Project 65033 - a 3D printed LNER J21

[Paul_sterling]

Hi Folks,

Though I have not posted recently, I have been somewhat busy. I've gone into production with the LH&JC No5 shells, as well as its associated classmates at the LH&JC, and also have produced NCB "Meteor" an early loco at the NYMR. (message me if interested in either)

IMG_20210501_110541_resized_20210504_015402446 by Paul Sterling, on Flickr

IMG_20210501_110530_resized_20210504_015400461 by Paul Sterling, on Flickr

The next project is one I've decided to do as I don't think any of the mainstream manufacturers seem willing to do it, its been asked about for years, and yet, to the best of my knowledge, is still not in the pipeline. So on receipt of Isinglass drawings, away we go.

IMG_20210428_112948_resized_20210504_015359356 by Paul Sterling, on Flickr

IMG_20210428_164607_resized_20210504_015356087 by Paul Sterling, on Flickr

Initially, this was designed to fit on a J15 chassis, the spacings being sufficiently close that it would still produce a largely accurate model, wheel dia close enough to suggest its wheels had been turned a couple of times, and spacings on the model very close also.

However, the motor framework is just too visible for me, the blue you can see under the boiler. so although otherwise feasible, I've decided against the J15.


The alternative is as follows.

IMG_20210430_091930_resized_20210504_015357257 by Paul Sterling, on Flickr

This is using a bachmann SE&CR C-class, which is dead on for wheelbase and measured wheel dia. the motor-gearbox will necessitate an overly long backhead, but otherwise offers an overall better packaging solution.

IMG_20210504_134355_resized_20210504_015354824 by Paul Sterling, on Flickr

Even the bachmann tender chassis is a viable solution, being only slightly long on wheelbase, but correct on overall length.

I'm hoping to get this one to an initial print stage later this week.


65033, like many preserved engines, is a potential trap for detail. She has a 67A boiler (and safety valve arrangement), but 67/67b smokebox. these details arent too bad to deal with, as I can create the alternative "bodies" within CAD in order to make any combination without too much trouble, so long as a purchaser (should I be lucky enough to get any) had done their own research on the combination required, I'm only doing 65033 for myself.

Thanks, Paul.

[Atlantic 3279]

Interesting Paul! How do the styles of the wheels themselves compare, and how cheaply / easily can one generally managed to pick up C class chassis?

I can see that the body might also go nicely on scratch built set of braced plastic frames with brass bearings, builders choice of wheels, Derby standard length rods, Mitsumi motor and cheapskate nylon gears...

[Paul_sterling]

Interesting Paul! How do the styles of the wheels themselves compare, and how cheaply / easily can one generally managed to pick up C class chassis?

I can see that the body might also go nicely on scratch built set of braced plastic frames with brass bearings, builders choice of wheels, Derby standard length rods, Mitsumi motor and cheapskate nylon gears...

I hope so Graeme!

The wheels are both 16 spoke, so a reasonable comparison, but like my usual shells, this project gets you 95% of the way to a J21, but it wont be perfect (but you know what I'll say next about OO scale and its gauge.....!)

C Class locos aren't too bad to get, circa £75 to £100, less for the black liveries, a green livery, a non starter! it didn't take much effort on my part to source one at the bottom end of the price scale (on a buy it now), so I guess auction items will be cheaper still, for now! I recall the Midland 1F effect I think I caused with LH&JC No.29, at one point they were £40-£50, now, they aren't...

Yes, in principle the shell will work fine with scratchbuilt chassis, as I've no doubt a vertically mounted mitsumi will offer good packaging over the current horizontal lump.

Thanks, Paul.

[Paul_sterling]

A little more work over the last few days.



Mostly detail work, time consuming etc etc. The loco is mostly there now, but there is still much to do on the tender, likely to take as long as a loco normally would to cad up in itself. 

20210507 by Paul Sterling, on Flickr

Paul.

[Paul_sterling]

Hi Folks,

Conitnued progress.

20210510-1 by Paul Sterling, on Flickr

The support framework (orange) has been designed. It used exactly the same methods as I have done previously, knife edges which can be easily twisted off post print, but gives a uniform support to the running plate, so it prints straight, even when positioned at an angle.

20210510-2 by Paul Sterling, on Flickr

Reversing lever, and Westinghouse pump added. the latter isn't always a feature of 65033, so I modelled it in a separate body that can be omitted from the STL, or chopped off the print.

20210510-3 by Paul Sterling, on Flickr

Cab interior, its crude, and includes some worked compromises in order to cover the bigger wheel pockets.

Thanks, Paul.

[Paul_sterling]

Last night I printed the latest CAD, I.e. the pictures shown yesterday, and I'm quite happy!

The C-class chassis has a slight visual defect when assembled, the bottom edge of the firebox makes the model look like its sitting high at the rear, but checking with the very near, its perfectly level. Optical illusions!

I use Elegoo water washable black for printing usually, as its easy to clean and details nicely, but its hopeless for photographs! I'll remember to use Siraya Tech Grey for future picture taking prints.

IMG_20210511_080956 by Paul Sterling, on Flickr

IMG_20210511_081003 by Paul Sterling, on Flickr

IMG_20210511_081101 by Paul Sterling, on Flickr

IMG_20210511_083955 by Paul Sterling, on Flickr

IMG_20210511_084005 by Paul Sterling, on Flickr

Thanks, Paul.

[Danby Wiske]

Well, it certainly looks like a J21!

How fragile is the reversing lever?

[Paul_sterling]

Not too bad, it's not all that exposed. And it's supported midway down by the bracket on the splasher. I could put something behind the westinghouse, but to be honest, the most stress that part will see, is the pulling forces during printing.

Paul,

[Atlantic 3279]

As Danby Wiske says, it certainly looks like a J21.

Voila! Instant loco - apart from all of the head-scratching, CAD fathoming, buying the equipment and materials, learning how best to use the printer, application of the benefit of previous experience, etc. I'm not implying that you've done it the hard way, merely that you've earned a result that didn't just fall "instantly" from the sky.

I know what you mean about the effect of black finish on the photography, but it does help to make it look like a loco...

[Paul_sterling]

As Danby Wiske says, it certainly looks like a J21.

Voila! Instant loco - apart from all of the head-scratching, CAD fathoming, buying the equipment and materials, learning how best to use the printer, application of the benefit of previous experience, etc. I'm not implying that you've done it the hard way, merely that you've earned a result that didn't just fall "instantly" from the sky.

I know what you mean about the effect of black finish on the photography, but it does help to make it look like a loco...

I agree Graeme,

A lot of work goes into producing CAD, though by now its second nature to me, as its a key part of my job (for now). Equipment is already bought and paid for by previous projects, skills to optimise the prints learned (as you can see by the support structure), so once you're in, 'you're in' so to speak.

Where is really comes good though, is duplication, the second print of a shell doesn't require a huge input from me to produce equal work. I know duplication also applies to resin casting, but I also recognise the skill that goes into each cast is still considerable.

Paul.

[Danby Wiske]

Where is really comes good though, is duplication

...and also variation? Once the CAD work is done for this, I would imagine there wouldn't be much more work involved to make an N8 or N9, and a J25 and N10 could then follow (if a suitable chassis can be identified).

That should keep you busy!

[Paul_sterling]

Where is really comes good though, is duplication

...and also variation? Once the CAD work is done for this, I would imagine there wouldn't be much more work involved to make an N8 or N9, and a J25 and N10 could then follow (if a suitable chassis can be identified).

That should keep you busy!

Doubt it'll be me, A lot will depend on me getting a suitable CAD package in the future when I cannot access CATIA anymore.

In respect of variation, its certainly possible to create the cad where I can change the boilers, and other details, but then each combination would still need to be run through slicing software, supports created etc etc. so a lot of work.

Paul.

[Atlantic 3279]

Will you still be able to print the designs you've evolved on that posh software when you no longer have access to it?

[Hatfield Shed]

... this project gets you 95% of the way to a J21 ...

I recall the Midland 1F effect I think I caused with LH&JC No.29, at one point they were £40-£50, now, they aren't...

That's way better than 95%.

Now, further potential for the loco mechanism from RTR. I am a happy 'basher' and since this is a Derby wheelbase, I would want to look at the mechanism from the 3F tank loco; (rewheeled with some 20mm Bach wheelsets I just happen to have) because this drives on the rear axle, has a sprung centre axle, and I suspect the motor will be better concealed.

You never know, you might manage a run on Bach's Jinty...

[Paul_sterling]

Will you still be able to print the designs you've evolved on that posh software when you no longer have access to it?

Print them, certainly, as all I need is the STL files, and I can play with those on the slicer software.

Step (STP) files of the CAD will be generally translate-able onto another CAD package, but it does risk creating defects, especially with boolean operations that are predominant in CATIA.

The plan is that I'm going to finish all of my current projects on CATIA, and start new ones on a different package.

Thanks, Paul.