SimonD’s workbench

simond

Western Thunderer
But…

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Loss of registration - looks bang on in X but has lost 1 - 2mm in Y

And whilst the engraving is nice, the cut, using yesterday’s test settings and new mirrors, hadn’t cut through

Weird.

(And thanks to @Giles for the brick s#!+house!)
 

simond

Western Thunderer
Thanks John,

better yet, my improved wagon suspension works very well. I am chuffed :)

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the wagon is sitting on its springs, there is up, and down movement (though not very much of either - about 1.5mm total)

the springs, which I suspect are Slaters, fit within the axlebox, which is 3DP’d as a single part with the spring attached.

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the spring acts directly on the axle bush, which is located by the slot in the axlebox. The hole in the underside of the axlebox was added after printing to allow the drill in to clean up the spring pocket. I’ll print the next batch with the hole. I’ll also add a couple of clips to the edges of the axlebox so it grips the W iron. The W irons are lasered from 0.8 mm Trotec as previous posts, and the chassis is arranged that the outer surfaces are scale width, axleboxes printed to suit.

This approach will obviously work for Parkside wagons too, though the axlebox design can be made to simply clip into the axleguard, and the spring can act directly on the moulded spring which is part of the solebar moulding.

I think I’m quite pleased with this.
 

3 LINK

Western Thunderer
I like this method of springing, very similar to a Slaters tank wagon I built years ago which has always behaved itself on the layout. Have you tried fitting the spring above and below the axle bush ? Just wondering if there would be any difference, obviously you would have to “ bung “ up the bottom of the axle box to retain the spring. Just a thought.

Martyn.
 

simond

Western Thunderer
Thanks Martyn,

I don’t think there would be much, if any advantage, (though I might be missing something obvious?) and it would be very much more difficult!


so I’ll pass…

atb
Simon
 

simond

Western Thunderer
An interesting day today, but mea culpa, no photos. Milk van repainted, bit of CAD, and three hours sorting a 3.5” 4-4-0 King George V to get it ready for a boiler test. Need to pickle the injector (and the boiler) and check out the displacement lubricator, but everything else was proven to work, which is pretty good considering the old girl hasn’t run since 2012.

more soon
Simon
 

simond

Western Thunderer
A bit lot more CAD today - the brakes, springs and axleboxes have been substantially reworked and now we need to see how it prints...

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Following suggestions from up North, I shall be trying the ABS resin, and will report further in due course.

I guess the print will be an over-night job, so there may be howls of anguish or yelps of delight before and/or after work tomorrow...
 

simond

Western Thunderer
Well, neither squeals of delight, nor howls of anguish, more the polite curate’s response, “good in parts”.

ABS does appear to be tougher than FNG.

The wagon body print was generally good, though there was a slight distortion in one solebar, which I can fix in the slicer - I probably need several more supports.

The small bits seem to have come out ok

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Photo is not brilliant but you can see a near prototype thickness brake lever, and the older style brakes look pretty good too.

Somehow, having modelled the older style brakes’ lever guard, I forgot to print it…. Pillock of the week award.

The other unsatisfactory aspect is that it has come out “sticky”. My feeling is that the washing alcohol is already too dirty to dissolve the un-polymerised resin, and has left a residue. I might get that sorted Wednesday. Meanwhile I’ve given the body a coat of Vallejo black so once that dries, I hope it will be nicer to handle.

I want to add some holes and pegs to ensure accurate assembly, so a bit more CAD will be required.

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I think the floor is just a smidgen too large so it’s tight as it’s popping up - it would be fine glued down so it’s pretty close.

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More soon
Simon
 
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magmouse

Western Thunderer
Very exciting to see this, Simon. A couple of queries:

- is the shape of the brake shoe hangers taken from a drawing? They don't look quite right to me. I'll see if I have a suitable drawing and PM you.
- can the plank lines in the laser cut floor be finer? As far as I know, floor planks didn't have chamfered corners, so the joint would be pretty tight, certainly when new.

Apart from these very picky points, this is really looking good!

Nick.
 

Kev T

Western Thunderer
Hi Simon
I thought that FNG was an ABS type resin. What resin are you now using. I'm in the throws of drawing and test prints. Not pulling my hair out yet but it's a close thing.

Kev
 

simond

Western Thunderer
Nick, thanks, yes, see detailed explanation in PM :)

Kev, I’m not at all sure. I really don’t have a handle on the chemistry at all.

These are the resins I have currently

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the ”Simple” is a clear resin, I started experimenting with that for lamp lenses, and the glasses for street lamps, etc. I need to pick up on that again. I want to do a large yard lamp for the loco shed apron, and a couple of wall-mounted lamps.

the central bottle is the new stuff I’m trying. Elegoo.

the right hand bottle is Siraya FNG, which I have used pretty much exclusively since I started playing with this technology.

Atb
Simon
 

Boyblunder

Western Thunderer
An interesting resin experiment Simon. I tried Elegoo's ABS-like last year and it worked but seemed to lose some small details so we went back to Fast Navy Grey until a few weeks ago. Love Lane and other projects have used quite a lot of resin lately & Giles had successfully tried Sunlu ABS Like Resin (Giles' misc. Work bench.) which is cheaper than Siraya Tech so I tried that. It works well but needs a higher temperature of about 26°c which is a nuisance in the winter in my cold garage. It is definitely tougher than F-Navy Grey and the detail is good but long thin items like gutters tend to warp more after curing.

Rhod in the Love Lane team is a materials scientist and suggested we should use a Charpy tester Charpy impact test - Wikipedia to calibrate the brittles of the various resins. So far I printed the test samples and collected 2 old hammers to make a crude Charpy tester but not assembled it yet. I’ll tell all when we have done the test.

p.s. this really is not an April fool joke.
CharpyTestSamples.jpg
 

simond

Western Thunderer
We have an entirely uncalibrated ballistic pendulum made from an old lump hammer for testing cables…

Charpy tester? Hell’s teeth, that’s posh :)

In previous jobs we had tensile testers & so on, but I can’t justify it here.
 
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