So far what is your favorite resin for detail?

[bbussey]

And the end, note the striation on the roof panels from when I printed the roof horizontally. The 30 degree printing is on the right:

The stepping always can be sanded out.  Looks like the roof wasn't perfectly vertical when it printed, otherwise the stepping would have been parallel with the car length.

This is a K7, which means a roofwalk will always be present.  Print the roof as two halves, parallel to the Z plane. then your stepping issue goes away.

[narrowminded]

That print, especially at the sharp transitions, looks like what you might expect from Siryatech Fast and/ or a too high normal cure time.  Maybe even worse but in that direction.  Anycubic should improve that but won't be as ductile as the Fast. 

When the transitions aren't important or don't really exist, as with most mechanical parts I've printed, I rather use the Fast for its impact resistance.  The blooming gets worse when you add Tenacious (20-30%) but the stuff gets really tough.  I haven't tried Siryatech Blu yet but have it and will try it.  I'm beginning to suspect it's basically a factory mix of Fast and Tenacious but I don't know that.

[Lemosteam]

You don't have to support the overhand if you build vertically.  It's self-supporting.  As are your separate slats.

Sounds are if you aren't supporting the vertical roof properly, or your curing interval is too high.  My best prints have been the verticals, far better than the 45-degree prints.  The upper and lower chords on the 70' circus flats extend out and there are rivets on all faces, they printed vertically without incident.  The only support was on the face-down end, and that was before I moved to the membrane method.

We'll have to agree to disagree.  FXD forces you to design for the printing as well, whether slicing up the model into components or proper orientation on the XY table (which Shapeways doesn't always honor DESPITE their supposed allowance of the modeler to hard-specify the build orientation, so that negates your orientation argument.)

My openings are prototypical as well.  I'm getting more crisp detail than you are.  It appears to be a resin-related issue more than your curing intervals.  I'd order a bottle of AnyCubic before trying anything further.

I think the clear will work just fine.  I have to finish designing some glass parts before can start trials.

The LSG parts will fit fine, I don't have to check.  Because the ends for the RBB&B stock cars and the ATSF RPO and the NH P-S fluted cars and the Erie boxcar all fit fine, as do the Mack LJ components (cab body, interior, chassis, payload).  And the steering wheel printed perfectly.  You know what didn't fit together perfectly?  The FXD-printed Popcorn wagon and donniker wagons.  They required additional filing before they fit together well enough

On your R7 ends, what is the thickness of those membranes?  I have .2mm from the part extended out 1mm, then I thicken to 1mm to extend down to the base.  The model face closest to the build plane is 6mm away and my raft is 1mm thick.

Not worried about the overhangs on the sides, I am referring to the overhangs on the ends.  If I make the roof part of the shell and turn the model vertical, the roof end overhang will be the first to print, meaning I will lose all detail on one end. I do not like visible seams and I will avoid them at any cost, so printing the ends separately is out.

My horizontal board gaps are 0.3mm so as long as they are supported on each end by the angled ribs with a wire support in the center, those layers should print, IMHO. Hoping the AC resin will solve that.

I tried to print the end sills at 45 degrees and that was a mess with too many small surfaces pooling resin and ballooning my fit areas so I turned them vertical and that solved that.

I use pre designed supports and copy theier bodies  from a comm9n body file into a special print file for each part, except for the tiny wires. I just construct them on one side an mirror them over. The tips of the membranes have a 0.15mm radius that I partially submerge into the part solid, but I can still see the tangents of the radius. I try to end my supports with a gap near any vertical surface, and run tiny 0.25 diameter wires up to any unsupported horizontal small planes that I cannot directly  use a membrane. My rule of thumb is any 3x3mm and sometimes smaller plane must be supported on any surface.

New resin will be on its way soon, along with some other helpful things.

[bbussey]

I run the membranes directly flush with the part, 0.2mm thick, works fine without having all of those extra pipes.  My main concern was eliminating curling and uneven faces, and the membranes solve that.

I try to avoid cross-wires now because the extra FEP suction force can distort the sides, if even ever so subtly.

I think you'll find that changing the resin will solve 95% of your issues.

These screenshots of the ends of the NYC canstock boxcar gives an idea of how I'm designing the membranes now.

[Lemosteam]

I run the membranes directly flush with the part, 0.2mm thick, works fine without having all of those extra pipes.  My main concern was eliminating curling and uneven faces, and the membranes solve that.

I try to avoid cross-wires now because the extra FEP suction force can distort the sides, if even ever so subtly.

I think you'll find that changing the resin will solve 95% of your issues.

These screenshots of the ends of the NYC canstock boxcar gives an idea of how I'm designing the membranes now.

I like a small undercut for the knife to follow. Though they are quite delicate, those end sills came off the supports without fear of damage, which is exactly where I want the design to be.

My shell prints with nothing inside, just my membrane around the lower perimeter, with the exception of four small wires under the roof locator tabs for the roof locator pins.

I do the same with the chassis except, following my rules, I have a membrane running down the spine, and 2mm tapered pins with a 0.15mm radius sphere on the end that I bury slightly into the model on each crossmember cross car centered between the membranes.  This is all shaved away to allow the brass plate to sit flat in the center pocket. The jack pads have a 0.3mm wire up to the membrane, which easily saves away. The jack pads serve as the vertical locators for the bottom of the shell. I had to add a thin wall inside the brake lines to prevent the meibg wavy.

The original print with the trucks tracks beautifully on the layout, no wobble, nice and smooth.

This kit is finally rounding the corner to production. 

Last step after I receive the resin is to print one entire kit in ther final orientation, build and paint it to judge its viability.

By the way I was able to lower the car quite a bit with my 2E-F2 coil-elliptical trucks which are prototypical for the PRR K7. Car will navigate (not surprisingly) an 8.5” radius, based on CAD.

[Lemosteam]

Ok, this MUST be the resin.  How the heck does this happen. 30 degree print, revised supports. 60 degree resin in my Michigan basement.

Grr. (I know Bryan, I know. Not printing vertical yet. Not after the great results I got on my roof)



Note the two waves in the side and a hard stop on the board gaps, except where the doors are. WTH? There is nothing inside the shell. Not sure what caused that bubble like hole either.



I think this was caused by the shell nit being rigid inside, above the tall support on the end.



These are the supports used.



I am now printing a revised model, after thinning the walls to be the same thickness as the doors, added an interior support that ties the sides together at the upper end of the print, fingers crossed, but I have virtually no faith in the Siraya resin any longer.

That first portion of the board gaps looks so good in person. May try a 45 degree print next. Tier of fussing and three bottles of AC grey on the way.

[SkipGear]

The waves are from different adhesion/suction amounts on the FEP. Been there, done that. Printing vertically or horizontally is the only way to solve it. You want as uniform of a contact area as possible to eliminate the waves. When you go from relatively large to relatively small surface area, the difference in the amount of force it takes to peel away from the FEP causes those waves.

[bbussey]

Yup. I gave up on angled prints a couple of days in, when I tried to print the Erie radial roof boxcar at an angle and Chris recommended printing it vertically as originally planned.

[bbussey]

Is it me, or does the AnyCubic aqua blue resin show the details prior to priming better than the gray, beige and transparent resins?  I have test shots of the NYC Canstock Boxcar and the G32B gondola (vertical builds) finishing up in about an hour.

[peteski]

Isn't 60 deg. F a bit cool for the resin?  Bryan I believe keeps makes sure his resin is warmer (probably less viscous too).

[bbussey]

I’m printing in a 72-to-74 degree environment most of the time. It could drop to 68 degrees during the overnight, but the printer is about 10 feet from the furnace room in a very well-insulated basement, so it tends to hold the heat well 24/7 this time of year.  The resin bottles stay next to the printer.

[bbussey]

John,

You always of course can leave the orientation of the roof as-is if you’re happy with the results.

[Chris333]

The thing about those test prints... all the stuff that is missing from your print is either floating around in the resin or stuck to the FEP.

[Lemosteam]

Isn't 60 deg. F a bit cool for the resin?  Bryan I believe keeps makes sure his resin is warmer (probably less viscous too).

Remember, the printer is inside a cabinet that I keep closed while printing. The lift handles are hot to the touch when I open it up.you can see the micro ceramic heater on the shelf below.

[Lemosteam]

Limited success printed horizontally with 2 second exposure. Might go to 1.8 see what happens. Need to improve the support on the corners better.