"Voiding the Warranty" - Mol's experiments in 21mm gauge

[Tullygrainey]

53 minutes ago, Mol_PMB said:

I’d still welcome some advice on the chassis though! How would you arrange the gearing? 
 

Cheers,

Mol

If you'd be prepared to drive only 2 of the 3 axles, I'd recommend considering High Level's range of QuadDriver kits which come in a variety wheelbases, one of which might be right for your project. You'll find them in the Bogies section on the High Level site.

https://www.highlevelkits.co.uk/bogies

The one described as "Planet Power Unit" is similar and works in the same way.  They all enable 4-wheel drive as well as some compensation. They need to be built into a chassis but that can simply be a pair of basic frames. 

 

I used the Planet version to build a model of the Belfast & County Down's 6 wheel uncoupled diesel electric No.2 a while back. It drives on the front and centre axles and runs well. As it happens, the prototype drove on only two axles too.

 

 

If it's useful, you'll find an account of the build here:

 

I like the sound of your project. Good luck with it.

Alan 

[Mol_PMB]

Ah great, many thanks, I’ll have a good read tomorrow! 

[Horsetan]

1 hour ago, Mol_PMB said:

.... I’d still welcome some advice on the chassis though! How would you arrange the gearing? 

I'm wondering if this might be a suitable place for a modern version of Rivarossi's S-drive system?

[David Holman]

Seriously clever stuff, well beyond my pay grade - which is probably why my eyes are glazing over!

 On my Deutz G class shunter, I used Delrin chain and gears, but can this be done in 4mm? Once built a Y10 Double Sentinel, which relied on single axle drive and a lot of ballast, to move half a dozen wagons. The other axle could rock, so pick up was reasonable.

[Mol_PMB]

35 minutes ago, David Holman said:

Seriously clever stuff, well beyond my pay grade - which is probably why my eyes are glazing over!

 On my Deutz G class shunter, I used Delrin chain and gears, but can this be done in 4mm? Once built a Y10 Double Sentinel, which relied on single axle drive and a lot of ballast, to move half a dozen wagons. The other axle could rock, so pick up was reasonable.

Thanks David. I've used Delrin chain in 7mm scale too, but it doesn't seem to be widely used in 4mm scale and these locos have particularly small wheels which would require small sprockets and a fine chain. With any small shunter I think compensation or springing of some sort is very important - not just to minimise derailments but to improve pick up, exactly as you say. 

 

From an enquiry on RMweb I have the following answer relating to the High Level gearboxes (though this is from someone who uses them, rather than the manufacturer):

• Most gears are module 0.4 but the likes of the reduction gear in the 54:1 gear boxes are a mix. The 27/10 twin gear is mod 0.3 for the 27 tooth and Module 0.4 for the 10 tooth.

 

The High Level 'Quaddriver' is a good call, it's available in 20mm wheelbase which would be right for the two closer wheelsets on the E401. Though to get the weight over the driven axles in that case would give a loco with very asymmetric weight distribution. I was thinking of using the same principle to power all 3 wheelsets, but it's a bit of a challenge to arrange that to work smoothly with compensation/springing as well. 

I'll keep working on the body artwork while I consider the chassis!

 

[Horsetan]

7 hours ago, Mol_PMB said:

....The High Level 'Quaddriver' is a good call, it's available in 20mm wheelbase which would be right for the two closer wheelsets on the E401. Though to get the weight over the driven axles in that case would give a loco with very asymmetric weight distribution. I was thinking of using the same principle to power all 3 wheelsets, but it's a bit of a challenge to arrange that to work smoothly with compensation/springing as well. ...

It will work if you make your drivetrain articulated, in other words the gear positioning is allowed to swivel, and thus not interfere with the vertical movement of the axleboxes.

The QuadDriver is a start, and if you look at the High Level gearboxes, some have an articulated section to the final drive, and there's also a DriveStretcher option to cope with more awkward layouts.

If High Level don't have exactly what you're after, do have a look at NWSL. USA-based, but they have a bewildering range of gears, from 0.2 to 0.75 MOD, and loads of other things that may be adapted. They even do bevels and a multi-start worm which is effectively a cross-helical, which is brilliant if you want a low-resistance non-locking drive.

Edited January 24 by Horsetan

[Mol_PMB]

Thanks for the tip re NWSL. I have successfully used their products in the past, though I got the impression that their range isn't as big as it once was. Certainly last time I looked to re-order parts I'd had from them in the past, it seems they are no longer stocked.

 

Anyway, here's a sketch I've worked up this evening. The wheels and 2mm axles are shown in black, the functional frame in dark grey and the cosmetic frame behind in grey:

The idea is to use a QuaDriver 20mm wheelbase to power the two closely-spaced axles, with the 'tower' at the left-hand end wheelset and the arm connected to the middle wheelset. I can't find any actual dimensions for this unit, but from @Tullygrainey's photo (reproduced below) it looks like it should be fine.

Then I'll have to create a custom equivalent of a Drivestretcher with five 20-tooth gears to connect to the third axle (sketched in blue above, I know they're not proper gear shapes but it's the PCD that matters and 4x8=32 so that works.

Having done a lot of searching online I think I've found the key dimensions of the hornblocks, datum holes and CSB pivot heights. I've had to refer to several different websites and documents because I haven't yet found any one source that provides a complete dataset. I think the following are correct:

• Hornblock slot in frames is 5mm wide.
• Top of hornblock slot is 4mm above axle centreline.
• CSB pivot points are 3mm, 4mm or 5mm above the axle centreline. I've used 5mm in the sketch above.
• Small datum hole above hornblock slot is 5.2mm above the axle centreline (this is an estimate, but it's more than 5mm as on the images of the CSB jig it's fractionally above the 5mm row)

I've then used one of the online CSB spreadsheets to work out where the pivot points ought to be if the wheels are to be equally loaded. A=18, B=11, C=24, D=16. Hopefully I've got this right - @Horsetan does this look plausible?

I still need to work out the width between the frames. Again it's hard to find published dimensions for the width of the QuadDriver gearbox, but it looks like it might be a tight fit between the the thinner 'spacesaver' hornblocks for OO gauge. I fear it might not fit at all. The thinner hornblocks are nominally 2.2mm wide, so with OO back-to-back being 14.5mm that leaves only 10.1mm for the gearbox as well as any clearance needed. The gearbox looks wider than 10mm! @Tullygrainey, is yours accessible to measure the width of the QuadDriver gearbox?

For once, 21mm gauge is easier in this case, but I need to make my solution work for both gauges.

This is becoming a headache!

[Horsetan]

16 minutes ago, Mol_PMB said:

.... I think I've found the key dimensions of the hornblocks, datum holes and CSB pivot heights. I've had to refer to several different websites and documents because I haven't yet found any one source that provides a complete dataset. I think the following are correct:

• Hornblock slot in frames is 5mm wide.
• Top of hornblock slot is 4mm above axle centreline.
• CSB pivot points are 3mm, 4mm or 5mm above the axle centreline. I've used 5mm in the sketch above.
• Small datum hole above hornblock slot is 5.2mm above the axle centreline (this is an estimate, but it's more than 5mm as on the images of the CSB jig it's fractionally above the 5mm row)

I've then used one of the online CSB spreadsheets to work out where the pivot points ought to be if the wheels are to be equally loaded. A=18, B=11, C=24, D=16. Hopefully I've got this right - @Horsetan does this look plausible?...

I got a broadly similar result on the spreadsheet, so it looks like you're on target.

NWSL make a lot of stuff to order now, rather than holding stock of every single part, so it's a matter of ordering and waiting, especially given average international postal times these days.

[Tullygrainey]

Measured at the point where the articulated arm overlaps the main body,  the QuadDriver is around 11.5mm wide. The axle bearings add a bit more but these can be filed flush on the outside if necessary. 

[Mol_PMB]

3 minutes ago, Tullygrainey said:

Measured at the point where the articulated arm overlaps the main body,  the QuadDriver is around 11.5mm wide. The axle bearings add a bit more but these can be filed flush on the outside if necessary. 

Many thanks - I feared that would be the case. It definitely doesn’t fit for 00 gauge!
I’ll have to find an alternative solution if this is to be buildable for OO with hornblocks. Maybe a rigid chassis would be sufficient for OO? 

[Horsetan]

15 minutes ago, Mol_PMB said:

Many thanks - I feared that would be the case. It definitely doesn’t fit for 00 gauge!
I’ll have to find an alternative solution if this is to be buildable for OO with hornblocks. Maybe a rigid chassis would be sufficient for OO? 

Are you planning around High Level standard hornblocks, or their spacesaver (thin, in other words) ones?

[Tullygrainey]

You're right. There isn't room for hornblocks on the rear axle. As I understand it, the QuadDrivers are designed to provide 3-point compensation - one axle running in fixed bearings and the articulated arm permitting the other axle to rock on a central longitudinal beam. QuadDrivers come as part of the package in Judith Edge kits for Ruston 4wheel shunters and also some RT Models kits and that's how they're deployed in these. That photo of mine shows the arrangement for the Ruston.

I'm not a great fan of rigid chassis but that's just me!

Alan

[Mol_PMB]

Just now, Horsetan said:

Are you planning around High Level standard hornblocks, or their spacesaver (thin, in other words) ones?

The thin ones! And there's still not enough room in OO. 21mm is OK, but I want to design this to work for both gauges.

Just now, Tullygrainey said:

You're right. There isn't room for hornblocks on the rear axle. As I understand it, the QuadDrivers are designed to provide 3-point compensation - one axle running in fixed bearings and the articulated arm permitting the other axle to rock on a central longitudinal beam. QuadDrivers come as part of the package in Judith Edge kits for Ruston 4wheel shunters and also some RT Models kits and that's how they're deployed in these. That photo of mine shows the arrangement for the Ruston.

I'm not a great fan of rigid chassis but that's just me!

Alan

Thanks for confirming. I'm not a fan of rigid chassis either!

For a 6-wheel loco I need a more complex arrangement of compensation or springing, which is why the hornblocks and CSB method appeal. But I think that works best if all wheels are sprung.

[David Holman]

Have a look at www.locosnstuff.com

Mark Clark is a Chatham Club member and seriously clever dude in all things mechanical. Taught himself CAD and 3D printing and now runs his own business. Mainly narrow gauge [& some exotic prototypes], but has produced various kits and bespoke chassis, which may provide inspiration or even something you can use.

 Either way, the website is well worth a look for its own sake.

[Mol_PMB]

5 minutes ago, David Holman said:

Have a look at www.locosnstuff.com

Mark Clark is a Chatham Club member and seriously clever dude in all things mechanical. Taught himself CAD and 3D printing and now runs his own business. Mainly narrow gauge [& some exotic prototypes], but has produced various kits and bespoke chassis, which may provide inspiration or even something you can use.

 Either way, the website is well worth a look for its own sake.

Many thanks! Looks like there's plenty of neat designs there, I'll have to see whether any are suitable for my needs or if I can just use some of the ideas.

 

I've had a look at using one of High Level's more standard gearboxes, the RoadRunner, which is only 8.6mm wide. The final drive gear is 23 tooth, and it would be possible to create a geartrain directly from that to the second axle either with five gears 23-12-12-12-23 (purple).

High Level don't offer gears bigger than 23 tooth, but other suppliers do. Replacing the three small ones with a 27 tooth in a straight line (red) would mesh fine, but the ground clearance would be zero with the 27-tooth gear, not ideal for a loco with suspension.

Another option would be a 28 tooth gear mounted slightly higher (green) though the motor might have to be tipped further forward to suit.  

With this type of arrangement, I'd need to provide some form of non-rigid torque reaction for the motor that didn't mess with the suspension too much. Why is it so hard? I thought having no rods would make it easier than a D class...

Maybe I should revert to the previous arrangement, make the leading axle rigid and just put the CSB on the other two axles.

 

 

[Horsetan]

1 hour ago, Mol_PMB said:

.... Why is it so hard? I thought having no rods would make it easier than a D class...

Maybe I should revert to the previous arrangement, make the leading axle rigid and just put the CSB on the other two axles.

CSB doesn't work well if one axle is rigid. You might as well use traditional beam compensation instead.

Having no rods is technically more demanding, because you're relying on the drivetrain to provide the link, instead of coupling rods. Have you seen the Penbits range of sprung diesel bogies, to see how Ian Penberth gets round the problem?

[Mol_PMB]

I'm going to keep thinking about the chassis while I carry on with the body etch.

The artwork for all the main parts is now done, just a few little details to do, and then I can finalise the etch layout and add all the tabs.

There are some options for grilles, exhaust cowl and brake dump valve so that most of the class can be modelled throughout their life - until someone finds a picture that proves me wrong!

There will be the following sub-assemblies:

• Bonnet sides and ends
• Bonnet top
• Footplate and cosmetic frames
• Cab sides, ends and control panel
• Cab roof

The two bonnet sub-assemblies will be made separately but then soldered together. The cab roof will remain removable if desired.

The footplate, cab and bonnet will all be held together by a bolt under the control panel in the front of the cab.

There will also be bolts at each end of the footplate which will connect the functional chassis to the footplate and either the cab or bonnet above. 

My current thinking is that coupling mounts will be on the functional chassis.

 

 

Three pics of the real thing from various angles and showing the three liveries carried, thanks to Ernie and Roger Joanes:

 

 

 

[Galteemore]

Last pic is especially interesting. Steam ‘officially’ ended on CIE in ‘63……just as in NI occasional steam lingered on until some months after the final spoil train. 

Edited January 25 by Galteemore

[Mol_PMB]

1 minute ago, Galteemore said:

Last pic is especially interesting. Steam ‘officially’ ended on CIE in ‘63……just as in NI occasional steam lingered on until some months after the final spoil train. 

E407 carries a CIE roundel, which means it can't be much earlier than 1964. So I think the photo date is correct.

[Galteemore]

Just now, Mol_PMB said:

E407 carries a CIE roundel, which means it can't be much earlier than 1964. So I think the photo date is correct.

Yes it probably is. By 1964, though, it was a rare sight to see a CIE steam loco in Dublin. Steam on ex GN into Dublin persisted until 66, mostly Jeeps by then.  The last VS run was in 65

[Mol_PMB]

The E401 body etch artwork is complete and I have sent it off to the etchers for a quote.

[jhb171achill]

On 25/1/2025 at 12:28 PM, Galteemore said:

Last pic is especially interesting. Steam ‘officially’ ended on CIE in ‘63……just as in NI occasional steam lingered on until some months after the final spoil train. 

Steam HAD finished on that date, but 130 was one of the locos used on the All Ireland 1964 Steam Tour organised by the SLS & LCGB & IRRS. In the north, while the last ACTUAL steam operations were in summer 1970, it wasn't until 1971 that the very last two "Jeeps" were officially withdrawn.

[StevieB]

Interesting how steam lingered on in Ireland after its official abolition whereas it was a clean break in the UK, save for Flying Scotsman’s contract with BR.

Stephen

[jhb171achill]

4 hours ago, StevieB said:

Interesting how steam lingered on in Ireland after its official abolition whereas it was a clean break in the UK, save for Flying Scotsman’s contract with BR.

Stephen

The 1964 tour was a complete one-off. Other than that, once steam ended on CIE in early 1963, it fully ended. Several locos remained in a static position as carriage heating boilers for a short time earlier, but they didn't go anywhere, and even these were gone by 1965.

[Horsetan]

19 hours ago, Mol_PMB said:

The E401 body etch artwork is complete and I have sent it off to the etchers for a quote.

Is the chassis the same as that used under the E421s? I wasn't quite clear on this. 

[Mol_PMB]

1 minute ago, Horsetan said:

Is the chassis the same as that used under the E421s? I wasn't quite clear on this. 

I haven't finalised the functional chassis yet, and it will have to be on a separate etch anyway as it will need thicker material. 

The wheel diameter and wheel spacing is the same for both classes, so the functional chassis could be the same.

However, the E421 is 2 feet longer overall, and the proportions are different (to improve the weight distribution), so the footplate and cosmetic sideframes would be different. Also the bodywork is different.

Let's see how the E401 works out. I could do an E421 version later if IRM don't beat me to it.

 

I've just paid the invoice for the body etch; should be a week or so until it arrives. I'll start a new thread for the build.

 

[Mol_PMB]

Photos from Ernie and Kevin Lane for comparison:

How the E421 differs from the E401:

• 2 feet longer overall, mostly at the front
• The bonnet does not reach right to the front
• The battery boxes are mounted either side of the frames at the front
• The fuel tank doesn't reach so far forwards (to make way for the battery boxes) but is extended back further under the cab
• The bufferbeams are deeper and festooned with rivets
• The cab has different/bigger/more windows and I think it's a bit longer too
• The bonnet is lower, has a less curved top, and there is no exhaust/silencer cowl on top
• Many small details such as lights, grilles, handrails, water fillers are different.

So although they are similar at first glance, there are very few bits of the etch artwork that would be suitable for both. However, the assembly concept could be re-used if it works well for the E401.

[MD220]

On 23/1/2025 at 7:53 PM, Galteemore said:

Fab work. Here’s one for starters - Eire Trains by Ciaran Cooney 

One small point worth noting in this photo is that the silver handle fitted centrally on the control desk was not a standard feature. This is only to be found on E428 and was a control handle for the vigilance system which was added in preservation to allow for main line use. The rest of the class were never equipped with vigilance. 

Edited January 27 by MD220

[Mol_PMB]

Many thanks - a good tip!

From what I can see on the old photos, the E401 desk was significantly different from the E421 but had some common features. 
On the E401 etch I’ve only approximated it, I don’t have complete info and it’s not very visible though the small windows anyway. But if I go on to produce an E421 I’ll make sure I get it right. If IRM don’t get there first…

[Mol_PMB]

Today I've been working on a few ISO containers, having received a couple of nice parcels from Arran.

Firstly I have painted the tops of some Bell containers. I'd done one of these previously in petunia, but I've bought 3 more now and they have also had their tops repainted into earlier colours - one more in petunia ans the other two in blue. I've used an old jar of BR blue which seems to be quite a good match - by the time they're weathered I'm sure it will blend in. Apart from the first one I did, they still need lettering on top, and I'll need to get some more transfers for that.

Arran was also kind enough to sell me five of the 20x8x8 boxes unpainted, same as the Manchester Liners and OCL ones. These are flush-sided with lots of very fine rivet detail. I will paint one of them (unmodified) as an early Bell Ferry container in alloy with the chevrons logo, and the name in petunia. Another (with minor modifications to provide fork pockets) will be finished in early Mitsui OSK Lines livery using the C-rail decals. One of 'mine'!

With the other three, I'm adding vertical ribs to the sides to represent the 'sheet and post' type of alloy container. The first one I did will become a white CIE insulated container. I scraped off the rivet detail and added ribs and extra strips at the base:

Having done that, I decided it was actually easier to sand off all the side detail and reinstate the top and bottom ribs from microstrip. So I've adopted that approach for the last two boxes, which will become B+I containers - one in the 'blue stripe' B+I LINE, and the other in the 'red stripe' B+I FREIGHTWAYS liveries. They have different numbers of ribs too. Here's a work-in-progress:

Next task with these is to clean, prime and paint the base colour. Also to complete the transfer artwork and get them ordered.

 

 

 

[Mol_PMB]

More progress on the containers, which have been painted, and I've completed the transfer artwork though I still need to do a final check that everything's on the right layer before placing an order for it.

A group photo:

Top left is a 30' dry box, shortened from a C-Rail 40' box: this will be finished in Irish Ferryways livery. Top middle a plain C-Rail 20' box, then another modified as a grain container. These two will be in CIE livery.

Bottom left a pair of 20x8x8 C-Rail boxes, no modifications apart from some fork slots. These will become early MOL and BELL alloy containers.

The other three on the bottom row started off the same, but have had their side detail sanded off and some ribs added, to represent early ribbed alloy containers. They all have different numbers of ribs to match the prototypes, which will be B+I (blue stripe), B+I Freightway (red stripe) and CIE Insulated.

A couple more pics:

And here's an image of the transfer artwork. I haven't quite decided on the shade of blue for the B+I ones, the artwork isn't always true colour for the inks used - they won't be so different in reality!