7mm US model dabblings

mickoo

Western Thunderer
Guys - quick question; do we want to ask Adrian to move the 3d content out to a separate Techniques thread?

Steph
As long as the GEVO truck 3D stuff stays here, I have enough trouble following my own three of four threads, I don't need another.

I will put the B1 stuff in the Finney7 B1 thread shortly, but the general 3D stuff can be calved off if people want.

MD
 

mickoo

Western Thunderer
Ok a little update on the GEVO 3D printing, some good, some not so and a couple of own goals :(

First off the service was painless, upload, pay, receive in the post, much as it should be these days.

Quality, despite picking the best material I (naively) expected a better finish, it's not bad but you can still feel the tiny ridges so it'll need some finishing and prep work and a good coat of filler primer I think.

The not so good are any surfaces supported by the wax, these on the whole seem to be very rough and I orientated the work so that these were on the upper visual surface (doh). It was done this way to reduce costs and have as little support wax in the process but next time I think a rotation of 90° whilst slightly more expensive will give those surfaces that need to be smooth a better chance.

The own goals, well two big gashes appeared in one side, distraught I blamed Shapeways for their personal checks and assumed they had fiddled with it, there were also two lifting lug brackets missing as well.

However a quick check on the Shapeways site showed the same issues on their preview render which I had totally missed, again I assumed it was their process so decided to check the Autocad model, oh dear, shot my self in both feet with one bullet :oops:

It appears that when you have a large solid shape, as I had at the end before sending, that making changes on one part can have an effect on another, I'd done some splitting down and rotations and for some odd reason Autocad decided to add more faces and split some others, oops. So, check before send next time.

The Autocad model with errors circled, I had even deleted the lifting lugs myself, small circle at right :(
Image4.jpg

The shapeways render.
Image2.jpg
Again the errors are very much self evident.

The final model, it's a bit of a witch to photograph naked so to speak.
IMG_0392.jpg

It does have nice hollow box sections with a small ridge around for the cover plate to seal them, one of the primary reasons for going the 3D printed route rather than cast though it might work as a lost wax part.

The dead beetle view is basically how it was orientated in the printer though the rear transverse beam was separate as the ultra detail printer only allows items up to 50 mm wide and the complete assembly is just a touch too wide. There's a square peg and socket on the ends and that has worked really well with a good fit.
IMG_0393.jpg

Similar to the first view but shows the sloped areas on top that were supported by the wax as a more solid white colour and quite rough to the touch.
IMG_0396.jpg

Next up is a clean (apparently) but it feels and looks clean enough already, but I'll give it a scrub in what ever anyone thinks is appropriate. Second is to find an adhesive that'll glue the rear section on and then think about filling the notches in the side frame and trying to smooth the roughest areas out. I'll also make a dummy inside frame to screw the printed frame onto for strength and handling.

I still think etched axle box carriers are the way to go but may make them rigid without rotating bearings on this one, something about too many steps in one process springs to mind.

In other news, back to the good ole US of A next year for three weeks, the boss is hunkered down in Mickey %&$£ Plastic Mouse World with the in laws (last time they'll realistically go due to age and health) and I have a pass out for rail-fanning. There's not enough action for me on the S line in Florida (24 trains in 24 hours, most at night), so up to the Folkston funnel (60 per day) to grab some action there for a couple of days.

However, I want more elevation so going to jump on an internal flight (I'll loose too much time driving the 2000 odd miles) and head West.

Cajon has 100 a day but it's arid and I'm no arid fan but could also pick up Tehachapi. Looking for bigger mountains I'm considering Donner (Yuba and Emigrant gaps), then up to Columbia River gorge and then Glacier park in Montana with the Marias Pass around Essex and Coram. Problem is, most of these are not that busy, ideally you want 40-50 trains a day to be sure of getting something.

Still a lot of research to do and working out where to stay, travel and how to get there on internal flights etc but looking forward to it now that I'm free of taxi driving and holding the hot dog / ice cream funds with a pass out of 10-14 days chasing trains :thumbs:.

MD
 

S-Club-7

Western Thunderer
Dunk it in white spirit for a couple of hours to remove all of the oil and wax (the Shapeways print, not the plastic mouse...) and expose to the sun to ensure that the UV setting of the resin is complete. Oh, and keep it oiled and waxed in it's plastic bag until you're about to clean and then immediately paint (and seal) it with a water-based acrylic primer; there are rumours that some prints degrade when exposed to oxygen. Never had any problems personally but the Shapeways forum has posts from those that have.

Those parts of the model in contact with the support wax during printing will be rougher as the wax is "printed" at a lower resolution to the acrylic.
 

mickoo

Western Thunderer
So,

Don't wash with soapy water and then spray with Halfords filler primer then :eek::rolleyes::))

I've only done the badly gashed side frame and it's all sacrificial really, part of testing I suppose.

The layers are still evident in some areas but areas sanded smooth have come up nicely.

Thanks for the insight on the wax support, it is definitely something to consider when laying your parts out and their orientation.

MD
 

Big Train James

Western Thunderer
It's good to remember that if you slice through a solid simply by specifying a slicing plane, that the plane is of course infinite and will slice through every part of the original object it intersects. This isn't necessarily a problem, as long as you don't delete or move one of the resultant parts. You can always union things back together if necessary.

If you want to slice something locally, then I've found that the better choice is to create a surface and use that to slice the solid with instead. You can create a surface by extruding a line or curve or create more complex surfaces with lofting or other manipulations. The first advantage of this method is that the line has a finite length, and you extrude it a finite distance. So your slicing "plane" is now only as big as you make it, and ideally only intersects the part of the original solid that you want to cut off. The second advantage is you can slice things in more complex ways then with a simple plane. The only caveat when using a surface to slice a solid is that all edges of the surface must fully meet or protrude past the faces of the solid, or the slice will fail.

I can slice only the nub below the red surface in this instance because it's the only part intersected, whereas simply specifying an infinite plane would also slice through the rest of the bogie sideframe as well. It's also useful to remember that everything on one side of the slicing plane is considered one solid, even if there are parts that don't touch each other. These can be separated after the fact.
surf-4.JPG

This jacking pad model is an good example of slicing with a complex surface. To create the complex transition from the side to front face either side of the part number, I had to create a surface by lofting a series of curves. Normally I would have tried to create a solid by lofting the curves and then closing the ends to create a watertight volume, which I could then subtract from the overall model. I couldn't get acad to create the solid, so instead used the curve to slice away the part I didn't want.
jp-solid.JPG

surf-3.JPG

surf-2.JPG

Hope that helps somewhat. Also, let me know if I need to post this type of content to the cad forum instead of this thread. It's topical here but I don't want to clutter things up. Lastly, I've tried a few things in response to the stack to smokebox saddle discussed earlier and have realized that you can "extrude" a non-planar face, you can "extrude" along a curve to an extent, and you can loft profiles using multiple guides (same as rails in the Rhino example). If anybody is interested in hearing about it, I'll work something up to post in the cad forum.

Jim
 

mickoo

Western Thunderer
James,

Sorry for the tardy reply, the reasons are many but primarily I've been researching a railfan trip next year, with a pass out for at least 14-16 days I want to hit the ground running :thumbs:

Time is my enemy and target locations are too many and why do y'all live in a country so bloody big!

So far I've a couple of loose options;

Orlando - Sacramento flight
Pick off Donner Pass, highly weather dependent as if its like this year with nearly 800" of snow then I'm not going to get up there even at the end of April, but I'll pick off Gold Run, Colfax, Dutch Flat for certain. Down side to Donner is lack of traffic, 20-25/day.

Then option one is to drive down to Techachapi and pick off Bealville, Caliente etc for a couple or three days. Better traffic flows but not mountains hopefully Donner will have satisfied that itch. Follow that with two or three days down at Cajon, plenty of traffic here with 100/day.

After that not really sure, two options;
1a, Head East, pick off Needles, Kingman and Flagstaff and try to get back to Denver then flight back to Orlando.
1b, Head NE to Las Vegas, Salt Lake City, Laramie, Cheyenne, Denver.

Option two, Donner for two or three days, then drive up to Portland and pick off the Columbia river gorge for two or three days, again 40/ day traffic flow and then head down to Boise, Salt Lake City, Laramie, Cheyenne and Denver.

On top of all that, whilst in FL hope to pick off Mulberry, Dade City, Wildwood and Ocala but that's one day and then a two day visit to the Folkston Funnel for a camp out there.

Couple of things I still need to research, drop in flights, eg just drop in a the desk and fly anywhere internally. Motel drop ins, it pays to book in advance but being as I've no idea where I'm actually going that's a bit difficult. No issues with spending the odd night in the rental vehicle (is that legal) lineside so that I get the pre dawn and dusk shots, Cajon is a definite, Bealville another possibility.

Anyway, back on topic, I'd love to see your work flows on those items as I've got quite a few bits I'm going to need for up coming US projects :cool:

MD
 

Tim Humphreys ex Mudhen

Western Thunderer
James,

Sorry for the tardy reply, the reasons are many but primarily I've been researching a railfan trip next year, with a pass out for at least 14-16 days I want to hit the ground running :thumbs:

Time is my enemy and target locations are too many and why do y'all live in a country so bloody big!

So far I've a couple of loose options;

Orlando - Sacramento flight
Pick off Donner Pass, highly weather dependent as if its like this year with nearly 800" of snow then I'm not going to get up there even at the end of April, but I'll pick off Gold Run, Colfax, Dutch Flat for certain. Down side to Donner is lack of traffic, 20-25/day.

Then option one is to drive down to Techachapi and pick off Bealville, Caliente etc for a couple or three days. Better traffic flows but not mountains hopefully Donner will have satisfied that itch. Follow that with two or three days down at Cajon, plenty of traffic here with 100/day.

After that not really sure, two options;
1a, Head East, pick off Needles, Kingman and Flagstaff and try to get back to Denver then flight back to Orlando.
1b, Head NE to Las Vegas, Salt Lake City, Laramie, Cheyenne, Denver.

Option two, Donner for two or three days, then drive up to Portland and pick off the Columbia river gorge for two or three days, again 40/ day traffic flow and then head down to Boise, Salt Lake City, Laramie, Cheyenne and Denver.

On top of all that, whilst in FL hope to pick off Mulberry, Dade City, Wildwood and Ocala but that's one day and then a two day visit to the Folkston Funnel for a camp out there.

Couple of things I still need to research, drop in flights, eg just drop in a the desk and fly anywhere internally. Motel drop ins, it pays to book in advance but being as I've no idea where I'm actually going that's a bit difficult. No issues with spending the odd night in the rental vehicle (is that legal) lineside so that I get the pre dawn and dusk shots, Cajon is a definite, Bealville another possibility.

Anyway, back on topic, I'd love to see your work flows on those items as I've got quite a few bits I'm going to need for up coming US projects :cool:

MD
Mick,
Happy to have a chat and pass on my experience of travel in the USA.
Tim
 

Big Train James

Western Thunderer
On road chasing an eclipse. I'll add some thoughts after I get home tomorrow.

I wish you could have made this trip while I was still in Denver.:(
 

richard carr

Western Thunderer
Mick

I was skiing near Truckee in February, I managed a couple of evenings down at the station hoping to see something before it got too dark, not a lot was the answer. It was the same in Feb 2015. There was lot of snow this year, but you could still get up there easily enough, there was almost no snow in 2015, you couldn't even ski to the base of the Mountain where we were.
Sacremento to Portland is a full days drive, I know I did it in June 2014, having taken the train from Chicago to Sacremento running 9 hours late to get the Portland train back to Chicago fortunately that ran largely on time so I could get me flight home.

Richard
 

mickoo

Western Thunderer
Richard,

Cheers on the snow conditions :thumbs:

Your Donner traffic rate seems to match what I'm finding now in photo research, those that live in the area have many shots of many trains on different days, those on vacation tend to have the same train on the same day in different locations. Being as track speed is limited to 25mph up and down the hill you can easily de camp and move to the next spot before the train gets there. The weather can also be a bit hit and miss too, when it socks in it socks in and even at 7000' it can still be nasty.

Tehachapi is a bit better, but also has big gaps at random where they do MOW work, Donner seems best at the tail end of the week with the weekend and early week being the quiet spells, Tehachapi is heavier at the weekend, Cajon is just full on all the time. Weather is much better on average over Tehachapi and even better at Cajon and perfect at Needles.

Sac to Port is about 500 miles and about the limit you can comfortably do in one day. I used to drive to Denmark overland and that's 610, which is the upper limit I'd consider safe for a point A to B trip with solo driver. The best I did it was 10 hours (overnight, less traffic....more trucks) but you loose a good hour on the Chunnel or two on the Ferry, mind in Germany you can make that up ;)

It'd be nice to get a range of photos from the high Sierra Donner mountains to the Mojave desert. Much as I'd love to get on Donner I'm hedging more toward hitting the high traffic flow areas and starting in LA and working back up to Denver. There's some nice mountains in Utah and Colorado.

All very fluid right now.

MD
 

Tim Humphreys ex Mudhen

Western Thunderer
Mick,
Trains magazine has an article each month on railfanning hotspots with an on-line library of their previous articles. Watching tains on the UP crossing the Great Divide in Northen Colorado/Southern Wyoming is spectacular. If you get a chance go to Helper in Utah, there's a clue to the action in the name.
Tim
 
Top