Finally getting down to business with sketchup

[eTraxx]

Havard. I ran into problems with that myself .. but figure it's something I did. I just lathed a simple spoke to test the program with this simple shape.

Wanting to create this



So the first step is to lathe the thing. I exported the .stl file and loaded into MiniMagics and it found no problems.



The next step is what I am curious to see .. if I slice the sides off and wedge the object like the spoke .. will I still get errors? Donno yet.

[eTraxx]

Well .. darn. Intersected a couple of planes in the lathed object, deleted out the bits I didn't want .. and got errors when I imported the .STL file into MiniMagics.

[Hauk]

Well .. darn. Intersected a couple of planes in the lathed object, deleted out the bits I didn't want .. and got errors when I imported the .STL file into MiniMagics.

It seems that MiniMagics is a tad too sensitive.
The real test is if  the service provider can use your file. It does not matter if MM gives errors if PAP or whoever can print it.

Regards, Håvard H

[eTraxx]

Yeah. I've about come to the conclusion that Sketchup just isn't working at the level I need. Full scale .. no problem but I had to simplify the wheel I was playing with to get it to scale to 1:48 .. it gets really confused with any small curves. I ran this through the MiniMagics program and it tells me that I have a bunch of errors. They tell you to goto their website to download a trial version of software that can repair errors .. but .. I swear. I have never thought myself dumb .. but I feel really stupid on that website. Oh well. I made a pretty picture at least!

[marc_reusser]

Why are you guys using MM, when you can just use CAD-SPAN??? http://www.cadspan.com/pluginguide/overview.....it even has a toolbar to integrate it right into SU?  So far none of the models I have run through CAD-SPAN have shown any errors or problems.  CAD-SPAN will even re-wrap everyting, in case you have touching individual non-combined componets, and output them as a single component in the .STL file.


MR

[Hauk]

Why are you guys using MM, when you can just use CAD-SPAN??? http://www.cadspan.com/pluginguide/overview.....it even has a toolbar to integrate it right into SU?  So far none of the models I have run through CAD-SPAN have shown any errors or problems.  CAD-SPAN will even re-wrap everyting, in case you have touching individual non-combined componets, and output them as a single component in the .STL file.

I am using Cad-span, I use MM just for looking over the finished .stl parts. I do get some odd results even when using CS,  sometimes it works better just to use SU2stl, a free ruby script for SU.

Since I have not really decided where to print my parts, it is really a somewhat wild chase.

I have found a service provider in Korea, it makes sence to print the parts in Korea if they are going to be cast in brass there.
Sending the parts by messenger should be safer than shipping them half around the globe by mail. Could save some on customs, as well, not to mention time.

Regards, Håvard

[eTraxx]

Why are you guys using MM, when you can just use CAD-SPAN??? http://www.cadspan.com/pluginguide/overview.....it even has a toolbar to integrate it right into SU?  So far none of the models I have run through CAD-SPAN have shown any errors or problems.  CAD-SPAN will even re-wrap everyting, in case you have touching individual non-combined componets, and output them as a single component in the .STL file.


MR

Marc, thanks. My answer is .. I wasn't aware of the CAD-Span plugin. I downloaded and installed it so that part is fine. Currently, I'm playing with a plug-in that scales .stl files. Since you can only use it 10 times or for 10 days I have to be careful not to waste the trial. With all the problems I had with trying to scale down anything with curves to 1:48 I thinking that 'if' I can scale the full-size .stl then I should be able to by-pass that.

[Hauk]

A little update on the design.
All the parts have been carefully redrawn to minimize trouble and errors in the stl files. Circles are now drawn with 24 facets rather than 96. It seems to pay off, far fewer crashes and much more easy to downscale the final models.



I draw at a 10 times enrlagement, since SU starts to act weird when the faces gets really tiny. I think this is the most important lesson learned from this excercise.

SU on the Mac is one of the most unstable programs I run on my mac, and I find this quite disappointing. I will look more into VectorWorks (I have this at Work) to see if I can get a smoother workflow with that software.

At the moment I would very much like to know the volume of the parts, since I am really unsure if the car will have a brass or resin body. I would very much like to know what the weight of the body will be. I have made some rough calculations, and my estimates  come out at around 100-150 gr. Anyone with opinions on how much a narrow gauge freightcar in 0 scale should weigh? There is a plugin available for SU that calculates the volume of models, but all I get is crashes... Dave, you looked over some earler versions in Solidworks, does SW calculate the volume of parts?

Some notes on the design. As someone noted, in brass it should be possible to make working hinges. I plan to go for this, so I have designed the parts so that the  hinges will be drilled out, and 0,4 mm brass rod inserted. How wellthis will work remains to be seen!



Regards, Håvard H

[eTraxx]

The MiniMagics page shows the volume under Properties

[Hauk]

The MiniMagics page shows the volume under Properties

Thanks!

-Haavard

[finescalerr]

This has been a wonderful thread and I can't wait to see the final result. Even so, the lessons we learn with each post are invaluable. -- Russ

[marc_reusser]

When you process it through PAP for a price quote, it also gives you resin/material volume.

MR

[eTraxx]

Ha. I have to massively reduce the number of triangle in my wheel. Seems that 28K is a bit much. Snicker.

[Hauk]

When you process it through PAP for a price quote, it also gives you resin/material volume.

Thanks!
I checked, and PAP  gives a precise figur for the volume.
The body clocks in at right over 100gr (3,5 oz.). Since  0m gauge is about the same as S scale standard gauge in actual gauge and volume, I looked up the NMRA RP  for car weight.

The NMRA suggests that my car should weigh 3,5 oz in total, so a brass body will probably make the car a bit too heavy.
But it would be fairly easy to trim some fat by making the floor in resin. The floor need detail only on one side, and has no bolt detail. I think it would work well to print these at PAP, and make my own resin parts. This brings the body down to 70 gr, and the wheels and underframe will probably bring the weight back up to around 100gr.

I might have  mentioned that I have found a Solidscape service provider in Korea, and I got a quote for exactly USD 100 for 3 wax masters. I put them in touch with caster, (MKTrading, formerly Korean Brass) and I am awaiting a quote for a batch of parts for 50 wagons.

But I am still agonizing over doing the body as a brass/resin project or just a resin one. Decisions, decisions...

Regards, Håvard

[Hauk]

I have now received prints both from Print-a-part and Korean Brass. The PAP part is the usual blue plastic. The brass sample is made from a wax print made on a Solidscape machine.

To sum up things:
The PAP part is utterly useless.
The brass pattern is promesing.

First, I do not blame either PAP or Korean Brass for the mixed results.  I tend to push thing as far as possible, and always try to challenge the limits of the technology applied.

The poor result on the PAP sample is possible due both to faults in the geometry on my .stl file, and that the features of the parts are actually too small/fine to be printed on a machine with the resolution of the PAP machine.

But I still find the difference in surface quality puzzeling, some areas of the parts are really fuzzy compared to others.  Anyhow, my conclusion is that PAP is not really suited for the quality I want.

The brass part is another matter. To the bare eye, it looks really good. It has a somewhat rough look that suits the subject rather well. The lines between the boards is a bit uneven. But look at the prototype photos, the boards do not have very distinct lines between them. They are not grooved in any way. It is tongue and groove boards, and the lines between the boards are probably due to the shrinkage of the wood.

But if you want to sure of consistent lines in the masters, you should use  grooves at least 0,3mm wide.

The general sharpness could be better, and I really wonder if the final LW castings will be even softer. If so, the results will probably not be satisfactory.

A  big problem with the brass master is that I have not seen the wax pattern. So I can not be sure if it is the brass casting process or the Solidscape wax printer.

So all in all, I almost have more questions than answers after receiving the parts. To be continued!