Garden Railway Forum

Update on the Dream Steam webpages for MSS locos and wheelsets:

"Please note: If running this product on Peco track, its tyre and flange profile means it requires a minimum radius of 3 foot 6 inches to avoid binding. This issue is not evident on the MSS or Mamod 2 foot 6 inch fixed radius track."

Direct relevance to another thread I started! Is this a known phenomenon on this forum that I had missed?

(Query to Moderators: should this sub-forum be renamed "Mamod and MSS" as there is so much crossover?)

It seems strange that the problem goes away on a tighter curve. This suggests to me its something to do with the track construction.

A fairly brief on line search has revealed non of the construction details for Peco SM-32 track I was looking for - but then I am technologically challenged!

My first thought is that Peco may be inclined in at 1 in 20 - which Mamod/MSS track certainly isn't! This shouldn't affect the gauge, which should be the same in both cases at the gauge corner of the rail head, however, the 'running table' (i.e the top of the rail) would present a very different profile to the wheel tread. My other thought was whether there was any physical clash between the bottom of the flange and the rail fastenings on Peco. I'd expect to see evidence of the rolling stock 'bouncing' over the fastenings if this was the case but if it's 'only just' foul then that might not be obvious.

I would expect 'flange bind' to be the main problem though and this is almost a pure function of wheelbase against radius - the tighter the radius or longer the wheelbase the greater the friction between rail and wheel. This may be linked to the first point above but I can't see it myslef. Hopefully someone cleverer than I (and there are many ) can shed some clearer light on the problem.

Andrew

I have never had a problem running mamod SL1s on peco track even with very tight radii. Whether the set track is different I don't know but on older flexible there are no issues that I have seen.
I don't know about MSS wheel sets but I thought they were the same as Mamod.

CSL wrote: ↑Tue Sep 05, 2017 8:39 am (Query to Moderators: should this sub-forum be renamed "Mamod and MSS" as there is so much crossover?)

I would need people who know more about these brands to confirm if this is the case as I understand Mamod and MSS are different companies making different engines?

tom_tom_go:

The MSS loco and rolling stock *are* the old Mamod products with a few minor changes (including the dome and the wheels - see my next post!). If I've understood it correctly, at some point Mamod lost or sold the rights to their traditional designs, and now offer a new range.

This explains why replacement parts for my old Mamod are from MSS - because the loco design is no longer Mamod's.

As well as this crossover, both MSS and Mamod's cheaper products are "entry level" garden railway/live steam equipment so it seems to me that this subforum covers them both and ought to be titled accordingly.

To clarify, the issue is that MSS wheelsets will negotiate the fixed curves from both MSS and Mamod which are 2'6" radius, but will bind on Peco SM32 flexitrack at less than 3'6" radius.

My old (c.1990) Mamod SL3 is quite happy with its original wheels on my Peco flexitrack bent to 3' radius , but when I fitted new MSS wheelsets (because the original wheels are loose on the axles) it would bind. No binding occurs on any other stock tried, including a Bertie, which has a longer wheelbase than the Mamod. There is no flange tip/rail fastening contact (except with Hornby O gauge stock, but that's another story!).

The issue appears to be that the MSS wheels are machined with a flange that doesn't taper to the tip (it is visibly thicker at the "point"), and this interferes with the Peco rail profile - but not with MSS or Mamod rail profiles - at radii less than 3'6". The original Mamod wheels do have a tapered flange and so have no problem on the Peco track. MSS wheelsets have noticeably less lateral play between the rails than other types, too.

To summarise, it seems that you will can expect problems if you try to run an MSS loco (or original Mamod SLx loco fitted with replacement MSS wheels) on Peco track at less than 3'6" radius. I am rather surprised this hasn't been noticed earlier - presumably other owners of Mamods with dodgy original wheels have more railway space in their gardens than I do and lay their curves accordingly!

Thanks for the additional information. thicker flanges could, theoretically extend the wheelbase slightly - and it wouldn't take much to cause the problem. It also sounds like the back to back dimensions has increased and that could have the same effect.

Your advice is very useful. This sort of freely shared information is one of the best features of this forum.

That is rather interesting. Thanks for the information.

It is interesting, but I cannot understand why there is a problem with Peco Flexi Track? Does the same occur with Peco Setrack?

I have just compared some Mamod/MSS track with some Peco Flexi Track and the profile of the part of the railhead which will be in contact with the wheels are very similar, with similar measurements between the rails.

I already mentioned on your other Topic ( https://gardenrails.org/forum/viewtopic ... 44&t=11255 ) that MSS flanges can be too thick so even with the correct back to back measurement they will be wide to gauge. This is confirmed with your statement above -

MSS wheelsets have noticeably less lateral play between the rails than other types, too.

So is your Peco Flexi Track actually at the correct width between the rails where you are having these binding problems?

Mamod wheels varied between production by the 4 different owners in the 1980s. Some had 90 degree straight flanges whilst others had tampered flanges. Just checked two Mamod loco wheelsets. Set on an old SL3 have 27.5mm B2B with 30.5mm between the tapered flanges. Unused set have 28.5mm B2B with 31.5mm between the straight flanges. There were also variations with the mazak cast Mamod/MSS track - we had some on a portable layout that were less than 32mm between the rails on a troublesome curve.

Chris Cairns

Chris Cairns:

Thanks for your past and present responses to my posts.

"Does the same occur with Peco Setrack?"
I don't know. My garden track is a circuit of Peco flexi only apart from a single Peco point, which if memory serves has a 3'3" turnout radius (and causes less of a problem than the 3' nominal radius curves elsewhere).

"So is your Peco Flexi Track actually at the correct width between the rails where you are having these binding problems?"
I would have thought that if this was a problem then I would have found binding with other types of wheelsets, notably the longer wheelbase Bertie. But it doesn't occur, and there is no visible sign of gauge distortion.

I believe that Dream Steam have conducted their own experiments before amending their website, i.e. they have independently validated the binding phenomenon that I had experienced.

I remembered this evening I had a MSS loco visit my line years ago when it had a continuous run and it did not have issues running on Peco ST-605 curves:

(Off topic) Wow - raised track, tight curves, no side fencing and a manual MSS loco. Not sure I'd be so brave!

(On topic) It's curious, but as I say, Dream Steam must have amended their website for a reason.

Just to close off the main subject of this thread, I have now fitted Roy Wood wheelsets with success (details on the thread about running MSS locos on 4' diameter curves).

Hi, chaps. Older thread, I know, please direct me to the nearest set of stocks for necromancing the thread.

Have you guys noticed massive variations in the MSS driving wheels, too? Last year sometime, I bought a set of leading and trailing wheels for my old Mamod SL1. That thing was shaking more than Michael J Fox on a bender with Mick Jagger. So, I reasonably thought, it's time for a new set of wheels.

So I order my wheels, and blow me down, here's a thing for you. They're machined so badly that they do not fit the track at all. The flanges were massive, and the machining was so rough that it was like the machinist either didn't care, or they were actively trying to get fired. This wasn't just one set either, it was both lead and trailing wheels. They simply would not fit O gauge, and it wasn't down to being sent 45mm wheels either. Luckily Dream Steam are lovely, and sent me new sets. They do have a problem too, but it's not as major. The central hub on the leading wheels are bare metal, whilst the back is painted black.

Which leads me to another thing; I just got myself an MSS brake van kit. The wheels on that aren't square either. What is it with MSS and not being able to machine wheels properly? Is it a common theme with MSS or something? I also noticed the rolling stock frames are a lot thinner than they were under Mamod, too. Bent straight out the box type thinner.

To be honest, I'm not too surprised. The MSS wheels I initially got looked ropey once I'd realised what was going wrong (at first I thought I'd bent the frames and caused the wheels to bind on them) and made me wonder about production quality at MSS. Replacements didn't improve things either.
Looks like I should steer clear of MSS rolling stock too - a bit of a pity as their ex-Mamod products look better at first sight than new-Mamod (e.g. opening doors).

CSL wrote: ↑Sat Aug 31, 2019 10:19 pm To be honest, I'm not too surprised. The MSS wheels I initially got looked ropey once I'd realised what was going wrong (at first I thought I'd bent the frames and caused the wheels to bind on them) and made me wonder about production quality at MSS. Replacements didn't improve things either.
Looks like I should steer clear of MSS rolling stock too - a bit of a pity as their ex-Mamod products look better at first sight than new-Mamod (e.g. opening doors).

Right, and that's the thing that irks me. Mamod's old rolling stock looks like it's toy quality, but it's not bland, and it can be modified. The new Mamod stuff, whilst it's bland and uninteresting, it's likely going to be made of heavier gauge stuff. So you're left at that rather annoying junction of "Do I want it to look good, or work?"

I will say once their stock is rolling, with all 2 bits of MSS I got, it runs fine. The wheel's a bit wonky on one axle, but that's a "small" gripe. The axle box does also seem to bind a bit when the axle moves to the one side. I'll drop some weights into it, oil it up, and run it behind my Brunel for an hour or two, and see if it improves it somewhat. If you buy a kit, FFS check the wheels on the track before building the set up. I'm lucky I did that before rebuilding my Mamod SL1. Though, at this point, I think I may just get some Roy Wood wheels. Anyone got experience with them? Are they worth it?

The tolerances on the original Mamod wheels aren't great at all, it's an "It'll do" kind of job, but I'm not even gonna bother checking the MSS ones with my micrometer, just for the sake of my own mental health.

The problems I've had with MSS consist of;
*2 sets of wheels that don't fit O gauge track, and the ones that did were machined pretty roughly, and paint doesn't match on the central hubs.
*The trucks I bought had bent frames, and the metal is clearly thinner. (I've not taken my micrometer to them yet, but it's visibly thinner, I'm guessing about half as thick)
*The uprated safety valve I bought has RUSTED, and the gasket that was on it didn't fit. It was literally rattling around the thing.

Also, do the MSS fuel tabs last less long as the old Mamod ones? Am I getting high off the fumes or something? Because they seem to only last a few minutes at most. Am I hallucinating? Definite gas burner upgrade job I think.

the words Touch and Bargepole spring to mind. I haven't tried Roy Woods wheels but the ones he was selling at Reading in May looked well made. Roy is a nice chap I would give him a ring if I was you and discuss your problem. He may well have been suppling wheels to others with the same problem. What I did buy from him was relacement lubricator and water top up syringes.

Don

Danker Than Clanker wrote: ↑Sun Sep 01, 2019 5:12 am Though, at this point, I think I may just get some Roy Wood wheels. Anyone got experience with them? Are they worth it?

Yes.
And...
Yes.
It's the MSS ones that are cheap, not the RWM ones that are pricey.
(But remember they're differently quartered than the Mamod/MSS ones, so even if you think you only need one wheelset, you need both.)

Danker Than Clanker wrote: ↑Sun Sep 01, 2019 5:12 am *The uprated safety valve I bought has RUSTED

Mine too. Bit of a theme here, isn't there? And is it telling that the starter loco comparison in the latest 16mm Today did not feature anything MSS...?

DonW wrote: ↑Sun Sep 01, 2019 12:36 pm the words Touch and Bargepole spring to mind. I haven't tried Roy Woods wheels but the ones he was selling at Reading in May looked well made. Roy is a nice chap I would give him a ring if I was you and discuss your problem. He may well have been suppling wheels to others with the same problem. What I did buy from him was relacement lubricator and water top up syringes.

Don

CSL wrote: ↑Sun Sep 01, 2019 4:00 pm

Danker Than Clanker wrote: ↑Sun Sep 01, 2019 5:12 am Though, at this point, I think I may just get some Roy Wood wheels. Anyone got experience with them? Are they worth it?

Yes.
And...
Yes.
It's the MSS ones that are cheap, not the RWM ones that are pricey.
(But remember they're differently quartered than the Mamod/MSS ones, so even if you think you only need one wheelset, you need both.)

Very telling responses. I think I shall contact Roy Wood. I want to get a large scale Youtube channel going where I review engines with humour. I tend to find videos like that are a little dry, so some humour might attract more to the hobby, so I wanna have a word with Roy on the basis of upgrading engines as part of a series.

CSL wrote: ↑Sun Sep 01, 2019 4:05 pm

Danker Than Clanker wrote: ↑Sun Sep 01, 2019 5:12 am *The uprated safety valve I bought has RUSTED

Mine too. Bit of a theme here, isn't there? And is it telling that the starter loco comparison in the latest 16mm Today did not feature anything MSS...?

That is rather telling. That said, the afore mentioned series I want to do is going to have an MSS episode where I tear them a new one. I would argue MSS can be a good starter engine, if you're looking to get into model engineering, rather than modelling in the garden. If you're looking to get an engine that just keeps running? Spring the extra cash and buy a higher end Mamod, or Roundhouse Basic. That said, even the Mamod SL1 runs pretty consistently. Lord, I have one that I bought straight from a house fire. It was still black and smelled of smoke when I got the thing and it's my best running oscillator. MSS spares are a no go. I'm tempted to just make my own and sell those, at this point.