michael mott
Western Thunderer
Wow Nick those pantographs are a work of art!
Michael
Michael
Nick Dunhill's Workbench - Pair of EM2s
- Thread starter Nick Dunhill
- Start date
Mike Garwood
Western Thunderer
Outstanding work! I'm no fan fan of diesels or electrics but that Sir is amazing stuff.
Mike
Mike
OzzyO
Western Thunderer
Hello Nick you could try pmrprm? Link should work better that me trying to remember the name.
ATB
OzzyO.
ATB
OzzyO.
Nick Dunhill
Western Thunderer
So this week I managed to finish the pantographs and mount them on the body. The Busbars were completed. The pantographs were fitted with springs from Slater's Plastikard from their gauge 1 vacuum pipes. They give a nice bit of tension to the mechanism.
The next job was fitting buffers. I had some Invertrain BR buffers but the castings of the stocks were a bit flakey and they'd not been drilled concentrically. I bought some Markits buffers and modified them. I soldered a small square of chequer plate on the top of each.
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Battery boxes with some water filler detail and an air reservoir were added to the centre of the underframes. You can see them in the foreground of this piccy.
On one side of the loco the BR emblem is mounted on a board to clear the body strapping. The name plates (Diane Carney) were added, one of them has packing pieces behind to clear the aforementioned strap.
Minerva (no. 5) was the loco that was broken up for spares by the NSR (when sold to them in 1971) to keep the rest of the locos running. The locos were modified quite extensively in their later lives in Nederland.
Well the work has now ground to a halt until I can get some bogies from MM1 Models.
More pics here; nick dunhill
The next job was fitting buffers. I had some Invertrain BR buffers but the castings of the stocks were a bit flakey and they'd not been drilled concentrically. I bought some Markits buffers and modified them. I soldered a small square of chequer plate on the top of each.
Battery boxes with some water filler detail and an air reservoir were added to the centre of the underframes. You can see them in the foreground of this piccy.
On one side of the loco the BR emblem is mounted on a board to clear the body strapping. The name plates (Diane Carney) were added, one of them has packing pieces behind to clear the aforementioned strap.
Minerva (no. 5) was the loco that was broken up for spares by the NSR (when sold to them in 1971) to keep the rest of the locos running. The locos were modified quite extensively in their later lives in Nederland.
Well the work has now ground to a halt until I can get some bogies from MM1 Models.
More pics here; nick dunhill
Nick Dunhill
Western Thunderer
A fellow modeller has kindly donated a set of MM1/JLTRT bogie mouldings to enable me to finish the build. Here's the first after a brutal bout of modification. I'll add more details as I go, I think a trip to MOSI or Butterley is in order! (Must remember to get my client to pay me in USD.)
Mike Garwood
Western Thunderer
Stunning Nick. The detail on the roof is incredible, really enjoying seeing this coming together.
Mike
Mike
Nick Dunhill
Western Thunderer
Thanks Dave. Another modeller on RMWeb told me that the loco shed at Butterley that houses Electra is also inaccessible due to roofing work. Luckily they suggested that I go to the EVR in Wirksworth in the Peak District to see the 'spare' EM2 bogies belonging to the 10000 Recreation Group based there. I had a very enjoyable (though a bit chilly!) motorbike ride there yesterday and got lots of useful pics.
Overseer
Western Thunderer
An etched kit for the fabricated bogies would look nice, with 3d printed 'traction motors'. They could have holes in the right places and no chance of structural resin deforming over time. I can't help with useful drawings but the English Electric publicity book elevation of 10000 suggests that JLTRT version may not have all the secondary suspension bits included.Thanks Dave. Another modeller on RMWeb told me that the loco shed at Butterley that houses Electra is also inaccessible due to roofing work. Luckily they suggested that I go to the EVR in Wirksworth in the Peak District to see the 'spare' EM2 bogies belonging to the 10000 Recreation Group based there. I had a very enjoyable (though a bit chilly!) motorbike ride there yesterday and got lots of useful pics.
Nick Dunhill
Western Thunderer
Hi Frazer
You may be right. I'd hoped that the JLTRT bogie would be a better representation than the awful cast white metal parts in the old MSL Hobbies. In most senses it is, but the end sections of the bogies are very different. The original Ivatt bogies have the sand boxes sitting in fabricated pockets on all four corners of the bogie. These had to be machined and reshaped to better represent the EM2 versions. The EM2 bogie sides don't have a raise section over the centre axlebox and there are differences in the axleboxes themselves. The bogie (coil) springs are enclosed on the EM2 version as well. The donor of the resin bogie parts didn't include any castings, so I don't have the leaf springs or spring planks and swivel links, but maybe they're not in the 10000 kit. The braking system of the EM2s are completely different from that fitted to the originals, so it doesn't matter that I don't have them. None of the commercially available versions of the bogie (PRMRP do a version too) give the impression of a bogie fabricated from plate sections, although I did drill some holes in the JLTRT resin ones to try and give the hollow look.
The JLTRT bogies have an inner chassis for the wheels and motor so you don't get that see-through appearence, but I'll take that because they're the best available and good in lots of other ways. The pantos for this build took 3 weeks to fabricate and I would guess that fabbed bogies would take longer, and the cost would begin to run away. If I were making them on an infinite budget I'd go for it and use a couple of ABC traction motor gearboxes on one of the axles.
I have never built owt with a Delrin chain and was intrigued by them. They work really well, and if the infinite budget applied I'd be faffing about with a chain tensioner design after the style of the ones in a (Meriden) Triumph Bonneville primary or an Alfa Romeo Duetto cam chain. It'd be a challenge to find a tensioner that worked with the chain spinning in both directions. Now there's a rabbit hole.........
Nick
You may be right. I'd hoped that the JLTRT bogie would be a better representation than the awful cast white metal parts in the old MSL Hobbies. In most senses it is, but the end sections of the bogies are very different. The original Ivatt bogies have the sand boxes sitting in fabricated pockets on all four corners of the bogie. These had to be machined and reshaped to better represent the EM2 versions. The EM2 bogie sides don't have a raise section over the centre axlebox and there are differences in the axleboxes themselves. The bogie (coil) springs are enclosed on the EM2 version as well. The donor of the resin bogie parts didn't include any castings, so I don't have the leaf springs or spring planks and swivel links, but maybe they're not in the 10000 kit. The braking system of the EM2s are completely different from that fitted to the originals, so it doesn't matter that I don't have them. None of the commercially available versions of the bogie (PRMRP do a version too) give the impression of a bogie fabricated from plate sections, although I did drill some holes in the JLTRT resin ones to try and give the hollow look.
The JLTRT bogies have an inner chassis for the wheels and motor so you don't get that see-through appearence, but I'll take that because they're the best available and good in lots of other ways. The pantos for this build took 3 weeks to fabricate and I would guess that fabbed bogies would take longer, and the cost would begin to run away. If I were making them on an infinite budget I'd go for it and use a couple of ABC traction motor gearboxes on one of the axles.
I have never built owt with a Delrin chain and was intrigued by them. They work really well, and if the infinite budget applied I'd be faffing about with a chain tensioner design after the style of the ones in a (Meriden) Triumph Bonneville primary or an Alfa Romeo Duetto cam chain. It'd be a challenge to find a tensioner that worked with the chain spinning in both directions. Now there's a rabbit hole.........
Nick
Nick Dunhill
Western Thunderer
I was thinking an eliptical slipper on both runs of chain with springs between them to maintain tension. The two examples above (Triumph and Alfa) both use a slipper on the 'slack' part of the chain (primary and cam chains only run in one direction,) and I wondered what would work best on the portion of chain that was under tension?
simond
Western Thunderer
Derailleur?
bit of bent phos bronze strip?
sprung jockey wheel?
actually, I think Dave’s suggestion is likely best.
simultaneous post! Most cam chain arrangements tension the slack side of the chain, as you say, it only goes one way.
I think an adjustable jockey wheel will add negligible friction on the drive side, and will work fine on the slack side. Alternatively, two jockeys on a sliding bar, but this seems too complicated for limited (if any) benefit.
bit of bent phos bronze strip?
sprung jockey wheel?
actually, I think Dave’s suggestion is likely best.
simultaneous post! Most cam chain arrangements tension the slack side of the chain, as you say, it only goes one way.
I think an adjustable jockey wheel will add negligible friction on the drive side, and will work fine on the slack side. Alternatively, two jockeys on a sliding bar, but this seems too complicated for limited (if any) benefit.
Tim Humphreys ex Mudhen
Western Thunderer
As an alternative to delrin chains these drive belts from First Class Kits work extremely well. I've used both methods and the belt drive is simpler to use, easier to put on the loco with no fiddly connecting and because they are produced to size no sag requiring a jockey wheel.
Tim
www.firstclasskits.co.uk
Tim
A superior range of O Gauge (7mm) Brass Etch Wagon Kits and useful modelling accessories
A superior range of O Gauge (7mm) Brass Etch Wagon Kits. Nearly Everything In The Box Bar The Paint!! First Class Kits also provide useful modelling accessories including Ball Bearings, Transfers, Delrin Products and many more….
www.firstclasskits.co.uk
Nick Dunhill
Western Thunderer
Do the belts tend to wind up and then jerk if pulling/starting a big load?
Tim Humphreys ex Mudhen
Western Thunderer
Nick,
In my experience no, they are quite resilient composite toothed belts which don't easily stretch. They are very like miniature timing belts. Although I haven't used them custom sizes can be obtained from;
Tim
In my experience no, they are quite resilient composite toothed belts which don't easily stretch. They are very like miniature timing belts. Although I haven't used them custom sizes can be obtained from;
HPC Gears Products - Pulleys and Belts
www.hpcgears.com
Tim
simond
Western Thunderer
Wide range of sizes of such belts & pulleys is available online - I got a few items for a turntable reduction gear earlier in the year, though haven’t done the baseplate machining yet. They are just like miniature timing belts, and don’t stretch.
I got mine from “belting online”. Be aware that there are at least two tooth pitches in the sort of sizes we modellers might use, they don’t mix!
I got mine from “belting online”. Be aware that there are at least two tooth pitches in the sort of sizes we modellers might use, they don’t mix!
Nick Dunhill
Western Thunderer
I had hoped that the bogies would just slot into the build but there's a number of detail differences between the Ivatt and later EM2 version. The biggy is the modification to the ends of the side frames. 10000/10001 have a fabricated pocket on the end of each side frame with a sand box within. The EM2 version side frame does not rise up over the middle wheel, the axleboxes are different and the springs are enclosed. Lots of hacking ensued. My budget was blown by now so I sent the bogie to Mick Davies to get some parts printed to save on fabrication costs. He printed new bogie ends as the ones I had were damaged and not quite the same as the EM2s. Here's the result;
He's also printing bits of the brake system:
In the meantime I made some bogie mounts and this is the result.
I'm hoping to finish next week.
He's also printing bits of the brake system:
In the meantime I made some bogie mounts and this is the result.
I'm hoping to finish next week.
mickoo
Western Thunderer
As Nick points out, there are quite a few changes between the 10000/1 bogies and the EM2.
The end beams are unlike each other and the secondary spring plank uses swing links as opposed to tie rods in rubber mounts for articulation.
Things have moved on a bit from Nicks photo earlier in the week, I was't overly happy with the surface smoothness so spent some time with orientations and printer settings to get it much better. I also added the flanges where the sand boxes were fitted and made the changes to the inner end to suit the JLTRT block and lack of guard irons.
Brake cylinders are now all done and fit on the square pegs as seen in Nicks image and new secondary leaf springs with plank and swing links added and fitted.
The end beams are unlike each other and the secondary spring plank uses swing links as opposed to tie rods in rubber mounts for articulation.
Things have moved on a bit from Nicks photo earlier in the week, I was't overly happy with the surface smoothness so spent some time with orientations and printer settings to get it much better. I also added the flanges where the sand boxes were fitted and made the changes to the inner end to suit the JLTRT block and lack of guard irons.
Brake cylinders are now all done and fit on the square pegs as seen in Nicks image and new secondary leaf springs with plank and swing links added and fitted.
Nick Dunhill
Western Thunderer
Thanks for these parts, and the update Mick. I look forward to getting them.
For the record Mick and myself often work together on etches and 3D prints. Custom etches are a great way to take all the financial pain out of scratchbuilding. I can offer a high quality scratchbuilt engines without having to spend hours cutting out parts and increasing the cost. Similarly 3D printing, as the technology improves to the level that parts don't show layering or distortion, big savings in time and/or cost are gained. Mick gets a full commercial rate for the design and printing work.
This build is a perfect example of that. The locos are built round some basic etched parts, a skeleton with attached detail panels. Some 3D printed parts to replace fabrications that would be awkward and/or time consuming to make. Lots of the locos are however scratchbuilt in the traditional sense, measure, cut, solder. Mustn't forget the bogies 'borrowed' from another model.
In the same way Mick has developed a successful business massively upgrading commercial kits using the above technologies. All power to him.
Are they scratchbuilt? You can decide.......
For the record Mick and myself often work together on etches and 3D prints. Custom etches are a great way to take all the financial pain out of scratchbuilding. I can offer a high quality scratchbuilt engines without having to spend hours cutting out parts and increasing the cost. Similarly 3D printing, as the technology improves to the level that parts don't show layering or distortion, big savings in time and/or cost are gained. Mick gets a full commercial rate for the design and printing work.
This build is a perfect example of that. The locos are built round some basic etched parts, a skeleton with attached detail panels. Some 3D printed parts to replace fabrications that would be awkward and/or time consuming to make. Lots of the locos are however scratchbuilt in the traditional sense, measure, cut, solder. Mustn't forget the bogies 'borrowed' from another model.
In the same way Mick has developed a successful business massively upgrading commercial kits using the above technologies. All power to him.
Are they scratchbuilt? You can decide.......