Sam builds a mamod (was building pioneer)

[Lner fan Sam]

So for Christmas I got a mss live steam loco kit. This thread will be about the build and modifying the kit to get the loco to a reasonable standard. The loco will be made in a comprehensive workshop in which I will be making some upgrade parts myself like pistons, wheels and most importantly a new boiler. I am doing this mainly to save money but also to get more experience on the lathes and milling machine we have up there.  

so lets begin...



So here is a general view of the workshop which contains 4 lathes and 3 milling machines, plenty I think for a mamod!



Here's a view of the lapped reverser lever, reverser block, cylinders and the port faces. I will be using these cylinders for testing purposes and then I will machine bigger and more powerful ones.



However it is not all plain sailing. This pic shows the combustion chamber has a slight deformity at the cab end of it. we have already devised a plan to rectify this.



And also the reverser lever solder paste had not sealed properly leaving three small holes. This has since being soldered up.



Here's a view of the lathe been set up to start turning up the wheels. it later turned out that the bar was high tensile steel which would not turn properly in the lathe.



another view of the lathe.



I also received a parcel from Roy wood models containing...  



all of this plus a pressure gauge and water top valve.

now I was going of to beamish this Saturday but this dam snow has stopped me!!!

[Chris Cairns]

Sam,

Welcome to the World of Mamodification. Interesting to see some of the modifications already planned before the kit is even completed.

If those are the original cylinders looks like MSS have taken a backwards step in changing them. One weakness of the old Mamod SL cylinders was the end cap through which the piston rod travels was either not drilled fine enough or wore out very quickly causing a fair bit of steam to leak there (one reason for gland nuts on after market replacements). Previously MSS had used a thicker gland on that end cap. Wonder why the change back to a previous configuration?

Chris Cairns.

[Lner fan Sam]

Yeah Chris I was wondering that myself. When I first got the kit and had a look at the cylinder I was surprised to find the end cap attached by a copper rivet. Checking both cylinders the rivet on both is poorly fitted.

[Chris Cairns]

Interesting.

The end cap I was referring to is A2 in this photo from my MSS kit build.



And also marked A2 in your photo.



I assume the rivet you are referring to is on the end caps marked E. As I cannot see how a rivet would attach to anything there I wonder if they have had too many plain end caps drilled and then just riveted up the ones fitted on the opposite end to the piston, to plug the hole.

Here is what an original Mamod SL cylinder looks like in pieces.



Chris Cairns.

[Lner fan Sam]

Thanks for the info there chris. It's a weird design chose that mamod and mss have made there.

[Keith S]

I'm looking forward to seeing what you do with this locomotive. With all those machine tools, you'll soon be building your own locomotives!

[Lner fan Sam]

Thanks Keith. After this loco's complete I will be scratch building some coal wagons for it. After that I might make industrial saddle tank loco.

The workshop is part of a 7 1/4 gauge railway set in the grounds of a museum called beamish, more info on the group can be found here:http://www.bmeg.co.uk/.

(and yes the railway is home to the world first 7 1/4 gauge rack railway)

[tom_tom_go]

Cor, I could lock myself away for weeks in that workshop!

[Lner fan Sam]

yeah its a great workshop tom, apart from tools going missing and the tripping hazards but apart from them its great!

The loco is now hopefully being built in two workshops to speed up the build as I only get to work on it once a week. Hopefully over the Easter holidays I can work on it more.

[Lner fan Sam]

Quick question guys, how slack should the bearings be on some steel upgrade wheels. Trail fitting them to the frames is causing some concern at how much the frames move.

[Spule 4]

The reverser and bodywork and the center brace are the alingment bits. Yes, it can take some work to get the frames bind-free with lcoking wheelsets.

[Lner fan Sam]

So once everything is in place on the frames should the frames lock in place (stop moving).

[DLRdan]

If it is just the wheel sets in then the frames will move a lot. The upgrade wheel sets have tapered holes in them to allow for small misalignment in the frames. if you want to stiffen it to take measurements quickly, put the central chassis spacer in.

[Spule 4]

Another recommendation is to get the "drive train" built and running on air for a while, I did it on my two locos for about half an hour before completing. Use plenty of machine oil.

[Lner fan Sam]

Thanks for the help guys, the parts are currently at mike lax loco works being assembled into a rolling chassis.

Next part to make, cylinders!!!!

[Lner fan Sam]

Another question guys.

I have decided to use the original boiler. It will be operated up to 26psi. I have a top up valve that is for use for boilers at 40psi. Can I still use this top up valve in the original boiler. (its threaded to 1/4 BSF)

Thanks in advance for the help Sam

[dougrail]

Hi Sam,

Fraid not, in short.

For some reason, the standard boilers and superboilers [IPE, DS, RWM, PPS, (Chaney?)] have different threads. In short, a 26psi SV for brass boilers won't work on a copper superboiler as made by the above, nor wil one of the above's 40+psi SV's work on a brass boiler loco.

One thing one has to consider when they consider just how far they want to upgrade and spend.

[DLRdan]

IF they are the same thread you can use it Sam but if not they are not hard to make, I've got it down to 25 mins

[Lner fan Sam]

Thanks doug and dan!!

I did try it in the boiler insert and it did fit but was rather tight (then again mss think that painting THREADS is good build quality)

Why mss why????

[dougrail]

Apparently one can make a standard Mamod 'nub' 12psi SV work akin to a 25psi SV by messing with the spring. Not 100% on it but believe it doable.

Dan, as an offtopic, very quickly, if you can make water topups in 25mins, may I ask how long it took to make the custom domes NarrowM and I have?