What's wrong with my chess pawn model & why so much to print it?

I’m not planning on printing this pawn, but trying to learn from it.

I first uploaded what I thought was a bad design of a chess pawn to Skapeways.com so I could see how the website worked. To my surprise it showed only something like $13 to print the chess pawn.

That was much cheaper then I thought it would cost. So I went back and made a different design of a chess pawn.

pawn 5 template.skp (1.6 MB)

I upload it to shapeways and get a price with the same white plastic finish I had selected when I first got a price of $13, but my new design is showing me a price of $99.81!

I try to figure it out. I go and remove the bottom of the pawn thinking it will print it out as a hollow piece instead of a solid and upload the new model, but I still get a price of almost $100.

https://www.shapeways.com/model/3dtools/4450800/0/6?key=cf7f6407f6cf4890b76af29f71d65292

What I’m I doing wrong?

Thanks,

Hmm, so I scale it on the shapeways site from 5" tall to 2" tall and the price drops from $100 to $8.00

I’m really confused now. The price really changes that much for 3D printing?

Too much plastic?

By the way, I had a little play with your earlier pawn model.

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Wow, awesome job on the pawns!

How can I tell how much plastic my model is going to use?

I just started reading, “3D Printing with SketchUp” by Marcus Ritland

The book talks about wall thickness. Are the walls to thick in my model?
How do I know if the pawn is being printed hollow or as a solid piece?

If you have a piece that’s 1" x 1" x 5", that’s 5 cubic inches. If you scale it to 40%, you get 0.4" x 0.4" x 2" which is 0.32 cubic inches … about 1/16th of the original volume. Note that 0.4 x 0.4 x 0.4 = 0.064 times the original.

Try drawing a hole in the bottom to join the inside and outside surfaces. That would ensure it’s being printed hollow. A small hole would do and if there’s little change in the price, you’d know.

The render could use some work. It was just a quickie and first draft.

Well now I’m pretty sure my model is hollow. I took the bottom and reversed the face. Then I selected the bottom and deleted it. Now I can see up inside it, just like I would expect to be able to if it was hollow.

pawn 8.skp (1.6 MB)

I upload the new version to Skapeways and still get a price of $99.

https://www.shapeways.com/model/3dtools/4451007/0/6?key=5b95c6cd2b4afaa53f28ac787c01c299

When I look at the bottom of the image of my model on Shapeways it looks as if it’s one solid piece and no longer hollow.

Maybe more of a question for the Shapeways forum, but thought I would try here first.

Then it does not matter if the pawn is a solid model or hollow inside?

it needs to be solid, but may only need a small wall thickness to print economically…

think of a salt shaker, it’s solid, but it has an internal cavity for the salt…

you don’t pay for the cavity…

john

No. But it’s pretty big for 3D printing.

FWIW, I’ve been checking it at iMaterialise and getting similar prices.

One thing you need to be working on is making sure it’s a solid. Just deleting the bottom isn’t helping and it’s not what I told you to do, either.
3dprint_upload8 solid.skp (1.5 MB)

If you make it about 2-1/2 in. tall the price drops to less than $15.

I was thinking it maybe on the large size. It’s a big pawn for sure.

Another place for me to check out, thanks!

I’m not for sure I know just what you mean.
By solid you mean selecting all of it and then making it a group?

Yeah, sorry about that. I had planned on doing what you said. Then as I was looking at the bottom I wondered what it would look like if I just deleted the bottom. After I deleted the bottom it looked hollow to me.

So I uploaded your version to Shapeways and the price drops from $100 to $48, wow!
Guess I should have put a hole in the bottom like you told me to do. :slightly_smiling:

What a difference!

So much to learn not only about drawing, but printing too.

Thanks,

The extra cost of a more solid part is $0.28 per cm3 … sometimes substantial savings can be realized. I used your profile and created a 2" tall hollow part that Shapeways prices at $5.30 ($6.30 in black):

In the model, I changed the units to “cm” and then used the entity info to get the volume:

Note how closely that corresponds to Shapeways volume. Using the entity info for volume allows you to compare potential price differences before uploading them to Shapeways.

Inside the hollow part:

I don’t seem to see the same thing in Entity Info. Maybe because it’s not a solid yet?
If so how do I make it a Solid?

I’ll keep reading…

Will work on it some more in the morning. You guys have been great. Thanks again for all the help.

OK, it’s a solid! I closed the bottom again. Never should have deleted the bottom to start with.
Then I highlighted it, made a group and now my Entity Info shows it as a solid and the volume!

Now I will sleep better tonight. :slight_smile:

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Very helpful info, thanks!

@appliancejunk, you should price printing the part locally via 3dhubs.com

You can compare prices and work with someone that you can pick the part up from face to face. It’s often cheaper. You should be able to select someone who is displaying the quality of the prints, and they should work with you to make sure that the part is being printed the way you are looking for.

Even with thickness there are some possible issue with over hangs. Even with allowed max of 45 degs I had to increase model size by ~2x to get supports installed and even then how to break them out is still a issue. Cost is based on more than just vol and since manpower is usually driver in cost you may see that affect.
This is first cut installing at angle on print table will probably not help much
Just for you info pawn_mac1 post.skp (740.9 KB)

One other observation … Shapeways charges a minimum of $4.99 shipping per part which increases the price of your 2" pawn from $5.30 to $10.29 total. If you are making a chess set, you can connect 8 of your pawns with a “sprue” (or “runner”) to effectively make it one part. For example, this arrangement costs $47.10 plus $4.99 = $52.09. However, you get 8 of them so they end up being about $6.51 each ( a savings of $30.20). Of course, you have to snip the runners off when you get them (I connected them to the underside of the part so they wouldn’t show).

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Amazing! Never would have imaged doing it that way.
Thanks for all the help and tips everyone. I can’t get enough of this site.
I have a long ways to go, but I feel I learn so much each day.