Doug Hewson style lubricator

[jma1009]

hi andrew,
for heavens sake make your own!
cheers,
julian

[baritoneplayer]

Hi Julian, Roger from the IWMES here.

Hope you don't mind me contacting you?

I see from your posting re The Jim Ewins style lubricator that you've made several ones of this type. I recently bought one of a very similar design from Steamfittings but I'm having lots of problems with it. Basically it only pumps oil on my B1 if the loco is pushed round the track. Once the loco is steamed the lubricator simply doesn't pump any oil at all.

With John the Pumps help we disconnected the pump and connected his pressure test set to the output to each of the pumps in turn (twin pump type) after pressureising the system upto around 90psi the lubricator was operated and the pressure gauge on his test increased.

Using the test set we then flushed through both of the oil supply pipes which seemed clear. Both of the non return valves have been checked and found to be ok.

Running the B1 today at the club the lubricator once again didn't pump any oil... Any ideas?

Regards

Roger

[jma1009]

hi roger,

ive only built the LBSC oscillating type of mechanical lubricator, with both types of drive ie ratchet and pawls and roller clutches. i dont have any experience of the Jim Ewins type (though actually published in ME in the late 1950's before Jim's 'version').

looks like the 'test' carried out on your's wasnt done properly otherwise it would work on the loco. happy to test it for you or send you some parts for an LBSC oscillating type.

personally i much prefer the hydrostatic displacement type with sight feed as fitted to my own locos.

cheers,
julian

[Roger]

Hi Roger,
You say that you have twin pumps but not how they're connected. Does one pump feed one cylinder in a separate circuits to the other? If they both supply a common feed, then one could be leaking the delivery of the other. You wouldn't notice that if tested the pumps separately and probably not when pushing the locomotive.

[baritoneplayer]

Thank you for your replies...

The Lubricator fitted to my B1 is a single tank, fitted with two pumps, driven from one shaft. One pump feeds one cylinder and the second pump feeds the second cylinder. The two systems are completely separate.

It has been suggested to me that oil could be getting into the roller clutches causing them to slip. Clearly just pushing the loco around the track means that the pumps have less work to do as there is no steam pressure acting against the pumps. This could also explain why the pumps worked on the test set... When on the test set I only put enough oil in the tank to cover the pump inputs. When on the loco the tank was full to the top, which I now hear is not a good idea.

Thanks again.

[andyhigham]

The oil doesn't make the clutches slip by its lubricating qualities. The thick sticky gloopy steam oil sticks the rollers to the cage so they don't return to the driving position

[jma1009]

hi roger,

i fitted the roller clutches and lubricator to the IWMES Super Simplex in the mid 1990s. if the shaft is hardened and the correct size for the roller clutches they shouldnt slip at all if covered in oil. it is a common fault not to fit a hardened shaft plus of incorrect diameter for the clutches which are almost invariably metric in size. the LBSC type or ratchet and pawl or ratchet never suffer from this problem anyway.

cheers,
julian

[Deleted]

I have built several of these lubricators. They are brilliant. I have filled them purposefully with water then oil and watched it pump out the water and then go onto oil without missing a beat. The secret is the pressure on the chamber onto the O rings. It has to be tight enough to create a vacuum as the ram goes vertical. Another tip is to set it up so that the spacers add up to .090". That way you can have a .040" and an .050" which can be swapped to change the amount of oil per stroke. My latest engine which is still being  run in is using a .060" as the main spacer. Plenty of oil. I cant recommend these enough, you cant go wrong. Cheers

[Andrew C]

Thanks guys I need to look at the lubricators again as I am still not happy I have a reliable pair. To answer Roger's question the Brits are fitted with two lubricators one feeding each cylinder as per the prototype

Need to get the engine working as the full track is now laid all 320ft all the way around and am itching to test the Brit again.

Andrew