Dodgy drawings

[DMBParticipant @dmb]

Beware of drawings on the Internet. Example: 5″G Netta mechanical lubricator. So-called drawings differ from the original.

I would say that any novice would be loco builder with as yet little or no major machinery such as a lathe, ought to try a relatively inexpensive trial to test his/her ability before spending a lot of money. Get proper paper drawings from a supplier or relevant ME mags., if design was published.Join local club. Lots of free advice, help and most clubs seem to possess at least a lathe. Obtain correct sizes of metals to construct the mechanical lubricator for the chosen loco. design. It will give experience in cutting, folding and soldering sheet brass for the oil tank.  Some lathe work, drilling, tapping and filing for the working parts. Club will probably have the necessary drills, taps and dies. If successfully made and it pumps oil, good! Proceed with increased confidence! My idea is that for a minimal outlay, a beginner can assess whether they have what it takes to complete their ambition.

Again, avoid junk drawings on the Misinformation Internet. What people get out of supplying disinformation absolutely beats me.

John

[Nigel Graham 2Participant @nigelgraham2]

The standard of published model-engineering drawings has always been one of the hobby’s bones of contention, varying from very good to poor.

Although I have personally encountered only one drawing that was responsible for the finished result being totally, irreparably useless if followed faithfully. It was a rather low-quality print, bore neither designer’s nor publisher’s name and we never found who was responsible – and that was before the Internet, let alone social[?]-media.

I would not like to say if a ‘Netta’ or any similar locomotive is a good choice for a first project, as so much will be very subjective and personal to the builder; but it certainly needs a lathe and reasonable skill in using that and other metalworking techiques.

[Paul LousickParticipant @paullousick59116]

Most drawings, I have found have some mistakes in them or have to be modified to suit available materials. It is sometimes difficult to find material for drawings that were made with imperial dimensions when they are now sold in metric.

Even drawings sold by reputable model suppliers have mistakes and are often simplified designs of the original engine and appear to be drawn by unexperienced draftspersons (if that is now the correct term) and not up to professional standards. (I have worked as an engineer/draftsman for 40+ years).

The drawings for my Ruston Proctor SD traction engine that are supplied by 2 leading suppliers differ from the original detail drawings of the engine. And both contain simplified details of some of the parts, not just a scale version.

So it is always advisable to double check everything before staring manufacture. Everything on my engine has been re-drawn in CAD to suit available materials prior to starting manufacture.

 

 

[DMBParticipant @dmb]

Nigel, apologies for my misleading post. I was not advocating a beginner to plunge in making a 5″ Netta, only the mechanical. lube. as I thought it to be a good example of LBSCs design.

John

[Phil PParticipant @philp]

I never use other peoples drawings, I always re-design/draw everything in Solidworks 3D myself.
Then if by any chance there are any errors I can only blame myself.

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