thibaultron

Its like modeling, you learn as you go. I always hated the computer language classes (I was a programmer by profession), I did not like the set exercises. I always preferred to learn by applying it to something I wanted to do. Same here.

I do, I just don't print them! :-)

Never mind, did not notice the link in the post.

What is the title of the build log? I searched and could not find it.

Part 04 There are some hidden problems that may crop up, in your drawing, that will bite you, unexpectedly. Not consistent ones in the program, but problems that can be internal to your part, and not visible, normally. The part that looks solid, is really a skin of flat surfaces, that is hollow inside. I will be referring to these surfaces either as surfaces, or walls. Sorry that’s how I think of them, though they are not the walls you think of in your house, or a wall drawn in the program. When you export the file to the 3D print type file, the program makes it “solid” (filled) as far as the printer knows. This type of output file is a .STL type of file. This is not the same type of file SketchUp uses to store your drawing, which is a .SKP type. The .STL is one of the universal file formats developed for exchanging files between different programs. Even if you don’t have Shapeways print your part, use their checking software often, as you progress. You may find there is a problem that requires redrawing a portion of it, maybe all. It’s better to check it frequently, so any problems can be corrected with minimum redrafting. Problems can include: sections or walls that are too thin to be printed, areas that do not really connect, small holes that would allow the part to “leak” if your part was hollow internally” and when filled water. An example of this would be two rods that cross, but have errors at the junction that leave some panels incomplete. If the rods were hollow and filled with water, it would leak out. These can be quite small, almost invisible unless you zoom in extremely closely. Another problem can be walls internal to your parts, that you don’t even know exist. They can be created by lines that go through parts, that perhaps you created when you drew in a new section of the part. This is an example of what I mean. The first picture is one of the dredge frame that the winch mentioned in the previous parts pulls in. This is one of the later versions of the drawing, when it is close to finished. Now we will zoom in to the hooked section at the front of the dredge. Looks good, but there is a hidden wall inside. In this case I knew the wall was in there, as I had drawn one side, then mirrored it and pasted them together here. What I found out later, was that it caused a “divot” in the 3D part right at the junction of the two rods, and the flat, in this view left area of the nose, when the 3D printer file was generated. Here is a picture with the end wall removed. Normally, of course, you would not delete the wall, but zoom into the inside of the part. If you keep zooming in closer you will zoom past this wall skin, into the inside of the part. You can see the gray surface in the center that is the hidden wall. In this view it has two parts. The line going down the center divides it into two separate walls. The right hand walls has been delete, in this picture There are, however still more walls inside this section. If we zoom in to the area where the rod is sticking inside, there are more walls to be deleted. There are three walls shown here that need to be deleted. You have to check carefully though, as there may be more you need to find. Zooming in closer, there is also a tiny wall near the junction. It is at the back center of the view. Sometimes you may also have to delete some of the interior lines. Experience will teach you what needs to be done, to correct some problems. You don’t have to do this all the time, most of these extra surfaces are harmless. If you do find a problem, though, this is one of the things to look for. As you are drawing your part, you will add lines to make part or as guides to placing them, and these can create interior walls you don’t know about. An example is a problem that I found during one of the test files I sent to Shapeways. This is a picture of the part in a late stage of producing the drawing. Looks good, but when I reviewed it a surface popped up that was not drawn in. This is a screen shot of the .STL file imported into a checking program I have on my computer. I run the file through this one, before sending it on to the Shapeways site. At least I do most times. Sometimes it does more harm than good. This program, and one of the checking features in SketchUp, will sometimes “Correct” a problem, by deleting the problem area! I’ll talk more about this in a later post. In fact, I was unable to use either correction program during most of the drawing of this frame, for that very reason. Not all problems these programs find, are really errors, they just think they are. As long as the Shapeways checks are good, you are fine. Anyway, the part looks good, until I run the correction feature! Suddenly there is a new wall/surface, on my part! As this is just a flat surface, with no thickness, the 3D printer cannot print it, and I would not want it to! What has happened is that while drawing the part, I unintentionally created walls inside the rods, that form a square, and thus this wall, as the software assumes that any lines that form a closed area, are meant to be a surface, not just lines. This surface probably popped into my drawing, and I deleted it, without thinking of why it was created. The correction software “fixed” the missing surface for me. The following pictures will show you where these walls are hiding. This is the side of one of the rods, close up. As I zoom in past the outer surface, we can see the wall, inside the rod. This shows the same area, after I deleted the wall. I had to travel through all the rods, and delete these surfaces. Below is an overall shot of the drawing at this point. There are lots of parts shown, but the one I’m working on, is the one at the right. The other parts are earlier stages in the drawing, or sub-assemblies that I am combining for the final part. I like to keep them as I progress, so if I make a mistake, I can go back to one of the earlier parts, and start from there. When I finish a major sub-part. I make a copy of it, and work on the copy, thus the progression from left to right as the drawing process goes on. The smaller parts are sub-assemblies I drew, then copied and pasted into the main assembly. When I go to check the latest part, I make a new copy of the file, say Dredge Frame_33 Test.skp. and delete all the old parts, leaving just the present part, I’m working on. The _33 means version 33, as I draw, I periodically save my work to a new version. Again this is so I can go back if I make a major mistake, or for some reason the file is corrupted, or accidentally deleted, or even if I need to see what I did to get to the present part in the drawing. Next time, actual drawing, and more pitfalls to look out for. Drafting for 3D is as much an art form, as a science, much like build parts for a model.

Had more success with the dredge frame drawing. It will now print out as one part in 1/32nd scale. I still have to add details, but most of it is done. Here are two pictures of the progress so far.

Still working on the dredge frames! They are kicking my A..! The frames are not that bad, but drawing them so they can be printed is taking a lot of trial and error. These are pushing the state of the art, due to the thin spindlely construction. I'm on drawing version, about 300 now. A version is not a complete redraw, just major points in changing the drawing. I've restarted from the original CAD drawing 3 times. The boxwood stock for the boom and mast are "In the mail", And the cheap numbered drill bits that I'm going to use for the winch rods, have arrived. It may be warm enough in the shop to paint this weekend, so I can prime the 1/64th scale winch parts.

Going From A 2D drawing To A 3D Printed Part Part 03 Now importing your drawing into SketchUp. My drawing was imported as a DXF drafting file, making it easier to work with, but unless you have an extra $700 or so laying around, or know someone with the Pro version, you will have to import it as a picture(graphic) file. The latest version of the CAD program I use DesignCAD (v 25), I use V 24, can export the SketchUp file format, Others may be able to also. The DesignCAD v25 also does the STL file export, but SketchUp is easier to use than trying to do the 3D in DesignCAD, for many operations (years of experience in DesignCAD). Though both will do some things the other will not. SketchUp will allow you to enter absolute dimensional points, when drawing. So you can start a line, for example and have it drawn 2” long. The first and most important thing to remember. SketchUp will import the drawing/graphic into Layer 0. If you have imported a DXF drawing file, you will be highly tempted to use the lines in the drawing to continue. Do not do this!! Strange things came happen, and if you make a mistake, you have possibly lost your references to correct it. Some of these lines might be erased. Create a new layer, select the layer name and change it to something you will recognize as the layer not to draw on. I use “XRef”. Then set this layer to be the active layer (selecting the little dot by the name). Unfortunately if you import a graphic file, SketchUp will not treat the lines on it as real lines, making tracing a little harder (It will not indicate the ends of the lines). You can, however, import it to scale. Have a line drawn to whole width of the drawing, that you know the length of. When importing select the origin, then when you go to place the second point to set the drawing size, enter that value. The second point will be X away from the origin, and your drawing will be to scale. Graphic of winch drawing. For this example I shortened the entered number to 149.5” rather than the 149.586”, but it would have done it, if I’d put the full dimension in. When I saved this image from my CAD program I made the image 5000 pixels wide. If you select the icon with the “!” in a circle to the right of the box that shows the presently active layer, a list of all the layers will be displayed. Now select all the things on this layer, right click, select “Make Group, then Right Click again and Select “Lock”, this prevents further editing of your imported reference drawing. Set the active layer back to Layer 0. A general note about layers. If possible do all your drawing on Layer 0. I don’t always follow this rule and it can cause problems. If you have an object on say Layer 4, then switch back to Layer 0 and continue adding to that object, part of it exists on Layer 4 and part on Layer 0, making some operations difficult or confusing when you turn off a layer for viewing, and find part of your object disappears. The only way to make the part exist on a Layer, when this happens, is to delete the layer and select the “Move contents to the Default layer. This will move everything on the layer being deleted, to Layer 0. I should follow my own advice more often. SketchUp also seems to have problems with moving things off of a layer (other than 0) once it is on that layer, and objects that are strewn on more than one layer, can’t be moved at all. You can now start your drawing by tracing over your reference lines. Unchecking any layer will make it invisible, checking it, of course, will make it visible. This is a view of what happened when I extruded a shape directly from the imported drawing lines. It extruded without the “bottom” face. This can be corrected, but it may cause problems later. A good habit to get into is regularly checking that some operation, mainly deleting something, does not cause this same thing to happen during your drawing operations. You can accidentally erase a face on an adjoining piece, while trimming another. I regularly save to a new version, while doing the drawing, especially if I’ve just completed, or will be starting a major change (completing a part, doing a major change to a part). For example I’m going to “drill” a hole in a part, I’ll save the present drawing, then save it again to the next higher version and do the drilling operation in the new version, in case I goof. Sometimes I’ve had to go back several version, when I discover I’ve done something that made changes, I did not notice, or think of a better way to do what I’m trying to draw. As an example if the present file name is: Dredge Winch_21.skp, the next version would be Dredge Winch_22.skp.

The plastic I had them printed in was the "Frosted Extreme Detail". The pricing is $5.00 setup, then based on the volume of plastic used. The price was the same whether I had all the parts on a sprue, or separate, so I choose individual parts, to save on trimming. The exception was the nuts in 1/32, I had to sprue them, as they were too small individually to print. In 1/64th, I had to sprue more of the parts. I discuss this more in my Carrie Price log. I'm presently drawing up a dredge frame similar to the one sitting next to the winch, in the picture in the first post. I will be able to print it out with scale rod thicknesses in 1/32 (smallest rod 7/16" scale). In 1/64, I will have to go to 3/4" minimum thickness, but it will still look better than I could fabricate, and will be round sections, not flat as they would be if I went the photo-etch route.

For 4 of the 1/32nd winches, about $20. For 4 of the 1/64th, about $10. I had 4 of each printed, so I can mess up a couple. I've already lost one of the crank handles, it flew off into the same place those drier socks go.

Part 02 I’m not going to try to give a step by step tutorial, but rather some specific steps and “Things to watch out for” help. Firstly here is a shot of the SketchUp screen. I’m using the 2015 version, they have released a 2016 version, but I did not want to have to reload the Extensions. The Red, Blue, and Green lines represent the X, Y, and Z axis respectively. The top most and left hand most icon bars are the standard SketchUp drawing commands. The lower two icon bars are commands for the Extension programs I mentioned last time. The icon at the very bottom left, is also for an Extension. You can access the Extension Warehouse from the Window menu, not the Extensions menu, that one shows a list of most (not necessarily all, hey it’s a free program) of the ones you’ve added. Selecting the Extension Warehouse item will bring up this screen You can select either the More button at the bottom of the Top Extensions window, or the Browse all of the Extensions button. I selected More and the following screen is displayed This is a list of the extensions available from this site. There are other sites that offer many more. A Google search will find them. You can scroll down the list to find the one you want. As you go down to the bottom, more titles will be loaded. If you open an extension, it will have a button to install that one. If you just go back to the list, the list will be displayed starting from the first item again, a pain. Read the descriptions, some will have instructions on using the Extension, as well as listing any other Extensions that may have to be installed before that one. Many require you buy them, but the ones I use are free ones. The Extensions I used for this drawing are: Arcs Circles Eneroth Upright Extruder CleanUp3 (not CleanUp, or CleanUp2) Rotate 90 Shapes SketchUp STL (Used to create the type of files to send to the 3D printing company) If I find any others I used, I will list them as I remember them. The SketchUp site, has several tutorial videos, and there are many others on YouTube. I’m going to assume you have some practice with the program. Watch the tutorial videos and get some practice. Next time getting your drawing into SketchUp.

I started the log, it is called: "Going From A 2D Drawing To A 3D Printed Part Tutorial"

For those interested, I've started a log on the process I went through to go from the 2D drawing to the 3D part. "Going From A 2D drawing To A 3D Printed Part Tutorial"

Part 01 Please forgive me for any typos. This log will be my journey from a 2D drawing to producing (well having printed), a 3D model. The subject model is a Hand Cranked Oyster Dredge Winch. These were used on Chesapeake Bay oyster dredges, before the advent of gas engine driven winches. The winches are used to pull in the dredge after it has scraped the oysters from the oyster bed. The original winch was about 36 inches high at the crank/drum axle. The original winch parts were castings for the major components. Here is a photo of the winch at a museum, with a dredge frame behind it. Here is a picture of the finished 2D drawing (the crank handles are still too long, I corrected this in the 3D SketchUp drawing), and a 3D projection, of an earlier version. Why didn’t I just go from the 3D CAD to a 3D printed part? For the 3D CAD drawing, above, I had developed it using just proportions, and some guesses. A friend, then sent me some rough dimensions, and I redrew it. The 2D drawing is of this final version. I decided to go directly from this drawing to SketchUp, a dedicated 3D solid CAD program. There is a free version of SketchUp, that I used for the majority of the drafting. The only real function it lacks is the ability to import DXF files, a standard CADing file type. I have an earlier Pro version, that I used for importing my 2D drawing. It also lacks some 3D solids Boolean functions, but these are not needed, you can do them yourself, it just takes a little more work. Parts you generated based on a drawing, which are generally “Extruded” from the 2D lines to give them height (You’ll see what I mean later), can’t be operated on by these functions anyway. The free version of SketchUp, can however, import graphics files, so you could either use your CAD program to create a graphic, and import that, or just use it as a reference when creating the parts in SketchUp. SketchUp has the ability to import “Extensions”, additional mini programs, to add functionality. I used several of them, and will list them later. For now here is the finished SketchUp drawing. This is the 1/32nd scale version, I had to modify the parts for 1/64th scale, to meet the minimum wall thicknesses the 3D printing company required. In this scale, I will be using metal rods for the axle and support rods tying the legs together. I’m creating both 1/32 and 1/64 scale parts for 2 different models. The 1/64th scale winches are for my Pyro Oyster Dredge model, which is a fairly good model of the skipjack “Carrie Price”. The 1/32nd ones are for a planed future scratch build of the same boat. I also need a set of 1/28th scale winches for my Midwest Skipjack. The 1/28th scale parts will be a simple scale up of the 1/32 drawing, no modifications needed. The company I used for the printing was Shapeways. There are others out there, but I choose Shapeways as they specializes in serving modelers. They also have an online file/drawing checking system to find any problems with your drawings, before you try to have them printed. Below is a picture of the printed 1/32nd scale parts. I stuck the crank handles into foam to hold them, hence the unpainted tips. The gear is 5/32” in diameter, and has 18 teeth. The teeth printed out sharply. 3D printing can give you quite nice detail. I don’t yet have any pictures of the 1/64th scale parts, I have not primed them yet, and without this they are hard to see even under magnification, but I can distinctly feel the gear teeth with my figure nail.

I want to at least test assemble, one, before making it public. I ordered 2 sets of cheap 61-80 number drill bits, to use as axles and support rods. The frames are coming along. I am also starting a log of the 2D drawing to 3D printed parts process.

When I am done with the 3D printed parts for the hand crank winch and dredge frame, I will make them public. You may be interested in the winch for your earlier version, and the frame for both.

Decided to scrap the dowels for the mast and boom. I'm taking the advice and will try making them from square stock. Today I bought some basswood square stock to practice on, and ordered boxwood strips, for the final parts. Been working on the dredge frame 3D plans, I'm fairly sure I may be able to print them as one piece in 1/32, and likely in 1/64th. I'm up to version 136 in the drawings. Probably be at 200 or so when done. I save increamently as I go. I've restarted 3 or 4 times as I've progressed, and come up with better ways to draw them.

Ok, I'll start writing it. I have to go back through all the steps.

They said that the plastic on all of their models is pourous and most glues would work.

Part 26 The 3D printed parts for the winches came in last week, both the 1/32 and 1/64 sizes. Today I took some pictures. The first couple are the “raw” parts, as they came, and unpainted. I primed the 1/32 scale parts using Badger Stynlrez gray primer, with my airbrush. The primer dries very fast, so fast that I managed to clog the airbrush. I took about ½ hour to clean it, and then I finished painting. The problem is most likely mine. I’m new to airbrushing, and there were a couple other factors. Some time ago I banged the air pressure gauge on my airbrush supply regulator. This is the first time I have used it since then. Yes, the gauge is broken. I had to use the regulator on the compressor, which has courser measurements than the airbrush one. So I’m not sure exactly what pressure I was using. Somewhere between 20 and 30 psi. The airbrush is both a cheap one, and brand new, so I am inexperienced with it. I think I may look into a decent external mix airbrush for priming. Even with a large (.050) needle, it was slow going. The pictures of the primed 1/64th parts will be next week. I have to figure out how to hold these very small parts, without them blowing away. Anyway here are pictures. To take them I had to put my magnifying lamp between the camera and the parts to make them large enough to see in the pictures. The camera was set for close up shots, and I even had to zoom in some, using the telephoto feature. These are the 1/32nd scale parts, with a quarter for comparison. At the left is a part that combines the clutch and the end of the winding drum that the clutch engages. There is a groove to guide the saw so I can separate them. I had to combine them, as the individual parts were too small to be printed separately. Going clockwise, the next two parts are the crank handles, then the other side of the drum. There is a hole through this part for the axle. Strangely, even though I drew a hole in the clutch side flange for the axle, it disappeared when I loaded the file to the 3D printing company checking software. I tried several different ways of putting the hole in, none successful. I finally gave up, but was able to draw a circular depression to use as a guide to drill the rest of the hole out. Next is the sprue with all the nuts on it. Once again the individual parts were too small to print separately. I had to leave the back of the legs flat, the smaller nuts will be attached behind the pawl, and clutch arm, to simulate the other end of the bolt holding them on. Next is the plain leg, this is the one opposite the clutch drum position. If you look closely you can see the four pads that the support rods will bolt through, They are on the back web, along the inside of the vertical webs. Next is the 6” diameter 18 tooth pawl gear. I was pleased to see that the teeth were “pointy” I thought they would print out as blobs I would have to shape by hand. Lastly is the complex leg. This has the pawl gear support, and both the clutch handle, and pawl gear attached. Again the clutch handle and pawl were too small to print as separate parts, and putting them on a sprue left relatively large areas that would have to be shaped, once they were cut from the sprue. So I just had them printed in place, on the leg. The pawl gear fits between the leg bearing and the support arm (See the primed part photos below). Here is the picture of the 1/64th scale parts. It is hard to see details on these, even with magnification and zoom. At the top is the sprue with the smaller parts, the drum halves, crank arms, and the feet for the legs. As I mentioned in a previous post, I had to make the vertical web on the legs thicker to meet the minimum that the company can print. I will sand the web to thickness then attach the feet to the thinner web. If I had printed the feet on the legs, I would have had to leave the webs thick, as the foot detail would have covered some of the area I have to sand. The nut sprue is attached to the rest of the sprue, not separate, as in the larger model. Even with the minimum wall thickness, I was able to have the hole through the larger nuts. I will use it as a guide to drill them to size. I was able to still have the hole through the large drum part. As mentioned below the clutch drum has the “left side axle. The hole in this large section will have a metal stub axle inserted, for the other end. The hole is long enough to allow me to adjust as needed, during assembly. Below these is the clutch drum on its mount. The circular mount makes the whole thing large enough to print. The vertical rod portion will be trimmed and used as the axle on that end. Next at the bottom right is the simple leg. It has a depression on the flat side, to accept the metal axle stub. On the front side the portion of the axle that the crank handle attaches to is printed in place. Even at this small size, the pads for the support rods could be printed. Last are the two parts on the left. These are two complex legs. I have the one turned to show the detail at the top (at least as much as can be seen). Once again the clutch handle, and the pawl are printed on the leg. I had to make them thicker, but did so in a way that allows me to thin them down. After looking at the part, I think I will leave the pawl, as is, and just file the clutch handle. To save a lot of hassle, the pawl gear is also printed in place. I can’t see it well enough to determine how it looks, but I can feel the teeth with my finger nail. I’m quite pleased with the detail that can be done. The other leg shows how the gear, pawl, and handle turned out. Those with good enough eyes, can see some indication of the teeth. As with the first leg there is a hole in the back for the axle, and the crank handle end is printed in place. Here are some shots of the primed 1/32nd scale parts. An overall shot. The ends of the handles were stuck in the foam to hold the parts and did not get painted, nor did the one side that faced the foam get a good coat. You can see that the vertical web gets taller as it approaches the bearing casting at the top. This transition is curved, not just a straight line. This came out in the print. You can also see the support rod pads, better. The gear teeth are “sharp”, as printed, no shaping needed. This one shows the back of the parts, and the top of the complex leg. It shows the crank handles, pawl, and clutch handle better. The support for the pawl gear (arm coming up from web), was printed as part of the leg, in both scales. This is a close up shot of the nuts and complex leg. Here is the pawl gear inserted into place. There is some roughness as you drag your figure nail along the parts, but a little sanding will fix that. I do not think I could fabricate these parts in 1/32nd, it would be pushing my skills to the limit, especially getting the leg webbing to match on all four legs. I know I couldn’t fabricate them in 1/64th! I’m glad that 3D printing is available! There are some modelers out there who could do this, and I applaud them! Next week I’ll prime the smaller winch parts, and post them. After some experimenting, I will be printing out the dredge frames, also. Even in 1/64th, the detail will be good enough, almost scale thicknesses on the frame bars, at this scale. They will look much better than ones I could make by hand. I found some pictures of the dredges, and have adapted details from them. The drawings for the Willie Bennett, simplify the detail somewhat. Every dredge I found differed in detail, so mine should look just fine. This is what I have so far. One major change is the bottom support bar. Rather than being welded in line with the cross pieces at the bottom, it runs along the top, and has a ring and hook arrangement, at the front. I'm not sure what this does, but all the pictures I've seen show a similar set to this. On a side note, at this time someone is selling real oyster dredges on EBAY! If they were not a 10 hour drive away to pick up, and my truck was not acting up, I’d buy one! What a display base/case I could make of one of these for the four boats I’m planning on, as well as other Chesapeake Bay models! The dredges for sale are smaller versions, than those commonly used on the skipjacks, but for my use, that would be better. The plastic material that the parts are printed in, is described as stiff and fragile. I have been playing with the parts, and there is some flex, and they seem quite strong. Not construction grade, but not delicate either. P.S. I had four of each winch printed. I’m glad! While getting the parts ready for painting, one of the crank handles flipped onto the floor, never to be seen again, at least until I step on it, and hear the crunch! All this would be so much easier if I was 40 years younger, and my hands didn't shake.

I got a good look at the parts today, nice! The bulb in my magnifying lamp went out, and I had to buy another one today to see the parts. The detail is very good, on the 1/64th scale winch, I can feel the teeth on the 6" dia, 18 tooth gear. I will have to prime them, before I have a hope of getting pictures, they are printed in a frosted clear plastic, that will be hard to see with my camera, until I do. In fact I will have to prime them before I can see the details on the smaller parts myself. I will do that in the next couple of days, I have a busy schedule until Sat. After some drawing, it looks like I will be able to have the dredges themselves printed in 3D, in both scales. I will have to throw away the last 4 or 5 days of drafting, but this is a learning experience. (I always used to hate being told that phrase, but now I'm doing for myself, not others.)

The 3D printed winch parts arrived tonight. I'll give more info tomorrow when I get a chance to look at them closely. I need to take the packages out to the shop, before I open them, or the pieces will disappear.

Yes

Well it looks like I will have to experiment with photo etch for the dredge itself. I drew it up and almost the entire thing has cross sections that are too thin, even in 1/32 scale, let alone 1/64th. It will have to wait until next year. The winch parts should be in Monday. I'll tell you how they turned out.

Ships in Scale sells a practicum on this model, " Progressive Scratch Building". It covers a couple other smaller boats too. I boght it several years ago, and read it cover to cover. You can get it on CD. I think someone else also offers a practicum.