Cleminson chassis drawing

[Portchullin Tatty]

Gents,

 

I have just started a workbench thread that kicks off with a Brassmaster's (nearly but not quite because it does not follow the patent) Cleminson bogie.

 

Whilst at this second the answer to MickLNER's is not posted, it will when I sort out some photo's - yes it can, yes it does improve their running (lots) but it is likely to require some surgery to the floor is a summary!

 

Ian, you seem to infer that your design twists the outer axles a bit - is this correct they look fixed to me? This struck me as the main advantage of either a true Cleminson or the Brassmaster's version.

[micklner]

Gents,

 

I have just started a workbench thread that kicks off with a Brassmaster's (nearly but not quite because it does not follow the patent) Cleminson bogie.

 

Whilst at this second the answer to MickLNER's is not posted, it will when I sort out some photo's - yes it can, yes it does improve their running (lots) but it is likely to require some surgery to the floor is a summary!

 

Ian, you seem to infer that your design twists the outer axles a bit - is this correct they look fixed to me? This struck me as the main advantage of either a true Cleminson or the Brassmaster's version.

 

thanks for update

[ianmaccormac]

Hi is it Mark? aka Portchullin Tatty,

Yes, the outer w irons rotate. The centre one slides sideways and lso floats. The outers twist about a bowtie shaped slot, this being controlled by how much the centre one slides sideways. Therefore anabling a tight radius to be traversed.

If you look carefully at the drawing you can see the shaped slot. I have also attached a photo I just took pushed the central wheel set over with a pair of pliers and you can now see, I hope, how the outer w irons are rotated. Oh yes, they have an adjustable wheelbase too.

Hope that helps,

Cheers

Ian in Blackpool

[ianmaccormac]

Hi

Here is a photo from the top showing the adjustable whelbase holes but you can just solder the w iron holder wherever you want it really.

Cheers

Ian in Blackpool

[ianmaccormac]

And this photo shows the real reason for developing this type of chassis - nothing sticking down! The coaches I model - early Stroudley - have a Westinghouse brake cylinder hanging down from the centre of the carriage and the operating wires went to each of the brake linkages at each outer w iron. The Brassmasters etch has a few things in the way of this so when I saw Dave at Roxey Mouldings idea for this, I asked if I could use the idea and develop it for other wheelbases, hence this etch. The main reason though, is that the LB&SCR used spoked wheels for brake carriages and this allows all the space to show!

I then went on to develop a sprung version that works well also.

This has been tested at Mke's Preston layout and with a shove, it went three quarters of the way around on its own - about 30 feet or so round curves down to 3 foot. It will go around a much tighter radius!

Hope that clears it all up.

Cheers

Ian in Blackpool

[ianmaccormac]

Sorry, I should have swapped the wheelsets earlier. This is what I mean. Clear space through to the other side and ends.

Cheers

Ian in Blackpool

[Portchullin Tatty]

Thanks Ian, I had not got this from your earlier posts.

 

In essence, this is closer to the true Cleminson patent (see I am learning Phil!) because the points of pivot are below the outer axles but uses a spring rather than a pivot and compensating beam. You need to ensure that the centre axle has sufficent weight to counteract the spring is about the only observation I have.

 

Certainly, this is a lot better than the fixed outer axles and lateral swinging only solution that comes built into the kit. I'll grab one next time I see the Roxey stand and give it a bash - as you say it makes affixing things lack a gas cylinder rather easier.

 

Has anybody cracked the tie bars between the W irons - they can only be soldered to one, as per the central spring in Ian's solution. I think I am going to use some tube on the other two and allow it to slide in and out.