|
Post by neathabbeyironworks on Jan 8, 2023 0:31:02 GMT
Thanks for all the replies in regards to my query on fabricating spoked loco wheels. Going off at a tangent, I am considering building an Industrial Garratt loco, specifically one of the 4 locos in class of which the William Francis at Bressingham is the only survivor. The prototype was delivered to the Hafod Copper Works in the lower Swansea Valley, it proved to be a very successful locomotive. The Beyer engineering drawings were converted to microfilm in the 1940s and 1950s. These are in the care of the Museum of Science and Industry in Manchester, and like so many of our museums they probably have not had the funds resources to archive and index the material fully. A 5 inch model was sold on two occasions by Station Road Steam and photos are present on their website. I am no expert but the level of fit and finish is really outstanding. The question I have is what are the minimum drawings needed to produce such a model to a reasonable degree of accuracy ie I would like to be able to say that this model is an accurate representation of the Vivian loco. Admittedly there are degrees of accuracy. Note that the K class narrow gauge locos in Australia have their cylinders the wrong way round and the Tasmanian example was compound. There is an article on Vivian on The Locomotive magazine which includes a drawing of the Walshaerts valve gear which I have veryv kindly been given.
|
|
|
Post by steamer5 on Jan 8, 2023 7:37:45 GMT
Hi Neathabbyiron works, My current project is a K1. Many years ago I found out that the microfiche for the drawings was available & purchased a set. (70 drawings) Then become the issue of printing them, I found our local port authority had a AO printer & were happy to print them IF i could find the paper.....even ringing the paper supplier didnt work! Eventually found the local council could do it but only to A2. The drawings are now available on the web. My advise would be if you find the drawings get them either hard copied, or electronic but NOT on microfiche! I was very lucky & found by shear chance a guy who was also making a K1 & who had made patterns & had castings done, he was happy to get a set cast for me. Sorry I'm no longer in contact with him...computa crashes & having to change email addresses i lost his contact info!!! Pre clound days!! as cast the LP cylinders are approx 11kg's, the HP approx 7kgs K1& K2 were the only compound Garratt's & the only one's to have cylinders on the inside ends of the engine frames to reduce the distance between cylinders. I would try The museum you mention you may be surprised at how helpful they are. Way back....late 80's..... I got info on K1 by a gent in the UK that had got his drawings from the same museum you mention.
Good luck & keep us posted!!
Cheers Kerrin
|
|
|
Post by dhamblin on Jan 8, 2023 7:51:54 GMT
Definitely get the general arrangement drawing as a bare minimum - this gives you the major dimensions to scale to and you can also use it to scale parts where detail drawings are not available e.g. platework.
If there is a drawing list get that first as it will aid your search and allow targeted selection of drawings for printing.
Best of luck, saw William Francis at Bressingham and thought it would make a good model engineering subject.
Regards,
Dan
|
|
weary
Part of the e-furniture
Posts: 290
|
Post by weary on Jan 8, 2023 9:10:40 GMT
The 2 1/2" gauge society have drawings to 2 1/2 gauge. Maybe worth contacting them to see what the drawings are like & if they may of assistance?? (Apologies if you are already aware) Phil
|
|
|
Post by neathabbeyironworks on Jan 8, 2023 11:49:26 GMT
The staff at the museum in Manchester are certainly very helpful. The 2.5 inch scale drawings are not suitable when I enquired. I visit to Manchester is going to be required I think along with a visit to Bressingham with a long selfy stick!! Manchester have a general arrangement, a drawing of layout of motion, connecting and coupling rods pipe layout, smokebox and engine frame(whatever that is). I suspect these date back to activities of the gent who built the 5 inch gauge loco. Would it be best to work off the drawings using a scaling factor or should I use software to make scale drawings?
|
|
mbrown
Elder Statesman
Posts: 1,721
|
Post by mbrown on Jan 8, 2023 12:47:29 GMT
It really depends how much you feel you need dimensioned drawings to work to. I made my Burma Mines loco from the GA and a pipe diagram from the North British archive at Glasgow. But not everything can be scaled perfectly, so the boiler and valve gear, in particular, had to be worked out from first principles (although the valve gear turned out very close to the original, as it happened). But if, like me, you use stock metal sections, threads etc., or prefer not to work to several places of decimals, your materials will probably only be "near enough", and that means a certain amount of interpretation rather than just reading dimensions off the GA and scaling them down. I would guess (but may be wrong) that you'd need to think about the design of the pivots and flexible steam and exhaust pipes on a Garrett to make them viable in a model, rather than just copying the original.
When modelling an extant prototype, there is, in my view, no substitute for loads of photos from every angle and covering as many bits as you can see. I am building my current loco (see my thread on 99 3462) mainly from photos and measurements taken on a visit - all drawings having been destroyed when the Russians ransacked the O&K factory Berlin in 1945. If I went again, I would take 10 times as many photos - I just didn't realise how ambiguous a photo can be without other angles to back it up. If you look at one of the earlier pages on my thread, you'll see my method of sketching parts when on the visit, adding as many dimensions as I could, then doing another sketch back home with the dimensions augmented by other photographic evidence such as rivet positions. I then do simple sketches of each part I want to make with the key dimensions. I don't do properly accurate drawings except for the frame plan (to be certain of centre lines) the boiler (for the inspector) and the valve gear.
Not everyone likes to work that way, but I am not a "proper" engineer and have not been brought up to do the drafting or to work to drawings. I make the odd blooper, but not too often. As the threads on this forum show, others have their own approaches - making full drawings, or designing things from scratch on CAD. I guess it is whatever you are happiest with. But in my view, full drawings beyond a good GA aren't necessary unless you are aspiring to be another Dr Bradbury Winter!
Good luck and do keep the forum posted on your progress.
Malcolm
|
|
|
Post by chris vine on Jan 8, 2023 14:11:38 GMT
One useful tip: If you do go to take (many) photographs of an extant loco, take some sort of measuring stick with very visible markings on it which you can place in all the photographs. it isn't possible to measure everything and make sketches during a visit, but a measure in the pictures makes scaling quite easy.
best to take pictures at right angles to the parts!!
Chris.
|
|
|
Post by neathabbeyironworks on Mar 3, 2023 0:01:49 GMT
Since my last post I have obtained a GA drawing and three other drawings for the Vivian Garratt from the Museum of Science and Industry in Manchester. Their archive of drawings is online but only goes so far. It is generally not possible to get a listing of individual drawing, for this a visit to the museum is required. The drawings were converted to microfiche by Beyer before being deposited with the museum. Getting copies requires that they be photographed, at a cost of 30 GBP per photo. The staff are unfailingly helpful, but they are clearly understaffed so turnaround times are a bit on the slow side. There are annotations on the GA that give drawing numbers of such things as the pivots, cylinders, hornblocks valve gear linkages, cross heads etc. I have counted about 35 of these drawing numbers which would provide me with a good start if I needed more drawings and did not visit the museum in person. I can see that the most drawing numbers are part of a sequence but some are clearly not. I suspect these drawings are for items in common with other locos eg grab rail stanchions.
Whilst waiting for the drawings I have been teaching myself FreeCAD with the aid of their documentation and Youtube videos- Mangojelly Solutions videos are pretty good but you really need to concentrate all the time. I have managed to construct a 3D decent model of a driving wheel using the Part Design workbench and which can be used for 3D printing. One of the club members has done just this for a bit of fun. Whilst I intend printing off hard copies of the drawings, I am considering using the engineering drawing workbench to make scaled drawings so avoiding scaling calculations in thr workshop with the attendant risk of errors. I am also hypothesising that it may bring to light problems in advance so saving on time and thrown away materials.
Kerrin above mentioned that drawings for for the K1/2 are on the web. Does anyone have a link?
I am still trying to work out the best options for items that are normally cast such wheels, cylinders and hornblocks. There is also the problem of the cut off linkage to accommodate rotation at the pivots. Flexible steam hoses could be used to obviate the need for steam tight spherical joints. Having said that, common shower heads have spherical joints which are readily available at low cost.
|
|
|
Post by steamer5 on Mar 3, 2023 0:23:34 GMT
Hi Neatabbeyironworks, Here you go….. libraries.tas.gov.au/tasmanian-archives/Hit search type in compound garratt & you get a list of the drawings. My old link didn’t work, they have updated their website so it’s quite different…… will have to have a play Cheers Kerrin
|
|
|
Post by neathabbeyironworks on Mar 18, 2023 5:18:02 GMT
Hi Steamer 5, having given the museum in Manchester drawing numbers for the hornblocks, driving wheel and cylinder, when they opened the relevant box, the drawings were missing. Such a disappointment. None of the drawings I have examined so far give me sufficient detail to understand the linkages controlling cut offs across the main pivots. Having built the K1 can you enlighten me as to how I proceed?
|
|
|
Post by steamer5 on Mar 18, 2023 9:11:50 GMT
Hi Neathabbyironworks, Have you had a look at the link I posted? All the drawings I have are there. As to built a K1, I would loved to say yes…. But it’s been a long project, with huge gaps of inactivity! I’ve only really put in a bunch of effort in the last couple of years even then I don’t yet have a rolling chassis. Ok for valve control. From the reversing lever in the cab rods go forward & aft to the ends of the boiler frame, at the point we’re the pivot frame center point is, well close to it, cross rods the come from approx the middle out with lever arms for them to connect to. Another lever arm is at the inner end in above the pivot. The connecting link from there has pivots both ends, this then joins to another cross rod with levers on it to take the motion out to the cross heads etc. Hope that makes sense.
Cheers Kerrin
|
|
|
Post by neathabbeyironworks on Mar 19, 2023 6:13:25 GMT
I have all the drawings for K1 safely downloaded, drawing numbers 28-31 are most relevant but do not tell me how they all fit together. The linkages on the power bogie are relatively straightforward. These start at a pivot that goes at right angles through the main pivot on which the boiler frame pivots on the bogie. I can find no drawing that shows how the various linkages between the reversing lever and main pivot are arranged. One of the linkages is square section and moves in and out of square section sleeve in much the same way as the splines of a prop shaft on a motor vehicle. I still do not understand how the arrangement prevents changes to the cut-off when the bogies rotate with respect to the boiler frame. The larger Garratts employed a steam operated mechanism obviating the need for mechanical linkages across the main pivot.
|
|
|
Post by steamer5 on Mar 19, 2023 7:20:24 GMT
Hi Neathabbyironworks, Yep nothing unsual in not being able to figure out how all this fits together! To figure out the dimensions for the motion frame...not a major part yeah right!.... there is no dimensioned drawing! I had to work across several drawings that you would consider unrelated to work it all out, time will tell if i got it right! I dont think your square section telescoping sleeve is correct. Drawing 35 gives an idea on how it works. There are .... for wont of a better description.... the links thru the pivot area have pins at 90 degress to the arms & links, allowing multi direction movement.... maybe i need to spend more time looking at the drawings to make sure this is correct. Anyway, have a look at this youtube clip.... youtu.be/aH05NLboJyc I have been behind this loco & it runs very well! I do have more info i can check & am happy to pass along. If you PM me your email address i'll have a look. Oh there is a guy on Flicker who put up a bunch of pictures of his 7 1/4 version, off the top of my head i dont think it shows these links. Cheers Kerrin
|
|
|
Post by steamer5 on Mar 23, 2023 4:05:14 GMT
Hi Neathabbyironworks, I’ve had a look thru another couple of sources I have & have found a drawing that will answer you questions , I hope. Sorry can’t post them here, copyright issue I would think, please PM me & we will work something out. I have a few photos of K1 in bits but unfortunately doesn’t show what you are asking….. part on the engine frame & I guess the other parts on the boiler frame or removed to part them!
Cheers Kerrin
|
|
|
Post by 92220 on Mar 23, 2023 11:12:42 GMT
For those who worry about contravening copyright, generally sharing info on the forum is not contravening the rules, as long as certain conditions are met:-
Generally, sharing SECTIONS of drawings on the forum, is not breaking copyright laws. This is the section that covers us:-
Permitted use of copyright works: You may not need permission if you’re using a copyright work for the following reasons:
non-commercial research and private study criticism, review and reporting current events teaching in educational establishments helping disabled people recording for use at a later date
Note the first clause, referring to non-commercial use and private study.That is what impacts the sharing of drawings on the forum. The models being built by forum members, are, in general, are almost all for private use and therefore, non-commercial. Model engineers are often non conversant with engineering drawings so come under the 'private study' heading when sharing information, as generally information is shared while doing research to clarify details, to enable something to be made for 'non commercial use'. The important point to ensure that one doesn't contravene the copyright rules, is to only copy sections of a drawing and ensure there is nothing in the copied section, that identifies the drawing. The other point is that it must all be for non commercial purposes. Another point to bring up is that many model loco construction drawings, are produced by people who have little or no engineering draughting experience or training, so don't produce drawings to general engineering standards. This often means that some details are just not clear enough for someone to actually make a part. Any shared information that includes scans or copies off a published drawing, that are used to clarify the drawing to enable the part to be made, for private purposes, will also NOT be in contravention of the rules as it is just clarifying what the copyright owner intended, and is also enabling someone to make the part that the original copyright owner intended to be made from the drawing.
This was something I checked out when I wrote my book on painting models. For example, if someone asks a friend the best way to mix paint to paint his model, the friend is not breaking my copyright if he copies/scans the particular section to help the enquirer. It is non-commercial and is 'educational', and so comes under the "Private study" heading.
Bob.
|
|
|
Post by steamer5 on Mar 23, 2023 21:36:28 GMT
Hi Bob, Thanks for clearing that up! I just didn’t won’t to step on somebody’s toes & have them go off the deep end. So far haven’t heard from Neathabbyironworks, so I’ll wait until I do
Cheers Kerrin
|
|
|
Post by neathabbeyironworks on Mar 23, 2023 23:37:52 GMT
Kerrin, thanks for taking the time to answer my queries around problem that has proven difficult to resolve. I have been looking at the drawings for K1, the drawings of valve gear for Vivian/William Francis, and photos on the Puffing Billy website for the B exam on G42. Drawings for G42 are available from Puffing Billy on a USB for around 150AUD. The bogies are allowed to rotate around the pivot, 9 degrees each side of the centre line. Somewhere along the line there has to be a linkage that accomodates the effects of this rotation between boiler frame and bogie. There is a linkage with a yoke at each end with securing pins on the vertical. Am I correct in assuming that it is this linkage that allows for the effects of rotation between boiler frame and bogie when the loco goes round a curved piece of track? I have purchased the G42 drawings as they are likely to be informative for my project, on the basis that the engineers would have reused concepts and design features for most of the small Garratts. I would like to take up your offer of drawings relevant to this problem. I still suspect that this arrangement may alter cut offs albeit by a very small amount.
|
|
|
Post by steamer5 on Mar 24, 2023 4:38:38 GMT
Hi Neathabbyironworks, That’s great that you have managed to find more info! Back when I first looked at building K1 finding info was hard, the net had only just been invented! Yes as best as I can work out you are correct the double pivoted link takes up changes due to the engine bogies pivoting, what effect that has has got to be very small else it will have a big impact. I’ll ask the gent who’s K1 I posted the YouTube link too & see if he’s got any photos he is willing to share of his build showing the link, the video does show a couple of shots of during the build.
The drawings I referred to above is in the book The Anatomy of a Garratt.
I’ve sent you a PM.
Cheers Kerrin
|
|
|
Post by nick952 on Mar 24, 2023 10:03:47 GMT
|
|
|
Post by steamer5 on Mar 24, 2023 20:45:55 GMT
Hi Nick, K1 is currently under the care of Statfold Barn, she is still owned by the WHR. From the YouTube & instagram feeds she does go to the WHR on occasions . She gets regular runs at Statford.
Stratford took over the completion of her overhaul a couple of years ago, when she had to have her 10 year, I believe, boiler inspection. At the time WHR didn’t seem to have the will to get her back to steam as they were moving to larger trains to cope with the increase in passenger hauling
One day we hope to get back to the UK & a visit to Statford to see her in person! Oh the WHR is also on the list of must do’s!
Cheers Kerrin
|
|