Is it time to give up?

This topic has 29 replies, 16 voices, and was last updated 11 February 2014 at 07:03 by Kenneth Lindeman.

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25 January 2012 at 20:38 #82975
nigel jones 5
Participant
@nigeljones5
Im very new to steam locos so I bought one which required a major refurb, or so I was told (Minx). Ive replaced and remade just about every moving part, but theres something woefully out of place. I cant get any drawings to find out which bit is wrong and ive no one to help me. I feel thoroughly miseable. Is now the time to give up?
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25 January 2012 at 20:38 #5894
nigel jones 5
Participant
@nigeljones5
25 January 2012 at 20:42 #82976
Another JohnS
Participant
@anotherjohns
Nigel;

Would be a shame to give up; what’s the issue? How do you know that it does not work??

(and, where in the world are you that there’s nobody to help? North shore of Hudson Bay?
25 January 2012 at 20:43 #82977
David Clark 13
Participant
@davidclark13
Hi There

MyHobbyStore sell drawings for Maid of Kent.

Most of this is the same as the Minx.

regards david
25 January 2012 at 21:13 #82985
Terry Lane
Participant
@terrylane
25 January 2012 at 21:16 #82988
nigel jones 5
Participant
@nigeljones5
http://www.stationroadsteam.com/archive.htm item 2531 shows the motion on a maid of kent – inside. Its not joy gear and is completely different. Any ideas as the mok drawings are very expensive if theyre not for my engine?
25 January 2012 at 21:26 #82989
nigel jones 5
Participant
@nigeljones5
ive looked at pictures of maid of kent and the valve gear(inside gear) looks completely different to minx. Minx definately has joy gear, no eccentrics but the mok ones have eccentrics
26 January 2012 at 06:15 #83021
Springbok
Participant
@springbok
Hi Nigel

Never give up could you describe the symptoms is it that you are getting binding

I am sure with the wealth of experience on this forum we will be able to help you.

Could you post a pic of your loco

Bob
26 January 2012 at 09:37 #83029
John Baguley
Participant
@johnbaguley78655
Hi Nigel,

Minx was described in conjunction with Maid of Kent in ME vols 98 to 101 (1948-49). I’ve got all the relevant issues if there is anything that you need to know.

John
26 January 2012 at 10:39 #83037
Wolfie
Participant
@wolfie
Dunno about trains, I haven’t got that far yet. But so far this gang has helped me every time I’ve got stuck and thought about throwing things .

Edited By Wolfie on 26/01/2012 10:39:38
26 January 2012 at 11:13 #83042
nigel jones 5
Participant
@nigeljones5
hi john…thats exactly what ive been searching for but have been unable to find. I need to check the position of every moving part, length of links and so on. Something is either too short, too long or in the wrong place! I would love to see this running!! Where in the world are you based?
28 January 2012 at 23:16 #83307
Cyril Bonnett
Participant
@cyrilbonnett24790
http://www.stationroadsteam.com/archive/2453/index.htm

http://www.stationroadsteam.com/stock%20pages/2763/index.htm

Couple more that might help
28 January 2012 at 23:47 #83311
John Olsen
Participant
@johnolsen79199
Nigel, you still haven’t told us the exact nature of the problem. If it is binding that is one thing, if the valve gear is wrong in some way then it may not run even though everything moves freely. Plenty of us can find the original articles, they should be downstairs in my cupboard for instance. I could email copies but you might prefer to find a more local source than NZ. They may only be of limited help if it turns out that there was some error in the original design, which may require either looking through the indices to find later references to the design, or, probably better, learning how to use the Dockstader program and checking the design against that.

My strategy for one like this would be:

If it is binding find out where, eg disconnecting big ends/ eccentric rods etc and reconnecting until I have identified the place where the problem is occurring. Then of course you have to figure out what remedial action is needed depending on the problem. (For example crosshead not aligned with the cylinder bore) If everything has been built with too much precision you can get binding, there has to be enough freedom for the axles to move up and down without causing binding.

If it is a valve gear problem, check the design against the Dockstader program to make sure it is correct. Then check the loco to make sure it is implemented properly. For instance you can blow low pressure air through with drain cocks open and turn the loco over and listen to see when admission and exhaust are occurring. (Low pressure because you don’t want it to actually run, you can take a finger off like that….you just want to hear what is happening) With some engines, you can do this by taking off the valve chest covers and watching the ports open, but not so easy with inside valves or piston valves. You want the barest whisker of lead, LBSC used to talk about the thickness of a tram ticket, which is only a few thou.

There have been engines that would not run because the cylinder covers or gaskets were actually obscuring the connection between the port and cylinder.

Generally steam engines are very forgiving, and will run with valve settings surprisingly far out, but of course they will not perform as well as they should. There are of course lots of things that can go wrong, but as with any trouble shooting, a logical and methodical approach should soon tell you what is wrong.

regards

John
29 January 2012 at 01:02 #83313
nigel jones 5
Participant
@nigeljones5
many thanks all…it looks like someone has confused mok with minx…minx frames with mok gear…and they aint the same! working on it, should be fixable but not hopeful!
29 January 2012 at 03:31 #83319
Jim Greethead
Participant
@jimgreethead
I love it Tel, that cartoon says it all. I need a BIG copy in my workshop. Thanks.

Jim
29 January 2012 at 11:16 #83338
Steve Withnell
Participant
@stevewithnell34426
A Winner never quits – and a Quitter never wins – John Wayne

but then again.

He who fights and runs away, lives to fight another day,

Whilst he fights and stands his ground, gets his blummin clock knocked round!

So I guess it’s about you striking a balance!

Steve

PS: And for those of you with long “to do” lists –

Nothing takes quite so long as the job that’s never started… -Bilbo Baggins.

Pretty smart them Hobbits.

Steve
29 January 2012 at 11:22 #83341
Anonymous
Personally I leave the balance alone, it never did anything to me!

Andrew

PS: I find that if I leave jobs on the ‘to do’ list for long enough sometimes I decide I don’t need to do them, which saves even more time.

PPS: Never did finish the ‘Hobbit’, just not my cup of tea.

Edited By Andrew Johnston on 29/01/2012 11:25:06
30 January 2012 at 19:48 #83479
Sub Mandrel
Participant
@submandrel
“If a job’s worth doing, it’s worth doing badly.”

George Bernard Shaw.
30 January 2012 at 20:11 #83485
Jim Greethead
Participant
@jimgreethead
I prefer:

If something is worth doing, it is worth overdoing

Jim
30 January 2012 at 21:14 #83495
John Olsen
Participant
@johnolsen79199
Nigel, It should be possible to get it going, even with the “wrong” gear. It may require a redesign, especially if the distances or the ports are different. By a redesign, I don’t mean a complete change to the loco, I just mean that you might have to adjust the dimensions of some valve gear components to get things right. If you are not comfortable with this, you could convert it to the original design, or you could get assistance in tweaking the design of what you have to work properly. Valve gear doesn’t have to be very far out to have an impact on performance. It is one of the reason why different locos of the same class often had very different performance. But it can usually be adjusted to give the best results for any given circumstance.

regards

John

“Mutton yesterday, mutton today, and blimey, if it don’t look like mutton again tomorrer.”
30 January 2012 at 21:16 #83496
Ady1
Participant
@ady1
Eagles may soar but weasels don’t get sucked into jet engines

william shakespeare
31 January 2012 at 05:21 #83514
John Olsen
Participant
@johnolsen79199
Ok, if we could just get back on topic for a minute or two, I have dug out the magazines for Volume 98 and 99 and had a bit of a look at them. There is more than anyone is likely to digest in half an hour or so, and I have only really looked through the first half, eg the MOK and Minx articles in vol 98. Issue #2455 has what may be the crux of the matter, It describes the link motion for Minx. However, one of the earlier articles showing the connecting rod for Minx shows a dotted outline of a boss for Joy gear. Also this article talks about going on to describe the Joy gear “which is also the same for both engines”. It would therefore appear that Minx AND MOK were described for either Joy or Stephensons link motion. So probably what you have is the Link motion version. Presumably he means “The same apart from some minor differences”. I think the changes are required because the relative positions of the axle, the weighbar, and the cyliders are slightly different on the two engines.

Although the Link motion for minx is similar to MOK, there are differences. In particular the following:

Eccentric rods (Centre to centre) MOK 4 1/4″ Minx 4 11/16″

Fulcrum pin differs

Weighbar shaft has a different offset

links have a differnt radius to suit the longer eccentric rods

Valve rods are 1/16 longer

The centre line of the weighbar shaft should be 3 7/16″ ahead of the vertical centre line of the driving axle and level with the top of the frame.

So issue #2455 June the 10th 1948 is the one you most want to see, if you wish to send me a personal message with an email address I will be happy to scan it for you. It has a side and plan view GA and details of the links and straps, as well as the text discussing the gear.

regards

John
31 January 2012 at 11:40 #83529
John Baguley
Participant
@johnbaguley78655
Nigel brought the chassis down to Derby on Sunday for me to have a look at. It’s a bit of a Heinz 57. The slidebar arrangement is for MOK which is not a problem but the distance between the leading and driving axle has been reduced to 8″ from 9.25″. It seems the loco was going to be based on another full size prototype as the frames are a different outline as well.This means that the connecting rods have had to be shortened which has thrown everything out. Hopefully, I should be able to redesign the Joy valve gear to accommodate the new dimensions and Nigel can carry on with the chassis as it is

John
31 January 2012 at 20:19 #83570
John Olsen
Participant
@johnolsen79199
Well, I can dig further down the stack and get the original Joy info from LBSC if it would help, although you can probably find the relevant mags at plenty of the clubs over there anyway. The Joy gear is a good gear, although I would check the proportions out with the Dockstader program before committing it to metal. The shorter connecting rods might not give quite such good events as longer ones. You probably would not want to change to the link motion since it would mean a new crank axle.

regards

John
1 February 2012 at 01:25 #83602
John Olsen
Participant
@johnolsen79199
Well, issues 2460 and 2461 were not much further down the stack as it turns out. The offer still holds if you would like copies of these, although being LBSC he tells you how easy it is to lay out a Joy gear, without actually saying how to do it. Still, I am sure there are books and articles we can track down on that if need be, and we can certainly check the resulting design out before it is built.

regards

John
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