Close
Login to Your Account
Page 1 of 2 12 LastLast
Results 1 to 10 of 16
  1. #1
    Join Date
    Feb 2014
    Location
    Mornington Peninsula, Victoria, Australia
    Posts
    20
    Downloads
    0
    Uploads
    0

    Does Size Matter?

    I am no engineer just a guy with an idea who cannot not afford a designer/engineer.
    For a while, I was designing a product which included several gears and shafts, fins etc. It also had/has two housings which need to be quite sturdy, as they would take quite a physical punishment, be sealed totally waterproof, with the largest being approximately 300mm L x 100mm W x 250mm H,. Originally I believed that it would be best cast out of aluminum and started to look towards 3D printing as a way to make the dummy mold. I also thought the gears etc would also need to be machined or cast from alloy, again using printed dummies for molds.

    Trying to learn a little, I love reading about all the new 3D printers and 3 printer technology (haven't absorbed much) and the one thing that stands out to me, is the print size. To me it appears the print size is fairly small and it seems the bigger you go the harder it is.
    From what I have read with some products (mostly plastics & resin), the bigger you go the more prone layers become to separation because of temperature. Also the threat of products collapsing as they are printed, plus shrinkage due to their size.

    Because of my design, I have become more aware of 3D printers, how they can be used in prototyping as well as production, and while my idea/design has been all but given up on, I am curious about what types of printing is more suited to larger printers, the products used, the pitfalls and more importantly, how to get around them.

    So what is your biggest print?
    How big would you like to print?
    What material/media do you print with?
    What are the pitt-falls and how do you get around them?

  2. #2
    Join Date
    Apr 2014
    Location
    Posts
    22
    Downloads
    3
    Uploads
    0
    I cannot answer your questions, but I too have some applications that would require a larger printing area.

    If there is no reason specifically why the printing area needs to be so small then one can perhaps make your own larger movement. Larger parts will just take longer to make.

    You know, they say everything about a man has to be bigger than the next bloke's. Except his cell phone of course

  3. #3
    Join Date
    Mar 2014
    Location
    Posts
    6
    Downloads
    0
    Uploads
    0
    The primary difficulty of a large build area is accuracy and reliability. Layer seperation and warping are just a result of incomplete hobby printer designs (lack of heated build chamber). Similarly, risk of collapsing is simply a result of poor support material solutions.

    A large print volume is much harder to keep aligned and rigid, and a large print might takes days to complete. Typical hobby printer construction is nowhere near ready to tackle that kind of challenge.

    The largest print I have done was a complete computer case that houses two separate motherboards. It It was printed on a Fortus 400.

    IMAG0091.jpg
    Capture.jpg

  4. #4
    Join Date
    Apr 2014
    Location
    Posts
    22
    Downloads
    3
    Uploads
    0
    It seems one stick to CNC then... or chop the part up in sections and glue them together afterwards

  5. #5
    Join Date
    Apr 2014
    Location
    Posts
    40
    Downloads
    0
    Uploads
    0
    If you do the design based on your build volume then you can add the proper types of joints into the item to piece into a large item.


  6. #6
    Join Date
    Feb 2014
    Location
    Mornington Peninsula, Victoria, Australia
    Posts
    20
    Downloads
    0
    Uploads
    0
    G'day all, thanks for replies.
    Quote Originally Posted by GornNR View Post
    If you do the design based on your build volume then you can add the proper types of joints into the item to piece into a large item.

    I get what you mean, but I think with the shape of my largest case, adding a join would be quite difficult, also the fact that I would want to use the part as a dummy for then ramming sand around. It will be hard enough to have it not warp out of shape as it is rammed, let alone a joint (if there was one), not come apart. Then you need to be able to "pull" the dummy part, without any pinching/dragging, the slightest hint of a joint line will make it much harder to pull. A lot of work would need to be done gluing then finishing the join.

    Another option is investment casting and burning out the dummy, but the technology is not quite there yet and in the sense of a production run, to slow and costly.

    @Fanie
    I originally thought CNC would be the way to go, but I do not think a CNC could accurately reach as deep into a confined space, also, would need to re-design lubrication tunnels within the housing, to tubes, and would prefer not to do that.

    @691175002
    So just how big was that 2 x mother of a case, it looks huge.

    I had only read of a heated build area after I logged off last night. Guy had wrapped insulating foil around his printer but they did not say what temperature he had inside. I was curious what sort of effect that would have on the print media and feed also would you need much more supporting media?
    When doing that sort of work, two heads better than one, second head the support crew?

    Eddie

  7. #7
    Join Date
    Apr 2014
    Location
    Posts
    22
    Downloads
    3
    Uploads
    0
    For some reason I always end up with something that is just beyond the machine's reach.

    You get multi-axle CNC's that are amazing... paying for them is something else and doing the code so the cutter doesn't take shortcut through the material is also another story.

    One thing I like about the printing process is there are no shavings.
    I guess after you got the printer the next step would be to make your own reels of print media.

  8. #8
    Join Date
    Feb 2014
    Location
    Mornington Peninsula, Victoria, Australia
    Posts
    20
    Downloads
    0
    Uploads
    0
    G'day Fanie
    I have my own lathe + HM50 mill/drill (wish it was cnc) and yes it is either to deep or just plain to big to fit between drill and knee.

    Didn't know you need spools thought they would come with the print media, do you have to spool down from bulk spool to smaller spools?

    Eddie

  9. #9
    Join Date
    Apr 2014
    Location
    Posts
    22
    Downloads
    3
    Uploads
    0
    You get media with the spools, but they go empty and then you have to buy more. With the price of the print media I'm surprised they don't give every one a printer for free, much like cellphones. Perhaps one can extrude your own print media from say ABS chips. I have a friend with an injection machine, he should know if you can make the worm.

    I CNC'ed my one mill, it was worth it, it paid for it numerous times over... and I'm dyslexic when it comes to freehand cutting circles. I have a Hermle as well, that must become multi-axle, they are so smooth...

  10. #10
    Join Date
    Feb 2014
    Location
    Posts
    9
    Downloads
    0
    Uploads
    0
    Quote Originally Posted by ELM View Post
    I am no engineer just a guy with an idea who cannot not afford a designer/engineer.
    For a while, I was designing a product which included several gears and shafts, fins etc. It also had/has two housings which need to be quite sturdy, as they would take quite a physical punishment, be sealed totally waterproof, with the largest being approximately 300mm L x 100mm W x 250mm H,. Originally I believed that it would be best cast out of aluminum and started to look towards 3D printing as a way to make the dummy mold. I also thought the gears etc would also need to be machined or cast from alloy, again using printed dummies for molds.

    Trying to learn a little, I love reading about all the new 3D printers and 3 printer technology (haven't absorbed much) and the one thing that stands out to me, is the print size. To me it appears the print size is fairly small and it seems the bigger you go the harder it is.
    From what I have read with some products (mostly plastics & resin), the bigger you go the more prone layers become to separation because of temperature. Also the threat of products collapsing as they are printed, plus shrinkage due to their size.

    Because of my design, I have become more aware of 3D printers, how they can be used in prototyping as well as production, and while my idea/design has been all but given up on, I am curious about what types of printing is more suited to larger printers, the products used, the pitfalls and more importantly, how to get around them.

    So what is your biggest print?
    How big would you like to print?
    What material/media do you print with?
    What are the pitt-falls and how do you get around them?
    Hi Elm

    I am just starting my 3rd RepRap build it is a Mendel 90 in 5mm Ali.
    It will have a build area of 400mm cubed.
    I will print ABS on a heated bed on this machine and from my experience of printing big (ish) on my small printers It will need a heated chamber.
    It is critical to use both a heated bed and heated chamber and allow the part to cool slowly and evenly to avoid warping.
    PLA is less prone to warping but much brittler, ABS is excellent for final useable mechanical parts.
    My biggest print so far has been around 220x 150mm
    I would like to print massive, like car size!
    I print with ABS/PLA so far, experimented with HDPE began with CAPAractalone (freindly plastic/PCL)
    I want to print in all materials, atoms and molecules would be nice ;-) but more realisticly I will be moving onto recycled HDPE and experimenting with printing different chemical compounds and recycled thermoplastics.
    The pitfalls of priunting large are entirely depending on what material you are printing with, already mentioned the pitfalls/workarounds of ABS above.

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. News RigidBot 3D Printer Delivers Simplicity and Size at a Low Price
    By 3DPFadmin in forum Manufacturer News & Announcements
    Replies: 0
    Last Post: 02-04-2014, 12:32 PM

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •