Answer to Bad Running SL1Ks & possibly other Mamods

[Chris Cairns]

I have 2 SL1Ks in the workshop which I have been working on for some time. One is Loco No.8 (http://gardenrails.myfreeforum.org/about395.html ), and the other is the one being sold to made-in-england.

As I did not like to sell a loco that is not running properly, and as both these locos had similar symptoms (more steam backwards than forwards, and max steam not like normal runaway Mamods), I decided to investigate further.

I thought that the cylinders may have been part of the problem, but when cylinders from an SL3 project were put into the SL1K, there was no change. However after a boiler repair in the SL3, plus fitting wheels that were missing, this displayed the usual runaway characteristics.

So my focus was now on the Reverser/Regulator valve, and the guilty part has now been found.

A comparison of the rotating part of the valve reveals all.



On the right we have the faulty valve from the SL1K, and on the left the valve that I fitted from an SL3. If you look closely you will see the faulty SL1K valve has had the slots cut out incorrectly, and they are full of solder as well. Thus the free passage of steam has been compromised. Interestingly, a mint boxed SL1K, which I have for collection purposes only, has a valve with the required cut outs, but with some solder contamination. So somewhere in the Mamod ownership takeovers which occured around the Railway System production there were some faulty valves made.

However the problem has not followed on to MSS, or perhaps they were aware of the problem and corrected it.



A MSS replacement valve from Dream Steam, the SL3 valve, and the faulty SL1K valve.

So for all of you having a similar restriction of steam and poor running for no other apparent reason, then take a close look at your valve.

My problem now is how I fix this faulty valve, and probably the one fitted to the other SL1K. I'll probably heat these up to separate the 2 parts that have been solder pasted together, and try and adjust the cut outs to something near to the required shape and resolder back together. I would like to reverse this faulty valve to get the slots better cut out, but I think the lever portion which has just been bent, will probably break off if I try to bend it the other way. So perhaps a new lever may need to be soldered onto the side of the repaired valve.

But that will have to wait until I've settled into the new job first.

Chris Cairns.

[ACLR]

thanks Chris for that useful information. will now take a look at my SL1k to see if it has the same problem

[SillyBilly]

Perhaps the solution is to purchase the PPS new design reverser? Not cheap at £20 a loco.

[Chris Cairns]

I have the PPS reverser/regulator fitted to my IP Jane, and personally do not think they are that much better for the price (still gets the odd bubble of steam leaking and of course is only normally to set direction on the IP Jane). And with 2 bad valves, £40 is a lot of money. So I'd rather fix what I have.

Just removed the valve from my 2nd SL1K. I remember when I first started to get this loco sorted out that I had to dig out the solder from those slots. Although as this photo shows, it has been subjected to a similar poor quality control on the cut outs, and has been mounted in reverse (you can just see where there should be a flat finish on the left side, is actually on the right side of this valve).



This valve looks easier to fix as the lever has not been bent over so much so hopefully some heat will persuade it to bend in the other direction.

Chris Cairns.

[grumpfuttock]

If I remember rightly, at some point in one of the Mamod ownership changes, production was moved to Slough. Parts that I bought after this time, were extremely badly made, in comparison to the quality of those on my original Mamod loco which was bought when the first loco's came on the market, and I believe were produced in Birmingham. I still have a cylinder somewhere, that was bought from Mamod after the change of ownership, it is classic, as one of the steam ports has half a hole ! Not a hole half drilled, but a "D" shaped hole---- just half the diameter it should be !!! Also the steam ports on any replacement cylinders assembly's I bought at that period in time did not properly line up. No wonder the loco's gained the unfortunate reputation of "either you get one that will pull the skin off a rice pudding, or one that doesn't".

Good luck with the correction of the reversing valve.

[steamyjim]

Thanks for posting the information Chris!

[Chris Cairns]

Yes I agree with the Slough theory.

SL3s appeared in 1981, but SL1Ks did not appear until 1983. My boxed SL1K is Slough addressed so would date it after December 1984 when Mamod was sold to Jedmond (Engineers) Limited, 197 Bedford Avenue, Slough. I have previously been aware of the holes not lining up, etc. and always check for this when I relap the cylinders. Just was not aware of the correct shape & orientation of the valve when I've been relapping these valves in the past.

I managed to get the 2nd faulty valve apart, and after some trouble removing the old solder, it has been re-assembled with the cut out portion in reverse. Only problem I have is the lever needs to be bent along the top of the valve before going up (should have looked at another one whilst I was doing it), so the lever is currently rubbing against the smoke box, and steam is leaking when it is supposed to be closed. A few more bends should sort that out. 1st faulty valve will need more work done on it.

[fred]

Thanks Chris and all just checked the valve and it seems to be cut out right, Does anyone know what the MSS saddle tank is like?
thanks
Fred

[Chris Cairns]

Does anyone know what the MSS saddle tank is like?

Very poor, not worth the extra cost & requires a lot of work to get it running properly. For some reason MSS will not release the Saddle Tank as a kit loco.

I've covered most of my problems in this posting - http://gardenrails.myfreeforum.org/about279.html This is currently sat back in its box awaiting time to modify the rear bodywork to allow the false steam chest to cover the water top up valve, but still be removable.

Sam's (South-Trethevy) Saddle Tank 'Golly Gosh' was a good runner but I think that is currently sidelined with the 'loose wheel syndrome' and a missing reverser/regulator valve which went to fix his MSS side tank whilst on loan to the MHLR.

[Chris]

Thanks Chris and all just checked the valve and it seems to be cut out right, Does anyone know what the MSS saddle tank is like?
thanks
Fred

My saddle tank was utter rubbish. Sent one back as it was damaged in the box. Second one ran badly backwards, not at all forwards and then the wheels fell off. Not good for something bought brand new.

My tale is over on the mamod forum (don't think this place existed at the time).

New things shouldn't need work to get them going. Sure a bit of running in, and a bit of tinkering to get them running better maybe, but they should at least stay together and run.

[SillyBilly]

New things shouldn't need work to get them going.  Sure a bit of running in, and a bit of tinkering to get them running better maybe, but they should at least stay together and run.

I'm not pointing fingers, and neither do i want this to go off topic, but I just wish some of the people who talk badly about Accucraft locos thought like this. Well done for having that attitude.

[steamyjim]

New things shouldn't need work to get them going.  Sure a bit of running in, and a bit of tinkering to get them running better maybe, but they should at least stay together and run.

I'm not pointing fingers, and neither do i want this to go off topic, but I just wish some of the people who talk badly about Accucraft locos thought like this. Well done for having that attitude.

I agree there Will. If something doesn't work i always have a go at some tinkering...if i can't get it working then (which has only happened once * cough Sussex Steam cough *) then i will send it back and get the factory to have a look over it...even then Sussex Steam couldn't get it working

[SillyBilly]

I didn't tinker with it, a friend offered. You don't tinker with stuff you get your grandad to !

[steamyjim]

I didn't tinker with it, a friend offered. You don't tinker with stuff you get your grandad to !

No, i get him to machine stuff

[fred]

I didn't tinker with it, a friend offered. You don't tinker with stuff you get your grandad to !

Ahem Gentlemen, there are some of us who don't have Grandads and have to rely on this Forum for help and it's members to learn about a new pastime I've found late in life and I say this as a GRANDAD, in his very low sixties in W/chair (and just getting over a stroke), so - be careful - 'walls have ears'
Fred