Brunel Vertical Boiler Engine

A very popular starting point for Live Steam. With their low cost comes a number of problems which can be discussed here
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artfull dodger
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Post by artfull dodger » Wed Dec 05, 2012 10:36 pm

Very nice. I would keep or install a condsate trap before routing the exhaust up the chimney. Unless I overfill the boiler, and thus flood the trap and overfill it, the only thing up my pipe on my Willi is steam vapor. Willi is also a poker burner and not the ceramic type. Next year I will have to decide whether to go for a Brunel or a Chaloner. Mike

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Chris Cairns
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Post by Chris Cairns » Wed Dec 05, 2012 10:57 pm

happen to have an Accucraft part number?
I'm also interested to hear more about this (what diameter shaft is it designed to fit?) as it is not listed on the Accucraft.com website, or the Accucraft UK website. ACME Engineering & Milton Locomotive Works do a brass one for Accucraft locos.

Chris Cairns.

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Post by mikewakefielduk@btinterne » Thu Dec 06, 2012 6:33 am

I don't have a part number I'm afraid. Accucraft were at a small garden railway gathering last Sunday, selling some damaged and surplus bits and pieces. The regulator handles were £1 each so I bought a couple.

Mike

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Post by Chris Cairns » Thu Dec 06, 2012 7:22 am

were £1 each
That was a very lucky break.

Chris Cairns.

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Post by mikewakefielduk@btinterne » Thu Dec 06, 2012 8:16 pm

The regulator handles have a 4mm hole which is close enough to accept 1/8" brass rod (which is the diameter of rod I used).

No idea why Accucraft happen to have had a number of spare regulators for sale last Sunday but it may be to do with them fitting R/C gear to their locos. (As I understand it, their locos arrive from China with manual controls and Accucraft UK fit R/C as required.)

Mike

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Radio Controlled Brunel

Post by mikewakefielduk@btinterne » Wed Dec 12, 2012 1:59 pm

My first attempt at Radio Controlling the Brunel. Far from perfect but good enough for me to continue experimenting.

http://youtu.be/jXlAEudkzrw


Mike

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Chris Cairns
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Post by Chris Cairns » Wed Dec 12, 2012 3:09 pm

The problem with using Kwiklinks is they can foul on the servo arms as you have found already.

What you probably need to use is an offset control linkage using ball joints or push rod connectors, so that your servo and regulator arms are not in-line vertically.

Some examples here - http://www.rcmodelcentre.co.uk/Multiple ... _1702.html & http://www.rcmodelcentre.co.uk/SINGLE-B ... _1810.html

And you will need some form of secure servo mount.

Looks like you have a very nice running Brunel, running at 15 PSI and no visible steam leak from the piston gland. Sadly mine does not run as well.

Chris Cairns.

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Post by mikewakefielduk@btinterne » Wed Dec 12, 2012 4:22 pm

Thanks for the advice Chris, I've ordered the bits you suggest.

Since I made the video I've made a proper frame to support the servo but little else - its just too cold to work in my garage at the moment.

I think I've just been lucky with the Brunel's smooth running. I'd like to say Mamod's quality control had improved since you got yours but I don't think it has. My Brunel came with a wobbly wheel (as I've mentioned before) and no O ring on the regulator shaft. I've also re-tapped the thread on one of the studs holding the cylinder block together as the thread was stripped on assembly.

On delivery my Mk11 leaked steam so badly between the boiler and regulator that I took it back to Mamod and they replaced the whole loco.

Its not just Mamod. I've had to replace missing washers and nuts on my other makes of locos before I could get them to run.

Reminds me very much what it was like buying a UK made car in the 70's (and presumably prior to that - but before my time) and expecting as a matter of course to have to return it to the garage a few times as it wouldn't have been put together all that well. We probably need the Japanese to start making model steam locos :D. (Its at this point that somebody points out that they already do.)

Mike

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Post by Chris Cairns » Sat Dec 15, 2012 10:29 am

That is a worrying list of further quality control issues.

Given the small number of locomotives currently made by Mamod one would expect better quality control.

I have given up trying to get my Brunel to run properly for now (too many projects on the go), and my William II is currently checking out how good my patience is!

We wait to hear how well Thomas Telford is progressing?

Chris Cairns.

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Radio Control Successfully Fitted

Post by mikewakefielduk@btinterne » Sun Feb 24, 2013 2:10 pm

After having to go back to the drawing board fitting a R/C to my Mk11 I put that project on hold and instead spent the last few days working on R/C on my Brunel instead.

Pleased to say I've got it all working and the Brunel will now trundle around my garden track, including tackling the slope in both directions without running away and derailing.

Only problem was the cold - its still only 2 degrees - so all started really well but as the cold began to get to the gas the burner flame diminished and by the end I had less than 20 psi of steam pressure. Brought the loco in and within 10 minutes the pressure was back up to around 35 psi.

Now the R/C work is hardly what you'd call pretty but then again neither is the Brunel. I've put everything on the opposite side to the cylinder assembly which, together with two steel blocks underneath, has made the side-to-side weight distribution about equal.

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Mike

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Chris Cairns
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Post by Chris Cairns » Wed Feb 27, 2013 6:02 pm

Sorry I've not replied sooner.

Looks like you now have a good working R/C control on the regulator Mike.

Interesting to see you get as much condensate pushed out of the piston valve/piston rod area as I do, which leads me to think there is a problem with my drive train somewhere causing my poor running.

Do you use a butane/propane gas mix as your burner keeps the pressure up very well?

Chris Cairns.

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Post by mikewakefielduk@btinterne » Wed Feb 27, 2013 6:47 pm

I was just using Butane when I ran the Brunel which is why I think steam pressure was fine inside on the rolling road but dropped outside after a few minutes only to come back up when I brought it inside.

I've since been down to B&Q to buy a can of the Butane/Propane mix which I've used today on my Mk11. I find it burns rather more fiercely than straight Butane so you have to open the gas regulator just tiny amounts to get quite a large change in the flame pattern. (I learned this the hard way by opening the gas valve my normal amount and leaving the loco to warm up while I answered the phone. The result was blue flames appearing around the side tanks and a part melted Mamod decal.)

I have noticed a metallic ticking noise coming from the cylinder area when I run the Brunel under steam, but can't seem to hear it when running on compressed air. The nut holding the slip eccentric shaft to the piston valve seems awfully close to the vertical support so I'm wondering whether things expand when hot and cause it.

As a slight aside it looks as though Mamod have used a gas control valve as the steam regulator. Is it the same on your Brunel?

Mike

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Post by Chris Cairns » Wed Feb 27, 2013 7:29 pm

Mike,

Well spotted. Yes Mamod have changed to type of regulator used. Mine is fitted with the Mark I/II style one and I did have problems with it leaking till I changed the 'O' ring.

The nut on the back of the piston valve rod is meant to fit inside that cut-out as it is the same style as used on the Golden Jubilee/William/William II - just make sure the sides of the hexagonal nut are vertical within the slot.

Welcome to the world of melted Mamod decals! Yes butane/propane mix burns much hotter than butane only, and is recommended for cold weather use. I need to get some more to see if that will help with my William II woes.

Chris Cairns.

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Brunel Successfully Re-geared

Post by mikewakefielduk@btinterne » Sun Apr 07, 2013 2:24 pm

Well, after a bit of fiddling around I've successfully re-geared my Brunel from the 2.5:1 gear ratio it comes with, to about 4:1.

I was inspired by the way my Regner Konrad successfully chugs around my outside track without using remote control, despite the centre straight section have a gradient of about 1:20

The Brunel will now do the same without having to adjust the regulator but I decided to retain the Radio Control as it means I can stop the loco if necessary.

I put a video on Youtube: http://youtu.be/ahlf23HUDNI

I've managed the re-gearing without altering the locos frames. I replaced the wheel on the flywheel shaft with a smaller one with only 13 teeth and meshed it with a larger new one on the intermediate shaft. I then pinned the new one to the existing one on the same shaft so that one can drive the toothed wheel on the final shaft.

Image

An easier way to do would be to extend the intermediate shaft out through the frame on the flywheel side and install new wheels in much the same way as Regner do with their Konrad.

On the down side, while I had the intermediate shaft removed from the loco I was disappointed by the poor finishing of the two shaft ends that rotate in the brass bushes. Really deep machine marks where the shaft had been turned in a lathe and then not polished afterwards. Needless to say, the shaft ends have been polished now.

Mike

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Post by Chris Cairns » Mon Apr 08, 2013 2:15 am

Well Done Mike. It runs nice & slowly now.

It does prove that Mamod could offer this modification to owners of current Brunel's, although it will require de-riveting the chassis to get access to the intermediate shaft.

Good find about the poorly finished shaft ends - something else to look for when I get my Brunel out of it's box again.

Changing the subject slightly you are running a Cheddar Iver on Mamod track. What have you done to the point levers to stop them fouling the Iver's cylinder? On your video it looks like you have cut off the semi-circular frame and removed the point lever, so I presume you just move the points over by hand? I have a Cheddar Iver and a Cheddar/GRS Tram but I've not run them for a couple of years now.

Chris Cairns.
Last edited by Chris Cairns on Sun May 12, 2013 8:59 pm, edited 1 time in total.

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