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nerys

Help making a hollow object solid ?

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nerys

I am making rocket components with my 3d Printer.

 

one project is to make interesting 3d SKINS to built a rocket out of that would be pretty hard to impossible to easily do without 3d printing.

 

anyway. I am starting simple. star shape.

 

Here is what I have done.

 

Star Shape. Adjust

Extrude

Taper

convert to editable poly

shell

 

Shell is a new one printer had problems till I realized I was wrapping a 2d plane into 3d space and that was ticking off the slicer.

 

adding shell "made it" a 3d shape and make the edge more nozzle compatible as well.

 

so I made a tube nose cone and fin can. all is well except the nose cone. will not print usable (thin and unstable)

 

I realize I don't need the nose cone to be hollow as only its exterior dimensions are important not its interior dimensions

 

the problem I am having is its coming out too thin and the tricks to thicken the body tube don't work on the nose cone for some reason.

 

if I made it solid I gain several advantages. for starters far far fewer polygons so my slicer won't puke its guts up trying to slice it.

 

Second I can tell it to make it hollow with 2 outer layers. ie get my thicker walls that I need.

 

I tried removing the shell modifier that will make it a solid part again but this changes the "shape" of the object and that is really bad since it won't match the outline of the other objects.

 

no adjusting of the outline seems to have the needed effect it works but I can not get the same shape. its always "off" by enough that it won't line up with the other parts (mostly the tips of the star points too skinny and I can't fatten them up.)

 

if I could just retain my shape with shell and gut the inside and make it solid that should work but I can not figure out how to do that.

 

suggestions?

 

Here is the file

 

https://drive.google.com/file/d/0B-XVTPUBrxzwUWxPZTR5Q29DQ00/view?usp=sharing

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Cad64

One thing I see right off the bat is that you have a ton of overlapping and interpenetrating geometry. Take a look at the screenshot below. See where the geometry is criss-crossing and protruding through the top? This is probably why you're having problems trying to print. I would recommend cleaning up the model and see if you have better luck.

 

As for removing the Shell modifier without changing the shape, don't delete it. Right click on it and choose "Collapse To". This will collapse all the modifiers in the stack and leave you with an Editable Mesh which you can then convert to Editable Poly. From there you will be able to clean up the model to get rid of all the overlapping geometry.

Overlapping Geo.jpg

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nerys

I know absolutely nothing about this software but "I THINK" I am kind of following what your saying. at least I recognize enough of the commands that I think I can do this. I will try it tomorrow night and see what happens.

 

the only part I don't understand is the "clean up" the model. what does that mean and how do I do it?

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nerys

OK I ran the commands you suggested. still had no idea what you meant by "clean up" after that however

 

I did however run the STL through the microsoft service to clean up 3d files on azura

 

that seems to have the desired effect to a point. the file is now half the size it was 2.48mb instead of 5mb AND it shows up as solid in maker desktop!! so I can use infill and shells and the resulting print is SO much better.

 

maker desktop still throws a fit slicing it however. I had to use .3mm layer height to get it to even chunk it without puking on it. it did work however. splendidly.

 

I wish we could tell these machines to never move the nozzle over a "void" area. ie always take the long path that keeps the nozzle over plastic no matter what (unless void is the only way) that would eliminate "stringies" though I only had very minor stringing on this one!!

 

I will post pics and files later so you can see what it did and if that is what you meant! for now must get my butt moving for work!

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Cad64

What I mean by "clean up" is to manually fix all the overlapping and interpenetrating geometry so that the models topology is clean and uniform and the model is watertight. It gets really messy towards the top of the model and would require quite a bit of work to clean it up. It sounds like you were able to fix it and get it printed though.

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nerys

Yes. I could print it before as well but it did not come out pretty. Now with double walls and infill it came out rather spectacular.

 

How do i clean it up? As is i still have to mess with the settings to get in through makerbots slicer without crashing though it does look fine at .3mm i have plans for more complex components so i am thinking i will eventually hit this wall again so i better learn how to do it now.

 

Took me a while to figure out how to use one shape to "cut" another shape using the boolean stuff (thanks to a youtube video i found)

 

So i was able to taper the extruded star fin can. Came out spectacularly clean.

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Cad64

In order to clean up a model you need to be familiar with all the various tools inside the program and understand how to use them. This is something I can't really teach you here in the forum without spending a lot of time creating elaborate tutorials. Studio Max has a pretty steep learning curve, so my best advice would be for you to buy a book or some video training tutorials to learn how to use the program effectively. There are a lot of free videos on YouTube, but those videos will only get you so far. You really need some professional quality training material if you're serious about learning the program.

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nerys

I figured as much when I first opened 3D Studio my first thought was holy s*** this makes AutoCAD look like a toy as far as complexity and number of commands that I have not played with AutoCAD since high school and R12 if you come across any particularly good videos on YouTube and happened to remember by all means please post a link so far everything I've learned to make these parts I got off YouTube

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nerys

Awesome. Thankyou.

 

One more question. I have been pulling my hair out trying to figure this one out

 

How do i make this shape. I know how to extrude and twist it etc.. but i cant find the original shape to start with

 

http://www.thingiverse.com/thing:38948

 

How do i make a square tooth gear like star like that?

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Cad64

I think you may have to keep pulling your hair out. That doesn't look like a very simple object to create. There is a lot of blending of shapes at the base and the tip where the fins begin and end. If you want to attempt it and begin with a gear shape, go to the "Splines" panel and select the "Star" shape. Under "Interpolation", set the number of steps to 0, then adjust your radius values and fillet radius values to get the gear shape you like.

gear.jpg

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nerys

Ahh thats it exactly. I am not trying to duplicate his design only that profile right there! Thank you!

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nerys

I tried to follow your instructiins but it does not seem to work

 

I could not find splines. Star is located under shapes for me so i used that. I opened interpolation and set steps to 0 but nothing happens remains a star.

 

Never mind spoke too soon seems i have to really change fillet to see the effect. Got it!

 

Thank you so much!

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Cad64

Glad to help. This section of the forum has been dead for quite some time. It's nice to see someone posting in here again.

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nerys

good. hopefully I can liven it up a bit and maybe get people interested in rocketry too. 3d printing is mind blowing and mine is but a "toy" compared to real rigs and I am already doing amazing things with it. at least they are amazing to me.

 

so. I lied. pick your brain some more. I got the gear thing going I even twisted it and am printing a body tube skin now and have a nose cone qued up. I think I know how to get the fins done.

 

SO. my problem is that the gears are never 90' the tip is always skinnier than the base. how do I "fatten up" the tips? ie make the "walls" of the star now gear spikes perpendicular to the tangent of the circle they originate from?

 

max files attached.

 

I was about to cancel the print when I realized I used too few segments so the faces were faceted instead of smooth curves but then I realized hey those facets look amazing. SO they stay :-)

 

do you know of a "relatively" simple of straight forward way to make a "coupler" for these things? IE a tube of the same shape that fits "inside" this tube cleanly (so I can "join" more than one together once printed since I am limited to 120mm of length (height))

 

the star one I just "shrank" the star in maker desktop till it just fit and compression took care of the rest. I don't think that will work as well with this more complex shape.

 

one way is to run the shell command "inside" instead of "outside" but I think that might be "too tight" a fit. not sure. I will try tomorrow night once I have enough parts printed (I can usually get 2 or 3 prints done a day)

 

Video help ??

 

 

 

work around did not work so well. when I duplicate the tube I do get 2 entries on the left but when I modify one it modifies the other as well. Grrr.

Gear Rocket Tube.max

Gear Rocket Twist Tube.max

Edited by nerys

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Cad64

SO. my problem is that the gears are never 90' the tip is always skinnier than the base. how do I "fatten up" the tips? ie make the "walls" of the star now gear spikes perpendicular to the tangent of the circle they originate from?

 

That's just the nature of a gear. The tips are always skinnier than the base. I'm not sure how to adjust that other than doing it manually.

 

do you know of a "relatively" simple of straight forward way to make a "coupler" for these things? IE a tube of the same shape that fits "inside" this tube cleanly (so I can "join" more than one together once printed since I am limited to 120mm of length (height))

 

the star one I just "shrank" the star in maker desktop till it just fit and compression took care of the rest. I don't think that will work as well with this more complex shape.

 

one way is to run the shell command "inside" instead of "outside" but I think that might be "too tight" a fit. not sure. I will try tomorrow night once I have enough parts printed (I can usually get 2 or 3 prints done a day)

 

What you need is a way to key the tubes together, (Like the way Lego's snap together), without having to make yet another tube to fit inside.

 

work around did not work so well. when I duplicate the tube I do get 2 entries on the left but when I modify one it modifies the other as well. Grrr.

 

Click on the tube that you want to duplicate and then right click and choose "Clone" from the pop up menu. In the "Clone Options" dialog make sure you choose "Copy". This will duplicate the tube and retain the modifier stack. The duplicate tube will be it's own independent object, so any changes to the modifiers will not affect the original tube.

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nerys

I tried that it just would not work for some reasons but when I booted up the next day and apparently did the same thing (I say apparently since I assume I must have done something wrong the night before) it worked as expected.

 

Also the coupler worked better than I thought. On the tube I added an outside 1mm shell. SO for the coupler I added a .5mm inside shell and then removed the 1mm outside shell. tight fit but it does fit and quite well. Nice. I was not sure if it had that kind of precision for a 0mm tolerance but I guess it does or close enough the parts can flex to make it work. Extreme nice joint!

 

The fin can is giving me caniption fits.

 

First I can't figure out how to delete 4 of the 8 "fins" so for now I figured lets try printing it with 8

 

but its adding a "webbing" across the fins top and bottom and I have no idea why. its another of those its simply not their but the slicer "adds" it for some strange reason.

 

I ran the file through Microsofts fixer and it does in fact remove the errant webs but it also "closes" my fins (they are supposed to be hollow) with and top and bottom cap. and I of course have no idea how to remove that :-) Grrrrr

 

any suggestions on how to remove 4 of the "fins" and how to stop the "net" from forming ? its not "angle hair stringing" its actually structure that the slicer adds for some reason.

 

max file attached.

 

I also did the boolean thing to hollow out a "tube" through the parts so the launch rod can slide through the rocket. I had to "assemble" the parts in 3ds and carefully line them up so it all aligns properly once the rocket is assembled.

Gear Rocket Twist Tube Fin Can mk2.max

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Cad64

If you add or remove points in the Star shape parameters, the program is going to automatically alter the shape of the star. I think you would probably have to do some manual editing to remove the 4 fins.

 

I'm not sure what you mean about the webbing? Can you post a photo? I have never done any 3D printing, so I don't know how to solve problems on the printing end. I'm sure there must be a Makerbot forum where you could ask for help with that sort of thing?

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MillerMG

Maybe you could try to reach out to Tanner his screen name is tzframpton. He has done 3D printing and may be able to help you out with the webbing problem. I am not 100% sure about that but maybe an option for you.

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Dadgad

Actually his name is Tannar, but he probably wouldn't bust your chops for it. :)

 

You're not the first one to get the spelling wrong. :beer:

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