Large Scale Central

Learning 3D-CAD

Modeling Technical Modeling
#1

I’ve been using 2D-CAD software (CADrail) for 19 years, but that didn’t really prepare me for the learning curve of a simple 3D-CAD application like SketchUp. Two weeks remaining on the trial copy of the latest Pro version and slowly pieces start to fall in to place. The impetus to get cracking is the desire to get a four car train of heavy-weights done for the 2015 season. Most of it straight forward except the shape of the roof ends.

Keeping at it paid off, looks like it will even pan out in Cut3D. I’ll keep you posted.

PS what’s involved is easier to show with the 3 views in 2D.

It was a “trial and error” operation to arrive at the correct rad at the bottom of that length profile. SketchUp has a routine that they call “Follow Me” i.e. one draws the path that the “face” (in this case the cross section) needs to follow. It gets tricky when one has predetermined dimensions that need to be matched.

#2

HJ,

Don’t be too worried about the “Pro” trial as it will convert to the regular basic program after so many uses. While I haven’t uninstalled and reinstalled Sketchup, it might function to work as a ‘clean’ install that resets the “Pro” version. I have Sketchup 7 & 8 installed because a plugin for 7 exists to export the .skp files into regular CAD files, but that plugin is only available on the Pro version after 7.I haven’t upgraded to the latest version yet, but I think the routine is pretty similar.

If you haven’t checked out “Sketchup for Dummies” at the local library I would suggest that you do. It has a lot of helpful tips for using the tools like “Follow Me”. You should be able to set a specific length anytime you draw a line, or object.

#3

Thanks Craig,

It’s on order/hold (1 of 1).

I signed up on the Newbie Forum at SketchUcation Community Forums. Quick replies pointing in the right directions and with multiple solutions — I like that.

Most likely I’ll spend the dough for the Pro version, allows imports of 2D CAD files with one click conversion to “faces” — that will save a lot of work and provides the accuracy — and export to different formats 3D formats. The proof will be in the pudding when the first samples come off the CNC router.

#4

This is a must have bookmark for Sketchup users.

http://extensions.sketchup.com/

Lots of Youtube videos (some better, some worse) that explain different functions of Sketchup. But I found the book much more helpful and check it out any time I do any serious Sketchup drawings.

One of the key things I found using Sketchup is learning the keyboard shortcuts if you don’t have a 5 button mouse. They help a lot to toggle from one setting to the next.

Are you drawing in 1:1 or in scale?

#5

Started out with the actual dimensions for 1:22.5 (imported 2D files) and had a few problems intersecting. One of the experienced users told me to scale it up, apparently SU gets a bit iffy in the low millimeter range.

Printing out the keyboard short cuts (from masterSketchUp.com) was an early action. All that mousing around is just not the cat’s meow.

Probably need to get a different mouse, too. The scroll wheel on the present one isn’t all that smooth.

#6

Hans-Joerg Mueller said:

Started out with the actual dimensions for 1:22.5 (imported 2D files) and had a few problems intersecting. One of the experienced users told me to scale it up, apparently SU gets a bit iffy in the low millimeter range.

Printing out the keyboard short cuts (from masterSketchUp.com) was an early action. All that mousing around is just not the cat’s meow.

Probably need to get a different mouse, too. The scroll wheel on the present one isn’t all that smooth.

I’ve never noticed the problems in smaller ranges, but I tend to design in 1:1 and then just model off the scale measurement (or upscale back to actual inches). I also take advantage of the different settings on start up (template). I think a couple of them are geared towards smaller designs, so it may be that the ‘code’ is slightly different say between the “Engineering” template (Units: Feet or Meter) or "Product Design and Woodworking (Units: Inches or Millimeter). Would be interesting to find out if that makes a difference.

#7

I’m using the “architectural design - millimeter” template, try the “woodworking- millimeter” next. See how that changes things.

#8

Hans, usually you can adjust the sensitivity of your mouse wheel. That might help.

#9

David,

The present MS mouse is old enough to be replaced. It runs just with the generic Win7 driver, has a rather stiff scroll button, which is a bother in SU.

OTOH it did well for many years, other than needing batteries on shorter intervals than some of our other cordless mice.

#10

There’s a new Mouse in the house and the difference is astounding!

#11

AND I picked up “SketchUp8 for Dummies” from the library. It’s a slightly worn copy. (http://rhb-grischun.ca/phpBB3/images/smilies/3.gif)Also took a step back and installed SketchUp Pro 8.

May the fun begin!

#12

Make sure that you save your old files under ver. 8. Should be a good read. Enjoy!

#13

Thanks for the heads-up!

#14

Hans
On the follow-me tool, you make the line to follow the length you desire the part to be.
If you desire a different length, double clik the face you need to move, double click selects the
face and all the lines connecting the face. Select move tool and move longer or shorter, until you get the desired length.
A good mouse and the short cut keys are the most time saving items for sketchup
Be sure you are familiar with perspective view and paralell projection under camera
Paralell projection makes selection alot easier
As in CAD dragging right to left selects all you touch
Dennis

#15

Thanks Dennis, I appreciate that!

Aha, another work around. The recommendation on the Newbie forum was: Extend the path to be followed before and after the section you actually need. Works like magic, no more partial polygon segments in a 90º radius feature.
The parallel projection selection was an “intuitive” thing for me — HJ’s “dumb” beginners luck. This, even after I did a lot of perspective freehand drawing practices, just feels more “natural”.

#16

I’m new to 3D printing as well, but, fortunately, the Sacramento Public Library has a few 3D printers and a 3D scanner. I did my first project last week: a four pane window 42mm on a side. The panes are about 18mm on a side. I designed it with Tinkercad, an online program. There is almost no learning curve with Tinkercad. It’s designed for fourth graders, so I could handle this pretty well. It took me about an hour to get comfortable with Tinkercad, about 20 minutes to manipulate the shapes the program uses. The Library’s Makerbot took about 15 minutes to make one.

I’ve got a 14 pane roundhouse window (two rows of seven windows) ready to go tomorrow when the lab opens.

#17

Hey Dick post some pictures when you get a chance I’d love to see what you made. I’ll also have to check out that Tinkercad software.

#18

Dick , I am interested too in seeing your work

#19

OK, guys, here are the first two of my prints. The four pane window is drawn in Tinkercad, the one I mentioned before. the 14 pane window was done in Invention, which I think is a PC only program which the library had. Another version is being designed in Freecad, which I think is another PC only program. I’m looking for a program which will run on Mac OS 10.4, but haven’t found one yet.

#20

I just downloaded the free Sketchup Make last night. Putzed around with it for about 3 hours. I am spatially challenged as it is, so taking my 2D CAD brain and making it think in 3D has not been easy. My BIL is a whiz at it so I have help close by if needed.

My first project will be 1:1 scale deck to replace the crumbling cement and stone stairs at the entry to our house. I’d like to be able to run track under the deck, but that will require trimming some 2x6 stringers for clearance; so I thought 3D CAD might help me figure out how to do that with curving track.