I am trying to discover if models can be modified to suit my particular 3D print needs. IE redraw a model to meet a specific shape and size


I am new to CAD and 3D printing. I need to be able to download models and alter their basic shape. IE I have a friend with a severe bunion on her right foot. I would like to be able to alter a model of a shoe to accommodate the bunion. I would also like to be able to alter a shoe for width and length specific to the person I am building for. I downloaded SketchUp a month ago but have not been able to use it because I am still learning how to use the printer --leveling and adhesion for example. I am almost there but need guidance for the first two questions.



Shapes can be altered. And the short answer is that you’ll typically do so with the ‘Scale’, or ‘Move’ tools.

If you post up the model which you want to work with, then I’m sure some useful input will start to flow in.

Scaling is straight forward, but in doing so everything scales along the chosen scale direction (/axis)… So wall thicknesses for example, might increase in one direction, but not necessarily in another – causing potential issues if you needed them all uniform. differences will be minor in small percentages, so changes might be fairly simple.

The Move tool can re-position things without resizing them as the scale tool does. . . but of course the Move tool comes with it’s own set of distortions which vary depending upon the distance of the move, and the shapes involved.

A Shoe is fairly complicated, and it might take a bit of finesse to modify. But it depends on a lot of variables. So posting up a model, and then commenting on what changes are needed is the best approach to take.


Me also same thing ( except long ago I was CNC Programmer ) So some of the things are normal to me . . Going to have to watch the video’s or down load them and watch over and over . .I use Linux (Ubuntu 15.10 64 bit for my Laptop ) much faster then windows and does not loose drivers . . I have Slic3r for making the layers for the 3 D Printer to make and Repetier-Host for the program to connect to and run the part (I got a Geetech I3 Pro C Dual Extruder 3 D printer to play with ) make parts for sale hopefully by Christmas . .


Lulzbot wants me to use Cura. It’s not bad. When I know more about what I am doing I will try applications like Slic3R. Right now I am a bit overwhelmed by all of the programs I need to learn to get where I am going. I just translated the InVasalius manual from Portuguese to English. Someone had already done that but they didn’t understand Latin syntax so their translation made no sense.

InVasalius is a program put out by the Brazilian government for medical research. It makes possible the printing of human bones and organs. You can print a mold of your brain in dark or white chocolate then eat it.


Thank you Jim,

I will do that.



Sketchup has a STL import / export function which you will probably need. It also has plugins to check you model for solidness which is necessary to 3D print, Also check Shpaeway’s free program Called Netfabb that is useful for model analyses, free has limited capability vs. the Pro version. Also Imateialise has teamed to give support to Su users check the link in the 3D ware house. They also have a tool called meshmixer for model analysis. Shapeway also has a free service wherein they will analyze you model. check their site.
Two basic Su tools for scaling and tape measure: Tape measure is used for Global scale and scale tool has several options of what/ how scale is done.
Here is link to series of tutorials to help you learn basic of SU
For the shoe problem it is best to post at least the basic starting model this forum. You will have to make modification over the problem area and folks will have to look at model to give some guidance there. If you can give like slices through the area you want to adjust so we have idea of desired shape that would greatly help.


Thank you very much for the tips. I tried to upload a model of the sandal I was going to print along with a foot outline but all I got loaded was the foot outline of the friend that I am trying to help. I have enclosed the sandal and the tracing of the foot.

I want to do this for my wife as well. She has a nasty one on the side of her foot. I can’t understand why people wear shoes that are impropery fitted. I am hoping this helps a few of my friends.


Thank you!



I am afraid the contrast is not good enough. I tried some edge detection in GIMP but if you can improve on that it would be helpful=> use Sharpe. What are the double lines and step discontinuity at heel ??
The solution you are looking for will be 3d so some way you need to add more detail. May first though an approach of some type of xyz grid in few spots across bunion could be possible. Draw grid on paper, stand on that then measure z height and tabulate that You will need to also have a wintness axis to align grid maybe like center line of heel and arch maybe. Think like the tools you see in the stores where heel goes in back then slides come in form two sides to measure width
Doing a net search may turn up some thing, have you done that??
Just some thoughts.


Can you get at least one side view? It is fairly easy to extrude something from at least the bottom and side view to start. Then the resulting model can be further customized also with tools in SU.


The problem is, I do not know how to make the adjustments. All I have is the outline of her foot. I am assuming that if I match the outline of the foot the rest of the model will adjust as well. I do not know how to “mirror” or to anchor one part of the foot where it fits then adjust the rest without changing the other part. I do not know how to create a point to point then “warp” or stretch the space in between… If I get to that point I can rotate the model then rotate and estimate the size from the view. She is tiny.

Can you help me with the adjustments?



Using the shoe last model John gave you in another thread

  1. import John’s shoes (it’s huge and needs to be Scaled down with the Scale tool). It’s a component. So left and right are the same. If the feet are different, make one of the forms Unique (select > r-click > Unique) so modification in one foot component will not affect the other foot.

  2. import foot outline(s) and scale it to life-size

  3. Some tips on using tool from the Sandbox extension that comes with SketchUp. **Tips **with the Move tool. **Tips **on the Scale tool.


Again the problem is that I only get one shoe with the downloaded model. I need to “mirror” the original so that I have two shoes, a right and a left, then make the adjustments per foot so that they fit each foot individually. Only one foot has a bunion and I am hoping to shape the shoe so that the inside of the shoe accomodates the bunion while the outside of the shoe looks normal. All I have to do then is to scale the shoes to the outline but I still need to adjust the width in a particular area of the shoe while leaving the heal stable. Feet come in many widths and shapes but manufacturers don’t think so.

Thank you for your hard work in your response. It is the best response I have had yet.



Odd, John’s model I downloaded contained 2 mirrored components, just like John’s attached image. But no matter. You just need one.

Ctrl+C will copy then Ctrl+V will paste a copy of the shoe in the workspace. Also look up how to make a linear array with Move+Ctrl (that’s useful tool.)

Then with the copy, mirror it with the Scale tool by tugging on the center handle, stop the tugging and type -1, press Enter on the keyboard.

Note, the shoes are components. So whatever geometry you modify with one with be done to all the copies of that component. So as in my tutorial, Select one component, r-click and Make Unique.


I got it. Fooling around with it now.


I should have mentioned to first model the normal shoe then copy/mirror that to adjust for the foot with the bunion - less modeling.

A few of the characters I modeled for the SketchUp Sage site started out as mirrored components. For the models that were not symmetrical, after the modeling got along far enough, I would either explode all the geometry to join the two halves together or make one of the halves a unique component to create the asymmetry.


Thanks for your patience and your valuable assistance. Most likely I am just missing something.

I have attached a darkened drawing of my friend's Right foot.  She's actually my wife's BFF but she and her husband have been really nice to me and I wanted to do something nice for them.  I don't know why women put themselves through this kind of pain.

I would also like to be able to adjust the thickness of one sole.  Selfish reason is that I was run over by a car years ago and the leg healed short.  I need to add thickness to one sole to compensate.

I made the right sandal "unique" and have resized it.  With this practice I can make the shoe "unique" and adjust it for the bunion except now I have to figure out how to adjust ...well you'll see.

Thanks again,



Hi Cat,

I am looking at Mirroring.  I found "flipping" which is not the same thing.  The sandals I sent you have only one shoe and that is the right one.  It is flipped so that one can see the bottom of the sandal but it does not create a Left sandal.  I am missing the tool.



You said copy/mirror. Is there a “mirror” option? I’m not finding it.



Flipping actually is the same as mirroring, but it depends on which axis you select to flip along. Assuming your footprint is sitting on a Red-Green plane (such as the ground plane) , flipping along Blue effectively turns it upside down–not what you want. However, if you flip along Red or Green, you’ll get the opposite foot.

Let’s say your foot is pointed in the Red direction, with the heel on the Green baseline. Slide a copy of the shown right foot to the left, along the Green axis so it is well clear of the original. Now flip the foot along the same axis along which you slid the copy–the Green–and you’ll have your left foot positioned correctly relative to the right.




I figured it out (I think). It has something to do with the handles on the scaling. If you use one handle it flips the part over if you use another handle it just alters the part. Originally I had two shoes but messed it up when I unknowingly flipped the part over and mirrored the other sandal from the bottom. The “flipping” is beginning to make sense now.