3d Printing

[daifly]

I've just enjoyed watching a 1956 BTF film about replacing some GWR bullhead track with flat-bottom track. The film visually entirely supports Dan & Simon's comments about bolts with top nuts. Apologies for suggesting that Cynric's nuts were anything but appropriate.
It's a most enjoyable 16 minutes if you've not seen it before:

 

[Simon]

I have just checked the GW Study group book ant bolts do seem to be the order of the day - without washers!

That's "chocks away" then!

Actually, being hyper-picky, it would look even better if you added some more to the bottom of the key, ie increased its depth. I appreciate that at its inner face this can't happen because of the foot of the (incorrect) rail, but this would surely only mean that the cross section presented at its end would not be uniform, ie it would be narrower in width at the bottom.

Although this in itself will look odd, especially on your beautiful drawings, I reckon that with the rail in place you wouldn't notice this, whereas with the current iteration the eye does see the key as being the wrong shape.

If its any consolation Cliff Barkers track suffers from this "skinny key syndrome"

Sorry, again.

Simon

PS Double check the rail inclination, Cliff didn't

 

[Dog Star]

Just in case this got missed in the flurry of comments yesterday...

Try this:- Extracts from Harvie...

The external link is to a post in Basilica Fields where I have written about the GWR Permanent Way circa 1895 based upon a paper, by Harvie, read to the GWR Engineering Society in that year. My post to Basilica Fields includes some of the diagrams from that paper and the one of relevance to this discussion includes a section through a chair with rail and key. The drawing shows nuts and bolts for fixing the chair to the sleeper with the bolt under the sleeper, a key which is an irregular section and which fills the web of the rail. What is not obvious from this drawing, and is described in the paper, is that the GWR keys were LH /RH in shape.

The chair in the drawing is that introduced in the early 1890s and has a life span of around 100 years (or until sidings from the steam era became an extinct species). The earlier photo in this thread, post no.37, shows two of these chairs as 2nd and 4th from LHS.

regards, Graham

 

[Eastsidepilot]

" 'Aint not no nuts not no how" possibly ?

Guv' I offer this for what it's worth, and I think the bolt head was an inch & a sixteenth across flats.

ATB, Col.

 

[Dog Star]

possibly ?

Colin, seems to me that Adrian Buckjumper has been providing you with some interesting academic texts... something by Mr Heisenberg - possibly?

BTW - what is the source the drawings in your recent posts?

regards, Graham

 

[28ten]

That's "chocks away" then!

Actually, being hyper-picky, it would look even better if you added some more to the bottom of the key, ie increased its depth. I appreciate that at its inner face this can't happen because of the foot of the (incorrect) rail, but this would surely only mean that the cross section presented at its end would not be uniform, ie it would be narrower in width at the bottom.

Although this in itself will look odd, especially on your beautiful drawings, I reckon that with the rail in place you wouldn't notice this, whereas with the current iteration the eye does see the key as being the wrong shape.

If its any consolation Cliff Barkers track suffers from this "skinny key syndrome"

Sorry, again.

Simon

PS Double check the rail inclination, Cliff didn't

It is but 3 clicks to change it Inclination is 3deg to match your standards.
Actually I really ought to draw up a wheelset so you can use it when you do your launch....

 

[Eastsidepilot]

Colin, seems to me that Adrian Buckjumper has been providing you with some interesting academic texts... something by Mr Hesienberg - possibly?
BTW - what is the source the drawings in your recent posts?
regards, Graham

"In quantum mechanics, the Heisenberg uncertainty principle states a fundamental limit on the accuracy with which certain pairs of physical properties of a particle, such as position and momentum, can be simultaneously known. In layman's terms, the more precisely one property is measured, the less precisely the other can be controlled, determined, or known."

Could be something to with nuts...

Graham, The source is from the third edition of British Railway Track, Design, construction and Maintenance.

ATB, Col

 

[28ten]

The UPS mad called today I have to say I am delighted with the results, you cant feel or see any banding A huge improvement on the last object I had printed 12 months ago, I can do something with this sort of quality.
Very difficult to photograph a frosted object with my old camera but here we go






Hopefully I can twist the Bath Bodgers arm to have a go at resin casting a couple...

All those little odd chairs (Sorry Graham!) are very much possible, it just hinges on casting.

 

[Simon]

The UPS mad called today I have to say I am delighted with the results, you cant feel or see any banding A huge improvement on the last object I had printed 12 months ago, I can do something with this sort of quality.
Very difficult to photograph a frosted object with my old camera but here we go View attachment 10981

View attachment 10983

View attachment 10984


Hopefully I can twist the Bath Bodgers arm to have a go at resin casting a couple...

All those little odd chairs (Sorry Graham!) are very much possible, it just hinges on casting.

That looks awesome, I'll very happily resin cast some but we/you really need a better medium/method for serious production.

Any chance you could finish the job off by getting them properly squirted, in an ideal (garden) world they'd be attached to sleepers too

Seriously, that is a terrific result Cynric - congratulations

Simon

 

[Dikitriki]

That does look really good - the first time I've seen one of sufficiently good quality that I would consider capable of being a master for brass casting.

Can I please ask how much the printing cost?

Richard

 

[Dog Star]

That is an awesome result... you just need to do the special chairs for crossings (and in 7mm).

If the key is attached to the chair then how will you cope with the chair which is against the fishplate? No room to swing a cat (at the key) let alone a key hammer.

 

[28ten]

That looks awesome, I'll very happily resin cast some but we/you really need a better medium/method for serious production.

Any chance you could finish the job off by getting them properly squirted, in an ideal (garden) world they'd be attached to sleepers too

Seriously, that is a terrific result Cynric - congratulations

Simon

If we can cast a few tests then I will draw up another more appropriate chair get CMA to cast a 1000 which should do me. If you are happy for resin casting in the garden then its easy to draw up a solid model with sleepers attached
The whole thing gets rather more serious when it comes to injection moulding them for garden use, but anything is possible given the cash

This also gives a green light to a 1/32 railbus....

 

[Simon]

This also gives a green light to a 1/32 railbus....

Crikey - that's a right knee trembler and no mistake Guv

As regards Grahams fishy question, you do another version with the key knocked in from the other side - simples.

If you do a sleeper unit, by having one of each on each sleeper (which I think is prototype practice) then you can turn the sleepers around to achieve the same result at joints. On my garden line each succeeding "panel" has the keys knocked in the "other way around" if you see what I mean.

Simon

 

[28ten]

That does look really good - the first time I've seen one of sufficiently good quality that I would consider capable of being a master for brass casting.

Can I please ask how much the printing cost?

Richard

£4 for the chair , £8p&p

That is an awesome result... you just need to do the special chairs for crossings (and in 7mm).

If the key is attached to the chair then how will you cope with the chair which is against the fishplate? No room to swing a cat (at the key) let alone a key hammer.

I guess I will need to do 2 masters. Having got over the first hurdle the next is getting a durable casting from them.

 

[S-Club-7]

... you just need to do the special chairs for crossings (and in 7mm).

I'm working on some 7mm ones but with only limited time they're taking over 2 months each (and there are over 100 different chairs on my "to do" list...). Try here http://www.shapeways.com/model/408214/check-rail-chairs-1-02mm.html for links to check rail chairs for various 7mm gauges. Pic shows the first S7 ones:

 

[Simon]

Cynric

I have tonight poured the mould for your exquisite chair.

First casting hopefully Thursday night.

Simon