LBSC Style Ratchet Wheel Mechanical Lubricator

[nigel jones 5Participant @nigeljones5]

[nigel jones 5Participant @nigeljones5]

This design employs an oscilating piston assy – surely the spring tension holding the piston to the port face must exceed that of the incoming steam pressure or the piston/cylinder would simply be forced off the port face? I need to ask as my attempt at a static piston pump lubricatot failed (it doesnt pomp!).

[DMBParticipant @dmb]

Fizzy,
Beware! Dont use drawing of this off internet -its wrong – use original ME drawings of say Maid of Kent or Netta 5″.
I am currently still struggling to make one. It isnt as easy as appears by reading instructions in mag. Mine is coming along ‘tween decorating and down sizing collections of books(railway of course!)/mags/tools/metal/junk/might-come-useful-one-day stuff. Example; recently cut a small piece of thin ali sheet to make shade around my new led light for the mill. Said piece of ali sheet waited about 35 years in my possession before it lived up to its promise of might be useful one day! It was blowing along the road in a strong wind. After all, it was only paper thin ali sheet.

[DMBParticipant @dmb]

It wasn’t until I got started on lube. project that I realised just how many little bits of this and that size and cross section of brass and steels of different types were needed.
Should have copied American practise and made a bill of materials.
Looking at other people’s engines quite a few have lbsc type lubes. which appear to be made better than the rest of the loco., suggesting that lube was bought in from a fitting supplier.
Having started now determined to finish the job.
Good luck with yours.
John

Edited By DMB on 21/07/2015 14:49:04

[DMBParticipant @dmb]

Fizzy,
On looking back,I see that I have not answered your query. Sorry. It is normal to fit a non-return valve ‘tween pump and steam pipe/chest so question of overcoming steam pressure within pump as suggested by you, doesn’t occur. Exception is when non-return valve fails and a blow back occurs which condenses to water and sinks to bottom of tank causing (lighter)oil to float to top and spill out of tank.
Hope this helps.
John.

Edited By DMB on 21/07/2015 15:03:08

[nigel jones 5Participant @nigeljones5]

Thanks all – but everyone has missed my point. If its the oscilating type the pressure of the ram must surely be greater of that of the inlet steam pressure, and by virtue the iol would escape from the assy by overcoming the resistance of the spring which keeps the two parts together? So how strong does the spring need to be?

[DMBParticipant @dmb]

Not very.
I believe its only a light spring. I am going to trial one from a liquid soap pump bottle.

[DMBParticipant @dmb]

Not very.
I believe its only a light spring. I am going to trial one from a liquid soap pump bottle.

[John BaguleyParticipant @johnbaguley78655]

Fizzy,

Don't forget that the pressure the pump actually needs to produce is proportional to the area of the ram. A 1/8" diameter ram has a cross sectional area of only 0.0123 sq. inches so to produce 100psi the pressure on the ram only has to be 1.23psi so the pressure trying to lift the cylinder off the port face is very low. Think that's right anyway!

Most good lubricators will easily produce several hundred psi. The biggest problem is getting the ram to be a good enough fit in the cylinder bore. I like the Jim Ewins type where the ram goes through two O rings which seal perfectly.

The LBSC oscillating type usually have a packed gland on the cylinder to seal the ram.

Whilst the ram may seem to seal perfectly when the oil is cold, as soon as it gets hot they may leak like a sieve!

John

Edited By John Baguley on 21/07/2015 18:26:30

Edited By John Baguley on 21/07/2015 18:27:57

[BazyleParticipant @bazyle]

The secret is the small cross sectional area of the hole.

DMB – A lot of commercial lubricators sold by our regular suppliers used to be made by one man ~(who owned that tiny stand at Ally Pally selling odd szes of silver steel cheap) but I understand he gave that up last year.

[DMBParticipant @dmb]

Bazyle,
I’m not surprised as fittings pumps valves injectors have been made by 1 or 2 producers and that probably still happens.
John

[DMBParticipant @dmb]

Bazyle,
I’ve just learnt something! However, I’m not surprised as many suppliers have flogged injectors made by one or two makers. I expect that most boiler fittings, pumps, valves are still produced by a very small number of makers.

[DMBParticipant @dmb]

I remember reading LBSC saying his lubricator registered 400 psi on test.

[VersabossParticipant @versaboss]

Posted by John Baguley on 21/07/2015 18:24:02:

I like the Jim Ewins type where the ram goes through two O rings which seal perfectly.

As I'm thinking about building a small oil pump can someone point me to a description / plans for this Evins lubriccator? I remember vaguely having seen it long ago, but have no idea where it was.

regards, HansR.

[DMBParticipant @dmb]

LBSC packed a gland on the pump cylinder with graphited yarn. Bill Stroudley made his water pumps so that the ram didnt touch the bore and just acted as a displacer. This meant he could pump hot water with no air locks and be self – priming. It seems to me that LBSC’s lubricator pump ram would work in the same way.

Edited By DMB on 21/07/2015 22:00:15

[Speedy Builder5Participant @speedybuilder5]

Like others, I am trying to get my LBSC 5" size pump to work. By experiment, the length of ram or distance of the hole in the ram to the end of the ram is critical. The drawing calls for a ram O/a length of 7/8" but doesn't give a dimension of the "pin hole" from the opposite end. If the ram is too long (but doesn't foul the end of the cylinder), then oll is not drawn into the cylinder/ pushed out. By using a slightly shorter ram, I am getting limited success – trials continue.
Incidentally, its the gland seal which is most important and not so much the fit of the ram in the cylinder I think.
BobH

[J HancockParticipant @jhancock95746]

Just a reminder , of those mini- O rings to be found in disposable lighters.

[julian atkinsParticipant @julianatkins58923]

this is a bit of an old thread which Bob has resurrected!

there is often/always an error in LBSC's drawings for same. if you draw everything out 2 times fullsize or more, or apply a bit of maths it is clear that the ports dont coincide when the pump is at an angle when the crankpins are at 3 and 9 o'clock. the discrepancy is only just 1/64th out but is worth checking and dealing with. it makes a huge difference to how they work! the ports must coincide, and very careful drilling is required for the oscillating LBSC type!

the gland seal on the ram has never been a problem – after all the whole thing gets covered in steam oil. i had a loco with a commercially made LBSC mechanical lubricator made in 1963 and with a new owner is still ok and pumps 100% reliably as the day it was fitted. that is over 50 years regular use.

i only made one myself for my first loco 32 years ago, but have repaired quite a few over the years. i have fitted hydrostatic sight feed displacement lubricators to all but my first loco.

cheers,

julian

[John PurdyParticipant @johnpurdy78347]

HansR

Details of Jim Ewin's lubricator can be found here:

Engineering in Miniature Jul '82 pg 48

ME 1999 Vol. 181 #4077 pg 401 & 4081 pg 636

2002 Vol. 188 #4164 pg 79

2005 Vol. 195 #4252 pg 87

2007 Vol. 199 #4314 pg 685

2008 Vol. 200 #4216 pg 29

John Purdy

[Speedy Builder5Participant @speedybuilder5]

Thanks for the replies – however I don't have access to the archives for J Ewin's lubricator, but from other pictures on the net it looks like an interesting alternative to LBSC's.
BobH

[Ady1Participant @ady1]

edit, info already posted

Edited By Ady1 on 12/11/2015 09:35:04

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