DrDuncan's 3D workbench

[drduncan]

10 hours ago, njee20 said:

I’m not sure it’s necessarily insufficient supports FWIW, they just bracing. A lattice is much stiffer, and will resist bending. You may want to rotate slightly in the X (or Y) axis too, so it’s effectively twisted, that’ll mitigate those layers lines you’re getting at the points of maximum suction. 

I’ll give the transverse axis a 5 degree twist and see if that improves things. However, I’ve been trying without success to print some axle boxes doing just that and they have been ripping off the supports. I’ll post some pics when I next go up into the attic 

D

[drduncan]

4 hours ago, Mikkel said:

I like the look of those CMR wagons. Very workmanlike and a lot of personality. Black suits them, it's almost a shame to paint them.

The black was Anycubic water soluble resin.  The Halfords red oxide rattle can will sort them as soon as the damn axle boxes are sorted.

D

[drduncan]

The latest set of axle boxes were a failure. 
 

From left to right we have 3 attempts at GWR grease axle boxes: first attempt was good (10 deg longitudinal/45 transverse) but with a little aliasing so the longitudinal angle was changed to 45 deg to match the transverse angle and things haven’t gone well since…

 

The fourth attempt is on the right; this was the first go at Gloucester axle boxes with a 20 degree on the longitudinal and 45 on the transverse.

 

I will persevere!

D

[garethashenden]

I've had good success recently just printing things flat. 5mm off the build plate and lots of supports. Looking at your failures I think the issue is around where the model meets the support, indicating to me that there's too big a transition in surface area and the supports can't pull the model off the build plate. Try adding more supports, make a thicket of them.

[drduncan]

I beefed up the supports on the GW grease axle boxes and they seem to have printed ok and I can fit 7 wagons worth on the build plate  

 

Awaiting the chance to escape to the attic to see  if increasingly the supports improved matters for the Gloucester axle boxes….

 

D

[drduncan]

So, the Gloucester axle boxes are for the West of England China Clay Co lidded broad gauge china clay wagons (of which there will be 4 or so gracing the BG china clay train on Nampara) and in looking for a half decent drawing to use as the base of the 3d CAD I found a drawing of a pre-1890 dumb buffered 5 plank mineral wagon (with enough detail of the axle boxes to be useful).  So as well as CADing the A/Bs, I have also been working on the CAD of the 5 plank wagon...

 

I have designed it to use etched W irons and you can see that the A/Bs have oval slots for the pin point bearings so it could be sprung too.  I need to finish the brake gear, and check that I have got all the bolts in the correct position.  I also need to find a magnifying glass to check the plank widths on the drawing to make sure that the spacing in correct - I've traced over the drawing but you can never take draughtsmanship accuracy for granted especailly after the drawing has been messed around and reduced to fit a book, and then you've scanned it!

 

I may come up with a fictitious livery or two for it; I'm pondering 'Poldark & Co', 'Nampara Harbour Company' or 'Nampara Amalgamated Mines' as possible candidates (Gareth has already done a 'Redford & Son' wagon for me) but any other suitable suggestions will be considered.

 

D

Edited November 27, 2021 by drduncan

[Nick Holliday]

4 hours ago, drduncan said:

So, the Gloucester axle boxes are for the West of England China Clay Co lipped broad gauge china clay wagons (of which there will be 4 or so gracing the BG china clay train on Nampara) and in looking for a half decent drawing to use as the base of the 3d CAD I found a drawing of a pre-1890 dumb buffered 5 plank mineral wagon (with enough detail of the axle boxes to be useful).

I don't know which drawing you have used, but there are a number of excellent drawings of dumb-buffered wagons in Len Tavender's Coal Trade Wagons book. Unlike your rendition, all but one feature the dumb buffers as being effectively an extension of the solebars, the buffer beam/headstock fitting between them, with no protrusion.  Another feature most of them would have possessed is the provision of the inside knees to provide the necessary support to the planking either side of the doors - described in one drawing of a Gloucester wagon as 'knees forged from 2½" x 1⅛" iron - upper limb tapered in thickness - external cover plate 2¼" x ¼".'  In addition, for most of the ones shown, there was a curved plate over each axleguard on the wooden solebar and the ends were seldom flat, many being slightly raised at one or both ends, and the use of a double hanger for the brakes is a bit modern for most dumb-buffered wagons. 

There is one drawing in the book, perhaps the one you have, of a GRCW wagon, which does have the headstock at one end protruding through the solebar, and no plates above the axleguards, but the author notes 'This wagon was one  "built ...not conforming to the Clearing House specifications" which was offered for registration to the GWR and which when rejected became the subject of an action.' The wagon does not appear to have been new, but only a refurbished one, so it may not have been a typical design.

[drduncan]

Hi Nick,

 

Thanks for the post and I agree with everything you say, except that doesn't seem to be Gloucester practice!  The drawing was from the Keith Montague book on the company and you can see that the wagon was built for J Butler of Pangbourne (it was their no 18 - which strongly suggests it was in traffic) and was actually prepared by the GWR.

 

You can also see in the picture of the Sully wagon above that the admittedly more complex way of doing the headstocks and then adding the dumb buffered wasn't a one off - although the Montague book happily for all of us shows that the construction method you describe was also used (see the image of the F Bauley & Co wagon) and that double brakes (often with wooden shoes) were commonplace in 1880s new construction. Also while the photo shows crown plates it doesn't show and reinforcement over the outer part of the W iron.  

 

It means that I'll be able to use both methods, metal and wooden double brakes, a variety of crown plates and other reinforcement  as well as rounded ends on my fictitious livery wagons - I designed the CAD so I'll be able to quickly amend the model.

 

Regards,

 

Duncan

[Charlie586]

You're making some great wagons here. I've found I get more failures at this time of year, and I think it's because it's much colder. I pre warm the resin and print block before using a small oil type radiator. You can change the point of contact size and shape in chitubox as well it may help if you get any more support failures.

[DGO]

Temperature of resin has a significant effect, if you are printing in a room where the ambient temp drops overnight then expect failures, a number of people who print in non centrally heated have been working out ways of keeping their printers warm, note also do not add cold fresh resin part way through a print job unless you enjoy starting again

[drduncan]

I’ve had a few minutes over the last couple of weeks working on the West of England Clay CO lidded China clay wagons.  The brake gear (from Wizard models) and my own axle boxes have been fitted, as have MJT broad gauge W-irons. Today, having made a tiny jig on the 3D printer, I was folding up and fitting the handles for the lids out of .5mm brass rod.

And here with the full side done…

 

 

only one more side to do on this wagon … and of course the other 3 in the rake!

 

Duncan

[drduncan]

Its been a bit too chilly in the attic to try printing for the last couple of weeks, but I have been working on some bits and pieces, chief og which is a Dean broad gauge 6'4" bogie.  This will go underneath my BG E17/19 low roofed brake tri-composites and the sundry 40ft convertible clerestories I have at various points on the CAD design bench.  

 

 

You'll notice that is has grease axle boxes and my plan is to fit 20 thou plasticard strip between the ends of the scroll hangers (only the bottoms of which can be seen poking out under the BG frames) and through the volute springs inboard of them. (Hopefully...)

 

The standard gauge version has yet to be done, but will have oil axleboxes.

 

My plan is to print all bogies with a 33% mix of Tenacious flexible resin and 67% standard Anycubic grey.  This will, I hope, proivde sufficient flexibility to allow the frames to be flexed enough to drop in wheelsets.

 

Best,

 

Duncan

[woko]

This time of year sucks for printing! Great time to get all the CAD work done for a Spring printing extravaganza

 

[drduncan]

49 minutes ago, woko said:

This time of year sucks for printing! Great time to get all the CAD work done for a Spring printing extravaganza

 

Very true!

[drduncan]

So I have been messing around with the printer.  I’ve installed a reptile heat pad and thermostat inside the enclosure which is keeping the temperature at the 23-25 degrees c mark. This seems to have improved the failure rate. I’ve also added 10% tenacious flexible to the Anycubic standard resin. (I’ve also got a 25% mix for bogies etc that I’ve yet to try). Lastly, I’ve replaced the FEP film and gave the new one a wipe with ptfe spray. This seems to have vastly reduced the suction on the bottom of the tank. As to which of this tweaks is responsible for the better results is anyone’s guess.  
 

I’ve printed a load of milk churns and to be honest I’m amazed the super thin lids didn’t fail.

 

 

ive also printed out the Gloucester dumb buffered open cad that is a few posts earlier. I did the body and chassis separately and the chassis is designed to take etched W irons.

 

 

In the close up above you can see all the methodological tweaks have produced some very thin structures such as the brake lever, it’s ratchet and the twin brake shoe push rods-or at least I think so!

 

 

And here is the body perched on top. Both the chassis and body need a proper clean up to get off the support residue, but I think it’s a definite step forward.

 

Best,

 

Duncan

[monkeysarefun]

On 25/01/2022 at 06:33, woko said:

This time of year sucks for printing! 

 

Here is the same but usually due to it being mid 40's and therefore 50+ in my printing shed. One particularly hot day sent one of my LCD screens black. Not on a printer happily, on a multimeter. 

[JCL]

18 minutes ago, monkeysarefun said:

Here is the same but usually due to it being mid 40's and therefore 50+ in my printing shed. One particularly hot day sent one of my LCD screens black. Not on a printer happily, on a multimeter. 

 

Nasty - the black screen happened to my laptop once as I was working outside on the deck. I'm a website designer, so you can imagine my panic.

 

@drduncan, I did something similar with a greenhouse plant propagator heater, which I could wrap around the casing of the printer. Around this I had some solid foam insulation sheet with a removeable front. It was 'rustic' but meant I could use the shed to print if the shed's ambient temp stayed about 10C

 

 

[drduncan]

The Gloucester wagon needs rework as somehow I’ve not got enough space between the solebars for the etched W irons  

 

On the plus side, the first standard gauge GW 3 plank wagons have printed and seem ok, apart from forgetting the coupling plate on the headstocks! Unfortunately I managed to blurt the pictures….

D

 

 

[drduncan]

For those with a passing interest in GWR 3 plank wagons see the thread https://www.rmweb.co.uk/community/index.php?/topic/170565-round-ended-wagons-2-and-3-plank/ 

[drduncan]

The broad gauge 6’4” bogie seems to have printed well and the 25% mix of tenacious flexible seems to have made the sides significantly less brittle. Whether this is enough to get the wheels in will have to be seen.

 

 

D

[drduncan]

So, as I’m supposed to be demonstrating 3D printing at this Saturdays GW Study Group members day at Didcot civic centre (open to non members too), I thought I’d better get some  worked examples a lot closer to being complete than they had been…

 

The results (still works in progress but the 3D printing bits are done) are:

Here are a BG lidded China clay wagon and GWR BG E19 brake tri composite (ignore the cluster of wagons in the foreground - their time will come).

 

Above is GWR standard gauge S7 fish wagon.

 

And here are a collection of SG GWR 3 plank with round ends and 2 plank wagons.

 

If you are in the Didcot area on Saturday with time to spare to drop round to the civic centre abs say hello.

 

Duncan

[stevel]

9 hours ago, drduncan said:

So, as I’m supposed to be demonstrating 3D printing at this Saturdays GW Study Group members day at Didcot civic centre (open to non members too), I thought I’d better get some  worked examples a lot closer to being complete than they had been…

 

The results (still works in progress but the 3D printing bits are done) are:

Here are a BG lidded China clay wagon and GWR BG E19 brake tri composite (ignore the cluster of wagons in the foreground - their time will come).

 

Above is GWR standard gauge S7 fish wagon.

 

And here are a collection of SG GWR 3 plank with round ends and 2 plank wagons.

 

If you are in the Didcot area on Saturday with time to spare to drop round to the civic centre abs say hello.

 

Duncan

wish I could be there, this looks very interesting, as I am 3d printing most of my rolling stock, for GWR Edwardian layout.

[Mikkel]

On 28/06/2022 at 08:55, drduncan said:

So, as I’m supposed to be demonstrating 3D printing at this Saturdays GW Study Group members day at Didcot civic centre (open to non members too), I thought I’d better get some  worked examples a lot closer to being complete than they had been…

 

The results (still works in progress but the 3D printing bits are done) are:

Here are a BG lidded China clay wagon and GWR BG E19 brake tri composite (ignore the cluster of wagons in the foreground - their time will come).

 

Above is GWR standard gauge S7 fish wagon.

 

And here are a collection of SG GWR 3 plank with round ends and 2 plank wagons.

 

If you are in the Didcot area on Saturday with time to spare to drop round to the civic centre abs say hello.

 

Duncan

 

Duncan, I hope the demo went well. It's good to see some of your stock on the rails, not least the E19. They look very good indeed. I assume the bogies are also 3D printed?

[drduncan]

9 hours ago, Mikkel said:

 

Duncan, I hope the demo went well. It's good to see some of your stock on the rails, not least the E19. They look very good indeed. I assume the bogies are also 3D printed?

Yes it did.

 

And yes the bogies are 3D printed using a 25% mix (or 1 in 4 parts) tenacious flexible to standard resin which allows the sides to be flexed enough to drop in wheels.

D

[drduncan]

Here are the latest test pieces from the 3D printer.

 

First is a broad gauge 1st/2nd luggage composite (U20 in SG days). These had 10ft wide bodies.  Following this in the CAD queue are U21 and U23 composites. These have the same side as the U20 but in BG days were narrow bodies on BG frames (and the U23 is a clerestory). With the SG versions that will be 6 coaches from one side of CAD and some relatively minor changes to the end profiles.

 

Next we have an N6 loco coal wagons. Again, broad gauge and SG versions plus the SG version cones as built and with extended sides.

 

 

The BG version (with a BG 6 wheeled fish truck lurking in the background while I try to get the cleminson chassis to work).

 

The SG version as built.

 

The SG version with extended sides.

 

Regards,

 

Duncan

Edited October 3, 2022 by drduncan