BR Class 28 Build

[A.R.]

Hi All, 

 

Having always been intrigued by the BR Class 28 with its Co-Bo wheel arrangement, I decided to try and make my own. The idea was to design the body shell, 2-axle bogie and bogie sides in CAD for 3D printing in resin and then use a modified Lima chassis with a motor upgrade. My plan is to build two locos at the same time, as they seemed to run in pairs relatively frequently!

 

The Lima Class 52 Western was the best starting place with the most accurate dimensions between the wheel centres on the 3-wheel bogie.  I decided to start with one loco and make sure the idea worked, before investing in the second, so I bought a second hand loco on an auction site and set to work on the chassis frame. This was shortened in places to bring the overall dimensions in line with those of the Class 28 and a new mounting hole drilled for the 2 axle bogie. This was then filled and sanded, followed by a coat of paint (note, this isn't the final colour of the chassis, it will get a final coat of black but the lighter colour made it easier to see any blemishes at the filling stage). 

 

Following this, I turned the old Lima wheels down to a more accetable width, painted them and then lined the wheels as per the prototype. I also replaced the old Lima motor and checked all was working!

 

 

The next stage was to set about designing the actual loco. Here you can see the final designs of the body shell and bogie sides. I also redesigned the 2-wheel bogie in order to get the correct wheel spacing, whilst still allowing use of the Class 52 wheels and mounting method. I will upload some higher resolution CAD pictures tomorrow, but this gives you an idea of the design. 

 

 

I will keep you all updated as the project progresses and I look forward to hearing your initial thoughts! 

 

Cheers, 

 

Alex

[Halvarras]

Your Class 28 project involving a Lima Western motor bogie reminds me that many years ago (32 I think!) I was handed a Hornby Dublo Class 28 in bits - the chassis could barely move itself (it got passed on) so its previous owner had cut the mounting lugs off the back of the bogie sideframes, making original reassembly difficult anyway, and glued the Co items to a Lima Western motor bogie frame with the detail filed down, but it had got no further. After it had sat in a box for about 15 years I decided to get it running, but spares box availability led to it being powered at the Bo end by a Hornby Class 29 motor bogie, with a Hornby Class 37/47 bogie at the trailing Co end - not only was the Western axle spacing in the Hornby casting correct but the smaller Hornby wheels represented the Class 28's 3' 3 1/2" diameter wheels fairly closely too (although had I also used Lima running gear, as you propose, the larger wheels wouldn't have bothered me). The HD sideframes were glued to the filed-down Hornby bogie frames.

The assembled bogies were then mounted in what must have been the UK's most butchered Hornby Class 37 underframe - the motor end obviously had to be shortened and the result adjusted to fit into the HD body, bogie bearing surfaces at both ends packed to get the ride height correct and the fuel tank area hacked about into a Class 28 likeness. Attaching the chassis to the body involved the original bolt and a piece of wood flooring from a 1970s Mopok BR CCT kit!

The body was stripped with Nitromors, excess rainstrips filed off and etched headcode discs fitted. I finished it as D5711 in green syp livery, but having no need for a Co-Bo I sold it at an exhibition around 2007 - I wonder where it is now.....?I

 

I'm interested to see how your project turns out - the design renderings remind me of why the Class gained the nickname 'wonderloaf'! They may have looked odd but the build quality was reputedly very good. Just a shame about the choice of power unit......

[uax6]

Have you got a copy of the Metro-Vick book by Anthony P Sayer? It would be a good buy if not. There are plenty of photos in it of the locos, and show that things like the cab side windows aren't the same height, and that the gutters weren't straight from new either!

Your cab front windows don't look quite right, the flat panes were fitted in rubber mounts inside the original apertures, which you could still see evidence of.

 

Andy G 

[A.R.]

Hi All,

 

Thanks for the interest and comments! Really interesting to hear about the ride quality (thanks @313201), and @Halvarras ‘s story of a slightly different build of the same prototype. With regards to the windows, thanks for pointing it out and for the book recommendation @uax6but, unfortunately, I had already ordered the prints by that point so I couldn't make the changes!

 

Progress on the Class 28s has been good, and I now have most of the required 3D prints.

 

Firstly, I have the body shells and these came in two parts, the centre with one end and then a separate end due to printer space limitations. Therefore, the first thing was to join these two together with superglue and then fill the gaps and sand back. I did this with both body shells and then once sanded smooth, gave them both a thin layer of primer to identify any issues. This was just done with my new airbrush. I am pleased with how little any of the print lines shows and most of the surfaces are very smooth.

 

The next 3D prints were the bogie sides. I designed these and then got them printed, measuring to make sure they would fit the donor bogie centres. These came out very well and, again, the printing lines are almost invisible with nice, crisp detail. Note: these parts have yet to be painted, hence the difference in colour to the body shells.

 

Here I have roughly put the parts together to get an idea of what the model will look like and I am pleased with the overall proportions.

 

Finally, I have actually designed some windows and had these laser cut out fo clear acrylic so that they fit perfectly into the window apertures. I will cover these at a later date in a different post! Next up is to start to put the bogies together and get some primer on the bogies!

 

I look forward to hearing your thoughts!

 

Cheers,

Alex

[Richard_A]

At first thought I wondered why you would do this when there is the Heljan model, but now I can see what you have produced I think, why would you buy the Heljan model?

 

If you don't mind telling people, how much did it cost to print? 

[MarkC]

This looks superb - beats my Q Kits version from the early 90s into the proverbial cocked hat! (Mind you, Q Kits weren't exactly a good thing anyway...)

 

Mark

[Halvarras]

1 hour ago, MarkC said:

This looks superb - beats my Q Kits version from the early 90s into the proverbial cocked hat! (Mind you, Q Kits weren't exactly a good thing anyway...)

 

Mark

 

I remember when 'Rail' magazine was called 'Rail Enthusiast' and included a few modelling pages somebody had built a Q Kits D600 Warship - it looked rather good, but the builder reckoned he'd spent around 200 hours on it! The bodyshell not being straight to begin with was a major issue I recall........sorry, a bit OT in a thread about Class 28s 

[MarkC]

24 minutes ago, Halvarras said:

 

I remember when 'Rail' magazine was called 'Rail Enthusiast' and included a few modelling pages somebody had built a Q Kits D600 Warship - it looked rather good, but the builder reckoned he'd spent around 200 hours on it! The bodyshell not being straight to begin with was a major issue I recall........sorry, a bit OT in a thread about Class 28s 

Sounds about right, tbh - as I recall only too well, the etched sides on my 28 were OK, but the castings... they had more holes in 'em than a pair of lace knickers, as the saying goes...

 

...and as for the motors supplied - out of cussedness I built the beast with parts as provided. It ran - for a few seconds then died... One day I'll build & fit a proper motor bogie. One day...

 

Mark

[A.R.]

Hi All, 

 

Thanks for the interest and comments! 

 

@rka I did look at getting a Heljan Class 28 but I could only find second hand, expensive ones! So, this, plus the fact I enjoy the (many) challenges of designing and making my own models, led me down the road of deciding to design my own. I think both bodyshells, all the bogie sides and the two 2-axle bogies cost me about £30 to get printed, in resin. I will then be adding brass/metal details to this to improve the detailing which will add a fair amount to the cost!

 

@Halvarras No worries about the slightly off-topic discussion, always interested to hear anecdotes! I have to say, 3D prints certainly don't always come out straight or level so I know how that builder must have felt trying to work out how to making everything align!

 

I have made a little more progress and now have the bogies sorted for one loco, so took the opportunity to put it on my photo diorama. You can see here that the bogies are still not painted, and this contrasts with the smooth grey finish of the loco body. I am also yet to fit pickups and wire them up to the motor, another job for the to-do list. I also put a black and white filter on one to get a feel for how it will look once finished.

 

 

I would like to get the second loco to this same stage and then get them both up and running prior to doing more of the details, painting and fitting windows etc. I also need to design the underframe detail and sort the fixings of the bodyshells to the chassis frame. 

 

Cheers, 

 

Alex

[A.R.]

Hi All,

 

Just a quick update, mainly on the chassis. This has now been finished for the first loco, given a coat of black paint and the fixings to the body sorted. You can see the two brass screws that hold the body shell in place on the third photo, leaving plenty of space for adding weight! All that remains to be done on chassis number one is for the pickups to be fitted, wiring these to the motor and then adding the aforementioned weight. I am pleased with how this has come out given some fairly extensive modification from the original (cutting a large section out of the middle, reducing the width and adjusting the motor bogie mounts!).

 

 

Work is now beginning on the second loco, and you can see the main parts spread out on my workbench. Still a lot of work to do on these parts but I will keep you all updated!

 

Cheers, 

 

Alex

[A.R.]

Hi All, 

 

I have managed to get the second loco up to the same stage as the first now, with the exception of a new motor (the old one has been removed, but I have yet to order the replacement). I have also managed to spray the underframes/bogies black, as well as fitting the NEM coupling pockets. This has really highlighted the details on the bogies such as the springs, and I am pleased with how the locos are slowly coming together. I have also started to add handrails to one of the locos.

 

The next major step is to fit all the pick ups, as well as to continue the detailing. I am about to order some brass parts, including sprung buffers from Markits, as well as some vaccum pipes and other small details that will help bring the locos to life. 

 

I have also been working on the underframe details, which like most of the project, will be 3D printed. This is a snapshot from CAD showing current progress - I still need to add a lot of the detail and make sure it will all fit.

 

I look forward to hearing your thoughts!

 

Cheers, 

 

Alex

[jessy1692]

Excellent work Alex these look fantastic. Iv been kicking myself for years for not buying a Heljan one back in the day to upgrade from my Silver Fox 28.

 

You may have already spotted this but the moulded/printed steps on the side frames don't line up with the inset doors, just shows how odd these locks were/are with nothing being symmetrical!

 

Also, for a quick and easy motor upgrade, a railroad 59/66 motor bogie would work a treat, just need to build a cradle to use the top pivot on them, 20 minute job with some plasticard.

 

Looking forward to seeing them develop.

All the best

James

[Halvarras]

1 hour ago, jessy1692 said:

 

 

1 hour ago, jessy1692 said:

Also, for a quick and easy motor upgrade, a railroad 59/66 motor bogie would work a treat

 

 

Surely the wheelbase would be too long for the Class 28's Co end, which is why Alex is using the Lima Western motor bogie. A pity, as a certain Cardiff-based retailer sells the Railroad Class 59/66 m/b's at astonishingly low prices......if only  there was a Hornby ex-Lima Western to go with the Warship......

Edited March 7, 2022 by Halvarras

[jessy1692]

5 hours ago, Halvarras said:

 

 

Surely the wheelbase would be too long for the Class 28's Co end, which is why Alex is using the Lima Western motor bogie. A pity, as a certain Cardiff-based retailer sells the Railroad Class 59/66 m/b's at astonishingly low prices......if only  there was a Hornby ex-Lima Western to go with the Warship......

I'm pretty sure the Lima Western used the same Co bogie as the 47, 59,31, 60 etc. Iv remotored my 28 that was on a lima Western bogie I think in such a way. Iv pretty much gone through all my ex Lima stuff with railroad power bogie upgrades. Brilliantly cheap from that certain Cardiff based emporium. 

 

Cheers

James

[jessy1692]

6 minutes ago, jessy1692 said:

I'm pretty sure the Lima Western used the same Co bogie as the 47, 59,31, 60 etc. Iv remotored my 28 that was on a lima Western bogie I think in such a way. Iv pretty much gone through all my ex Lima stuff with railroad power bogie upgrades. Brilliantly cheap from that certain Cardiff based emporium. 

 

Cheers

James

Scratch that, I was thinking of the Hornby ring field blocks... Halvarras is quite correct the Lima 52 wheel base will be shorter so probably a no go for the Co end using a Railroad 59/66. I'll have to check mine now and see what we did...

Cheers

James

[A.R.]

Hi All, 

 

Thanks @jessy1692 and @Halvarras for the discussion! Interesting to hear about those very low priced motor bogies - I will definitely remember those for future projects. For these locos, I am actually using the Western bogie and wheels (that have been ground down in a drill to a more suitable flange depth) and then a replacement motor kit which, I believe, are based around old CD drive motors. I have used one before on a Class 70 I made (using the same method as these Class 28s) and it has worked really well. 

 

I will hopefully have some more updates soon and I need to start thinking about what livery to paint these in (probably BR green). 

 

Cheers, 

 

Alex 

[jessy1692]

3 hours ago, A.R. said:

Hi All, 

 

Thanks @jessy1692 and @Halvarras for the discussion! Interesting to hear about those very low priced motor bogies - I will definitely remember those for future projects. For these locos, I am actually using the Western bogie and wheels (that have been ground down in a drill to a more suitable flange depth) and then a replacement motor kit which, I believe, are based around old CD drive motors. I have used one before on a Class 70 I made (using the same method as these Class 28s) and it has worked really well. 

 

I will hopefully have some more updates soon and I need to start thinking about what livery to paint these in (probably BR green). 

 

Cheers, 

 

Alex 

No probs Alex, I'll check over my Co Bo next time I'm at the layout to see if it jogs my memory of what we did to it!

 

Them CD re motor jobs are pretty good, I did a 47 with one and it does improve things but a new Railroad bogie makes all the difference, silent running. Check out Lendons of Cardiff, lots of good stuff for projects.

All the best

James

[A.R.]

Hi All, 

 

@jessy1692 Apologies, I forgot to acknowledge your good spot of the steps being misaligned - something I had completely missed! It's a bit late to change them now, so they can remain as a point of interest, but thank you for pointing it out! I would be interested to see your Class 28, so feel free to upload pictures of it here if you'd like.

 

I mentioned a few posts ago about laser cut windows for these locos. As I have now started to detail the cab ends, I test fitted some of the windows and, to my delight (after a tiny bit of sanding), they slotted straight in. These have been laser cut to drawings I made from the original CAD out of 1mm clear acrylic. There are tiny lugs in the window frames as part of the design that allows the windows to sit at the correct depth (see CAD picture below).

 

I will admit, they are not 100% perfect but I think for homemade glazing, they go a good way to achieving a similar result to modern RTR flush glazing! It also highlights one of the key benefits of using CAD and how this can be used to create other parts. 

 

I look forward to hearing your thoughts on this, and whether anyone knows if this has been used before as a way of doing glazing. 

 

Cheers, 

Alex

[Richard_A]

Can I ask what software do you use? 

[A.R.]

Hi @rka

 

I use FreeCAD for all my CAD drawings. Its the best free software I can find and has served me well for a while. I then use a separate online rendering tool. 

 

Hope that helps!

 

Cheers, 

 

Alex

[Richard_A]

5 minutes ago, A.R. said:

Hi @rka

 

I use FreeCAD for all my CAD drawings. Its the best free software I can find and has served me well for a while. I then use a separate online rendering tool. 

 

Hope that helps!

 

Cheers, 

 

Alex

Thanks, 

 

I've been pondering buying autocad as I sometimes use it at work, but it is expensive for what I would use it for, I might try these out if I get the chance. 

[A.R.]

Hi All, 

 

Just a quick update! I have now finished the underframe details (I restarted them as I wasn't pleased with the first iteration!). These have been sent to get printed now and should arrive soon. I have also added these to the overall CAD drawing and I created a render so you can see how the finished locos will look!

 

I am hoping the buffers arrive soon as I always these make locos look a lot more "finished"!

 

I look forward to your comments!

 

Cheers, 

Alex

[A.R.]

Hi All, 

 

Apologies for not posting in a while! I did eventually finish these locos and am really pleased with how they came out! They are both cosmetically completed, but only one is currently fitted with a motor - they look good as a powered and dummy pair though! 

 

 

I ended up getting the windows laser cut and it has worked really well! 

 

I won't post anything else on this thread, and will update my main workbench thread with some other projects that I have completed recently to keep it all in one place but thought it would be nice to round this thread of with some complete pictures!

 

Cheers, 

Alex