3 D Printing

Questions on how we spend our money and our time - consumer goods and services, home and vehicle, leisure and recreational activities
Post Reply
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

3 D Printing

Post by gatorman »

Anybody tried this? I'm thinking about getting one. In addition to the printer, my reading indicates I need some 3D cad software to design my parts and some printer software to generate a file the printer can use. Right now, I'm thinking about buying a Gigabot printer because it will print at the size I need. But I'm wondering which cad program would be easiest to learn to use? Ideally, I'd like something that can easily generate bodies of revolution, circles, ellipses and can smoothly fair in transitions from one shape to another. Any ideas as to a good but inexpensive (and easily learned) program? Any helpful comments on the topic of 3D printing in general?

Thanks for any assistance.
gatorman
EHEngineer
Posts: 1077
Joined: Sat Feb 28, 2015 3:35 pm

Re: 3 D Printing

Post by EHEngineer »

Hi Gatorman,

I can help a little.

Google sketchup http://www.sketchup.com is a free 3D modeling software (there is also a paid pro version, but I haven't found a need for that). There are sketchup produced tutorials on youtube, and also plently of amateur how-to videos. From sketchup you export .stl files for slicing and printing.

Slic3r http://www.slic3r.org is a free software that converts .stl files to gcode. gcode is the file that that 3d printers use (as well as CNC mills and lathes, etc).

I don't know about the gigabot. I have a xyz davinci 1.0, $500 at amazon. With a hack I now use slic3r and repetier to replace the xyzware (which is functional but buggy). The free software has better results and far fewer bugs.

3D printing with ABS and PLA may leave you frustrated if you are used to designing for basically any other material. It is good for nicknacks and mockups, but material properties, layer adhesion, precision, warpage, and print area all serve to limit the quality and design envelope of what you can do.

PS - All the news stories about the threat of making a gun out of printed plastic are overstated in my opinion. It's hard to make a drinking straw that doesn't leak, crack or warp; much less a complex mechanism that actually functions and can handle even one cycle of stress and heat.
Or, you can ... decline to let me, a stranger on the Internet, egg you on to an exercise in time-wasting, and you could say "I'm probably OK and I don't care about it that much." -Nisiprius
hicabob
Posts: 3794
Joined: Fri May 27, 2011 5:35 pm
Location: cruz

Re: 3 D Printing

Post by hicabob »

My local tech-shop (a really nice place and excellent idea) has 3 quite nice 3-d printers, cad software + workstations, instruction & encouragement for those wanting to learn about it. I think spending the $$ for lessons if available locally would be a good idea for most people before committing to your own rig.


http://www.techshop.ws/
User avatar
Watty
Posts: 28813
Joined: Wed Oct 10, 2007 3:55 pm

Re: 3 D Printing

Post by Watty »

I took a half day class on 3 D printing at a local museum and I would highly recommend that you find something similar at a local college or museum. For the class they had some of the lower cost 3 D printers and the printed items were not all that impressive since the size of the “dots” was not very small.

An alternative to buying a printer would be to use a service like Shapeways to print your items and mail them to you. (I have not used them) You might also be able to find a local place to do your 3 D printing.

http://www.shapeways.com/

You could get started like that and then buy a printer later if you wanted to. In a lot of ways this is like using a photo processor for film photography instead of setting up your own darkroom.

One thing to research is what software software you will need and how much it would cost. Some of the commercial software is pretty expensive. The free or low cost soft ware, like we used in my class, was not that was not very easy to work with but that might just be that there is a large learning curve for it.
Greentree
Posts: 252
Joined: Sun Jul 28, 2013 9:34 am

Re: 3 D Printing

Post by Greentree »

What are you looking to use it for exactly? Is it just a learning thing or will the parts serve a function?

I have used a 3d printer a lot and the news stories are overhyped. They are cool and make neat little parts but it takes a while to get going and the parts are still either rough or not that strong (depending on which material your printer uses). Home Depot sells one and they show samples of a small room printed that an architect could use. I look at it and think - no way an architect is going to spend that much time printing that out. It takes a while through cad and then the print might not be perfect off the bat.

Anyways googles sketchup is supposed to be good.
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

Greentree wrote:What are you looking to use it for exactly? Is it just a learning thing or will the parts serve a function?

I have used a 3d printer a lot and the news stories are overhyped. They are cool and make neat little parts but it takes a while to get going and the parts are still either rough or not that strong (depending on which material your printer uses). Home Depot sells one and they show samples of a small room printed that an architect could use. I look at it and think - no way an architect is going to spend that much time printing that out. It takes a while through cad and then the print might not be perfect off the bat.

Anyways googles sketchup is supposed to be good.
Thanks, I'm going to use it to make a plug from which I'll pull a mold. The mold will be used to make carbon fiber parts for a business I'm in. Right now we make the molds from plugs we build up by hand. That takes awhile, and I thought the 3D printer might cut down on the time required to make a plug and give us a better product. Good surface finish is essential, and it takes a long time to develop it by hand.
gatorman
MoneyIsntEverything
Posts: 166
Joined: Sat Sep 13, 2014 9:43 pm

Re: 3 D Printing

Post by MoneyIsntEverything »

Deleted
Last edited by MoneyIsntEverything on Wed May 17, 2017 4:42 pm, edited 1 time in total.
Wiki
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

hicabob wrote:My local tech-shop (a really nice place and excellent idea) has 3 quite nice 3-d printers, cad software + workstations, instruction & encouragement for those wanting to learn about it. I think spending the $$ for lessons if available locally would be a good idea for most people before committing to your own rig.


http://www.techshop.ws/
I wish we had one near us, what a great idea! Unfortunately, I'm way down South, lots of swamp, no tech shop.
gatorman
ourbrooks
Posts: 1575
Joined: Fri Nov 13, 2009 3:56 pm

Re: 3 D Printing

Post by ourbrooks »

If you want to design your own parts, learning 3D CAD software will be the hard part. Designing a part for actual manufacturing is much harder than producing a picture of a 3D part. Surfaces have to line up exactly and not just look like they line up, etc. Even simple things can be really hard to do; try modeling a wood screw from scratch (as versus downloading one from a library).

If you're interested in designing your own parts, I agree with the other suggestions to look for classes. Many community colleges now offer Associate's Degrees in using CAD tools and you could take just one or two of their introductory courses.

If your interest is just in printing parts that other people have designed, there are web sites from which you can download .stl files ready for printing, no CAD package required.
Greentree
Posts: 252
Joined: Sun Jul 28, 2013 9:34 am

Re: 3 D Printing

Post by Greentree »

gatorman wrote:
Greentree wrote:What are you looking to use it for exactly? Is it just a learning thing or will the parts serve a function?

I have used a 3d printer a lot and the news stories are overhyped. They are cool and make neat little parts but it takes a while to get going and the parts are still either rough or not that strong (depending on which material your printer uses). Home Depot sells one and they show samples of a small room printed that an architect could use. I look at it and think - no way an architect is going to spend that much time printing that out. It takes a while through cad and then the print might not be perfect off the bat.

Anyways googles sketchup is supposed to be good.
Thanks, I'm going to use it to make a plug from which I'll pull a mold. The mold will be used to make carbon fiber parts for a business I'm in. Right now we make the molds from plugs we build up by hand. That takes awhile, and I thought the 3D printer might cut down on the time required to make a plug and give us a better product. Good surface finish is essential, and it takes a long time to develop it by hand.
gatorman
You may save time in the long run, but you may also want to throw the printer out the window when you are frustrated in week two learning and it is not working like it seemed it should.

I agree with some of the other responses. You should probably take an intermediate step first. Learn some CAD. You could then find a local prototype shop that would take your files and make a nice prototype. If there is nothing local, there are places like Protolabs. This will help you get an understanding of the design side and see how the prototype looks. You can definitely save by doing the prototype yourself at some point, but early on the learning curve is steep and you will spend time getting it right.

It seems like a great application for what you are trying to do if you have the time to commit to learning cad and prototyping. I'm not sure how effective sketchup will be without seeing the parts. A pro cad software is ~$5k-$10k. You'll have to see what meets your surfacing needs.
ourbrooks
Posts: 1575
Joined: Fri Nov 13, 2009 3:56 pm

Re: 3 D Printing

Post by ourbrooks »

gatorman wrote:Thanks, I'm going to use it to make a plug from which I'll pull a mold. The mold will be used to make carbon fiber parts for a business I'm in. Right now we make the molds from plugs we build up by hand. That takes awhile, and I thought the 3D printer might cut down on the time required to make a plug and give us a better product. Good surface finish is essential, and it takes a long time to develop it by hand.
Sorry, I missed that post the first time through.

If you've got a good enough 3D model of the plug, then you could just make the mold directly, without making the plug first. If you want to make the mold out of wood or high density foam, then a CNC machine, not a 3D printer, is probably the better choice.

If the plugs are unique enough to build a business around manufacturing them, I'm betting they're not just simple geometric shapes, so building the 3D models of them will require some degree of expertise.
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

ourbrooks wrote:
gatorman wrote:Thanks, I'm going to use it to make a plug from which I'll pull a mold. The mold will be used to make carbon fiber parts for a business I'm in. Right now we make the molds from plugs we build up by hand. That takes awhile, and I thought the 3D printer might cut down on the time required to make a plug and give us a better product. Good surface finish is essential, and it takes a long time to develop it by hand.
Sorry, I missed that post the first time through.

If you've got a good enough 3D model of the plug, then you could just make the mold directly, without making the plug first. If you want to make the mold out of wood or high density foam, then a CNC machine, not a 3D printer, is probably the better choice.

If the plugs are unique enough to build a business around manufacturing them, I'm betting they're not just simple geometric shapes, so building the 3D models of them will require some degree of expertise.
We use composite tooling to make our parts, so the plug is used to make a fiberglass mold, then the part is laid-up into the mold and the entire assembly is vacuum bagged until cured. If the volume ever gets high enough, we'd probably go with metal tooling and autoclave it. But we are not at that stage yet.
gatorman
User avatar
lthenderson
Posts: 8499
Joined: Tue Feb 21, 2012 11:43 am
Location: Iowa

Re: 3 D Printing

Post by lthenderson »

I used to work for an engineering company and we utilized a 3D printing place that made parts out of sintered bronze. They were quite good and in many cases, I would put them directly on our machines to test form, fit or function. Of course the machines that made these parts probably cost over $100,000 which is why we hired it out. We just sent them the CAD file and money and in a week we had our part.
whomever
Posts: 1198
Joined: Sat Apr 21, 2012 5:21 pm

Re: 3 D Printing

Post by whomever »

" Good surface finish is essential, and it takes a long time to develop it by hand."

I'm no expert, but I've been watching the 3D market (I'm a hobby machinist). FWIW, my sense is that the lower end/more affordable machines have a pretty poor surface finish. There are some ways to improve that (acetone fuming etc), but I'd check pretty carefully before buying a machine.

Maybe it would be worth it to come up with a simple-ish 3d model vaguely like what you'd like to make and have it printed by one of the services and see if the surface finish works for you.

Also FWIW, 3D printing gets all the hoopla, but 3D machining is old hat. You might send a sketch out to some machine shops for a quote. If non metal materials are OK, get quotes for a 3D router as well - the routers, not having to be built with the rigidity you need for metal, are a lot lighter/cheaper.
Crow Hunter
Posts: 1054
Joined: Wed Jun 27, 2012 12:05 pm

Re: 3 D Printing

Post by Crow Hunter »

I use a Maker Bot (known here as the Maker Not) and a uPrint SE Plus all the time as part of my job. My first step after I have a concept and a drawing is to create a prototype for fit/form/function. Some materials can be strengthened by "painting" in superglue if you need tensile strength.

There are several different technologies out there. Both of ours use extruded material. Before purchasing the uPrint we investigated a powder base model but didn't like the fact that it required secondary treatment to reach suitable part strength and the model was susceptible to fracturing before this was completed.

If you are going to do complicated parts with extruded material a heated bed will prevent warping. Don't use cheap material (Maker Bot). It is a false economy. The time the machine is down while you are rebuilding the extruder will more than offset the increased material cost.

I design my parts using Autodesk Inventor. It is ridiculously easy to learn. WAY, WAY, WAY easier to use than basic 2D AutoCAD. Much more intuitive. Once you know where to find the commands it is basically like visualizing how you would want the part machined. If you are doing molds, it should be a breeze. Just sketch out the square block that you want to make the mold out of, extrude that and then start cutting away material that you don't need to make your part.

With the Maker Bot it requires dumping to a card and uploading to the machine. The uPrint is networked in with a very, very simple printing interface.

Neither of our units can produce a part with a good surface finish. The individual extruded layers can be felt with your fingernail.

There are companies out there that have much more expensive machines that can do multiple materials/nearly production parts as lthenderson mentions below.
User avatar
Aptenodytes
Posts: 3786
Joined: Tue Feb 08, 2011 7:39 pm

Re: 3 D Printing

Post by Aptenodytes »

You might find this Scott Hanselman post illuminating. I believe he has posted updates on the topic too, which you can search for.
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

Crow Hunter wrote:I use a Maker Bot (known here as the Maker Not) and a uPrint SE Plus all the time as part of my job. My first step after I have a concept and a drawing is to create a prototype for fit/form/function. Some materials can be strengthened by "painting" in superglue if you need tensile strength.

There are several different technologies out there. Both of ours use extruded material. Before purchasing the uPrint we investigated a powder base model but didn't like the fact that it required secondary treatment to reach suitable part strength and the model was susceptible to fracturing before this was completed.

If you are going to do complicated parts with extruded material a heated bed will prevent warping. Don't use cheap material (Maker Bot). It is a false economy. The time the machine is down while you are rebuilding the extruder will more than offset the increased material cost.

I design my parts using Autodesk Inventor. It is ridiculously easy to learn. WAY, WAY, WAY easier to use than basic 2D AutoCAD. Much more intuitive. Once you know where to find the commands it is basically like visualizing how you would want the part machined. If you are doing molds, it should be a breeze. Just sketch out the square block that you want to make the mold out of, extrude that and then start cutting away material that you don't need to make your part.

With the Maker Bot it requires dumping to a card and uploading to the machine. The uPrint is networked in with a very, very simple printing interface.

Neither of our units can produce a part with a good surface finish. The individual extruded layers can be felt with your fingernail.

There are companies out there that have much more expensive machines that can do multiple materials/nearly production parts as lthenderson mentions below.
Thanks for the info. I was about to pull the trigger for an Autocad course, but believe I'll look into Autodesk Inventor instead. I'm looking at a Gigabot printer, but that is basically because of size constraints. Is there anywhere one can find objective evaluations of printer capabilities?
Thanks again,
gatorman
Crow Hunter
Posts: 1054
Joined: Wed Jun 27, 2012 12:05 pm

Re: 3 D Printing

Post by Crow Hunter »

gatorman wrote:
Crow Hunter wrote:I use a Maker Bot (known here as the Maker Not) and a uPrint SE Plus all the time as part of my job. My first step after I have a concept and a drawing is to create a prototype for fit/form/function. Some materials can be strengthened by "painting" in superglue if you need tensile strength.

There are several different technologies out there. Both of ours use extruded material. Before purchasing the uPrint we investigated a powder base model but didn't like the fact that it required secondary treatment to reach suitable part strength and the model was susceptible to fracturing before this was completed.

If you are going to do complicated parts with extruded material a heated bed will prevent warping. Don't use cheap material (Maker Bot). It is a false economy. The time the machine is down while you are rebuilding the extruder will more than offset the increased material cost.

I design my parts using Autodesk Inventor. It is ridiculously easy to learn. WAY, WAY, WAY easier to use than basic 2D AutoCAD. Much more intuitive. Once you know where to find the commands it is basically like visualizing how you would want the part machined. If you are doing molds, it should be a breeze. Just sketch out the square block that you want to make the mold out of, extrude that and then start cutting away material that you don't need to make your part.

With the Maker Bot it requires dumping to a card and uploading to the machine. The uPrint is networked in with a very, very simple printing interface.

Neither of our units can produce a part with a good surface finish. The individual extruded layers can be felt with your fingernail.

There are companies out there that have much more expensive machines that can do multiple materials/nearly production parts as lthenderson mentions below.
Thanks for the info. I was about to pull the trigger for an Autocad course, but believe I'll look into Autodesk Inventor instead. I'm looking at a Gigabot printer, but that is basically because of size constraints. Is there anywhere one can find objective evaluations of printer capabilities?
Thanks again,
gatorman
Definitely go Inventor. AutoCAD "can" do 3D modeling but I put that in quotes for a reason. :D Inventor is much more powerful and simpler IMHO. SolidWorks is very similar if that is easier to get training on. I had actually never done 3D modeling before taking my current job. I learned how to do it in less than a week just playing around with it and working through examples in the training documentation. Once you know what "button" on the ribbon does what and where to find specific ones when you need them, it is really, really simple to do. It is really just 2 basic commands. Sketch and extrude. Most of the rest of the functions are just "commands" to make things faster/simpler/easier. If it is a common engineering "feature", chances are there is an command for it somewhere. For instance, if you wanted to put a hole in a part, you could sketch it, then cut (negative extrude) out the hole to the depth you want. Or you could just use the hole command, click where you want the center and enter in the depth/diameter and hit execute and the hole appears. 8-)

For molds, you can draw exactly the part that you want to have, then "sink it" into the mold surface you want via a negative extrusion. That would give you the cavity side of your mold and then mirror that the "other way" and the you have your cavity side and "boom" you have your mold minus your draft angles which you may not need depending on the size of your part, but if you do, there is a command for that. :wink:

There are several sites out there that we used to do comparisons but you really need to see and understand how they work before buying to make sure it will work for your application. Most of the companies that we were dealing with had demo models at their distributors that you could visit and see how they worked. Most of them allowed us to send them a model, in their preferred file format (usually .stl or .stp), to make us a sample part so we could see what the part would look like finished by their process. Actually watching the powder forming machine work, and handling the parts, and thinking about our clumsy, ham handed engineering tech :twisted:, made us change our mind about it. It was originally our first choice based on our limited experience with the Maker Not (and extrusion problems).

Since you are actually wanting to use your parts in a specific application (mold making), I would hit up the different vendors about their suitability for doing that. We have used our uPrint to make several molds here but we were doing it to custom form some gaskets out rubber so we didn't really care what the surface finish looked like.
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

Crow Hunter wrote:
gatorman wrote:
Crow Hunter wrote:I use a Maker Bot (known here as the Maker Not) and a uPrint SE Plus all the time as part of my job. My first step after I have a concept and a drawing is to create a prototype for fit/form/function. Some materials can be strengthened by "painting" in superglue if you need tensile strength.

There are several different technologies out there. Both of ours use extruded material. Before purchasing the uPrint we investigated a powder base model but didn't like the fact that it required secondary treatment to reach suitable part strength and the model was susceptible to fracturing before this was completed.

If you are going to do complicated parts with extruded material a heated bed will prevent warping. Don't use cheap material (Maker Bot). It is a false economy. The time the machine is down while you are rebuilding the extruder will more than offset the increased material cost.

I design my parts using Autodesk Inventor. It is ridiculously easy to learn. WAY, WAY, WAY easier to use than basic 2D AutoCAD. Much more intuitive. Once you know where to find the commands it is basically like visualizing how you would want the part machined. If you are doing molds, it should be a breeze. Just sketch out the square block that you want to make the mold out of, extrude that and then start cutting away material that you don't need to make your part.

With the Maker Bot it requires dumping to a card and uploading to the machine. The uPrint is networked in with a very, very simple printing interface.

Neither of our units can produce a part with a good surface finish. The individual extruded layers can be felt with your fingernail.

There are companies out there that have much more expensive machines that can do multiple materials/nearly production parts as lthenderson mentions below.
Thanks for the info. I was about to pull the trigger for an Autocad course, but believe I'll look into Autodesk Inventor instead. I'm looking at a Gigabot printer, but that is basically because of size constraints. Is there anywhere one can find objective evaluations of printer capabilities?
Thanks again,
gatorman
Definitely go Inventor. AutoCAD "can" do 3D modeling but I put that in quotes for a reason. :D Inventor is much more powerful and simpler IMHO. SolidWorks is very similar if that is easier to get training on. I had actually never done 3D modeling before taking my current job. I learned how to do it in less than a week just playing around with it and working through examples in the training documentation. Once you know what "button" on the ribbon does what and where to find specific ones when you need them, it is really, really simple to do. It is really just 2 basic commands. Sketch and extrude. Most of the rest of the functions are just "commands" to make things faster/simpler/easier. If it is a common engineering "feature", chances are there is an command for it somewhere. For instance, if you wanted to put a hole in a part, you could sketch it, then cut (negative extrude) out the hole to the depth you want. Or you could just use the hole command, click where you want the center and enter in the depth/diameter and hit execute and the hole appears. 8-)

For molds, you can draw exactly the part that you want to have, then "sink it" into the mold surface you want via a negative extrusion. That would give you the cavity side of your mold and then mirror that the "other way" and the you have your cavity side and "boom" you have your mold minus your draft angles which you may not need depending on the size of your part, but if you do, there is a command for that. :wink:

There are several sites out there that we used to do comparisons but you really need to see and understand how they work before buying to make sure it will work for your application. Most of the companies that we were dealing with had demo models at their distributors that you could visit and see how they worked. Most of them allowed us to send them a model, in their preferred file format (usually .stl or .stp), to make us a sample part so we could see what the part would look like finished by their process. Actually watching the powder forming machine work, and handling the parts, and thinking about our clumsy, ham handed engineering tech :twisted:, made us change our mind about it. It was originally our first choice based on our limited experience with the Maker Not (and extrusion problems).

Since you are actually wanting to use your parts in a specific application (mold making), I would hit up the different vendors about their suitability for doing that. We have used our uPrint to make several molds here but we were doing it to custom form some gaskets out rubber so we didn't really care what the surface finish looked like.
Thanks for the info! Can you draw an ellipse in Inventor? If you can, can it be rotated around its long axis to create a body of revolution. Also, if we wanted to machine a mold from aluminum, will it output a cam file suitable for machining?
Thanks,
gatorman
Crow Hunter
Posts: 1054
Joined: Wed Jun 27, 2012 12:05 pm

Re: 3 D Printing

Post by Crow Hunter »

gatorman wrote:
Crow Hunter wrote:
gatorman wrote:
Crow Hunter wrote:I use a Maker Bot (known here as the Maker Not) and a uPrint SE Plus all the time as part of my job. My first step after I have a concept and a drawing is to create a prototype for fit/form/function. Some materials can be strengthened by "painting" in superglue if you need tensile strength.

There are several different technologies out there. Both of ours use extruded material. Before purchasing the uPrint we investigated a powder base model but didn't like the fact that it required secondary treatment to reach suitable part strength and the model was susceptible to fracturing before this was completed.

If you are going to do complicated parts with extruded material a heated bed will prevent warping. Don't use cheap material (Maker Bot). It is a false economy. The time the machine is down while you are rebuilding the extruder will more than offset the increased material cost.

I design my parts using Autodesk Inventor. It is ridiculously easy to learn. WAY, WAY, WAY easier to use than basic 2D AutoCAD. Much more intuitive. Once you know where to find the commands it is basically like visualizing how you would want the part machined. If you are doing molds, it should be a breeze. Just sketch out the square block that you want to make the mold out of, extrude that and then start cutting away material that you don't need to make your part.

With the Maker Bot it requires dumping to a card and uploading to the machine. The uPrint is networked in with a very, very simple printing interface.

Neither of our units can produce a part with a good surface finish. The individual extruded layers can be felt with your fingernail.

There are companies out there that have much more expensive machines that can do multiple materials/nearly production parts as lthenderson mentions below.
Thanks for the info. I was about to pull the trigger for an Autocad course, but believe I'll look into Autodesk Inventor instead. I'm looking at a Gigabot printer, but that is basically because of size constraints. Is there anywhere one can find objective evaluations of printer capabilities?
Thanks again,
gatorman
Definitely go Inventor. AutoCAD "can" do 3D modeling but I put that in quotes for a reason. :D Inventor is much more powerful and simpler IMHO. SolidWorks is very similar if that is easier to get training on. I had actually never done 3D modeling before taking my current job. I learned how to do it in less than a week just playing around with it and working through examples in the training documentation. Once you know what "button" on the ribbon does what and where to find specific ones when you need them, it is really, really simple to do. It is really just 2 basic commands. Sketch and extrude. Most of the rest of the functions are just "commands" to make things faster/simpler/easier. If it is a common engineering "feature", chances are there is an command for it somewhere. For instance, if you wanted to put a hole in a part, you could sketch it, then cut (negative extrude) out the hole to the depth you want. Or you could just use the hole command, click where you want the center and enter in the depth/diameter and hit execute and the hole appears. 8-)

For molds, you can draw exactly the part that you want to have, then "sink it" into the mold surface you want via a negative extrusion. That would give you the cavity side of your mold and then mirror that the "other way" and the you have your cavity side and "boom" you have your mold minus your draft angles which you may not need depending on the size of your part, but if you do, there is a command for that. :wink:

There are several sites out there that we used to do comparisons but you really need to see and understand how they work before buying to make sure it will work for your application. Most of the companies that we were dealing with had demo models at their distributors that you could visit and see how they worked. Most of them allowed us to send them a model, in their preferred file format (usually .stl or .stp), to make us a sample part so we could see what the part would look like finished by their process. Actually watching the powder forming machine work, and handling the parts, and thinking about our clumsy, ham handed engineering tech :twisted:, made us change our mind about it. It was originally our first choice based on our limited experience with the Maker Not (and extrusion problems).

Since you are actually wanting to use your parts in a specific application (mold making), I would hit up the different vendors about their suitability for doing that. We have used our uPrint to make several molds here but we were doing it to custom form some gaskets out rubber so we didn't really care what the surface finish looked like.
Thanks for the info! Can you draw an ellipse in Inventor? If you can, can it be rotated around its long axis to create a body of revolution. Also, if we wanted to machine a mold from aluminum, will it output a cam file suitable for machining?
Thanks,
gatorman
If you can think it, you can draw it in Inventor. It might take some finagling, but you can do it. :wink: I know you can draw an ellipse but I have never tried to make an egg.

I know if you have InventorCAM it will. We use that here, although I don't mess with it much. The manufacturing engineers take some of my designs and dump them into our machining centers using InventorCAM. Depending on your post processor you can probably save it as a .stl or .stp or other file extension and convert to G&M code but I don't think that you can do it directly from Inventor.

ETA:

You got me interested since I had never done an egg before so I looked online to see how to do it.

Skip to about halfway on this video and you can see how simple it is to create.

https://www.youtube.com/watch?v=iGrQpmfYVbc
User avatar
lthenderson
Posts: 8499
Joined: Tue Feb 21, 2012 11:43 am
Location: Iowa

Re: 3 D Printing

Post by lthenderson »

gatorman wrote:Can you draw an ellipse in Inventor? If you can, can it be rotated around its long axis to create a body of revolution. Also, if we wanted to machine a mold from aluminum, will it output a cam file suitable for machining?
Thanks,
gatorman
I have used Inventor for ten years, you can definitely draw an ellipse that can be rotated about any axis you care to define. It will also output into files that can be used for 3D machining or printing.

Over the years, I've also used Pro/E and Solidworks for 3D modeling and all work well. They are all similar in function with Pro/E being the most powerful but also the most expensive and steepest learning curve. Solidworks and Inventor are very similar in function and learning curve but in the engineering market, it always seemed to me as if more people used Inventor. They make a lite version of Inventor that I think retails around $450 but I never used it so I don't know which features it has or doesn't have compared to the full blown version which I think retails up near $4600.
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

Aptenodytes wrote:You might find this Scott Hanselman post illuminating. I believe he has posted updates on the topic too, which you can search for.
Thanks for posting that, very informative!
gatorman
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

Crow Hunter wrote:
gatorman wrote:
Crow Hunter wrote:
gatorman wrote:
Crow Hunter wrote:I use a Maker Bot (known here as the Maker Not) and a uPrint SE Plus all the time as part of my job. My first step after I have a concept and a drawing is to create a prototype for fit/form/function. Some materials can be strengthened by "painting" in superglue if you need tensile strength.

There are several different technologies out there. Both of ours use extruded material. Before purchasing the uPrint we investigated a powder base model but didn't like the fact that it required secondary treatment to reach suitable part strength and the model was susceptible to fracturing before this was completed.

If you are going to do complicated parts with extruded material a heated bed will prevent warping. Don't use cheap material (Maker Bot). It is a false economy. The time the machine is down while you are rebuilding the extruder will more than offset the increased material cost.

I design my parts using Autodesk Inventor. It is ridiculously easy to learn. WAY, WAY, WAY easier to use than basic 2D AutoCAD. Much more intuitive. Once you know where to find the commands it is basically like visualizing how you would want the part machined. If you are doing molds, it should be a breeze. Just sketch out the square block that you want to make the mold out of, extrude that and then start cutting away material that you don't need to make your part.

With the Maker Bot it requires dumping to a card and uploading to the machine. The uPrint is networked in with a very, very simple printing interface.

Neither of our units can produce a part with a good surface finish. The individual extruded layers can be felt with your fingernail.

There are companies out there that have much more expensive machines that can do multiple materials/nearly production parts as lthenderson mentions below.
Thanks for the info. I was about to pull the trigger for an Autocad course, but believe I'll look into Autodesk Inventor instead. I'm looking at a Gigabot printer, but that is basically because of size constraints. Is there anywhere one can find objective evaluations of printer capabilities?
Thanks again,
gatorman
Definitely go Inventor. AutoCAD "can" do 3D modeling but I put that in quotes for a reason. :D Inventor is much more powerful and simpler IMHO. SolidWorks is very similar if that is easier to get training on. I had actually never done 3D modeling before taking my current job. I learned how to do it in less than a week just playing around with it and working through examples in the training documentation. Once you know what "button" on the ribbon does what and where to find specific ones when you need them, it is really, really simple to do. It is really just 2 basic commands. Sketch and extrude. Most of the rest of the functions are just "commands" to make things faster/simpler/easier. If it is a common engineering "feature", chances are there is an command for it somewhere. For instance, if you wanted to put a hole in a part, you could sketch it, then cut (negative extrude) out the hole to the depth you want. Or you could just use the hole command, click where you want the center and enter in the depth/diameter and hit execute and the hole appears. 8-)

For molds, you can draw exactly the part that you want to have, then "sink it" into the mold surface you want via a negative extrusion. That would give you the cavity side of your mold and then mirror that the "other way" and the you have your cavity side and "boom" you have your mold minus your draft angles which you may not need depending on the size of your part, but if you do, there is a command for that. :wink:

There are several sites out there that we used to do comparisons but you really need to see and understand how they work before buying to make sure it will work for your application. Most of the companies that we were dealing with had demo models at their distributors that you could visit and see how they worked. Most of them allowed us to send them a model, in their preferred file format (usually .stl or .stp), to make us a sample part so we could see what the part would look like finished by their process. Actually watching the powder forming machine work, and handling the parts, and thinking about our clumsy, ham handed engineering tech :twisted:, made us change our mind about it. It was originally our first choice based on our limited experience with the Maker Not (and extrusion problems).

Since you are actually wanting to use your parts in a specific application (mold making), I would hit up the different vendors about their suitability for doing that. We have used our uPrint to make several molds here but we were doing it to custom form some gaskets out rubber so we didn't really care what the surface finish looked like.
Thanks for the info! Can you draw an ellipse in Inventor? If you can, can it be rotated around its long axis to create a body of revolution. Also, if we wanted to machine a mold from aluminum, will it output a cam file suitable for machining?
Thanks,
gatorman
If you can think it, you can draw it in Inventor. It might take some finagling, but you can do it. :wink: I know you can draw an ellipse but I have never tried to make an egg.

I know if you have InventorCAM it will. We use that here, although I don't mess with it much. The manufacturing engineers take some of my designs and dump them into our machining centers using InventorCAM. Depending on your post processor you can probably save it as a .stl or .stp or other file extension and convert to G&M code but I don't think that you can do it directly from Inventor.

ETA:

You got me interested since I had never done an egg before so I looked online to see how to do it.

Skip to about halfway on this video and you can see how simple it is to create.

https://www.youtube.com/watch?v=iGrQpmfYVbc
I've been watching other videos on Inventor, but didn't find this one. This is very exciting! Do you know if it will calculate centers of gravity and moments of inertia as well? Probably too much to expect, but it would save me from having to set up a spreadsheet to do the calculations.
Thanks,
gatorman
Last edited by gatorman on Tue Mar 10, 2015 12:22 pm, edited 1 time in total.
autonomy
Posts: 334
Joined: Fri Jan 24, 2014 1:22 pm

Re: 3 D Printing

Post by autonomy »

Greentree wrote:What are you looking to use it for exactly? Is it just a learning thing or will the parts serve a function?

I have used a 3d printer a lot and the news stories are overhyped. They are cool and make neat little parts but it takes a while to get going and the parts are still either rough or not that strong (depending on which material your printer uses). Home Depot sells one and they show samples of a small room printed that an architect could use. I look at it and think - no way an architect is going to spend that much time printing that out. It takes a while through cad and then the print might not be perfect off the bat.

Anyways googles sketchup is supposed to be good.
Pretty much what I would write for a summary. There's a $3K Makerbot Replicator at work, and let me tell you, there's a lot of fiddling that goes into the machine. Yes, we end up with usable parts, but they're mostly prototypes, minor brackets, holders, or boxes. They take a very long time to print - say about 6 hours for a reasonably-sized, reasonably-complicated part, the larger parts end up curving up/warping, and don't forget the time that goes into the design. Sometimes you get the print right the first time and then it's pretty amazing. I suggest you sign up for a maker/hacker space, download a model from Thingiverse (or design a somewhat simple model in Sketchup) and try it out.

We printed parts designed in Sketchup and SolidWorks. Sketchup is best for a novice (free and easier to learn than SolidWorks).
As far as making molds, keep in mind that the part you end up with is just a bunch of strands of plastic hot-welded together. In the best case, hopefully most of the strands will fuse, but the resulting prints are not watertight. If I understand your process correctly, the epoxy in the fiberglass molds may get fused with the model and could be really difficult to pull off.
User avatar
Topic Author
gatorman
Posts: 2493
Joined: Wed Oct 31, 2007 9:35 am
Location: The Swamp

Re: 3 D Printing

Post by gatorman »

autonomy wrote:
Pretty much what I would write for a summary. There's a $3K Makerbot Replicator at work, and let me tell you, there's a lot of fiddling that goes into the machine. Yes, we end up with usable parts, but they're mostly prototypes, minor brackets, holders, or boxes. They take a very long time to print - say about 6 hours for a reasonably-sized, reasonably-complicated part, the larger parts end up curving up/warping, and don't forget the time that goes into the design. Sometimes you get the print right the first time and then it's pretty amazing. I suggest you sign up for a maker/hacker space, download a model from Thingiverse (or design a somewhat simple model in Sketchup) and try it out.

We printed parts designed in Sketchup and SolidWorks. Sketchup is best for a novice (free and easier to learn than SolidWorks).
As far as making molds, keep in mind that the part you end up with is just a bunch of strands of plastic hot-welded together. In the best case, hopefully most of the strands will fuse, but the resulting prints are not watertight. If I understand your process correctly, the epoxy in the fiberglass molds may get fused with the model and could be really difficult to pull off.
From what you are saying, it looks like we would have to apply bondo to the outer surface and then sand until smooth. Still, we would start with a profile very close to what we ultimately wanted and would avoid the tedious and time consuming glue-up process we currently use to generate plugs from thin sheets of foam. All in all, I think it would cut the time required to generate a prototype significantly once one gets past the learning curves for Inventor and the printer.

Also, as I think about it, we could generate the mold directly, bondo that and then fiberglass it to develop a mold, thus saving the huge step of generating a plug. Lots of possibilities.

gatorman
Crow Hunter
Posts: 1054
Joined: Wed Jun 27, 2012 12:05 pm

Re: 3 D Printing

Post by Crow Hunter »

gatorman wrote: I've been watching other videos on Inventor, but didn't find this one. This is very exciting! Do you know if it will calculate centers of gravity and moments of inertia as well? Probably too much to expect, but it would save me from having to set up a spreadsheet to do the calculations.
Thanks,
gatorman
Yes, it will in all 3 axis both principal and rotation to principal as well as mass moments and centers of gravity in Ixx, Ixy, and Ixz if you enter in your other physical properties as well as mass, volume and area. It is in the iProperties tab under "Physical".

It is a very powerful tool. It lets you take some serious shortcuts compared to how we used to do it when I was in college in the late '90s. :D
Post Reply