Northumbrian First Project

[ChrisParticipant @chris16039]

Hi,

Being as I may be partly responsible for this section on the site I guess I’d better introduce myself. Very much a begunner working on a limited budget. Hence I have made a start on the Northumbrian.

If anyone tries to tell me that buying laser cut frames is just a time saver and making them with hack saw and file is not real engineering I’ll…………… Well I’ll have a reasonable discussion with them!

There is a  slight problem with the drawing. Hole 8 does not ‘appear’ to be in line with the centre of the axel however measurements and taking the edge of the horn plate as a datum line works for both the axel and hole 8. LBSC’s original drawing showed a bottom measurement line giving axel centres from each end and between centres. Similar would have been useful.

Please keep those instructions as clear and simple as the first article Tony. It may be patronising to the more experienced but we beginners need it.

I would be pleased to hear from other builders.

Chris.

 

[ChrisParticipant @chris16039]

[David Clark 13Participant @davidclark13]

Hi There

There a few omissions on the frame drawings.

If anyone spots any then email me direct and I can get confirmation of correct dimension and post on here.

regards David

 

david.clark@myhobbystore.com 

[David Clark 13Participant @davidclark13]

Hi There

Omissions are as follows:

The angular run out of the cylinder centreline is 3/8 inch from the extreme top of the frames. This line is in line with the left hand top of frame that is 3/8 down from the extreme top.

 

The trailing horn slot centre is 2 inches from the right hand end.

This is on the top of the drawing but the line has not been carried down to the horn slot.

 

The holes for part 10 are 1 5/8inch to the centre hole.

Again see top of frame dimensions.

 

Two vertical holes C at front of frames are equispaced around the front hole.

 

regards David

 

 

[ChrisParticipant @chris16039]

Thanks for that David. I can now drill with confidence.

 (Had to leave the Shand Mason on the shelf for a while. Gunter was running faster than my little grey cells could handle but I’ll be back)

Chris.

[Kieran SparksParticipant @kieransparks65317]

Hi there,

 

Like most people, at some point you run into problems……The other weekend i thought i would draw out the frame diagram from the magazine just to check that it worked and to get an idea of overall size. Suprised that it could fit on a single sheet of A4 paper, it is a very compact loco! but was disheartend when i had worked around most of the drawing and then could not place the rear horn……..due to a lack of dimesions from either end…….

 

To this end i went down my local club and pulled the ME volume with the original LBSC model, to make comparisons ( Vol 84, 1941 Issues 2082-2089 “Rainhill” )

 

Indeed the plans of LBSC, have measurments at both ends for horns! So i am very glad that Dave has made some corrections……althought bear in mind that not everbody has internet access, and will not know about these?

 

 “There a few omissions” comes as rather a big shock!  not wanting to sound like a broken record David but are the plans proof read? This problem stems back to the days of old when there was “c**k up corner” which you had to hunt for in a small box about three issues ahead of the section in earlier ME’s. Why should these problems  still keep happening.

 

On a more cheerful note, as i am a fairly newish model engineer  at 24. I have taken alot of interest in the new projects of ME and found them to be very well geared towards the beginner. Charlie and northumbrian are great and the magazine generally seems to have turned around for the better recently. The shand mason and trams cars sections have also been enlightening even if i am more heavily interested in locomotives, modeling of this high nature is a joy to see photographed and is encouraging that the subject is not limited. Please may it continue

 

Kieran

 

 

Edited By Kieran Sparks on 19/07/2009 14:38:11

[David Clark 13Participant @davidclark13]

Hi There

The rear horn dimension is on the drawing at the top of the frame as is the front one.

The only dimension missing is the angular one and that is on the original as a short dotted line so I missed that one.

 

I do proof read the drawings on the Northumbrian. I go through them with a magnyfying glass. I have not spotted an error yet but I was looking to make sure the dimensions were correct as redrawn. In future I will check to see if any dimensions are missing as well.

regards David

 

[Mike TupperParticipant @miketupper58399]

Hi David,

               having laid out the frame I find the position of the cylinder to appear to be too far back, as though the 6″ stroke is 1/4″ too long.

Looking at the plan, the rear-most hole in part 10 seems to square with the top centre hole of the cylinder but is 1/4″ out when I lay it out according to the given dimensions.

Forgive me if I have miss-read a dimension but I have checked several times. Even the photo 4 page 30 (4355) suggests my layout has an error.

 

Any others aware of this?

 

Regards,

               Mike

[David Clark 13Participant @davidclark13]

Hi There

Once you have marked the centerline of the main horn, the 6 inch dimension is struck from that along the angle. I don’t see how it can be out?

 

Do you have a protractor to mark out the angular cylinder holes?

 

regards David

 

 

[Mike TupperParticipant @miketupper58399]

Hi David,

                thanks for the prompt reply.

My reluctance to drill is my observation that the top centre cylinder hole appears to be vertically above the rear hole of part 10 according to the plan but not on my layout.

 

Can I have some cross reference measurements, for example distance between axle centres?

I have 7.0625″ (71/16).

(Frame length overall 11 9/16″.)

 

This may show if I have miss-read the drawing.

 

Many apologies,

 

Mike

[JasonBModerator @jasonb]

I would agree with your overall and ctrs sizes

 

The problem seems to be that there is no actual front/rear location dimension for the three holes for part 10. Or are we to assume that the central one is directly below where the 3/8 radius meets the top of the frame.

 

Having just tried laying it out I’m inclind to agree that the 6″ dim seems wrong as this puts the set of six bolts for the cylinder far closer to the rear, in fact the top rear one is only 1/8″ from the edge of teh 5/8 drop in the frame

 

My layout here

 

Jason

Edited By JasonB on 31/07/2009 19:11:48

[JasonBModerator @jasonb]

Just been checking a few of the proportions on the frame drawing and the 9/16 dim mid way along the top of the frame is the same proporting as the 3/4″ spacing of the holes for part 10. and much wider than the 9/16 spacing of teh cylinder holes.

 

So the question is is the drawing not to scale or even proportion or should the 9/16″ dimension actually be 3/4 which would seem to put the cyl holes and part 10 holes in line as drawn and as it seems to be in the photos.

 

I can see some scrap metal about

 

Jason

 

Edit position of part 10 holes was covered by david in earlier post

Edited By JasonB on 31/07/2009 19:48:35

[David Clark 13Participant @davidclark13]

Hi There

I will see if I can draw it out.

regards david

 

[Robert HParticipant @roberth70523]

Hello David,

 

Ive just bought issue 4357 and found part 2 of this construction article. As I missed part 1, please would you tell me what scale/gauge this loco is to.

 

Also can ME supply a back issue of issue 4355 if needed.

 

Regards,

 

Robert

[JasonBModerator @jasonb]

Its 3 1/2 gauge

 

And there should not be a problem getting back issues, try the “Myhobbystore” link on the right.

 

Jason

[JasonBModerator @jasonb]

Just in case anyone following this thread has not seen Davids reply in the “footplate” thread .

 

The 9/16″ distance mid way along the frame should be 3/4″ which means anyone who has started to cut or drill their frames will likely have to start again.

 

Jason

[Robin KingParticipant @robinking15611]

I’ve plotted the frames in CAD for the fun of it (bit quiet in the studio!) and just to add to the list:

 

Fig 10  Firebox support doesn’t give a length for this item (guessing about 2″) – anyone got any clues?

 

The rivet hole spacing for the rear horns is not shown on the drawing but works ok if 3/16″ / 7/16″ / 7/16″ centrally to ech leg working from the bottom.

 

Incidentally setting out the cylinder C/L works equally well if set out from driving axle centre to extreme top right hand corner of the frame plate blank i.e. north east of the circled 3, and equates ok to the 3/8″ down dimension mentioned by David in earlier posts.

 

Robin

[JasonBModerator @jasonb]

I mentioned the firebox support length in the footplate thread. The holes are also not drawn to scale/preoportion, 1/8 is shown larger than the 6BA but thats nit picking

 

There rear horn holes are shown different on the frame drawing to the layout on the horn drawing, one has the top holes above the 1″ cut out, the other below

 

How do your hole sline up on the CAD drawing, any chance of attaching it so we can have a look.

 

Would be nice to get an answer Today as I’m sure some builders are holding off cutting any more metal until these issues are resolved and would have liked to spend the weekend in teh workshop

 

Jason

Edited By JasonB on 07/08/2009 16:55:31

[Robin KingParticipant @robinking15611]

I don’t know if my earlier attempt at posting this succeeded so attempt no. 2! (apolgies if repetition)

 

On my CAD frame plot I’ve plotted the rear horn rivet holes based on item 7, page 31 of ME with holes central to each 1/4″ wide leg, and at the vertical spacing I gave earlier; this puts the top holes just above the top of the axlebox slot.

 

I’m not sure if many would be able to use the CAD drawing unless they have facilities for reading an AutoCAD .dwg file so attaching the drawing may not help; unfortunately I don’t have the facility to produce pdf’s.

 

As an alternative I tried a frame plot using the earlier suggestion of increasing the 9/16″ dim from the 1/4″ dia hole to pump stay (6) to 3/4″, giving an overall frame length of 11 3/4″. By then setting out the 6″ cylinder C/L radius from the driving axle position, and aligining the C/L with the top right hand corner of the frame blank, that puts the centre pair of bolt holes almost exactly central to the 1 5/8″ raised section of the frame, which I suspect is where it’s intended to be (if plotted to precisely central the 6″ radius is actually 6.003″ – more than close enough for my needs). That seems to resolve the cylinder position, but I’d be interested to know how that compares to the designers original drawing. All other dims on the frames are set out as the ME published drawing, working from the left hand end.

 

For those interested in the CAD element I’ve used settings of primary units of fractional inch to 1/64″, with alternative units set to 0.000″.

 

Hope that is of help; I’m away from the computer until late Sunday but will pick up the discussion from there and may by then have some other way of attaching a drawing.

 

Robin

[ChrisParticipant @chris16039]

Could someone explain to me in reasonably simple language why the cylinder position is so critical. I appreciate that the throw of the piston has to match that of the wheel crank etc but as the cylinder is external would the fact that it prodrudes in to the footplate area by 3/16 more be critical. The original LBSC drawings show the cylinder so far back that the top mounting hole is unused as it is above the frame.

Yes I am the guy who has been building as the articles appear and am not too happy about starting again. Equally unhappy that I have spent the last two days decorating the living room because ‘her good self’ convinced me that continuing in the workshop was futile. These are indeed bad times!!!!

Chris.

[JasonBModerator @jasonb]

The actual position of the cylinder is probably not that critical so long as the 6″ dimension is retained.

 

BUT

 

The 9/16″ vs 3/4″ anomoly will have far greater implications

 

1 The overal frame length is wrong

2 the position of the 1/4″ for the valve gear will be 3/16 further from the valve chest and throw all the linkages out

3 exhaust pipes will be too short/long?

4 Boiler will be too long and affect many parts

5 Grate and firebox will be in wrong position

etc etc.

 

If the 9/16″ does turn out to be wrong then there are really two options either scrap the frames and start again or alter all subsequent parts and drawings to suit but this option will be a suck it and see method as no engine has been build to the reduced length and its likely changes will be missed.

 

I know it does not help you Chris but my original advice when you said you were going to do this project was to give it a few month to see how the series progressed before making a start, looks like it was better advise than I thought.

 

Jason

[Robin KingParticipant @robinking15611]

Although the possible error(s) may have been pinned down I think this needs to be resolved by the original designer, rather than this forum, and so as Jason says it’s probably a case of waiting a while. That said, the assumption so far has been that the 6″ dimension is correct – may be it isn’t,  and the rest of the frame dims are correct after all, in which case it would just be cylinder bolt holes needing correction?. Again – back to the designer for confirmation. 

 

Robin

[David Clark 13Participant @davidclark13]

Hi There

Both the 6inch dimension and 9/16 are correct – frames and valve gear will work fine.

regards David

 

[Robin KingParticipant @robinking15611]

David,

 

Fair enough but if that be so then it confirms that the cylinder bolt holes are set further back in the frame than shown in the published drawings, just as Mike/Jason raised in earlier posts, as confirmed by my CAD plot. If it would help then I’ll gladly email a JPEG scan of the drawing to you direct.

 

Robin

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