Going From A 2D Drawing To A 3D Printed Part Tutorial using SketchUp

[thibaultron]

Part 11C

 

Now I’ll do this again, but with the left hand extrusion vertical, as in the original curve setup.

 

Follow me creates this new extrusion.

 

 

Again the left hand end, is not in line with the original surface.

 

Upright Extrude gives this.

 

 

Notice that without the second extrusion to mate to, the right-hand end finishes at an angle not at a right angle to the last line.

[thibaultron]

Part 12A

 

Now we will switch to the hand dredge drawings and some problems I had, and examples of the procedures I used for some of the parts of the drawing.

 

I started out Extruding the parts from the reference drawing to their full height, and the base to it’s full outline.

 

 

 

Then I overlaid them to form the leg, ending up with this.

 

 

In fact I had drawn almost all of the winch, before I bothered checking it at the Shapeways site. That was a mistake!

 

 

I checked just the simple leg at this point, and it leg came out a mess.

 

 

 

Drawing the leg with everything overlapping, was not the correct way to go! Not checking the drawing frequently was also a mistake. Even the holes in the legs for the support rods are partially filled in.

 

The smaller parts came out OK, except that some of them were too small to print as separate parts.

 

So I started over. I drew each major piece so that they did not overlap.

 

First I drew the back of the web for the leg, drawing it so its outer rim was along the inner rim of the vertical portion of the web.

 

 

Before I extruded this I deleted the outlines for the tabs, so that the center portion was all one solid.

 

Then I copied it to another location, and deleted all but the outer outline. This makes sure the next parts will mate completely with the next subassembly.

 

I then drew the vertical portions of the web, and the top support rod bosses and the feet separately, as can be seen in the left of the picture below.

 

 

Here is a view from the side. Note, that the bosses are set at the correct elevation, to fit on top of the back web. The horizontal line is at the level of the bottom of the back web.

 

 

Then, once again using copies of the originals, I combined them into one assembly.

 

 

This leg is just about finished, but I need to add the angled section that ties the two levels of the vertical web together. This section has a curved profile, not a straight line slope, so it took a little more effort.

 

After drawing in the proper length line to give me the correct position of the center of the curve, I drew in the curved line for one side of the transition. I used the 3-Point Arc command to do this.

 

 

Then selecting both portions of the curve, then the rear vertical surface, I used the Follow Me command to draw in the section.

 

 

Opps, the rear of the extrusion, does not meet the original starting surface. In this case it is off both in the vertical, and horizontal axis. The legs flair out as they go towards the feet, and this threw off the Follow Me command in the horizontal axis.

 

Also the extrusion cut into the existing web, As the height remains the same as the solid is extruded. This is not a problem, as it is easily repaired. The Upright Extrude, will do the same thing.

 

Here is a view from the other side.

 

 

I redrew It using the Upright Extrude.

 

 

Then I went in and erased the curved lines that are the bottom of the extrusion, to clean up the drawing.

 

 

I repeated this for the other side.

 

[thibaultron]

Part 12B

 

The other leg is the one the handles mount to, and it has a more complex geometry. Where the vertical portion of the leg web meets the handle bosses, it widens at the transition. On the first leg it stayed the same thickness. On this leg the inside of the vertical web stays straight, and the outside angles off to widen the leg web.

 

 

 

This complicates the shape of the extrusion, as the extrusion will stay the same width as the top, when created, making it wider than the leg web at the bottom.

 

Because the inner surface stays straight, I drew the curved path line on that side. We can fix the extrusion shape later.

 

After using the Upright Extrude, I had this. It matches the inside web surface, but sticks out at the bottom on the outside.

 

 

 

We can delete the portion that sticks out, but first we must draw in a new curved line for the top outside edge.

 

I deleted the outer wall, and drew a midpoint for the new curve, by drawing in a vertical line from the edge of the outside web top.

 

 

Using the 3 point arc command, I drew in a new curved edge.

 

 

 

When I erased the flash along the top, part of the curved surface was erased, along with the flash.

 

 

I filled in the void using the triangle method discussed in a previous post.

 

 

As you will see in later pictures, when I did this originally, I was lucky, and the curved surface did not need to be filled in.

 

I finished cleaning up the excess flash and lines.

 

 

 

[thibaultron]

Part 12C

 

The two handles were too small to print as separate parts, and attaching them to a sprue, would have left a lot of trimming to do on small parts. So I attached them directly to the leg.

 

 

 

 

The pawl “handle” is positioned on the leg so that it correctly engages the Pawl Gear teeth, when the gear is installed.

 

The clutch was also too small to print as a separate part, so I attached it to the left hand drum disk. I left a groove to guide the saw when I cut them apart.

 

 

No matter how I drew the left hand drum disk, the Shapeways software deleted the center hole. I gave up and just put in a depression in the back for a drill guide, this depression the software left intact.

 

 

 

I drew up a sprue of nuts, for detailing the final model. I also added small feet to the end of the crank handles, to stabilize them during printing, I’ll sand them off during construction..

 

Edited February 6, 2016 by thibaultron

[thibaultron]

I think for the next post, I will show how I drew the pawl gear.

[thibaultron]

Part 12D

 

There seems to be some confusion in what I meant by “overlapping parts”.

 

I’ll show an example. We need an open top box 24” square by 3” high, with ½” thick base and sides.

 

If we were making it out of wood, we could make it two different basic ways. There are several fancier ways that it could be made, but I’m going to stick to basics. I will be eliminating the front side, to show the joints better.

 

The first way would be to cut the base 24” square and ½” thick, then nail on 2 ½” tall with ½” thick sides.

 

 

The second way  would be to cut the base 23” square and ½” thick, then nail on 3” tall sides with ½” thick sides.

 

 

To draw this for 3D printing I can draw it 3 basic ways. The first two are just like I drew them above. The third way is to draw a 24” square base, ½” thick, then paste on 3” tall sides.

 

This causes the base and sides to overlap at the edges, as shown by the darkened areas.

 

 

Theoretically all three ways will produce the same 3D printed box, but the Shapeways software choked when my drawing with overlapping solids was submitted.

 

The final 3D printed box would look like this.

 

 

[thibaultron]

Part 13

 

I originally drew the Pawl Gear assembly with my CAD program, but here I’ll show how it can be done with SketchUp.

 

In the CAD program the three standard views (front, side, and back) gear look like this.

 

 

For the model, I simplified the tooth shape some, from what I think it would be shaped like in real life. I made the surface that the Pawl catches on close to a 90 degree angle (see left hand tooth shape). Basically as you will see shortly, I used the radial line as that side of the tooth. In real life that surface would likely be a bit deeper angle, to better hold the pawl in place when under pressure (see right hand tooth shape). In the model, you wouldn’t be able tell the difference, at least not without major magnification, and the nit picking type of personality that would. :-)

 

 

SketchUp has no Polar Coordinate line draw capability, despite what the help file seems to indicate. The polar coordinates described, are for the Layout program, which is a feature of the Professional License version only, and this is a separate program from SketchUp.

 

Polar coordinate lines, are ones drawn from a point, X long, and at Y degrees from and axis or another line. For example: “Draw a line from this point 10” long and at an angle of 20 degrees, from the X axis.

 

SketchUp will however allow you to specify how many sides a circle has. The gear was drawn with 18 teeth. The pictures showed a gear of about this many teeth (as far as I could make out.), and I could have gone with 18 or 20. I used 18, simply because it was easier to draw, and more likely to print out correctly than a finer tooth size. I also assumed a ½” tooth height.

 

So, I started by drawing two 18 sided circles, one the outer 7” diameter gear dimension, and an inner 6” circle representing the bottom of the tooth (1/2” tooth X 2 teeth, one on each “Side” of the gear).

 

 

Next I drew lines from the center out to each of the circle vertices (endpoints that form the flat surfaces of the circle).

 

 

To create the tooth shape I drew a line from each of the outer vertices to the next counter clockwise inner one.

 

 

Be careful to make the teeth point in the correct direction! When I first extruded the gear, I accidentally used the bottom view (right hand gear drawing above) of the gear, rather than the front view. When I placed the central cylinder in, in the correct direction, my teeth were backwards, and had to go back and correct it, later.

 

I then continued around the gear.

 

 

Then I removed the extra lines.

 

 

 

 

Using this I extruded the gear to the correct height.

 

 

 

To draw the pawl gear, I placed the parts in position, and used the gear tooth surface as one end, and drew a couple curves, that did not interfere with the next tooth, when engaged, for the body of the pawl.

 

 

I originally did this in my 2D CAD program, but couldn’t find the version of the drawing I did it on.

 

These posts cover all the SketchUp tips I can think of.

 

Next time I’ll take you through the downloading of the file to Shapeways, and after that I’ll show the program I use to check the drawing on my computer, before submitting it.

[thibaultron]

Part 14A

 

I was doing some drawing on the 1/64^th scale version of the dredge frame, and I had to do a couple of operations that I have not covered, rotating an object, and copying parts between drawings.

 

Rotating An Object

 

The rotation operation in SketchUp can be almost impossible, if you do not have a flat surface to reference when attempting to perform this function. The rotate operation looks to be designed for architecture, where you have many flat surfaces to reference when doing the operation. If you do not have such a surface, SketchUp will pick an axis that it thinks you want to do the rotation in. Generally it will select the Blue axis, and whatever axis it chooses, it insists on, it will frequently stubbornly refuse to allow you to use another axis.

 

For an example: We want to rotate the shape below 45 degrees CCW up the X axis (around the green axis).

 

 

The program places the rotation axis everywhere but the X axis.

 

Here it says rotate around Blue axis?

 

 

Red axis?

 

 

Here it is indicating rotation along the front face.

 

 

 

The only way I have found to have it consistently allow me to use a specific axis, is to draw a rectangle along the axis I want to rotate around.

 

 

Before drawing the rectangle, I make the object a group, so that I can easily delete the rectangle later. Then I make the object and rectangle a group, so that they can be rotated together. The rectangle does not have to touch the object, as long as it is grouped with it.

 

Now, when I place the cursor on the rectangle, the green axis is chosen.

 

 

After selecting the corner (as the rotation point), then selecting the other corner as the handle to use as a reference for rotating the group. I moved the reference point up (CCW rotation, and entered 45 in the box at the bottom to specify 45 degrees of rotation (see the highlighted area).

 

 

Voila, the object is at 45 degrees! There is one possible problem, though. The left edge is no longer at the origin (see the highlighted area below)

 

 

If we need the edge to still be at the origin. We need to select the point and handle at the edge where the object and rectangle meet.

 

 

Then I ungrouped the rectangle and object, and deleted the rectangle.

 

Edited February 11, 2016 by thibaultron

[druxey]

Aeee! When I was playing  with SketchUp, I never got as far as figuring out strategies to defeat its defaults. That is a great example of fooling the program to submit to your will. Thank you.

[thibaultron]

Part 14B

 

Here is a real world example of this process. I needed to rotate the assembly below to match the angle of the lower part of the dredge frame. These are the ends of the various frame parts that are bolted together.  I will have to blend them into the rods, as detailed in an earlier post.

 

 

 

 

 

 

After selecting the rotation point, I selected a point on the edge of the rectangle, as a handle, I pulled it up until it fell on the line I wanted the rotated object to match.

 

 

 

The object is now lined up at the correct angle.

 

 

After moving it into place and cleaning it up it looks like this.

 

 

Copying A Part From One Drawing To Another

 

I recently ran into the situation where I had made a mistake several versions back on my drawing for the 1/64^th scale dredge frame, but had done several things that I did not want to redo. So I needed to copy some parts of the drawing to the earlier version.

 

SketchUp only allows you to have one drawing open at a time per program window. So to copy from one drawing to another, you have to open two different instances of the SketchUp program, and copy from one to another.

 

Start up the first program and open the donor drawing. Then select the portions of the drawing you want to copy. Copy the highlighted portions, with either Ctrl C or Copy.

 

 

Start a new SketchUp program. If copying to another existing drawing, open it.

 

 

Next paste the objects to the new drawing using either Ctrl V, or Paste. The objects will be displayed, and you can move them around until you have them where you want them.

 

 

Once they are properly placed, click the mouse to set them. They will be displayed in blue, like when you normally select object(s).

 

 

They will be placed in the red/green plain (x and Z plane). If you need to rotate them, as I did here, group them, and use the regular or 90 degree rotate function (one of the plug-ins I mentioned at the start of the thread) to get them where you need them.

 

 

[thibaultron]

I'll resume this log shortly. My desktop computer died, but I was able to get my files off it. I'm left with my laptop, which has less computing power and a lower resolution screen. The screen shots will thus be a little lower resolution.

 

Sorry for the delays in finishing this tutorial, I spent quite a while trying to get my other computer going. It would intermittently either just turn off or not reliably turn on. Now it just won't turn on. It is either the motherboard, or the CPU.

[ianmajor]

Ron,

 

It is well worth the wait. Thanks for sharing your knowledge.

[mtaylor]

Ron,

 

Quick question.... are any lights coming on?  Exterior?  Motherboard?   Reseat all PS connectors first.  Get a meter and check the power supply.  I've seen the PS's die and they're fairly cheap and simple to replace.

 

Lastly, it could be the power button is bad.

Edited February 27, 2016 by mtaylor

[thibaultron]

No its the motherboard, or CPU. Had three different PS in it 2 from working computers. It started to cut out while  was working on it. Now nothing.

 

I've disassembled it cleaned it. Checked the power switch, etc. The only thing left is to try forcing the ps on, but that is not a permanent solution.

 

A new MB will have to wait until at least April, I have to take my wife to several different doctors this month, and that will eat up all my cash.

[thibaultron]

Well I managed to get the desktop running, I don't know for how long, but I was able to generate the pictures for the next to parts.

[thibaultron]

Part 15A

 

This section will cover cleaning up the drawing, and processing it to prepare it for review by the Shapeways checking software.  The part I will be using has some errors in it, this is due to it being an earlier version, than the final part. I discussed in the earlier post some of the problems, and solutions that might have to be looked for, while you are drawing your parts.

 

I will be going back to the dredge frame for this and the next post. It has more extra “things” to  work on.

 

As part of the processing/checking steps, I use a new program for additional checks. It is netfabb Basic. This is the free version of this program. It has more features than the checking I use it for, but I have not explored them. I just use it for those checks.

 

The raw part is shown below. It has several guide lines that need to be removed, before we start the checking processes.

 

 

I used these lines as guides while drawing the internal braces.

 

 

First I used a plug-in to remove the extra external lines. It will also remove the internal lines that do not form edges of internal walls. So do not do this step until you do not need the lines for future references to place new sections!!

 

The plug-in used is CleanUp3, available free from the Extension Warehouse.

 

To use it go to the Extensions Menu, select CleanUp3, then either Clean or Clean with Last Settings. The first time you use this plug-in, you may want to select some of the non-default options, after that first time, you can use the Clean with… selection, it just saves a few steps in the process.

 

 

If the Clean item was selected, the menu shown below is displayed. If the Clean with… item is selected, the cleaning operation is run without this and the next few steps being used.

 

 

Change any options you want, then select Cleanup.  After several seconds, to several minutes, the operation will complete. There is a time to completion counter at the bottom of the screen.

 

 

When it is done a couple of information windows will be displayed showing what was done. Just select OK to continue.

 

 

 

Here is the part after cleaning.

 

 

 

This clean up is not required, but it does make the part easier to see.

 

Be sure to record the overall dimension in one of the axis, you will need this for scaling when submitting the finished part to the printing company. I used the X axis (length of the frame from the tip of the nose, to the furthest part of the curve of the rear of the frame.

 

 

Note that the Cleaning operation does not remove any dimensions shown, they have to be removed manually, before or after.

 

 

The checking processes are next. I export the STL file before checking and after each check. I first submit the uncorrected file, to see if it works. If it fails, I then submit the file from the first check, etc.

 

Select Export STL… from the File Menu. This is another free plug-in from the Extension Warehouse.

 

 

The STL Export Options window will be shown. Check that the units of measurement you are using is correct (inch or Metric). When correct select Export.

 

 

The Save File window will be shown. Change the name, etc…, if desired, and select save.

 

 

The first uncorrected part STL file has been created. Do this again after using the Solid Inspector2 operation shown below.

 

[thibaultron]

Part 15B

 

The first check is the Solid Inspector2 (be sure to used the 2 version). When this operation is started the screen showing the  problems found will be displayed. Select Fix All.

 

 

It will tell you that it could not repair all the problems, Select OK and continue.

 

 

The fixes that the operation can do will be done, and a window showing the remaining “problems” will be displayed. Most times these remaining problems will have no effect on your final part, and can be ignored. Be aware that the correction may involve erasing areas of your part, so check carefully after this step. This is why I save an STL file before and after this and the next netfabb steps.

 

 

Save an STL file after this operation.

 

The final check will be done with a free program called netfabb Basic. It has many operations it can do, but I have only used it for the checking/repair operation.

 

Start the program, then select Open from the File menu.

 

 

 

 

Here I selected the STL file from the uncorrected drawing.

 

 

OK areas are displayed in green. Any gross problems will be shown in a different color. The brown areas shown here are from the sections of the original drawing that were shown in light blue. These indicate surfaces that are reversed from the normal white exterior surfaces. They are “inside” surfaces, the back of the white surface. This normally does not hurt the drawing, but you might have to correct these in the original drawing.

 

Select the Repair function, the red cross in the menu bar.

 

 

The program will display the part with problem areas shown in yellow.

 

 

Select Automatic Repair.

 

 

The Default Repair should be highlighted, if not, select it, then Execute.

 

 

 

The program added a sheet between the frame parts that is not desired! This is due to interior walls as discussed in a prior post. As I said at the beginning, this is an earlier drawing than the final one.

 

 

 

For this example I manually erased this plain.

 

Now the correction has to be applied. Select Apply Repair, then Remove old part.

 

 

 

Shown is the corrected part.

 

 

As with the Solid Inspector, this program might delete portions of your drawing.

[thibaultron]

Part 15C

 

Now we have to save the part to an STL file, the program converted it to its native format when it was opened.

 

Select the file in the right hand window, then right click on it. The menu below will open, select Export, then as STL.

 

 

 

Select the menu item.

 

The window below will open. Notice that the program used the same file name as originally opened, for the first part of the new file name, then it added its “(repaired)” text at the end. Rename, if desired, then select Save.

 

 

The window below will be displayed, select Export.

 

 

You can now close the program. Select No for saving the drawing as a netfabb project.

 

 

The next post will be the process of importing the STL file to the Shapeways site, and checking it for errors that might affect or prevent printing of your part.

[thibaultron]

Part 16A

 

Now we finally get to send something to the printer’s!!

 

We have our STL file from Part 15, and this post will show the process of sending it to the printer to be checked for printability.

 

Shapeways has a site where you can upload your drawing, have it checked for printability, be given the cost, and then order your part(s).

 

Below is the opening screen, with the address circled. They have a page on their site where you can see what you have downloaded previously, and order more parts if you need to.

 

 

Select the Upload button, and the screen to select which file you want checked will open.

 

 

Select the file before you select a measurement unit, or you will not be able to select a file.

 

Click on the SELECT FILE button, navigate to your STL file, select it and open it.

 

 

The window will show what file has been selected

 

 

Now you can select your unit of measure. In my case it is inches.

 

 

The Shapeways printers are metric machines, and they prefer that you use metric for your model. You can use inches, without problems. When you scale the drawing, as shown later, the displayed measurement may be slightly different than the one you entered, due to the internal conversion to metric, but it will be undetectable in the finished model. Generally the difference is in the hundredths to thousandths of an inch. If it is more than this, rescale the part, or restart the download process.

 

Select the UPLOAD button, and your file will be placed into the system. First a screen showing you that the file is being loaded will pop up.

 

 

After the file is loaded the software will display the scaling screen with the values at zero.

 

 

After some time, depending on your file size, or how busy they are, the window will display a scaled value. I assume that they roughly scale it to fit in their printer volume.

 

 

As the given measurements are unlikely to match what you want, you need to rescale the part. Give it a few moments after the initial scale is displayed before you go to the rescaling screen. If you click too soon, you will generate an error. If this happens exit the window and try again. Sometimes I’ve had to restart the whole process.

 

Select the SCALE button.

 

The window below will be displayed.

 

 

Notice that the unit’s defaults to CM, if you are using another type, select that first, then enter your scale measurement. The available units are shown below.

 

 

I am using inches. Almost all my models will be based on US ships, or older European ones, before metrification, so I will probably always use inches.

 

Now enter the scaled value for one of the dimensions. In this case, and generally, I’m going to use the X axis length. You can use any axis that will scale well.

 

 

In 1/32^nd scale the dredge frame comes out to about 2.25 inches long. For this post I did not take the time to calculate a more precise measurement. The other axis measurements will automatically be rescaled, and the scale factor will be displayed.

 

Select the SAVE button, and the first screen will be displayed again, and after some more time, the new dimensions will be shown.

 

 

As I stated earlier, the disadvantage of using inches, is that some small difference between what you entered, and the new measurement may occur. In this case I get 2.252 inches. Unless you are making parts for a nuclear reactor, it makes no noticeable difference in the finished part.

 

The columns below the scale display show the various materials you can print your model in, whether your model is acceptable in that material, and the cost to print it. Shipping is extra, but if you submit several files at the same time, they will combine shipping.

 

For our parts we will almost always need to use the materials that print the finest, the Frosted Ultra and Extreme detail plastics. I’m not sure what the detail definition difference is between the materials, but I use the Extreme, which has the finest detail. The cost difference is minimal, so I have not tried the Ultra Detail material.

 

The picture below shows the screen of the progress to the checking. The Auto Checks column will say Loading until the checks for that material are finished. The checking for the Frosted Detail material generally takes the longest.

 

 

The picture shows that the software has already determined that there are problems with printing it using the Metallic Plastic material. You can also see how much it will cost to print in each material, assuming that it passes the requirements.

 

When the checks for each material are completed, a Passed, or View Issues result will be shown. For the dredge frame, either Frosted Plastic material can be printed.

 

 

If you select View 3D Tools, a window showing the detailed results is displayed.

 

 

For these parts, everything checks out, but you need to look further at the Wall Thickness requirement. There can be hidden problems, that while allowing it to be printed, might have to be corrected for a good detailed part.

 

[thibaultron]

Part 16B

 

One thing that can keep your part from printing, is that it is too big to physically fit on the printing bed. The Bounding Box requirement is what determines this. Selecting that text will display your part, as it will fit inside the machine. At least most of the time the box will be shown, if not, you just have to check which of the axis may be too long, if the check fails. Another Bounding Box problem may be that there are parts, in the file, that are too small to be printed individually. I discussed this in an earlier section.

 

If you will be printing multiple parts in the same file, looking at this will show you roughly how many you can fit in one print. Each file that you have printed has a $5 setup fee, so if you can fit multiple parts in each file, you only have to pay for the additional material costs.

 

 

Now we need to check the Wall Thickness requirement, before we try to print the part. Select that text and the window below will be displayed.

 

 

The minimum thickness limits are shown, as well as a graphic of the part. Green means good, but we need to inspect it closer.

 

For one thing that sheet on the bottom is back. This will have to be corrected before the final part is ready.

 

Looking more closely at the part there is another problem.

 

 

There is a defect at one of the braces, shown by an extra nub/flash on the brace, and the red color. The red means that the part may be too thin. All these are probably caused by those interior walls.

 

After cleaning everything up I came out with this for the final part. I combined two frame sets into one file (four frames total) to save setup costs.

 

 

 

Looking at the scaling sheet, the four frames will cost.

 

 

For an example of a failed part, I chose one of the other materials that the part was too thin to be printed in.

 

 

 

It fails the wall thickness requirement.

 

 

Some sections are thick enough (green), some are of questionable thickness (yellow), and most of it is just too thin (red).

 

After these tests pass, there is a manual check that Shapeways performs after you make your first order of the parts. If these checks pass your parts are printed. If they find problems they will notify you, and give you the options of either having your money refunded, or to have the parts printed anyway, so that you can see what the results are.

 

Here are some pictures of the printed winch parts. This is as good as I could photograph them. To get these pictures I had to film using my magnifying lens lamp and some zooming in with the camera, to even begin to see them.

 

1/32^nd scale parts as they arrived.

 

 

1/64^th scale parts.

 

 

The 1/32^nd scale parts primed.

 

 

 

Notice that even the teeth on the 6” diameter 18 tooth gear are sharp. Much better than I could ever hope to make.

 

 

You can see some roughness on the vertical surfaces due to printing the part in layers, but a little sanding will smooth them out. The horizontal surfaces are smooth.

 

I have not had the frames printed yet. I’m still working on the 1/64^th parts, and funds are a little tight right now.

 

[thibaultron]

Part 16C

 

As I mentioned earlier, Shapeways has a page that shows all your models, so that you can order more parts, and you can also make your models available to the public. I am not sure what the later entails, maybe a subject for a future post.

 

Here is a sample of my page, with the address highlighted. The page is a private page that I have to log into, in the future I plan to make some of these public, but that will be a while.

 

You will get your own page, once you start submitting projects.

 

 

Every time you upload a file, it will be placed on your models page, so you will have to periodically clean out your test files. You can see some of the files from making this article, and some from my ongoing 1/64^th scale version. Notice that if you submit the same file, with the same name, more than once, you will get multiple instances of it in your model list (last two entries in this list). Be sure to name your final file a unique name, to avoid confusion.

 

 

What do the particle limits on minimum printing thicknesses mean on a model?

 

On my 1/32^nd scale winches, the minimum is a little more than 3/8” in full size. For my model I choose ½” thick webs on the legs (vertical and horizontal). The free standing gear brace is 1” scale thick. It could have been printed as thin as about 0.8 scale inches, if necessary. The crank handle also shown below was able to be printed with scale 1 ½” diameter handle shafts and 1” diameter handles.

 

 

For the 1/32^nd scale parts I was able to print them as separate pieces, except for the nuts which I had to put on a sprue, and the end of the drum and the clutch. These parts were too small to print individually. The large nuts are 2” square, with a 1” diameter hole (scale sizes).

 

 

For the final printed version, I combined four winches into the file for printing. This cost little more than printing 2 winches (number required for model), and allowed spare parts when assembling the winches for the model. This turned out to be a good move, as one of the crank handles vanished into the black hole in my floor, while I was priming a set for the pictures in this article.

 

For the 1/32^nd scale winches, I will use drill rod for the axles and support rods. On the 1/64^th scale winches, the drum axle is printed into the parts, and drill rod will be used again for the support rods.

 

 

I had to make some compromises for the 1/64^th scale parts. The minimum web thickness for the legs had to be increased to 0.9” and the one handle attached to the complex leg had to be made thicker. I increased to thickness on the outside edges, to make it easier to sand them down closer to scale. I also had to attach the rest of the smaller parts to a sprue. Even in this small size, I was able to put a hole in the larger nuts. It is under size, but will serve as a drill guide for bringing them to the needed scale 1” diameter.

 

 

The axle shafts are printed as part of the assemblies, and the gear is attached to the leg. Attaching the gear still allowed for printing it the scale size.

 

The feet for the legs are separate parts here, this makes sanding to thin the leg webs, later, easier.

 

The drum parts, back of the legs, and the handles have recesses in them to fit the printed axles.

 

Yes, one leg is missing; I deleted it from the drawing, so that the remaining parts could be displayed larger.

 

This ends this series. I hope that some of these hints will help you in your endeavors.

 

For those of you who may want further explanations, of how I drew the parts, and the history behind them, check out my Carrie Fisher build log.

 

Feel free to ask questions, or if you run into a problem drawing your parts, maybe I can help.

[mtaylor]

Ron,

 

This is a great tutorial.  Thanks for sharing and removing the mystery of 3-D printing.

[thibaultron]

Your welcome. Now I can get back to building the model they were designed for. Finally at the point I can move my workbench Model Railroad layout combo into the new section of the shop, and start using the workbench again.

[dgbot]

Thank you for this tutorial Ron.  I still remember when I was attending a club meeting when a member brought in some items that were 3D printed.  Bur the main problem is the cost of owning one.  You have taken the mystery out of it.  

David B

[druxey]

Whew! Exhausting and exhaustive. Thank you for taking the time to take us step by step through the whole process, Ron. I've learned a lot reading this thread, which should be 'pinned' by the moderators as a valuable resource.

[thibaultron]

Anyone know how to contact the Moderators?

[mtaylor]

Ron, 

 

PM Chuck.  He seems to be the most active member of staff.  Otherwise, go back to the first post, hit report and put in the suggestions of pinning it.

[thibaultron]

Part 17

 

Scaling

 

Well, it looks like I may have to continue this thread. I came across a new operation, that will be of interest to everyone.

 

One feature SketchUp lacks, in its native functions, is Scaling of a model. It has a stretch operation, but it is difficult to use, especially if scaling in more than one axis is desired.

 

Now that I have finished both the 1/32^nd, and 1/64^th scale versions of the dredge frame, I wanted to combine one model of each into a single file, so that I could print a test sample with one of each in it.

 

1/64^th scale version.

 

 

1/32^nd scale version.

 

 

Looking through the available extensions/plug-ins, I found one that suits the bill! s4u_ScaleTool.

 

This plug-in lets you rescale your part, by

 

1. Distance: Push/Pull with mouse, or you can enter the distance value, like when drawing lines and figures.
2. Ratio: 2 – twice as big, 0.5 – half size.
3. Fixed Length
4. Reset Scale.

 

You can only scale one axis at a time, but the function lets you select which axis, so you just have to do it three times, once for each axis. This gives you consistent results, which is much harder to do with the stretch function.

 

 

 

After installing, the menu below will be added:

 

 

Here is the drawing with both models combined into one file. As both parts were originally drawn full size, both are shown the same size in this drawing. I need to make the right hand part, the one that will be 1/64^th scale, half the size of the 1/32^nd scale part on the left.

 

 

I will be using the Ratio function. I have not used the other types, but you can experiment with them.

 

So, I selected the right hand part, for shrinking, then I selected Ratio (second from left). The following window pops up.

 

 

 

The default is 2, twice the original size, and the Z Axis for the operation to be performed on.

 

I entered 0.5, and hit OK.

 

 

The part is now 50% thinner.

 

 

Next I repeated the scaling, but selected the Y Axis.

 

 

 

And finally the X Axis.

 

The right hand part is now the correct size, in proportion to the left hand one.

 

 

After some clean up and aligning the parts so they are in the same horizontal plain along the bottom, I have this, the file I sent to the printer’s.

 

I also moved the right hand part so that the far end of the two horizontal bars, are 128 inches from the front most part of the nose on the left hand part. When I scale the parts at the printers, the total length will be 4 inches, using 1/32 as that overall size. This gives me a 1/32 left hand part, and a 1/64^th right hand part.

 

 

I’ve sent the file to the printer’s and I’m waiting to see if it passes their manual check. Even if it doesn’t, I’ll still have it printed, to see what it looks like, then make the corrections needed. I think the 1/32^nd part will be Ok, the 1/64^th may need changes.

Edited March 26, 2016 by thibaultron

[thibaultron]

I contacted Shapeways, and found out the trouble with the dredge frame designs. Their page shows limits of .3mm for walls supported on both ends, and .6mm for those that are hanging in mid air at one end.

 

This applies to square/rectangular shapes only! For round cross sectional parts the limits are .6mm and .8mm respectively.

 

I can redo the 1/32nd part, with work, by increasing the smaller 5/8" scale frame parts to about .8", not bad. I just wish I had known this when I started!

 

For the 1/64th parts, I will have to get creative. I think that if I design the parts to lay flat in sections, with the bottom square, I can do it. I will then have to scrape the flat parts of the sections round, like if I was scraping wooden parts to a shape for molding, or other formed surfaces.

[vossiewulf]

Some important general considerations for people thinking about this -

 

There are two main classes of modeling programs, one is the CAD type the others are generically known as 3D modeling programs, and they are very different in their conception and functioning even though there is considerable overlap of visual appearance of the building process and some modeling tools.

 

CAD programs are used to create plans and drawings that will be used to make tangible, real-world objects. Therefore absolute precision is at the core of their design, and you generally end up doing lots of typing while modeling because all sizes must be set exactly to the intended/required values. Their main strength is this precision that's built into every aspect of these programs; if you're making something like a house plan or a replacement part for your minibike engine, CAD is the right way to go.

 

3D modeling programs are used to build digital models where that digital model is the final product. And these are the programs that take those digital objects and turn them into the amazingly-realistic looking objects and textures and surfaces that you see in games and movie CGI. And it's gotten pretty amazingly easy (speaking as someone who started working with 3D modeling programs back in the stone knives and bearskins era) these days to generate beautiful and realistic images. There's a new Pandora build log and everyone is oohing and ahhing at his renderings, and I'm sure the guy is giggling to himself because all he's done is apply a default aged wood material and is rendering with a dirt-simple GI (Global Illumination) test scene. Different rendering engines do GI in various ways but they're all getting pretty accurate where there is an accurate simulation of the light energy emitted by the various lights (sun and sky count as lights) and how that energy is distributed through the scene through a series of bounces or by using what are called radiosity calculations. Whatever way they do it, they're all getting real accurate and you can set up a scene like his in five minutes with a default clear blue sky and a noon sun.

 

Now in general since most people here using some modeling program is making something they want to be a real part you'd say they should use CAD, right? Not so simple. Reason I say this is I think that in general, 3D modeling programs like Blender and 3DS MAX are generally considerably more intuitive in their modeling flows, and the rendering systems are very powerful in helping you visualize what you've made- trust me it's very easy to get to a point of complexity where you're having a hard time understanding what you've made.

 

Also modeling programs can work at the same level of precision of CAD and output the same files, just by default you don't usually type specific sizes. And finally, for something like Ron just made, CAD precision just isn't necessary - I could make the same thing in MAX that would be +/- a couple thousandths of an inch of his when printed, and I think in general that I could do so considerably faster.

 

So if anyone wants to try printing objects, I recommend you try both Sketchup and Blender. Blender is a full-featured free 3D modeling program that's only somewhat less capable than MAX which costs $1000/year for a license.

 

One or the other is likely to be easier for you to understand depending on how your brain works.