TSD's Workbench - SECR and Industrial modelling

[sem34090]

A 3D printed 'O' from you, Mr T. Snail, would save me a job!

 

Need to make a start on a certain Stirling Single, of sorts, at some point too...

[TurboSnail]

I was planning to use the chassis I'm currently developing for the R class, provided it works - the wheelbase and wheel diameters are the same, the outline is very similar and would just need some modifications to the cab end to reflect it being a tender rather than tank engine. The tender is very similar to the F Class's and the way I've set up my CAD models means that I can just adjust a few dimensions (hopefully) and most of the work is already done.

 

Those F Class print photos will follow tomorrow if I have 5 minutes to spare - 100 kids descend on this place tomorrow, so it's all going to get pretty hectic...

[CarriageShed]

To add a bit more to the N gauge discussion about this project, I wish I could claim this as my own idea, but the truth is I still greatly rely on others to come up with the smarts!
 

Is the Terrier chassis without its body heavy enough to be used as a tender drive? Would replacing the weighted Dapol body with a 3D printed plastic (featherweight) tender top body produce a drive that won't pull anything (just like the M7)?

 

A suggestion made to me is that the tender design alone is made available to be printed in a metal. Apparently Shapeways do metal via a casting process. You may not get quite the detail but it will make a big difference to haulage.
 

https://www.shapeways.com/materials

What do you guys think? Possibly even some details could be added to the tender afterwards, such as mounted springs (available from BH Enterprises) and real coal.
 

 

[Gareth Collier]

All of my Terrier tender drives are currently under etched brass bodies which are no heavier than a 3D print. They have benefitted though from a tin layer of liquid lead under the coal and there is room either side of the worm for some more weight and over the front drivers. Not had a problem yet with haulage although these small locos weren't designed to pull 10 MK1's

The M7's lack of haulage isn't so much lack of weight but poor design as the rear bogie steals weight away from the drivers. Perhaps if its pivot had been sprung more weight would have been transferred forward. I've improved mine by adding lead weight between the frames of the drivers. 

[TurboSnail]

Well, this is looking rather promising...

 

 

 

 

It will be interesting to see how things look with primer on so the surface truly shows up, but the finish is much better than Shapeways WS&F material. Clearly I have some support removal and cleaning up to do but if the finish is good, that's a price worth paying. Even the spring detail on the safety valves has come out well, as well as the tender springs and all the rivet detail.

 

Shame I have to wait another week before I can get back to working on it.

[Edwardian]

That does look very good.  As you say, the primer will help assess the surface, but that looks like a pretty good finish for a start.

 

Well done!

[RedGemAlchemist]

Wow. That. Is. A. BEAUTIFUL print. Excellent work TS. You must be proud, and so you should be!

[Guy Rixon]

WANT! Where can we buy these prints?

[CarriageShed]

You can't yet. We're all encouraging and helping where we can so that just that thing happens.

[TurboSnail]

Wow. That. Is. A. BEAUTIFUL print. Excellent work TS. You must be proud, and so you should be!

 

Can I be held responsible for it if a printer did the work?

 

Thanks for all the kind comments everyone, I'll try and answer some questions about availability later, but just as a gauge for now: how would you prefer the models to be distributed?

 

As a kind of rough poll, as I don't want to open this up to the entire site in the poll section:

- please rate this post as 'funny' if you'd prefer just the prints, as is shown above and source your own wheels/parts etc (although I will provide a list of recommended bits),

- or rate this post as 'friendly/supportive' if you'd prefer a full boxed kit with wheels, motor, gears etc. (I'm not sure how this would work out with reselling other people's parts though)

 

If I have a rough idea, then I can crack on with working out logistics and so forth.

[Compound2632]

I am curious to know the thickness of some of the parts representing sheet metal. I can see the smokebox wing plates but you've been a little coy with the cab...

 

Not that I want to appear too fussy - that 3D printing makes this kind of thing possible at all is a boon not to be sneezed at.

[CarriageShed]

Can I be held responsible for it if a printer did the work?

 

Thanks for all the kind comments everyone, I'll try and answer some questions about availability later, but just as a gauge for now: how would you prefer the models to be distributed?

 

As a kind of rough poll, as I don't want to open this up to the entire site in the poll section:

- please rate this post as 'funny' if you'd prefer just the prints, as is shown above and source your own wheels/parts etc (although I will provide a list of recommended bits),

- or rate this post as 'friendly/supportive' if you'd prefer a full boxed kit with wheels, motor, gears etc. (I'm not sure how this would work out with reselling other people's parts though)

 

If I have a rough idea, then I can crack on with working out logistics and so forth.

 

I rated it 'funny' because I'm not sure how you'd be able to source the parts for a full boxed kit in N gauge anyway.

 

Having said that, there's a confirmed need to construct a scratchbuilt loco chassis, so providing the driver wheels would be very handy. At least noting the best existing N chassis to get hold of for parts would be helpful. I'm not sure that you can get N driving wheels separately - someone else will know better than me. The bogie can be sourced from N Brass Locos.

[Caley Jim]

.....I'm not sure that you can get N driving wheels separately - someone else will know better than me. The bogie can be sourced from N Brass Locos.

But if you went finescale all the parts you need for a loco chassis are available from the 2MM Scale Association shop! :-)

 

Jim

[CarriageShed]

But if you went finescale all the parts you need for a loco chassis are available from the 2MM Scale Association shop! :-)

 

Jim

 

Nice try, Jim, but I'm not going finescale. Just fine N gauge

[Gareth Collier]

I rated it 'funny' because I'm not sure how you'd be able to source the parts for a full boxed kit in N gauge anyway.

 

Having said that, there's a confirmed need to construct a scratchbuilt loco chassis, so providing the driver wheels would be very handy. At least noting the best existing N chassis to get hold of for parts would be helpful. I'm not sure that you can get N driving wheels separately - someone else will know better than me. The bogie can be sourced from N Brass Locos.

Most Farish tender locos come with a spare 'scale' bogie which I've used on a number of projects as an alternative to the NBrass offering. Unfortunatley I don't think anyone will be prepared to offer a range of driving wheels, check out Ebay, Beaver wheels regularly pop up and they've been out of production for decades. Even the 2mmSA doesn't produce every size and there would be far more demand down the 2mm route.

Having measured up my pile of spares the rear pair of drivers of a Dapol B17 are 13mm over the tread and 14mm over the flanges so close enough for the 7' drivers of the real thing with a 18mm wheelbase  so only 1mm over the 8' 6". Depending how it looks under the body it may not be necessary to scratch build the chassis. I'll keep looking though as something else may turn up to be closer.

As for sourcing new wheels I think DCC Supplies still have stock of B17 wheelsets and I've often rung the Farish spares department to buy spare wheelsets.

Edited August 13, 2018 by Gareth Collier

[TurboSnail]

Apologies, I meant the full kit/body only debate for OO gauge, N gauge stuff will be the prints only as I'm not providing a chassis in that scale. I was leaning towards providing prints and a parts list rather than a full kit, so it's nice to see the general consensus is also going that way.

 

To answer the question of part thicknesses - to print properly, the minimum thicknesses of walls are 0.75mm in OO gauge, 0.5mm in N. But the resin it's made from is very easy to thin down with a sharp craft knife if that is a compromise too far for you. Details that are not walls (e.g. springs, rivets) are a lot finer.

[CarriageShed]

Most Farish tender locos come with a spare 'scale' bogie which I've used on a number of projects as an alternative to the N Brass offering. Unfortunately I don't think anyone will be prepared to offer a range of driving wheels, check out Ebay, Beaver wheels regularly pop up and they've been out of production for decades. Even the 2mmSA doesn't produce every size and there would be far more demand down the 2mm route.

Having measured up my pile of spares the rear pair of drivers of a Dapol B17 are 13mm over the tread and 14mm over the flanges so close enough for the 7' drivers of the real thing with a 18mm wheelbase  so only 1mm over the 8' 6". Depending how it looks under the body it may not be necessary to scratch build the chassis. I'll keep looking though as something else may turn up to be closer.

As for sourcing new wheels I think DCC Supplies still have stock of B17 wheelsets and I've often rung the Farish spares department to buy spare wheelsets.

 

Hmm... Sourcing a Terrier for the tender motor and a B17 for the loco chassis means that the costs for this project are quickly escalating beyond the reasonable... and I'd guess this would be true for a larger proportion of the N gauge modellers who are interested in it. On a personal note the only way I could justify it is if the B17 was being offered for a tenner as 'spares or repair', with a knackered loco body or tender motor.

 

I've seen the odd pack of Beaver wheels on eBay, but the only ones visible at the moment are 6' 6'...

 

Anyway, please do keep on trying to find a closer/better solution. I guess we won't really know for certain until you get your hands on the finished 3D print.

[Gareth Collier]

Apologies, I meant the full kit/body only debate for OO gauge, N gauge stuff will be the prints only as I'm not providing a chassis in that scale. I was leaning towards providing prints and a parts list rather than a full kit, so it's nice to see the general consensus is also going that way.

 

To answer the question of part thicknesses - to print properly, the minimum thicknesses of walls are 0.75mm in OO gauge, 0.5mm in N. But the resin it's made from is very easy to thin down with a sharp craft knife if that is a compromise too far for you. Details that are not walls (e.g. springs, rivets) are a lot finer.

A full kit for N didn't even cross my mind. Demand would never make it worth it. So what sort of materials were you thinking of the N version being made from? As you say resin can be thinned but FUD or whatever its latest name is can be printed more thinly I believe.

[Gareth Collier]

Hmm... Sourcing a Terrier for the tender motor and a B17 for the loco chassis means that the costs for this project are quickly escalating beyond the reasonable... and I'd guess this would be true for a larger proportion of the N gauge modellers who are interested in it. On a personal note the only way I could justify it is if the B17 was being offered for a tenner as 'spares or repair', with a knackered loco body or tender motor.

 

As with most kit/scratch building in N it won't be cheap as sources for parts are smaller. Over the years whenever I've spotted a cheap non runner I've picked it up but if I was looking for specific bits now and add up all the other costs you're soon hurtling towards the cost of RTR locos. It's what you consider reasonable. If you want a loco that will unlikely ever be available RTR it will cost. By collecting spares it is actually cheaper. If it were a direct fit on a RTR chassis you could be paying around £100 before you get the print, paint, transfers etc.

[TurboSnail]

A full kit for N didn't even cross my mind. Demand would never make it worth it. So what sort of materials were you thinking of the N version being made from? As you say resin can be thinned but FUD or whatever its latest name is can be printed more thinly I believe.

I used the minimum thickness requirements for FUD/FXD when designing in resin, so it would be the same. I can make it available from shapeways in FXD (slightly more expensive but no support removal needed) or resin from 3Dhubs via me as they don't sell direct (cheaper but needs support removal and cleanup).

[Gareth Collier]

I used the minimum thickness requirements for FUD/FXD when designing in resin, so it would be the same. I can make it available from shapeways in FXD (slightly more expensive but no support removal needed) or resin from 3Dhubs via me as they don't sell direct (cheaper but needs support removal and cleanup).

Interesting, being available through Shapeways will possibly attract more potential sales but I've not had a play with the resin before. I'm guessing resin will be a tougher medium as FUD etc can be brittle. Either way both would need some level of cleanup.

[Edwardian]

I used the minimum thickness requirements for FUD/FXD when designing in resin, so it would be the same. I can make it available from shapeways in FXD (slightly more expensive but no support removal needed) or resin from 3Dhubs via me as they don't sell direct (cheaper but needs support removal and cleanup).

 

From what I have seen, the resin you have used is the way to go.

 

I have some FUD from Shapeways.  It's certainly no better, probably not as good, a finish as this resin and it's brittle and more expensive. 

 

So, I say "b8gger Shapeways and do it in resin".

[TurboSnail]

So in terms of supply, the overwhelming preference seems to be prints only, rather than a full kit. This is something of a relief as it reduces my expenditure and risks. However, I think I will supply the basic cheap motors and gears the chassis was designed for as they are a little tricky to source. Then the user can replace them with higher quality parts if they wish.

 

By way of explaining the lack of modelling or CAD work recently, this is my workbench until next week.

 

[Compound2632]

Ah now that is clearly an attempt to replicate in analogue electronics the functionality of DCC. We won't enquire how many wires...

[Edwardian]

So in terms of supply, the overwhelming preference seems to be prints only, rather than a full kit. This is something of a relief as it reduces my expenditure and risks. However, I think I will supply the basic cheap motors and gears the chassis was designed for as they are a little tricky to source. Then the user can replace them with higher quality parts if they wish.

 

By way of explaining the lack of modelling or CAD work recently, this is my workbench until next week.

 

IMG_20180813_201129.jpg

 

Very nice. Controls for the Death Star?

 

I think for a beginner like myself, the use of the gears and motor for which the chassis was specifically designed would be a boon, and I would be grateful for their inclusion if they are not that easy to find.

 

Sounds like a plan!