Started running-in Brunel!
- mikewakefielduk@btinterne
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I'm not the first to suggest this easy fix. Back in the May 2013 edition of 16mm Today Peter Aldridge did exactly the same thing as me - place some nuts to act as spacers under the boiler and the burner behaves a lot better.
I don't recall having read the 2013 article before today and that particular edition of 16mm Today of mine looks awfully pristine - none of the usual coffee stains and oily fingermarks - so perhaps I didn't read it in detail back then. May last year was a particular hectic period.
Anyway, if you have a copy of the article I urge you to read it. The photos were taken on The Portland Light Railway where I've also run my Brunel, and I can confirm it tackles the whole track, including the spiral, with ease.
Mike
I don't recall having read the 2013 article before today and that particular edition of 16mm Today of mine looks awfully pristine - none of the usual coffee stains and oily fingermarks - so perhaps I didn't read it in detail back then. May last year was a particular hectic period.
Anyway, if you have a copy of the article I urge you to read it. The photos were taken on The Portland Light Railway where I've also run my Brunel, and I can confirm it tackles the whole track, including the spiral, with ease.
Mike
- Chris Cairns
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Just re-read the May 2013 article, plus the August 2014 article, and got my Brunel out of storage for some measurements.
Looks like we have had another Mamod 'improvement' which means, as Mike has already pointed out, Dave Birkby's modifications will not work on other versions.
Both those articles refer to what I call the Mark I Version 3 Brunel. Mine is the Mark I Version 2 which has the different axles and the longer air slots in the chassis.
My burner is 33mm diameter so it is impossible for that to fit between the 28mm back to back wheels whilst running in 32mm. Measured the gap between the burner and the axle as 70 thou (1.78mm) so not much adjustment there, but there is already a spacer fitted between the burner & the running plate. And just to add 'insult to injury' I have 2 different length of screws holding the boiler clamp to the running plate so 2 of those would need replacing to allow the clamp/boiler to be raised above the running plate.
Certainly some 'food for thought' when I get the workshop time available to fit the modified lubricator, and will probably be rotating the boiler around as well.
Chris Cairns
Looks like we have had another Mamod 'improvement' which means, as Mike has already pointed out, Dave Birkby's modifications will not work on other versions.
Both those articles refer to what I call the Mark I Version 3 Brunel. Mine is the Mark I Version 2 which has the different axles and the longer air slots in the chassis.
My burner is 33mm diameter so it is impossible for that to fit between the 28mm back to back wheels whilst running in 32mm. Measured the gap between the burner and the axle as 70 thou (1.78mm) so not much adjustment there, but there is already a spacer fitted between the burner & the running plate. And just to add 'insult to injury' I have 2 different length of screws holding the boiler clamp to the running plate so 2 of those would need replacing to allow the clamp/boiler to be raised above the running plate.
Certainly some 'food for thought' when I get the workshop time available to fit the modified lubricator, and will probably be rotating the boiler around as well.
Chris Cairns
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I tried the BA nuts under my Mark one Brunel boiler though I did not notice any improvement to the flame. The Brunel that I am currently converting to 7/8" scale is the Mark 2 version with the burner right in the centre of the boiler. As a result of this there is no longer a slot provided for owners to move the burner over! I painted calibrations on the gas control nob and the regulator housing for fine control. In the current issue of SMT if you look closely at the photo's of what the 'Brunel' owner has done I believe he has directed the exhaust pipe DIRECTLY to the chimney area for steam effects. Judging what comes out of my exhaust pipe I wonder what state his burner wicks are in with all the waste condense that comes out of this pipe?!!........
- mikewakefielduk@btinterne
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As we are all aware, Mamod have a policy of "continuous improvement" which has resulted in many tweaks to the Brunel since it was first launched.
From talking to Mamod I understand the latest Brunel now has a lower centre of gravity (boiler body shorter in height, thicker side frames, lower cylinder, etc) but there's been relatively little change to the burner.
Bill, any chance of a photo or two of the underside of your new Brunel so we can see how the burner has been positioned under the centre of the boiler?
Mike
From talking to Mamod I understand the latest Brunel now has a lower centre of gravity (boiler body shorter in height, thicker side frames, lower cylinder, etc) but there's been relatively little change to the burner.
Bill, any chance of a photo or two of the underside of your new Brunel so we can see how the burner has been positioned under the centre of the boiler?
Mike
- mikewakefielduk@btinterne
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They have consistently been improved and now are more stable with both the lower centre of gravity and the 4:1 gearing, so the loco you bought in Llanfair is likely to be a good 'un.I´m beginning to wonder what Brunel I actually received. I bought it at Llanfair 2014 on a whim.
However, the numerous small improvements since the Brunel's launch means anything you read in an article may or may not apply to your own loco. Which says something considering how simple they are.
Mike
Last edited by mikewakefielduk@btinterne on Wed Oct 15, 2014 10:04 am, edited 1 time in total.
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- Chris Cairns
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Should be the current Mark II then, as they were close to selling the last Mark I's after the Peterborough show earlier in the year.kandnwlr wrote:I bought it a Llanfair 2014 on a whim.
Must admit I did not look too closely at the Brunel displayed on the Llanfair stand (my focus being on the Thomas Telford), and when David Terry asked me if I was going to upgrade my Brunel to the Mark II standard, as Mike Wakefield has done, I explained that it would be even more expensive as mine has the earlier style of dual gauge axles which are not compatible with the Mark II gearing.
I've been generally disappointed with the go then stop running of my Brunel (similar to the original running of my William & William II), and I'm hopeful the modified lubricator is the solution having already applied other tweaks.
Chris Cairns
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- mikewakefielduk@btinterne
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Thanks for that Bill. As you can see, if I arrange my Brunel in the same way as your photo, my burner appears to be just about where yours is.
Which still leaves open the question of how Dave Kirby in his article managed to centralise his burner under the boiler without it fouling the wheels. As we're told his line is 32mm the only way I can think he's done it is to have a different shaped burner.
I suppose the sensible thing would be to email him and ask rather than speculate.
Mike
Which still leaves open the question of how Dave Kirby in his article managed to centralise his burner under the boiler without it fouling the wheels. As we're told his line is 32mm the only way I can think he's done it is to have a different shaped burner.
I suppose the sensible thing would be to email him and ask rather than speculate.
Mike
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Way back in the first message of this epic I asked about the exhaust pipe on my Brunel and that it appeared a loose fit. You....Mike suggested soldering the pipe in. Soldering is no problem with me but I am not sure about soldering Copper pipe to Brass and what flux to use. I also don't want any problems with the engine block caused by the gas gun HEAT for heating the joint. I am currently debating adding a 'steadying' bracket to hold the pipe rigid and using Milliput to seal the join of the engine block/exhaust join. There is now a tight fit of the exhaust pipe as the pipe has another route to travel....to a on board condenser....
- mikewakefielduk@btinterne
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Although I used solder to hold the exhaust steam pipe to the cylinder block, the joint doesn't have to be steam tight so you could use some sort of sealant instead or even tap a thread in the block and screw in some kind of union.
I took the cylinder block off when I soldered my steam pipe in place. Common multi-core soft solder will do, you don't need silver solder.
and yes, a bracket is a good idea.
Mike
I took the cylinder block off when I soldered my steam pipe in place. Common multi-core soft solder will do, you don't need silver solder.
and yes, a bracket is a good idea.
Mike
- Chris Cairns
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On my William II & Brunel piston valve blocks I soft soldered a brass screw into the 2nd exhaust hole to block them. The exhaust tubing that Mamod supplied for my Brunel is a tight fit but I am also considering the use of a condenser/oil trap.
I'd be wary of tapping a thread and fitting something into the exhaust hole. Alan Dunster (the original Mr Dream Steam) tried that with a Mamod Golden Jubilee but the resultant exhaust back pressure caused some poor running - presumably a factor of the internal diameter/bore of the fitting/tubing being used.
Chris Cairns
I'd be wary of tapping a thread and fitting something into the exhaust hole. Alan Dunster (the original Mr Dream Steam) tried that with a Mamod Golden Jubilee but the resultant exhaust back pressure caused some poor running - presumably a factor of the internal diameter/bore of the fitting/tubing being used.
Chris Cairns
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I had a steam up recently with my Brunel conversion. I found that as usual the gas adjustment is spot on and I don't get the flaring and flame creep like I did on the Mark 1 engine, The tubing to the condenser worked well however due to a boob on my part all the steam came out of the condenser base along with the water/oil mix!....(I weep)...A bit of alteration work on the condenser to get a steam plume arising into the air is now going through the works. I will send a picture in of the (hopefully) full steam ahead engine in due course....Happy Christmas to all you fumblers.... like ME!
- Chris Cairns
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Yes indeed, congrats to Mike on that article about the Brunel lubricator in SMT though the text was a bit above me! I wonder when Mamod will introduce a replacement lubricator? A question....does water act as a 'oil' as the Mamod lubricator runs out of oil? I ask as my Brunel has a 'run time' like my old 'Millie'!
- Chris Cairns
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My understanding is that the old Mamod oscillating cylinders which had plain pistons (no oil ring(s) or 'O' ring) just relied on the wet steam as a lubricant, but as we know they could wear out quite quickly if no piston oiling regime was adopted or a displacement/dead-leg lubricator fitted.
With the Brunel cylinders you have an 'O' ring on the piston, an 'O' ring on the piston rod, and a separate piston valve all relying on adequate lubrication. On my Brunel (seems to be a one-off Friday Afternoon Car) it will slow down & stop when the oil has been used yet there is still steam pressure available. Emptying the water out & filling the lubricator up again sees it off on its way again. The use of a flywheel on the Brunel (and the stationary & mobile engines fitted with these piston valve cylinders) generally seems to overcome this stiffness due to lack of lubrication whilst running despite the obvious steam leaks as clearly displayed in some YouTube videos.
I have been fortunate in being provided with one of Mike's modified lubricators to fit to my Mark I Version 2 Brunel, but it will need to wait for a convenient slot in my workshop schedule as there is a lot of work to be done here (complete de-rivet/stripdown to iron out any residual stiffness, raise & re-orientate the boiler, and form a new steam pipe). Given its limited running potential (it is now out of gauge for our indoor 45mm layout as the high cylinder fouls a scenic arch) this is another low priority project.
Chris Cairns
(edit to correct grammar)
With the Brunel cylinders you have an 'O' ring on the piston, an 'O' ring on the piston rod, and a separate piston valve all relying on adequate lubrication. On my Brunel (seems to be a one-off Friday Afternoon Car) it will slow down & stop when the oil has been used yet there is still steam pressure available. Emptying the water out & filling the lubricator up again sees it off on its way again. The use of a flywheel on the Brunel (and the stationary & mobile engines fitted with these piston valve cylinders) generally seems to overcome this stiffness due to lack of lubrication whilst running despite the obvious steam leaks as clearly displayed in some YouTube videos.
Presumably if there has not been sufficient feedback from Brunel owners about this apparent lack of lubrication (I know that Mike Wakefield has discussed it with Peter Johnston) then there is no perceived need to correct it. Mike's solution would not easily work with the Mark II's boiler without a redesign (the regulator housing would need to be reversed).Bill/Rubery wrote:I wonder when Mamod will introduce a replacement lubricator?
I have been fortunate in being provided with one of Mike's modified lubricators to fit to my Mark I Version 2 Brunel, but it will need to wait for a convenient slot in my workshop schedule as there is a lot of work to be done here (complete de-rivet/stripdown to iron out any residual stiffness, raise & re-orientate the boiler, and form a new steam pipe). Given its limited running potential (it is now out of gauge for our indoor 45mm layout as the high cylinder fouls a scenic arch) this is another low priority project.
Chris Cairns
(edit to correct grammar)
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