Dean 8'6" Bogie Drawings

[MrWolf]

Does anyone out there have drawings for the Dean 8'6" coach bogie? 

 

 

 

 

Edited December 7, 2022 by MrWolf
Stupid autocorrect

[drduncan]

There are GAs in the Russel book GWR coaches vol 1, but I don’t have a scan.

Duncan

[Harlequin]

8 hours ago, drduncan said:

There are GAs in the Russel book GWR coaches vol 1, but I don’t have a scan.

Duncan

Ah yes. Thanks!

 

That should be enough to create a CAD model, along with the drawing of the 10ft bogie on the next page to fill in the gaps if needed.

 

[drduncan]

1 hour ago, Harlequin said:

Ah yes. Thanks!

 

That should be enough to create a CAD model, along with the drawing of the 10ft bogie on the next page to fill in the gaps if needed.

 

The 8'6 bogie and 10 ft are on my CAD to do list (which is getting longer not shorter).  If you can be patient...

 

NB.  I have a standard gauge 6'4 dean bogie completed (sans foot boards) with oil OK axle boxes if that is any help (the BG version I've done with grease axle boxes as photos suggest no oil boxes at that point).  I print it with a 25/75 mix of Tenacious flexible and standard resin, so it remains flexible enough to spring the axle guards apart and put the wheels in.

 

Duncan

[Harlequin]

22 minutes ago, drduncan said:

The 8'6 bogie and 10 ft are on my CAD to do list (which is getting longer not shorter).  If you can be patient...

 

NB.  I have a standard gauge 6'4 dean bogie completed (sans foot boards) with oil OK axle boxes if that is any help (the BG version I've done with grease axle boxes as photos suggest no oil boxes at that point).  I print it with a 25/75 mix of Tenacious flexible and standard resin, so it remains flexible enough to spring the axle guards apart and put the wheels in.

 

Duncan

 

I'm very keen to have a go at these myself. (MrWolf asked because of discussions we had elsewhere.)

 

I will update this thread as I progress but I might need to ask you some questions, if that's OK? Hopefully, the end result will be good enough that you'll be able to knock one item off your TODO list.

 

(Interesting note about using flexible resin, thanks.)

 

[drduncan]

Ask away…

D

[MrWolf]

That was something that I considered a possible problem with a one piece, rather than three piece bogie as the whitemetal ones were, in that the generally brittle nature of 3d printing wouldn't stand being flexed to fit axles, let alone being drilled for bearings. I presume that a 2mm bearing socket is accommodated in the print? 

Hornby et al always used a particularly evil form of plastic for bogies which is virtually indestructible, but throws up other problems for those of us who like to hack things about, or need to because the desired items are unavailable / unaffordable. Being made aware of the ability to print in a semi flexible resin has upped my interest in this project.

[drduncan]

Yes, the axle box is designed to accept a waisted bearing cup. 
 

Tenacious flexible is very expensive compared to standard resin- c£65 per litre so you do t use it unless you have too! And test prints are done in standard resin only…

D

[stevel]

3 hours ago, drduncan said:

The 8'6 bogie and 10 ft are on my CAD to do list (which is getting longer not shorter).  If you can be patient...

 

NB.  I have a standard gauge 6'4 dean bogie completed (sans foot boards) with oil OK axle boxes if that is any help (the BG version I've done with grease axle boxes as photos suggest no oil boxes at that point).  I print it with a 25/75 mix of Tenacious flexible and standard resin, so it remains flexible enough to spring the axle guards apart and put the wheels in.

 

Duncan

I'm part way into doing these two bogie sizes. Trying to design them with CSB's, to give them a smooth ride, currently testing prototypes on a 9ft wagon to make sure it works.  here is the current state of drawing.

[drduncan]

12 minutes ago, stevel said:

I'm part way into doing these two bogie sizes. Trying to design them with CSB's, to give them a smooth ride, currently testing prototypes on a 9ft wagon to make sure it works.  here is the current state of drawing.

Very nice work. Will you be doing it as a complete bogie or just side frame? And without footboards?

 

Duncan

[stevel]

3 hours ago, drduncan said:

Very nice work. Will you be doing it as a complete bogie or just side frame? And without footboards?

 

Duncan

Originally it was just side with footboards, to be glue to brass bogies, but since working on the CSB wagon chassis which is progressing well, I'm thinking of complete bogies. For the Edwardian period I will print them with the footboards.

[drduncan]

Could I suggest that for the Edwardian period you print them without the footboards? In the Edwardian period the lower footboard was continuous from one end of the coach to the other, not separate footboards for the bogies. Later, during the 1920s, when the lower footboards started to be removed then the bogies had separate (and the only remaining part of the ) lower footboards. There are drawing of the chassis arrangement in Russell vol 1 showing the lower continuous footboard and how it was mounted on the chassis.

 

Duncan

[stevel]

It would be easy enough to print without the footboards, but I am basing these on a photo from the Falmouth branch, which shows them as a separate units.

[Miss Prism]

I estimate the transition period on bogie stock from continuous one-piece lower footboards to 'continuous but split' * lower footboards to be 1897-1900.

 

*  where the middle section of the board continued to be hung from stanchions attached to the solebar, but the bogie sections of the board now hung on the bogie frame itself

 

[Harlequin]

This may not be what you were expecting but here's where I've got so far:

 

A bit of explanation:

• I'm making the model exactly as per the drawings in Russell Coaches Appendix 1 so that I can understand the construction and so that I don't make mistakes confusing model dimensions with real dimensions.
• At a later stage I'll do what's needed to make it workable as a 4mm model but I'll try to keep as much of the detail as possible, with modern RTR detailing standards in mind.
• I've concentrated on the frame and the parts fixed to it so far - the moving parts will come later.
• There are a few stray lines, especially around rivet heads. They are just to help during construction and they will be removed.
• Some castings are so close they intersect in the model. To be resolved.
• Still lots of rivets and a few bolts to add.
• The colours just help me to identify the separate parts - they don't have any particular meaning.

Interpreting the drawings and turning them into a model is a fascinating process. The smallest smudged line tells a story and I'm really getting a feel for the engineering of this beastie.

 

Edited December 17, 2022 by Harlequin

[MrWolf]

Nicely done and a very clear rendition. I could confidently say that given suitable dimensions I could fabricate a full size bogie frame from that, all of the key details are visible.

[Harlequin]

Update: Struggling with the complex shapes of the axlebox castings:

 

I think I'm going to have to start that one again!

 

[Miss Prism]

Were the stops (in green) angled like that?

[Harlequin]

19 minutes ago, Miss Prism said:

Were the stops (in green) angled like that?

Yes, the drawings and the accompanying photos in RCA1 all show them to be angled.

 

[Harlequin]

Further progress:

 

 

I had great fun drawing the Mansell wheels! (Still some work to do on them.) They won't be part of the print obviously but they really help to visualise the thing.

 

Still some big elements to add (axles, suspension girders and associated gubbins) and a lot of little details - just for completeness.

 

I'm hoping that I will find a cheap/free renderer that can produce more realistic images.

 

Edited December 26, 2022 by Harlequin

[Harlequin]

@Miss Prism It has been suggested to me that the brake blocks I've shown above might be a BR era introduction. (I based them on photos because the drawings are not so clear in this area.)

 

In the Dean era would the brake blocks have been simple solid chunks of material? Hardwood?

 

Do you know what form the brake blocks might have taken in the mid 1930's? 

 

[57xx]

On 17/12/2022 at 12:36, Harlequin said:

Update: Struggling with the complex shapes of the axlebox castings:

 

 

You're doing a lot better than some "professional" companies. 😉

[Harlequin]

Another update. I have created the cross girders and scroll irons, added connections to make the brake rodding work and added various nuts and bolts:

 

The springs are wrong, I know! I've only just realised what a volute spring is (it's shown more clearly on the drawing for the 10ft bogie. They are going to be a real challenge to model!

 

Notice that the lower end of the spring assembly is fully visible, as shown in the original drawings but every photograph I've found shows them enclosed by a kind of "bucket" arrangement. The "bucket" is shown with dashed lines on the 10ft bogie drawing sop I guess that they were introduced soon after the 8ft6 bogies were in service. If I model the bucket then the volute spring won't be visible so perhaps I don't need to model it after all - but I like a challenge and I like correctness...

 

I made two types of scroll iron:

The one in the foreground is the original as shown in the drawings and the one behind is the version seen far more commonly in photographs (and in fact in photos the scroll irons never look quite like any of the drawings!). I think this different style is partly to do with coaches getting wider.

 

I still need to add some fillets where the irons join the fixing plates - another set of very complex compound curves.

 

Edit: Oh, and I have also done the axles:

 

Edited December 29, 2022 by Harlequin

[Miss Prism]

There's a good drawing of the Dean 8'6" in one (P_011.pdf) of the Swindon Lectures series (or click on the link of the resources page of gwr.org.uk). I'm kicking myself for not remembering it earlier in this thread.

 

I can't remember reading anything regarding the material for brake shoes, so I suspect they changed to cast iron from a very early date (1860?).  

@MikeOxon will know a lot more than I do.

 

The thing that held each brake shoe probably did change from cast to fabricated at some stage, but I've no idea when.

 

 

 

 

[Harlequin]

1 hour ago, Miss Prism said:

There's a good drawing of the Dean 8'6" in one (P_011.pdf) of the Swindon Lectures series (or click on the link of the resources page of gwr.org.uk). I'm kicking myself for not remembering it earlier in this thread.

 

I can't remember reading anything regarding the material for brake shoes, so I suspect they changed to cast iron from a very early date (1860?).  

@MikeOxon will know a lot more than I do.

 

The thing that held each brake shoe probably did change from cast to fabricated at some stage, but I've no idea when.

 

 

 

 

Thanks Russ,

 

The drawing of the 8ft6 bogie from the lecture pamphlet is the very one that is reproduced in Russell's Coaches  Vol1 and Coaches Appendix Vol1, along with a significant chunk of the lecture text. I started using the drawing in Russell and then JimC mentioned that a PDF version of the lecture is stored on the GWR e-list and I have been using that since.

 

I'd like to see the versions on the OneDrive link you posted but sadly none of the PDFs work for me. They won't download or view online.