Templot Plug Track Developments

[simond]

[Editors note : This thread has been split off from a wanted request C&L chairs - hence the rather disjointed start]


I'm sure I will need some GW 2-bolt chairs at some point. I'm happy to prepare the CAD if anyone can help with a drawing.

I have a vague memory of a drawing somewhere, GW Switch & Crossing Practice? GWRJ? I will look.

Templot plug track is an exciting development which I hope to indulge in soon. I don't know which chairs @martin_wynne has modelled so far - 3-bolt I think, but would have to look.

PS - here's a start April 2011 – Basilica Fields

 

[Lancastrian]

I'm sure I will need some GW 2-bolt chairs at some point. I'm happy to prepare the CAD if anyone can help with a drawing.

I have a vague memory of a drawing somewhere, GW Switch & Crossing Practice? GWRJ? I will look.

Templot plug track is an exciting development which I hope to indulge in soon. I don't know which chairs @martin_wynne has modelled so far - 3-bolt I think, but would have to look.

PS - here's a start April 2011 – Basilica Fields

Simon,

oldpway List of Drawings

oldpway.info's list of drawings of old permanent way.

oldpway.info

 

[simond]

Thanks Ian!

there's a chair drawing that matches the one in the link I posted, I think it helps get a good definition of the 1895 chair. I think the common GW one was 1902 or thereabouts.

atb
Simon

 

[Lancastrian]

Thanks Ian!

there's a chair drawing that matches the one in the link I posted, I think it helps get a good definition of the 1895 chair. I think the common GW one was 1902 or thereabouts.

atb
Simon

There should be one there in the 1905 Ross drawings

 

[Mike W]

Personally I'd 3DP a few and use them as patterns for casting. That's what I did, but mine will be no good for you because they are 3-bolt LNWR and Gauge 3.
Mike.

 

[adrian]

Nice idea - apart from the fact that I do not have an appropriate GWR dwg to prepare the 3D CAD... and experience with using 3DP chairs that do not stay stuck to the ply sleepers. I used superglue for fixing 3DP chairs to ply and there have been instances of chairs breaking free of the ply if knocked sideways (shades of real life results of driving wheels hitting chair jaws).

rgds, G

If you do go down that route I'd be interested if you'd keep an accurate log of time and costs, at the end of the day I can't help but feel that buying from C&L would be more cost effective (time and money).

 

[simond]

Adrian

I’ll try to do so

Atb
Simon

 

[simond]

1895 chairs




About 2.5 hours so far. I suspect the 1905 version will be a bit quicker. The currently have holes - but I can put nuts on in a couple of seconds.

I'll have a go at printing them tomorrow, as I have some work stuff running at the moment and that will not finish this side of midnight.

I am pondering the rectangular pegs that Templot Plug track uses, or simply round ones. I can see that rectangular will keep the sleepers perpendicular to the rail, which is probably a good thing, but does mean that you can't just drill a hole where you want a chair. Anyway, they are not mutually exclusive - having got to this point, I can easily add whichever type of peg (or no peg) and print to suit. Need to get on Templot and work out where the peg is in relation to the gauge face of the rail.

I will print the same way I do multiple items - I use a rectangular raft a little less than the shorter side of the build plate, with as many parts as I can fit comfortably spaced - I stand the parts on a leg (or legs) which rather than using chitubox, I design in the CAD. The whole sprue can then simply sit on the build plate. And as many as will fit. The whole print will take an hour or so. I'll work out costs when I slice it. They'll be cheaper than C&L by a long way, I guess. Whether they'll be cheaper than the S7 stores is another question.

Convenience - once I have printed them once, I can then print another build plate any time I want to make some track. No faff, no ordering, no waiting for the post.

atb
Simon

 

[Rob R]

Simon,
Which make of (model) rail have you designed the chairs for?
Different makes (Peco, C&L etc have different web thicknesses and none of them are to scale.. (so big brother says - S-Club 7).
A scale sized gap in the chair will be a bit of an interference fit...

 

[oldravendale]

A scale sized gap in the chair will be a bit of an interference fit...

A non-engineer asks can one have a bit of an interference fit? Sounds like an oxymoron to me. I suggest that what you are proposing is that if the track web doesn't fit one side or another of the chair will go PING. Followed by many rude words like "Oh goodness me, where did that go?"

Brian

 

[Rob R]

"A bit of an interference fit" = 8oz hammer
" interference fit" = Lump hammer (or bigger)

 

[Osgood]

A non-engineer asks can one have a bit of an interference fit? ......

If it helps any, I recently went into a shop (now there's a novelty) to get a replacement pair of stretch jeans (I'd put a best pair on thinking they were a work pair ).
I tried the same size on and was very pleasantly surprised at the significant clearance - so much so that I asked for the next size down.
My optimism was short-lived however, as I was aware of a bit of an interference fit which, although acceptable, was going to remind me I was pushing my luck a bit.
Now had the fabric been non-stretch the fit would have had to have been described as a significant 'interference fit'.

So, is there maybe a printable stretchy plastic that will do the same number on the rail as those stretch jeans did on me?

 

[simond]

Simon,
Which make of (model) rail have you designed the chairs for?
Different makes (Peco, C&L etc have different web thicknesses and none of them are to scale.. (so big brother says - S-Club 7).
A scale sized gap in the chair will be a bit of an interference fit...

I think it’s C&L or Peco, but maybe Marcway, err, dunno…. but it’s easy to adjust

And of course I do not know whether it’ll tighten or loosen when I print, so the best options to print a couple of sprues, adjust to fit, and then print as many as needed.

Brian, yes, of course, you can choose your fit to suit your application, they are tabulated based on the dimension you are tolerancing. The book of limits and fits is extremely useful but as interesting to read as a log table.

Here’s a summary

Preferred Mechanical Tolerances Metric ISO 286

The following defines the preferred tolerance basis for hole and shaft per. ISO 286.

www.engineersedge.com

Annoyingly, I forgot the fillet rad all round the upper edge of the baseplate. Easy to fix!

 

[Lancastrian]

Simon,
Which make of (model) rail have you designed the chairs for?
Different makes (Peco, C&L etc have different web thicknesses and none of them are to scale.. (so big brother says - S-Club 7).
A scale sized gap in the chair will be a bit of an interference fit...

Rob,

I'd agree in respect of the Permaway and S7 Code 125 rail, but the new C&L Code 131 should be a match for BS95R. I believe code 125 rail is a close match for BS85R. What would be good to know, is if the Exactoscale chairs were designed to match BS95R rail.

 

[simond]

And about another hour last evening, printed a few overnight. Not perfect, but certainly a promising start. They fit the rail well, I have not used Templot plug dimensions here but that would be easy to do - mine have a 3mm stub centred on the gauge face - I’ll laser cut a few timbers at some point.

I don’t yet have a cost per chair, but I’d estimate well under a fiver for a whole build plate full - that would be about 240 chairs I think





I reckon it’s perfectly feasible, it’s certainly cheaper and more convenient than buying chairs.

 

[OzzyO]

I reckon it’s perfectly feasible, it’s certainly cheaper and more convenient than buying chairs.

Only if you have the gear to draw it, and the printer to print them.

ATB

OzzyO.

 

[OzzyO]

Hello Simond,

are you going to have the chair fixing bolt heads at random angles and the keys going in from different ends of the chairs?

Looking good,

OzzyO.

 

[simond]

Hi Paul, thanks for the positive feedback.

well, you could make them with different angles, but time is the ever-present enemy. I have made right and left handed keys, 6 of each on each sprue of 12, and I put the four heads on at random angles. You’re not going to be able to tell that they’re all the same, they are tiny!

I’m not happy with the print supports on this batch, I probably lost 10% during printing, and maybe another 10% were just not very good, so they went in the bin. A bit of revision is called for.

I have had a brief e-chat with @martin_wynne and will replace my 3mm stubs with the standard Templot plugs, I’ll also print some without plugs.

It occurs to me that for those without plugs, I can print with the nuts, but without the tails of the fang bolts, just having a clearance hole through nut and chair. This is 7/8” so 0.51mm. That suggests that a couple of 0.5mm pins could be used to add a bit of rigidity/robustness to the chair/sleeper assembly. They can be over length, and simply be snipped off after insertion.

I do want to laser a panel’s worth of sleepers and assemble a short piece of track, but when I’ve done that, the chairs are going to go on my back-burner, as I’ve no immediate need for them, and I now know I can print useable parts with various options when I need to. I will put the STLs up on the resources section of WT when I get time.

Cheers
Simon

 

[martin_wynne]

I'm sure I will need some GW 2-bolt chairs at some point. I'm happy to prepare the CAD if anyone can help with a drawing.

@simond

Hi Simon,

Here is an actual GWR / BR(W) 2-bolt serrated-base ordinary chair, for BS-95R rail.

Overall dimensions are the same as REA S1 (14.5" x 8", corner rad 1"). The top of the outer jaw is 5.5/8" above the underside of the chair. The jaws are 4" wide at the top:







I can measure any other dimensions you want.

cheers,

Martin.

 

[martin_wynne]

@simond

GWR / BR(W) plain track chairs. Paddington R.3798A drawing -- Nov. 1948, amended 1958.

GWR / BR(W) 2-bolt versions of REA chairs on the left (for use with BS-95R rail.)

GWR chairs on the right (for use with GWR 00 rail).

Hi-res scan at: Plug dimensions




Martin.