Garden Railway Forum

After discovering the remains of another mamod in a box of bits un opened since I moved to Wales many years ago I have had a bit of a yearning for some Mamoding.
I think the cylinders need an upgrade to O rings.
What is the current situation regarding the quality of the piston upgrade kits offered by the various dealers, or am I better off going down the new cylinder route?

A slightly naughty question I know but I have heard a few rumors about some suppliers providing some slightly iffy parts.

I do not want to start a massive slagging off a suppliers session either.

Cheers Jim

Big Jim:109260 wrote:After discovering the remains of another mamod in a box of bits un opened since I moved to Wales many years ago I have had a bit of a yearning for some Mamoding.
I think the cylinders need an upgrade to O rings.
What is the current situation regarding the quality of the piston upgrade kits offered by the various dealers, or am I better off going down the new cylinder route?

A slightly naughty question I know but I have heard a few rumors about some suppliers providing some slightly iffy parts.
I
I do not want to start a massive slagging off a suppliers session either.

Cheers Jim

Love the last sentence! It seems to me that one of the problems of Mamods is the general perception of the locos both past and present. Regarded by many as useless toys, as model steam loco easily made suitable for dependable running, or indeed by others as a challenge from start to finish, They really are all things to all men. Quality of spares is also entirely dependent on how the end user of aftermarket goods reviews their purchase. To an experienced modeller with lathe and well equipped workshop the term "quality" applied to basic simple engineering may be completely different to that of the bolt it together and hope for the best type of modeller. I have received both excellent service and good advice from RWM and other suppliers regarding a recent Mamod rebuild. Mostly the advice given so freely in this forum though has been the biggest aid to the restoration of my little loco. Now I am looking for another "cheap as chips" toy to play with.

This subject is currently/ historically and exhaustively discussed on http://modelsteam.myfreeforum.org under various 'Locomotives & Railways' threads - as I'm sure many readers here know.

If you are actually going to renovate a Mamod, that's probably the place to be asking the technical questions.

steampig:109286 wrote:This subject is currently/ historically and exhaustively discussed on http://modelsteam.myfreeforum.org under various 'Locomotives & Railways' threads - as I'm sure many readers here know.

If you are actually going to renovate a Mamod, that's probably the place to be asking the technical questions.

What technical questions. I don't actually have any.

Enginehouse:109288 wrote: What technical questions. I don't actually have any.

The thread founder appears to have some.

Thanks for the info and the link folks, I shall peruse it carefully

Its not so much technical questions as I have stripped and re built various Mamods and for the most part I know what I am doing (well sometimes) its just a question of who is making parts that are actually worth fitting as the last time I attacked a Mamod was nearly 20 years ago and most of the spares and upgrade parts suppliers that I used then are long gone.

I have read most of the posts one here about people producing parts that are possibly not fit for purpose and I don't want to end up spending the wifes housekeeping on iffy bits.

I'll just put my Tin Hat on first Jim, as the originally disagreements by 2 former Directors indirectly created this Mamod sub-Forum, and the last fallout creating the only Locked topic in this sub-Forum which scared many of the previous contributors away (I've been restricting my postings to Mamod's Brunel & Thomas Telford since then).

The only trader that sells the 'O' ring piston upgrade kit is Dream Steam. I do not have any experience of that particular kit, but I've fitted the IP Engineering kit (out of which the Dream Steam kit was developed where they include an 'O' ring for the piston gland although their instructions are a direct copy of the IP Eng ones where no packing was provided for that gland), and have a couple of locos fitted with the Mike Chaney/Salem Steam/MGM Engineering 'O' ring piston upgrades.

The weakness of these kits is you are reliant on using the original Mamod SL/MSS cylinder bore which had/have variable tolerances throughout their production. Thus you may find the end caps might be too loose a fit for your particular cylinder. Whilst you can re-use the plain end cap from your cylinder, the end cap with the piston gland presents another problem. I've heard of some trying to fit these end caps with Loctite, but you risk having an end cap that may not be removed again if using too high a temperature version (the cap will probably come off again with a lower temperature Loctite). I know some have been successful in soft soldering the cap back in place.

Assuming your kit has fitted OK you now have the problem of stiffness that a new 'O' ring introduces. You will read here (& elsewhere) of Mamodificationists running into troubles with major steam leaks and stiff cylinders after upgrading and they go off looking into replacement reverser valves, etc.

Here's what I do (and it worked with a brand new set of cylinders on my PPS/RWM De Winton). I flood the cylinders with a light 3 in 1 oil and work the piston back & forth. With the kit you get replacement springs which are stronger but I would recommend using the original Mamod SL/MSS ones at least until you have bedded in the 'O' rings then you can fit the replacement springs. I then run in my loco using the lighter ISO 220 steam oil.

Most Mamodificationists will prefer to fit an inline lubricator but have they considered what steam oil it has been metered for (the size of the hole drilled into the steam pipe). The Roundhouse lubricator is drilled for their 220 steam oil. I think the RWM lubricator is drilled for 460 steam oil (a question for Roy at Peterborough). The Dead Leg lubricator was/is designed for 460 steam oil.

You may have seen the MSS cylinders which have a blind copper rivet fitted into the hole on what should have been the plain end cap (they have obviously had too many piston rod holed end caps made up). Reports from owners is that those blind copper rivets are fouling the piston thus badly affecting the loco's running. Not sure if these faulty MSS cylinders are still being produced (one to check with Dream Steam at Peterborough if I've got time).

Chris Cairns

Jim, I've had good results from the dream steam upgrade kit on two locos. Provided the cylinders are reasonably smooth inside they work well. I don't fit the upgraded springs as I find they are much too strong, however my locos don't run above 20 PSI. I've got 3 locos with different upgrades to the cylinders and can't tell the difference between them. If there is something specific you want that isn't around anymore I could probably make a copy.

Thanks Chris for the essay!

I had a feeling that Dream Steam upgrades were the only ones still available. I don't know what I will do to the engine (if any thing) as I do have other well modded Mamods that did run really well but have been dormant for quite a while.
I remember 20 years ago when every man and his dog seemed to be making bits to nail on to your Mamod, some quite sensible and exquisite in their designs and others that almost defied belief. I remember at Merston one year a chap who had marketed an RC kit that consisted of a servo that you screwed to the front of the saddle tank and covered with a brass box with a lid on it in a vain attempt to make it look like a sandbox (remember this is before micro servos appeared on the market!)

Dan, thanks very much for your offer, I may well be in touch.

Jim

Dream Steam - use piston upgrade kits that keep your original cylinder housing. Dr. Cairns has already expounded on these already. Not personally tested these, cannot say.

RWM -'off the shelf' power upgrades - see their cylinders rtr and inline lubricators, always been a good thing.

Any one got any idea if the old style regulator kits are still available? The ones that worked off the steam line from the dome rather than fitting in the whistle aperture.

im in the process of upgrading my mamod at the minute and im going for RWM uprated safety valve and water top up valve along with a tony green meths burner which works very well. i dont have alot of money so for me its make the best out of my little mamod which gives me hours of fun (although decided to start playing games this evening). the little upgrades im doing on mine are knowhere near to the extent that some people go to with theres (each to their own) as i like to keep things looking as original as possible but get the best from them.

the only reason im using RWM is that everyone ive spoken to has suggested him, thats not to say that dream steam or manor models are bad or anything along those lines as ive had good dealings with both.

Big Jim wrote:The ones that worked off the steam line from the dome rather than fitting in the whistle aperture.

Those would be the Mike Chaney regulators (there were two versions) Jim. Unfortunately no longer available.

Not seen any come up on eBay for some time now.

Chris Cairns

Cheers for that Mike, I think a post in the Wanted Section is in order then!

I've always been curious as to how that style of regulator worked as I have heard rumors that it was no better than the original valve. Not sure if that's good or bad as I've never had a problem with the original set up. I suppose the alternative is an exhaust regulator.

Nice and simple. It came with a replacement pair of steam pipes. You fitted it to the backhead with the two retaining screws. The only issues you might have had was if the backhead was riveted on then they needed drilling out and the holes tapping. You had to cut a little bit away from the meths burner flame guard to run the pipes under the boiler.

My two engines with these fitted ran very well and were very controllable with the long regulator lever. I even fitted RC to one. The regulator only needed about 90 degrees to go from off to supersonic and a crawling speed was possible.

On my first mamod it was the first mod I fitted after the meths burner and high pressure safety valve.

DLRdan wrote:I've always been curious as to how that style of regulator worked as I have heard rumors that it was no better than the original valve.

I have one fitted to a modified SL1K, which also has Mike's upgrade boiler, dead leg lubricator & 'O' ring piston upgrade. It definitely offers better control over the original combined regulator/reverser valve, and as Jim has said can be converted to Radio Control operation.

I have a similar regulator fitted to a Samson Locomotive Works Mamod inspired locomotive. On that regulator it has less than 90 degrees movement between closed & fully open so I need to use the reverser valve as well to keep this loco tamed.

Chris Cairns