Bringing down the price?

Discussion in 'My Work In Progress' started by astetson, Oct 6, 2011.

  1. astetson
    astetson New Member
    Boy am I dismayed at the enormous price tag of my creation! It's a small mount for Macetech Megabrite LED modules, my thickest wall is 3mm, the base (the largest piece) is only 5cm square (3mm thick), and the mount (most of which is a single support arm) stands only 7cm tall. Yet the price is an astronomical $45 per unit!

    Given that I had envisioned an $8-10 product, you can imagine my dismay. Can you think of any techniques that I might employ to bring this cost down?

    I believe 3D printing on-demand (and eventually in the home) is absolutely the way of the future, but boy the cost must really come down by orders of magnitude for this business to spread. :(

    Thanks for your input!

    PS - it is made of several parts which I laid out next to each other in my file, with about 2mm between each piece.
  2. mctrivia
    mctrivia Member
    if the model is relitevely simple you can buy a 3d printer for $1000 to $2000 that will print for less then a dollar. the problem is time. It may take 2 to 3 hours to print your part. This is what you are really paying for not the material. As for at shapeways. any material you can cut out will reduce your price. Can you drill holes in it, cut slits, use ribs for strength and make walls thinner?
    Last edited: Oct 6, 2011
  3. mctrivia
    mctrivia Member
    multiple parts. why not 1 piece? can you provide a picture or link?
  4. astetson
    astetson New Member
    Thanks for the reply! That's actually not such a bad idea - ditching solid plastic for the "spider web" of support. It's kind of silly that I'd need to do that, but hey - whatever makes it cheaper, right?

    Here's a photo of the "cheap" ($25) version. Three basic pieces. The base (big square), then the hexagonal piece on the right that fits into the base - you, the user, gets to determine the orientation that you insert it. Then the piece on top screws onto the piece on the right, allowing free rotation around the screw. The Megabrite LED module screws onto that top piece. Basically, that allows for total freedom of positioning the LED module; with those three pieces, you can achieve any direction you want across a whole hemisphere.

    I could reduce the wall height of the hexagonal pieces but I'm afraid of it falling out, that's why I made them 1.5 cm tall. My best bet is reducing that base to the spider web spaghetti, don't you think? I'd reduce the size, but it's actually sized to screw onto a small PC fan which will keep the LED module cool while it's operating.

    Attached Files:

  5. mctrivia
    mctrivia Member
    first place you can save by doing a large bevel on corners marked in green. will take away no structural strength,save some material and look nicer.

    how thick are these parts? if over 2mm then you can gain reduce material usage by cutting vs into the plate where i marked in red with minimal structural strength loss(on twist). the thinist point should be no thinner then 2mm. Thinning like this will make more suseptible to tearing but at 2mm and the likely forces cause by just an LED that is probably not a problem.

  6. christopherlowe
    christopherlowe New Member
    you might also want to re-arrange the parts there so that they do not take up as much room... there is what is called a density penalty to a printed item. basically shapeways takes the bounding box volume of your work and compares it to the actual volume of the piece expressed as a ratio and increases or decreases accordingly.

    so re arrange those objects so that the bounding box is the smallest it can be...

    by the way they do this because the more dense an object is the more they can fit into one print...
  7. astetson
    astetson New Member
    Wow you guys are so awesome! How can I thank you? I've reduced the bounding box of the product, and I've eliminated a bunch of material from the base. My price is currently $12.95 - I haven't even put in any bevels or anything yet! Definitely on the right track. Thank you!

    Attached Files:

  8. stannum
    stannum Well-Known Member
    Bound box only matters for WSF materials and when volume is above 20 cm3. Then you pay half price for the volume above 20 if the bound box is used by 10% or more: for 25 cm3 item, you will pay 5 cm3 at half price (and 20 at full) if the item fits in 250 cm3 or less.

    If you are going with that shape, maybe you should use some fillets and reinforcement struts, to reduce stress in sharp angles and increase stiffness.
    Last edited: Oct 7, 2011
  9. astetson
    astetson New Member
    Thanks everyone. I got the final version down to $11.69 after bevels, and reducing many of the surfaces to simple support beams. That's good enough for me. I've placed the order for the first prototype. Yay!