Need help adding something to a project

Hey all,

I have started printing with a Printrbot and am really enjoying it. I found a project I wanted to print on www.thingiverse.com but am needing to add one thing to it. It is a scan of a yellow lab I am wanting to print for my daughter. the problem I am having is I cannot get the front feet to adhere to the print bed because they are so small. I would like to add a square base that the dog is standing on to fix this problem. Is there anyone that would be willing to do this for me? I don't have any 3D software or the knowledge of it to do it quite yet. Here is the link to the project: http://www.thingiverse.com/thing:214467 Thank in advance.

I'd be happy to do that for you but you can print a wide "skirt" around the dog and then snap it off. Find the "skirt" setting in your slicer and give it a high number like 10 or so. You'll get rings like an island around the whole first layer that's easy to snap off and clean up with and xacto blade. If you can't find skirt look for "raft." It will print a raft under the whole dog that can be snapped off too. It's a little harder to get the raft off and the bottom of the feet will be rougher (unless you sand it down).

Thanks for the reply. I have tried using a raft and due to the small size of my printer, the rafts underneath the paws of the dog are just not big enough. It prints a separate raft under the left paw, right paw, and body. Once it gets to around layer 10, any pressure from the printer knocks the feet off the print bed. I have tried many, many different tweaks with a skirt along with the raft but I just don't think it's going to work without having a full square platform added underneath the whole dog. Could you help me out with that?

Sure thing. What should I do, just download the dog and put a platform under it? If so, how tall do you want the dog and what dimensions would the platform be do you think?

It is too big at full size for my printer so I scale it to .18 in Repitier. If the platform could be around 3 mm bigger than the base of the dog and maybe .18mm thick (6 layers at .03mm) would work great I think. If you can do all that on the original size, I can scale it down to the size I need. Thanks for your help!

I sent you a PM. Look for that.

PM returned. Thanks.

Would there be any way you could add in a couple of supports that connect the feet and legs to the body. The feet get to the point where the print starts each time in the same place so there is one spot that is slightly higher. As it builds up, the print head starts hitting that high spot when it moves to it and breaks the feet off the base. It is much stronger than it was before but I think it is going to need some kind of support for it to print correctly. I was thinking maybe right at the base of the feet and halfway up the leg. Let me know if that's possible. Thanks a bunch!

Here is a picture as the foot gets higher, it starts to curl up and that is where the print head starts each layer. Attachment 732

Ok, looking at your photo I think you have bigger problems. The printer should never print a line higher than what’s on that slice so I’m not sure what’s going on. It's hard to tell from your photo but are you getting any curling of the base meaning, is the base warping and pushing up one corner so that it’s higher and gets hit by the head?

Attachment 733

Using the photo above I've marked some things we need to look at with numbers. Before you can get a good print of anything I think you have a few things going on.

1. This looks like a ridge that is higher than the overall layer. This should not happen. Is there warping on that far corner that we can't see? Any plastic that is higher like that will get bumped by the head and cause trouble.
2. There is some roughness here that looks like a high spot too. It looks as if the printer is randomly extruding too much material and making high spots. I'm not sure how that can happen randomly though as it's generally a global problem.
3. This looks like a warp but the closest edge to the camera looks straight. I looks as if the print head dipped lower in just that spot. Could your printer have loose rods or is the extruder platform loose. Something is not making sense there.
4. and 5. These look odd, maybe a bubble or gasout from moist filament. It needs to be stored in a bucket with desiccant or something to keep it dry. You can't leave it out for weeks and then have it perform well as it absorbs moisture.

Have you printed any of the "torture" tests from Thingiverse? Until you get a clean print and good calibration of your printer you are going to have issues printing "anything" and will produce bad prints or have prints knocked loose. Below is an example of a clean test print. Until you can print something like this, the dog may not ever print well.

Attachment 734

What is your printer and what have you done to calibrate or fine tune it? That will help us diagnose. Someone else may join us here also who may have a better idea of what's causing your poor printing issues.

Now, to address the immediate problem, getting the dog to print. Have you tried printing it with support material turned on. This will print thin risers that support overhangs, etc. It also gives a little rigidity to the print to help with warping, although, that depends on where it is and how much there is. In your case. I don't think it would stop warping but may improve the overhang issues. It makes more work because you have to remove it with an Xacto knife or something but for many overhangs, it's critical that you use it, or the print will never survive.

Why don't you do this, print a test cube and post it back. Once we diagnose that cube, we can solve issues so that the dog will print well. Here's a link to a test cube. http://www.thingiverse.com/thing:38108

I just read over your post again and you saw at the end you are getting curling. I missed that earlier but did suspect it. How are you sticking your print to the bed?

I realized there was something off with that first print and my bed ended up being un-level. The spots that look like high spots are where there starts to be an overhang and there is no support underneath. The material just curls up in those spots with no support. I am using a printrbot simple with painters tape attached to the bed and do the calibration instructions before each print. I was able to set the Slic3r to raise slightly each time it traveled to keep from hitting those spots and tried the dog again after leveling the bed. It's not perfect but here's what I got:Attachment 741

I printed this for the Y axis right after: Attachment 742

It looks like you are doing pretty well now. I'll still modify the model if you want me to but I think with a little more finesse and tweaking you will be good to go. Glad you worked it out. You might try printing the outer perimeters at a really slow speed like 15 or 20 and get some clean outer edges. Let the fill print at 30 or 40. That always gives me a cleaner print for things that I want to look nicer.

Let me know if you want that model modified and if there is anything else let me know.