The Great Bear

After a frustrating few days, back making progress. Gave the z axis another clean and also realised that the coupling on the between the stepper motor spindle and screw the grub screw had come loose, which I think was cause of the issues seen in last couple of prints. Following the suggestion, I thought I would give the Siraya Build resin a go and be extra careful noting my previous issues. Initial impression is positve, it seems to have solved shrinkage issue (though that could also have been the z axis thing), perhaps less prone to warping and less brittle when cured.

Talking of 2933 Bibury Court, I'm trying to work out what livery and tender it had in 1947. In 1948 there are several shots of it running with an intermediate tender. It was painted black in April 1943. There's this photo which I have seen dated either March 1948 here or November 1945 in the Maidmont Saint book with an intermediate tender newly painted in green. Either dates are plausible are the loco was recorded as entering Swindon Works (though I don't know what for) in October 1945, February 1947 and February 1948. There's also photo of a grimy 2933 without smokebox number plate with an intermediate tender. It looks like it's got a sign hanging on the smokebox. It's parked outside a large workshop like buidling but I don't know the location - maybe somewhere in Swindon. the loco parked awaiting attention?

6 hours ago, heraldcoupe said:

What resin are you using? I've stuck with Siraya Tech Build for my bodies, it's been very good for the (quite similar in concept) work I'm doing, no significant issues with shrinkage.

One thing I have found is that curing under UV brings a lot of issues with distortion where multiple cross section thicknesses are at play - might your shrinkage issues be related? I've taken to let my prints cure in ambient light. There is some reports mileage in curing at elevated temperature rather than under UV, but I've not experimented for myself in that area. Having worked with casting Polurethane and silicone resins for the past 20 years, the difference in curing with those media can be significant.

Secondly, are you working with a print angle calculated from pixel size and layer heights, ie arctan(layer/pixel)?

 

 

For transitions in cross section, I try as far as possible to adjust the inside faces where the external ones are fixed. There are still many frustrations though.

 

I believe the printer you are using is an older 2K design (do correct me if I'm worong on this). My Elegoo Saturn 2s aren't state of the art (8K), but are a significant upgrade in terms of layer visibility over my (now retired) 2K Longer printer. The differences was dramatic from the very first print.

 

Cheers

Bill.

Firstly, Bill, I must say I've been very impressed with your printing work, the various Bulldogs. The resin I'm using is Sunlu water washable dark grey. I use water washable resin because I had very bad skin reacation to IPA some years ago as a result of poor precautions when cleaning prints and now get skin irritation if I come in contact with it. I prefer the dark grey, I tried white but didn't get as good results. It had been working well until last few prints, including less shrinkage. When I've cured under UV distortion has been limited on the dropped section at front of running plate warping upward. Curing in small goes flipping model over seems to have helped with that.

Print angle, I tried printing at 33.69 degrees (arctan 50/75), not too bad but some horizontal layer lines on the buffer beam and stepping on the splashers where the print angle led to it being locally a flat surface. Twisting the model a bit removed some of that, the stepping on the splashers of that and reducing the inclination to 30 degrees also helped reduce prominance of marks on the buffer beam and smokebox front flat bits. I may try the arctan angle once again.

Some of the lines/stepping I'm sure my ancient printer doesn't help with. You'e right it's nearly 6 years old 2k one with colour lcd, Phrozen Shuffle XL. It's been taken apart several times to replace cracked LCD screen and a bunged up stepper motor. The last time it broke I was secretly hoping I couldn't fix it! Because it is old it is sturdily built, metal case and it has a hinged lid which most new printers don't have but I need due to the printer's location.

3 hours ago, billbedford said:

 

I would suggest it was something on the leadscrew, maybe dried on resin?

Thanks, I'm giving that a go. No obvious debris on it, but giving it a clean and new dose of lubricant. Fingers crossed that works.

The distortion as in my first post has gone away, went back to using the resin I was using before with a longer exposure time. For good measure I applied some lubricant to the z axis.

To answer a point made earlier, given the nature of the model changes in cross-section there lots of and some will of necsssity be abrupt. Not sure what I can do.

The last couple of prints (only) have now got a new issue: a noticeable step in the model.

I

It's done it for two pints in a row using the same sliced file, with different exposure settings same resin. Other prints with same model and similar arrangement of supports didn't have this. What could have caused this step?

Another niggle is smaller banding on the print, in line with the layers. I tried changing the print orientation reducing the angle from horiztonal down to 30 degrees from 35 and keeping the same 15 degree twist. Is this a print orientation thing? I tried shorter exposure which possbly helped

Final issue is shrinkage of the print. Some earlier prints (with same resin) it was negilible but recent prints it's been a bit more, still not a lot 2mm over a 140mm model so not a lot around 2%. But, when trying to get model aligned with the RTR chassis I'm using for this bodged Saint and fixing scews it starts being a problem. How can I correct for this? (I am using Chitubox.)

Earlier prints didn't have these problems and I don't know why. My frustration compounded by that on my ancient printer each print takes 12 hours.

A bit more progress, some parts added. Was about to post a couple of hours ago then realised, if this is to be Bibury Court in its later life it had Collet parallel buffers not the earlier tapered type.

My bending of the handrail on the smokebox could be better!

2 hours ago, DCB said:

 

 

I don't have the  Noch Saint Book but I think I can borrow one. I did look in Russel with little to see  But it looks to me from the photos I have seen that the Courts may have deeper splashers than Saints and rebuilt 4-4-2s to compensate for the cylinders boiler and running plate being mounted 2.5 " lower. relative to the frames.  The front and rear drops would also need to be "adjusted" as would the rear boiler mounting, but I doubt anew diagram would have been issued  as none of the affected parts were "Standard" pats which would ordinarily be changed. I shall do ore digging 

The drawings I've used are a GA drawing for Lots 185, 189 and 192 (ie the Court series) dated 1911 and one for Lots 138 and 145 (ie nos.98 and 171) dated 1902. In both the running plate looks to be at the same level and the splasher radius on both 3'7". It looks to me like with 1902 drawing the top of the cylinders is tight up to the level of the running plate whereas with the 1911 there is a small gap due to the cyclinders being set that 2.5".

4 hours ago, DCB said:

Looks good.  BUT.    GW locos were very standardised.    Harold Holcroft  who designed the Saint drop ends wrote a book I  borrowed once, and the   "Cab side sheets sweep down to match the Tender."  All the tenders had the same height to the top of the frame so to look right the Saint cab  must match the tender to better than 1 mm.
Likewise the cylinders.  There was only one type of cylinder and smokebox saddle casting for the Saints, and two were bolted back to back, when the moulds and patterns were altered to have outside steam  pipes the exits became exactly half way  along the cylinders,  its also why the cylinders and the smokebox saddle had to be horizontal.     Later K.J.Cook  suggested  making up up complete Saint front ends with bar frames etc so when new cylinders were needed the whole   assembly could be grafted on to the repaired (?) main frames. These were Hall type with a shorted saddle rather than  Grange , but they looked much like the Grange  as the new drop frame was a short distance further forward than the Saint/  Court type.  Most but not all outside steam pipe conversions were this  type and it makes for a much beefier less effeminate front end.   The Hall boiler was raised in the frames to make firing easier by raising the firehole  I understand,  and  became very similar in height to the centreline to the Saint but with a lower running plate and smaller splashers.
Most Saint Bodges miss the Short Cab.     Mine is using a Hornby Grange Boiler but 1990s  Hornby wheels to get the 27mm dia and the long piston stroke

Yes, mine rides a bit high. Not sure I can lower it any more... the Ringfield motor in the chassis I think is the constraint and I've already attacked that with the Dremmel to get this far. (And, if I could change the wheels to the right size that would make it even higher.)

I think the issue with the front is the cylinders in the inherited chassis, a tad too forward. The cylinder centre, steam pipe, smokebox saddle centre and chimney centre should all be in line, shouldn't they?

48 minutes ago, Hal Nail said:

Total guess given i havent got a printer but is it it perhaps that as you add more detail, the printer does more 'passes' or takes longer and that causes it to be less smooth?

Thanks, but it's not that. FYI for a resin printer the numbers of layers depends on the height of the model (including the supports as the model is at an angle dangling down from the build plate as it lifts out of the resin vat) and on the layer height (in this case 50 microns) . For all the prints I've done of the loco I've gone for the 50 micron layer height to try and get smooth surface and better detail. There are around 2300 layers in the print which then takes around 12 hours to print.  (More modern printers with a mono LCD screen and rapid resins would do it faster.) The exposure time per layer depends on the printer, the resin and the layer height.

Hi there

On many of my prints I get random hoziontal lines aligned with the layers, varying in spacing and severity.

Some prints are ok, but many aren't with similar print orientation and support density. I can't pin down why some are afflicted and some aren't. In hindsight keeping a systematic record of variable like resin, exposure, print orientation etc would have helped! I don't think it's a temperature issue as the resin was warmed prior to the print and the printer enclosure has a heater in it.

My printer is 5 years old, Phrozen Shuffle XL and is rather battered as it's been taked apart several times recently replacing the stepper motor as original one got jammed from a resin spill and then lcd replacement. I recalibrated the z axis after fitting the new lcd. The FEP is only a couple of prints old.

Any suggestions as to the cause and solution would be much appreciated as I've got a growing pile of nearly there but not quite prints.

Been a while since I gave an update on progress. Some major problems with the printer, firstly a resin spill which managed to get into the stepper motor for the z axis so I had to replace the motor. Then I managed to damage the lcd screen. As my printer is ancient, 5 years old, I had to get replacement screen from Ebay, arrived in 2 weeks from China. Meanwhile I kept on thinking I could add more bits and pieces and kept on noticing things in photos to take account of eg the washout plugs, the top row at least aren't level. Here's where it's got to...

Getting the rear of the body to sit down low enough was a bit of a challenge, ending up shaving bits off the casing of the Ringfield motor as the body shell over the firebox top was already pretty thin.

Printing the reversing rod was ambitious and it was difficult to get to it to print straight, thickening it up and some supports and also some props to the firebox you can just make out in this angle sorted that. 

I wasn't originally going to do the cab interior just use whitemetal detailing bits but then I got carried away...

As this is the end which is printed first all the details hanging down need supports, so it is a bit hit and miss whether they survive or not and the density of the supports means careful removal isn't possible. This one part of the regulator lever and one handle on the reverser were the victims. Most of the pipework is a tad oversized and also filled in the gap to the backhead to help them stay intact.

This print isn't perfect, there is some banding in line with the printing layers variable in spacing and severity. I get that in many of my prints can't work out why as some of the earlier prints of this model were ok. A more structured approach keeping track of variables (resin, exposure, orientation, supports etc) would have helped. Whilst not perfect I think I'll run with this one and add things like handrail knobs to see if my allowance for these worked.

1 hour ago, No Decorum said:

I bought two 2-8-0Ts and a 2-8-2T when they first appeared. They later appeared with upgraded chassis. Having been disappointed with the original mechanisms, I decided to buy the upgraded models and fit the new chassis into the older bodies. The 2-8-0Ts were fine but the 2-8-2T wouldn’t fit. All due praise to Hornby for picking up the differences in detail but it did rather spoil my cunning plan.

Thanks, I had same idea. Having damaged (in a fit of rage!) my original 72xx - which wasn't runnign well, terrible pick up perhaps not helped by a hamfisted attempt to fit the Brassmasters detailing parts - I was hoping to swap with a new chassis. Maybe a bit of surgery on the body might do the trick or I'll have to try and repair the one I "dropped".

Is difference between the 72xx Hornby models with the curved/raised footplate and those with the square one solely in the bodyshell or is the chassis, cylinders and the motion bracket different too? I'm stuggling to tell from photos of models,

Lanarkshire Model Supplies do/did the GWR short buffer stop for bay platforms their reference BS14. Comes with web page unavailable when click on that today, however.

What's the small brass cylinrical thing on the running plate on the fireman's side by the front spasher?

Looking at photos some more I think the shorter front dropped section rebuilt when outside steam pipes were added only applies to the Court series.

On 17/03/2024 at 15:59, checkrail said:

 It had the same treatment plus the fitting of lamps. I'd just run out of Modelu lamp lenses so improvised in the time-honoured way with white and red paint and a drop of gloss varnish.

As someone who struggles (well, indeed, has given up) with the fiddlyness of fitting the lenses to the Modelu lamps, I'll have to give this a go. You've probably mentioned it and I've missed it but do you do the same with the headlamps, any colour behind the varnish "lens"?

2 hours ago, Miss Prism said:

I'm confused about the front end of the Saints. From the drawings, there seems to be a difference of 2" in the bogie wheelbase between the old locos and the later ones, so it's difficult to judge the length of the dropdown portion. From photos, it does seem the dropdown portion begins significantly closer to the front end of the cylinders than yours. (I don't have the Nock book, which may address the matter, and it may be connected to the cylinder height setting, where the main piston axis, originally 2.5" above the wheel centres as per the initial Churchward setting, became inline with the wheel centres from the Court series onward. Was there a change in cylinder size?)

 

Also, I wonder whether your steampipe is fractionally short?

Thanks, Russ.

There's 2 versions of the curved front original where start of the drop is tight to the cylinders vs revised with outsdie steam pipes where there is a gap. But, looking at the photos again it looks like I've pushed it a bit too far forward I, too much of a gap. Having just found this photo which is pretty much dead side on, I'll have another look.

Similarly, I think you're right my steam pipes are a tad short. I didn't have any drawings of them, positioning or size. (I've drawn at 8.5" outside diameter.)

Some photos taken a while back of my "Pseudo Saint", an Ebay purchase of a Hornby Bachmann-bash, here paired with a couple of my home brew coaches.

In the past month I've been playing around to upgrade this loco, putting a more accurate body onto it, details here.

On 26/03/2024 at 16:54, checkrail said:

Really enjoying seeing views of your layout again Jon  - it's always been a favourite of mine.  More please!  

 

Great looking track, regardless of your current ballast issues. And neat looking Mogul.

Thanks for the compliments and encouragement, John. The mogul is a good loco, and was in my opnion a great choice for Dapol to do, being so commonplace. I have another (of the first batch) in a box somewhere to relivery from BR black to GWR wartime black.

11 hours ago, Cwmtwrch said:

Printed on thin paper from my own artwork.

I like the pattern, the wear effect you've achieved. Can I ask how you did that, some filter? I've got Photoshop but I haven't found a convincing effect for canvas sides on a wagon.

1 hour ago, BenL said:

The smoke box on the new one also appears to have lost its rivets on the front and rear edges, or is this a prototypical feature?

The Andrews books says that in the early years flush headed rivets were used, A few pictures in that book show locos which rivets on the smokebox aren't visible - photos up to the mid 1920s perhaps, but all the others show visible rivets. So the flush finish looks to be correct only for a limited early set of prototypes I think?

For info of others if they have the same issue it looks like battery replacement has solved the problem. Because of the location of my gear it was easier (and safer, I am rather butterfingered, dropping the battery and shorting the unit was quite conceivable) to change the battery with the power unplugged keeping the PSU where it was. The unit held memory for the 30 seconds or so to change the battery, preserving my saved macros.

51 minutes ago, Bernard Lamb said:

A quick rough and ready count on an OS map gives 23. There could well be more private crossings, but as these are not marked more work would be needed to get an accurate number. Any attempt to close that lot will take years, and a lot of cash.

Bernard

Some closed and diverted, some technology added/upgraded eg miniature stop lights,  others existing CCTV retained details here https://eastwestrail-production.s3.eu-west-2.amazonaws.com/public/Route-Update-Announcement/4c8cb5ea3b/Route-update-report.pdf