4

Well, they don’t need density as an input for calculating price. The hub sets the price per volume of material used. 3D hubs slices the customer’s model with 20% infill. The volume of the sliced version of the model is divided by the price per model set by the hub. They would only need to know density if the hub was charging per mass of material used.

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??? 1 cm3 of PLA is 1.25 grams of plastic 1 cm3 of abs is 1.04-1.08 grams 1 cm3 of petg is 1.32 grams. That’s up to a 25% ish difference in material cost.

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3d hubs quotes are for 20% infill 1 shell and I believe 1 top/bottom layer. The density for FDM prints is set at either 1 or 1.25 you could run some tests with cubes. I highly recommend you run tests using 100 cm3 cubes and report back so we all know :). And try and PLA and petg to see the difference. See below about density not taken into account This is based on the FAQ and posts from 3d hubs admins. For actual data tag “@bennyheretohelp” and he will work tirelessly to get you answers.

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But they’re not charging by weight, they are charging by volume. Just factor the material density into your pricing per cm3 and it doesn’t matter.

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ROFL. $.10 for water $.125 for PLA $1.08 for abs $1.32 for petg etc. Go ahead put those values in and let me know how that works out for you. The concept of ignoring physics is bullshit. If you disagree please stand in the way of a semi truck traveling at 70 mph or more and report back on how physics can be ignored.

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I’m not trying to make you angry or anything, I’m just curious as to why you think that density matters to 3D Hub’s once you set the price per cm3 for a material. This is how I see it: Of course you need to know density of materials as a hub because the hub IS buying the material by mass (21.99/kg for example). But once you research the density of the material you are buying, (1.25 g/cm3 for PLA) you can use basic algebra to crank out a number for price per cm3. (I got $0.027 in this case) Plug that number into your hub’s page in price/cm3, and you’re done. 3D Hub’s has no reason to know what the density of the material is. It sure would be helpful if they posted densities of various materials to make research faster, though.

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I kindly request you cease with the mockery. Please do as you said and enter $.027 into the cost box on your hub. Let me know how that “simple algebra” works out for you. "You must cut down the mightiest tree..." - YouTube

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…it works out fine. That’s the pricing model my hub has been using. I can link you to the spreadsheets I use if you want. It’s awesome seeing another Monty Python fan here! My brother and I dressed up as the Knights Who Say Ni for Halloween. It was amazing.

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Still would like to know :

How many perimeters are they assuming? How many top/bottom solid layers? What infill pattern?

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You mean .27? I just looked at your pricing, and it seems inline with .27, not .027, unless I am crazy…

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Unless a code change was made the minimum price 3d hubs forces is $.01 per cm3 in increments of $.01. And $1 per order. All of this .00x bs has never been possible. Neither has a $0 start fee. As for the decimals, I’m working on $.025 per cm3 pricing for select models though it looks to be a few weeks out. For others I have a $.08 threshold that I can’t seem to shake due to operational costs.

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You’ve never been able to enter less than $1.00 for the start cost or less than $.01 for the per cm3 cost and both only allow increments of $.01 if this isn’t the case for you please take a screenshot and prove it! If you have a pricing spreadsheet that would be awesome! I listed all of my pricing basis on another thread a little while back and I’ve been wondering how other hubs figure out the nightmare of buying in weight and selling in volume vs selling in time and materials.

16

$0.027 is MY cost per cm3. To that number, I add my profit margin of 300% and then the 12.5% service fee that 3D hub’s charges. I also have multipliers for various resolutions. So I’m not breaking even here, im making a profit. I’ll send you the spreadsheet I use once I’m back home on my computer (I’m on vacation at the moment)

17

Sorry, I should have clarified. $0.027 is the hub’s COST of material. I would expect a hub would sell it for a higher PRICE to make a profit. In my hub, I make a 300% profit margin. I also factor in the 12.5% service fee that 3D Hub’s charges along with my $4 start up cost, so the price ends up being higher than the cost. I’ll send you a link to my spreadsheet in a few days, since I’m on vacation and don’t feel like using my phone to do all that. Cheers!

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I would genuinely appreciate that.

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For all those who are interested, here is the link to the spreadsheet I made for calculating the price of material: 3D Hub Pricing - Google Sheets You can save a copy of your own onto your Google Drive account. I may add more features in the future. Enjoy!

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@bennyheretohelp , could you provide any insight on this?

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Thank you, seriously, for sharing that. I like your approach.

However, I notice that you only charge 10% for each increase in layer height. I find this interesting, I always feel like if a print takes 4 times as long to print, it should be much more expensive. That is 400 microns takes 1/4 the time as 100 microns, give or take. Would you be willing to share your thoughts on that?

Thanks again!

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My machine is just a wooden-framed Prusa i3 I built myself, so I found the extra time spent printing at higher resolutions amounts to a pretty negligible increase in electrical costs, as it draws only 300 watts, roughly. I also don’t want the higher price for higher resolutions to deter people from ordering nicer parts, unless they are really big and the electrical costs starts to become significant. The values are adjustable, so you are free to tweak them to your liking! I should probably add an input for electrical cost so people with more power-hungry machines can make use of my spreadsheet. Thanks for the feedback! I want this tool to be as usable as possible.

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Guys I’m pretty sure that 3D Hubs just takes the straight-up volume of the model and subtracts 20% of that volume to get “sliced volume.” Just did the math on a few parts, and that theory is holding true.