the cab leaving only the gutters to graft on and the splashers, these are white metal, quite thick and shorted on the wheel rims, I contemplated all new brass fronts and tops but really didn't fancy all that cutting out and faffing around, luckily I managed to thin the top curved plate from below with a mini sanding drum to give enough clearance, they still have some surface defects that'll get filled with Milliput before paint.
Next up, sanding pipes, remaining brake linkages and cylinder and inside motion.
mickoo
Western Thunderer
Cheers, they are grim and probably took as long as making new ones, on the bright side I've saved a few oz going in the waste recycling, mind the back head is going there, doesn't look right to me and it's clothed, lots of 4F and Midland engines had unclothed backheads.
mickoo
Western Thunderer
More 3D wheel skulduggery, this time some Peckett H spoke wheels for a friends build of a GWR 1340, in this case Trojan.
The H spoke is easier to draw up but getting a thin front and rear face is awkward, too thick and it looks naff, too thin and it runs the risk of deforming during the print.
I also reduced the boss thickness closer to prototype, the Slaters boss is around 4.4 mm thick and stands proud of the rim by a large margin, reducing the boss thickness to just stand proud of the rim then means the axle ends and csk screws need altering.
You need to countersink the end of the axle and reduce the square section depth to suit, around 1 mm shorter is sufficient, then the retaining screws bottom out in the hole; you can either drill it deeper or trim the length of the screw, that way it'll pull the wheel tight up against the shoulder.
The H spoke is easier to draw up but getting a thin front and rear face is awkward, too thick and it looks naff, too thin and it runs the risk of deforming during the print.
I also reduced the boss thickness closer to prototype, the Slaters boss is around 4.4 mm thick and stands proud of the rim by a large margin, reducing the boss thickness to just stand proud of the rim then means the axle ends and csk screws need altering.
You need to countersink the end of the axle and reduce the square section depth to suit, around 1 mm shorter is sufficient, then the retaining screws bottom out in the hole; you can either drill it deeper or trim the length of the screw, that way it'll pull the wheel tight up against the shoulder.
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mickoo
Western Thunderer
That took longer than planned but worth it I think. The requirement was for fixed inside motion and normally I'd not use 3D for such fine parts, but it's in a low/zero impact zone and on the whole, once fully assembled and secured will be quite robust.
I do need to redo the weigh shaft, I can probably push the printed bearings out to envelope the metal stub in the frames and thus bring them nearer to the cosmetic true scale frames on the footplate; I also need to scale the balance weights much larger, they looked okay in CAD but in the model....no cigar.
The original concept was all one print but it was a mare to support and print well so it was broken down into sub parts for better printing and easier installation.
Nothing fixed permanently yet, so pats can be modified and swapped out later if needed and/or painting.
I do need to redo the weigh shaft, I can probably push the printed bearings out to envelope the metal stub in the frames and thus bring them nearer to the cosmetic true scale frames on the footplate; I also need to scale the balance weights much larger, they looked okay in CAD but in the model....no cigar.
The original concept was all one print but it was a mare to support and print well so it was broken down into sub parts for better printing and easier installation.
Nothing fixed permanently yet, so pats can be modified and swapped out later if needed and/or painting.
Clarence3815
Western Thunderer
Exquisite craftsmanship.
mickoo
Western Thunderer
Sorry darlingBeat me again! I'm plotting a set of GW valve gear for a Dean Goods and later for the Aberdare. All the other life bits have rather got in the way
Looks bostin, by the way.
I am running out of things to ponder on high mileage trips now
Dog Star
Western Thunderer
Try "does the theory of relativity support the concept of deja vu?" .I am running out of things to ponder on high mileage trips now
Nah! I’ve seen it all before!
As
Ask Schrödinger!Is the cat dead or alive?
3 LINK
Western Thunderer
Wow, amazing work on the valve gear. I take it the brass tube in the above photo is used to thread on the balance weights and gubbins, and then just push the axle through the tube ?
Stephensons Link Valve Gear is very commonly used, any chance you could print some of them ? I have recently fitted some inside valve gear to one of my locos, and although there is a great sense of achievement to see it all wiggling around, the wiggling is hardly noticeable
… I for one would benefit greatly, as my next two loco both have Stephensons valve gear, and life’s too short..
Cheers, Martyn.
Stephensons Link Valve Gear is very commonly used, any chance you could print some of them ? I have recently fitted some inside valve gear to one of my locos, and although there is a great sense of achievement to see it all wiggling around, the wiggling is hardly noticeable
… I for one would benefit greatly, as my next two loco both have Stephensons valve gear, and life’s too short..Cheers, Martyn.