Errors on drawings

[dscott]

Oh what a lovely day, a quick drive to the track, a lovely mix of locomotives in steam and gauges 3 1/2 to 7 1/4. Dear Katie even got to drive a Western which she enjoyed, mum came along for the ride and also enjoyed!!!
Now in the steaming bays sat a Maid of Kent built to drawings finished and sat on display for so many years. She was blowing off so the safety valve was opened and whoosh!!!! Drop of fire and a close look at the other valve. Now the drawing says probably an 1/8 thick but the resultant chat works out that at least a 1/4" of thread is needed and a pocket for the spring!
There is a prize for the person finding the bits of the first valve!!! And it is autumn!!!

Now I remember a resent Model Engineer re printing a LBSC design showing a valve that you can screw out completely, now come on please if you are going to put drawings out in the general populace get them right. The steam issuing from the hole went a good 10 feet into the air!!! Think of the cab!

Maybe it is time to withdraw all boiler and fitting drawings until they are all brought up to modern specifications. And can be purchased separately from the body overseeing the operation?

We walked round the park and on my return home managed to apply more foil wrap on the workshop roof. This is going over Jab-floor then covered with 11 mm of OSB and felt which may get done tomorrow!!!
David.

[Midland]

Since this thread is errors on drawings, I have found one, my first. Princess of Wales. If you make the blow down as per Martin Evansd drawing it conflicts with the brake rigging so one has to make a little rectangular harness to go around it. Decided to make a proper blow down and found this after 30 years of ownership.

Cheers david

[GWRdriver]

Oct 10, 2014 10:04:48 GMT Roger said:

My guess is that less than half the locomotives started actually end up in steam...

I can't say with any certainty whether this is a reasonable percentage for the USA. I think in recent years the percentage of completed locos against starts would be considerably higher. Historically speaking however, going back to say the end of the War, I would certainly not be surprised if the percentage was less than half.

In a post above Baggo suggesteth that poor documents, errors, and lack of skills or guidance, etc, are major factors in never completed projects, and while I would agree with those causes an even greater cause IMHO, at least in the USA, is the tendency for folks to bite off more than they can chew. They often choose, or are pushed into, attempting projects which are too large and complex and which require more time, energy, skill, patience, or tooling than they are capable of, especially the time and patience parts.

PS - While I can't say it happens regularly, from time to time I'm given the opportunity to pick up an unfinished project and in all those years I've accepted two, and one of those was a built an then dismantled OS kit. The rest fell into one of the following categories: irretrievable junk, overvalued, or not my cuppa. My approach for some years has mostly been not to consider anything I can't see in person. The only time I was tempted top deviate from that was when I came across a completed and running chassis for a 3.5"ga 3-cyl Schools. I was assured it was 1st rate by a friend whose opinion I trusted, but it was snapped up before I could respond. I'm always astounded in the great differences in what the term "museum quality" means to people.

[Deleted]

How come there are many well documented errors on many locomotive drawings yet if you buy the drawings today they have still not been amended? Surely one day somebody with enough money is going to sue somebody for selling a product with known faults. I may be wrong but shouldn't the drawings be supplied with a list of known errors. After all a lot of these errors have been known about for many years!

[fostergp6nhp]

It's because the trade can't be bothered to have the drawings corrected.

[Geoff]

I think I have found another error on the Maid of Kent drawings (sigh)
The cab is 5 1/4" long but does not reach far enough over the firebox to clear the steam header.
Luckily I haven't cut my cab sides and roof yet, but they will need to be a good 3/4" longer..... I hope it doesn't look silly.

[Midland]

May 10, 2015 4:09:36 GMT Geoff said:

I think I have found another error on the Maid of Kent drawings (sigh)
The cab is 5 1/4" long but does not reach far enough over the firebox to clear the steam header.
Luckily I haven't cut my cab sides and roof yet, but they will need to be a good 3/4" longer..... I hope it doesn't look silly.

Hi Orville

Yes you are right. I have a MoK made into a Compound and the manifold on the top exposed to the cab is soure of great embarrasment. I live with it but not happily. One day I will redo the cab and hide it!
Cheers david

[Geoff]

Thanks Will for that confirmation. I am trying to think of ways of steam collection other than a turret on top of the boiler..... I think I'll have to end up with a cab as long as a rather small coach!

[ejparrott]

My Lion has pipes soldered into the back of the backhead bushes for the valves, which then go up to the top of the haystack. I've been reading DY article while my machines been running, and he's been advocating a banjo bolt to secure fittings which also has a pipe on the back of it up to the dome, though I've not looked at drawings yet

[stevep]

This thread seems to have diversified somewhat, but as I have just started to build a DORIS and found a couple of minor errors on the tender (which I'm building first), I thought I'd share them.

The brake column is drawn as 2" from the centreline, but if you have used angle to fix the drag beam to the frame, there won't be enough room underneath to fit the securing nut. Reducing the distance by 1/8" or 3/16" will fix the problem, but then you have to adjust the position of the levers on the brake shaft to line up.

And the bearings for the brake shaft are shown with the securing screws above and below the hole in the frames, but as the hole (5/16") is only 1/4" above the bottom of the frames, this isn't possible. Simple solution is to put the fixing screws horizontally.

Steve

[Geoff (Carlisle)]

Hi all, I guess there is a few out there building a 5" Britannia well, don't be a chump like me. J.P. drawings show 36 screw holes in the smoke box / saddle. Non of these are seen so why not just use half a dozen 6 B.A.screws instead, it's going to be a lot easier. I ended up tapping the saddle 8 B.A.x36 times.

Geoff (Carlisle).

[springcrocus]

Six months too late, Geoff!

Never mind, it's fun proving to yourself that you can do it, whatever the outcome.

Steve

P.S. Haven't seen many pictures of the Clan lately?

[anna]

Cock of the North (P2)
Hi, all.
I am building the Michael Breeze. Cock of the North,  To Michaels credit, so far I have found very little in the way of errors in the drawings. I have however now come across one, albeit too late for me, ( I must wake up before I start in the workshop) The combined lifting arm and lever (drg 5108) is shown with an internal angle of 89 degrees. This does not allow the die block in the expansion link to travel downwards much below mid position before the vertical arm of the lever clashes with the top of the expansion link at the extreme of its rearward travel. I have not yet worked out what the angle should be but suspect it to be around 110-115 degrees. This also has a knock on effect to the length of the reach rod. I have had a close look at pictures of somebody elses model P2 and it is clear that they have also had the same problem.  The only other things I have discovered so far is that there were no details of the lower brake linkage in my set of drawings, however, all this can be deduced from the general arrangement drawing, and the details and fitting of the brake shoes required some tweaking.
If there is anybody out there who is also building this loco I would be very pleased to hear from you.

Anna

[Geoff (Carlisle)]

Hi all, Geoff Routledge here, to anyone who is building J.Ps Britannia and in my case a Clan. The drawings show that the cylinder centre's being 7.106" well if you achieve this figure then the connecting rod will foul the leading wheel crankpin, therefor the cylinder will have to be packed further out. I've had to do it and so has Jim (70036).

Geoff (Carlisle).

[Geoff (Carlisle)]

Hi all, Geoff's here again, well if anyone is building a 5" Brit or a 9F and they fancy making the tender water filter to Les Warnett's 9F drawings which are a bit finer than JP.s. On Les's filter box it shows having to silver solder in the brass block, which I did. Then the top plate is held down with two 10 BA csk brass screws. Now this whole issue is then soft soldered, top plate to the box, so what's the point in silver soldering, well I won't be on the second one.

Geoff (Carlisle).

[Gary L]

Nov 29, 2008 23:12:57 GMT alanstepney said:

Thanks everyone for the information so far.

I'll make notes of it and add it to my website when next I update it.

For information and future reference, builders of David Adam's Paddington might be glad to know of Barry Leach's invaluable (and growing) catalogue of drawing errors at www.cheltsme.org.uk/index-paddington_project.html

Hope this helps someone else as much as it has helped me!

Gary

[jma1009]

For builders of Don Young's 5"g Hunslet

I have today run the original 'as drawn' valve gear on the Hall simulator. As expected valve events go wild and haywire as the gear is notched up (the Milner Hunslets are even worse).

Don specified the wrong radius for the expansion link slot which should be 4 5/8" not 4 7/8". The 4 5/8" is the eccentric rod plus strap centres - Don Ashton's OJ dimension. I have never understood why Don Young always got this wrong - or perhaps he just perpetuated the error to avoid accepting that he made a mistake.

He also provided no suspension offset on the expansion link suspension trunnion. If you add a forward suspension offset of 0.1093 (7/64") then the valve events become very good if not perfect.

Reducing the lifting arms to 1 9/16" centres also eliminates another error - or the weighshaft could be moved 1/16" to the rear.

Angle of advance for eccentric setting 6.75 degrees.

Set the gear for nil lead in full gear of 79%.

Just a few small alterations that make a huge difference to the valve gear events.

Cheers,
Julian

[Midland]

Sept 12, 2017 19:29:11 GMT jma1009 said:

For builders of Don Young's 5"g Hunslet

I have today run the original 'as drawn' valve gear on the Hall simulator. As expected valve events go wild and haywire as the gear is notched up (the Milner Hunslets are even worse).

Don specified the wrong radius for the expansion link slot which should be 4 5/8" not 4 7/8". The 4 5/8" is the eccentric rod plus strap centres - Don Ashton's OJ dimension. I have never understood why Don Young always got this wrong - or perhaps he just perpetuated the error to avoid accepting that he made a mistake.

He also provided no suspension offset on the expansion link suspension trunnion. If you add a forward suspension offset of 0.1093 (7/64") then the valve events become very good if not perfect.

Reducing the lifting arms to 1 9/16" centres also eliminates another error - or the weighshaft could be moved 1/16" to the rear.

Angle of advance for eccentric setting 6.75 degrees.

Set the gear for nil lead in full gear of 79%.

Just a few small alterations that make a huge difference to the valve gear events.

Cheers,
Julian

Julian

As we found out a little while ago!!!!!!

Cheers David

[dscott]

Just off to build a second scale scrap wagon for a growing selection of Hunslet parts!!!

Yes the Asia motion plate is headed this way now I have reworked the valves from my general
arrangement.
In fact, like the Speedy,1500 A full new drawing is the only way forward before any metal
gets close to the laser or waterjet cutters.

The real reason that only possibly 10 Asia's have been built is down to the drawings?
3 on Station Road Steam since they started I checked!
Ok you have a cylinder casting and have to cut 1/4" off about £35 worth then you realize
it is down to dimension error!

Now, where shall I put the blowdown valve on the boiler??

[jools]

Julian,

I am curious to know whether these problems you identify are perpetuate through to the DY Black 5 valve gear design ?

Knowing little about how lead and lag applies to valve timing and its effects etc leaves me a bit perplexed. Forewarned is forearmed as they say.

cheers

Jools