Garden Railway Forum

I have read a very well written review in 16 mm today about the new Brunel. SLIDE VALVE! I love Mamods but Dont want the problems. The reviewer said he was pleased with it as it didn't stop and go into reverse as he expected up a slight gradient. Then I saw a you tube video of one going up a gradient and self reversing. It was portable track and possibly a bit slanted. Uphill-- perhaps.also Mamod were going to change the gearing. I will if I have to , continue saving for a Regner But I d rather not. It s better then an is I but is it worth the hassle?

Although we have a few members who own Brunel's , only 3 of them have decided to share their experience of running these with the rest of the Forum - http://gardenrails.myfreeforum.org/ftop ... -asc-0.php

I recently posted a link to a video which includes another Brunel changing direction (on the flat) by itself. I have not experienced that with mine but have had other problems.

My personal view is the problem is the type of piston valve cylinder used, and that is backed up with the other piston valve cylinder loco, the William II, being removed from their catalogue, and the upcoming Thomas Telford failing to steam properly leading Mamod to have a new slide valve cylinder designed for them along the lines of the Roundhouse slide valve cylinder.

We have confirmed that Mamod use nitrile 'O' rings (would viton be better?) on the pistons and their design of lubricator means it is a total displacement one, so the 'O' ring is not being lubricated over the whole run. By lots of perseverance I have now got my Brunel to run OK and that included doubling up the 'O' rings in the piston gland to stop the steam leak there which was then washing out the lubrication on the drive shafts.

I've just read the 2 reviews again (Garden Rail & 16mm Today) and whilst the Garden Rail one did not have the problem, the 16mm Today had problems with the burner. I have covered the flame creep problem on the other Topic (just needs the burner moved a little towards the centre) and the other thing that most owners miss out in the instructions is you light it up on a minimum setting, wait 30 secs for the burner to warm up then turn up as necessary.

Having seen a Regner Willi running recently very well & much slower than my Brunel I can see the advantage in changing the gearing ratio such that the engine will be running faster (thus overcoming the 'O' ring friction better). Mamod told us that the change could not be retro-fitted onto earlier models. Not aware if they have made the gearing change yet - if you do Facebook Mamod are active there so you could ask the question.

If you've watched my YouTube video ( http://youtu.be/JHmlCPxFo1o ) the reason you do not see much of my Brunel running is because I only had 3 items of serviceable centre buffer rolling stock at the time, which is why I added the Llanfair footage showing a Brunel running well with a heavier load.

Hopefully Mike Wakefield can add his comments here to give a more balanced view, as he has changed the gearing, fitted radio control and runs on a graded line.

Chris Cairns.

(edited to correct grammar).

OK, here's my experiences/opinions of the Brunel:

Straight from the box I found it had a tendency to run away on the downhill gradient of my outside track (steep gradient and tight curves) and then overturn when it came to the first bend. I therefore fitted radio control which enabled me to get it all the way round without a problem.

If it stops on the uphill section it will roll back and hence go into reverse because of the slip eccentric. I've had the same happen to another loco (not a Mamod) so its really just a feature of my track.

The Brunel is quite top heavy and the centre of gravity is over to one side because of the cylinder location. To get around this I moved the gas tank to the other side side and also fitted some steel blocks offset underneath so the centre of gravity is much nearer the middle and there's less likelihood of it turning over.

I haven't had any problems with the burner although I did move it to be more central under the boiler so the frames didn't get so hot.

As Chris mentioned I have managed to re-gear it from around 2:1 to around 4:1. This has enabled the loco to get around my track without running away on the downhill stretch and still to climb back up again without me making any regulator adjustments.  Its not perfect and would be better as 6:1 but there just isn't the room to fit the required gearing. Mamod say they're going to change the Brunel so it has wider gearing but this will require new frames. They'll be at Warley this year so I'll ask them for an update then.

After I re-geared my Brunel I removed the radio control as I wasn't using it (that's the great thing about Mamods - you can endlessly change things.

Here's a video of it:
http://www.youtube.com/watch?v=ahlf23HUDNI
At the time I still had the radio control fitted and hadn't altered the lubricator.

As Chris mentioned, the lubricator  was a total displacement design - ie all the oil at once and then nothing, just like the Mk11. I've since altered mine so its still a displacement lubricator but the steam simply passes over the oil in a tube with a small hole in it, which seems to work a lot better.

I've also got a Regner Willi which is beautifully engineered but gives me endless problems getting the burner to light, so it doesn't come out of its box very often.

Mike

Thank you. Lots of information.i was looking for a simple life! I might wait for a lower geared version.

thats what I am going to look at when i go to nec on the sunday. I will also wait until next year to get one or possibly a roywoods brunel,but as a few will know themself its spare money at the end of the day and many just dont have £500 to put on a model engine..

You can sometimes pick up a second hand Regner Willi for around £350.

Mike