Nesting & creating a labelled map of the stock

[hfcandrew]

Hello,

I'm looking for help with my CAM process.  So anyone daring enough to assist, grab a coffee and settle down as this is a long read, I figured I might as well give all possible info at once instead of 20 messages back and forth.

My name is Andrew I make custom made foots orthotics. A few months ago we purchased BobCAM but are very unhappy as it is not doing what we need and they have said the program in unable to accomplish what we need, so I am in the market for a new one. I'm trialing Fusion360 but it is  complicated!

I am a medical clinician and not at all a machinist.

Our orthotic manufacturing process is:

1. Take a 3D scan of each patient's foot (We use the Occipital Structure Sensor)
2. Reshape, modifiy and correct the .stl of the feet. (This is our CAD, we use Meshmixer: https://www.youtube.com/watch?v=rVXdSo2i0wQ)
3. Import 3-4 different .stl's of pairs of patients feet, into CAM software, arrange/nest within the stock. Create a toothpath and a labelled reference map/image etc to help quickly identified who's foot is who, as to not mix up these custom orders
4. Using our Techno CNC LC Series 3024, we mill the custom 'positives' of patient's feet out of polystyrene foam. (End product looks like this)
5. Remove the positives from the stock, vacuum press a hot sheet of polypropylene on top to make the orthotic shell
6. Cut off the excess plastic by hand and put a liner on top

We purchased BobCAD V31 as our 3 axis CNC CAM solution to replace our current old (but quick & automated) DOS CAM program we have, because this old one is incompatible with .stl files.

For CAM we were just going to use the free version of deskproto as the replacement, but it was missing two main features which made investing in a paid program worthwhile for us. (BobCAM said it had these features but it definitely does not.)

These two features required in our CAM solution are: 

1. The ability to quickly click and drag geometries to manually 3D nest 3-4 sets of the .stl custom foot geometries in the stock (or automatic nesting would be ideal, but more on that later). We ideally want to only spend about 2 minutes to load the 3-4 geometries and slide them within the stock.
2. The ability to automatically (or at least quickly/easily) track/map and then print a page of a labelled image/map of the stock of which customer's foot ended up where within the stock. (again you can see how it could be confusing tracking the orders in this, so a printed labelled map layout of the stock arrangement is needed).

To note, toolpathing customization was of no concern because polystyrene can be done in a single pass if needed, nothing fancy is required.

From BobCAM we were sold on a promise of meeting these two criteria and to do so in a productive fast process. Spending around one minute manually nesting the 3 or 4 pairs of feet (after an understandable few weeks of getting 'comfortable' with the program). But based on our work time we measured of our process, it takes about 10 minutes to nest 3-4 feet and cannot print out the stock map at all. And this 10 minutes of nesting is filled with what seems like so many illogical unnecessary speed-bumps of selecting, unselecting, menu changes, accepting, zeroing/deleting translation values and typing labels.

Here is a list I emailed to BobCAM of several things we believe were misrepresented during the BobCAM sales process and a few logical design features which need solving for our intended use. It may not make much sense to you as the reader without the context of ever using BobCAM, but again I'm just giving the whole story just in case:

• Merge - When you merge in a geometry to the stock it doesn't use the original file name it was saved under on the pc. This is a huge problem because we have one stock with many different customers feet being cut out and we need them identifiable as to not mix up the orders. We don't want to have to manually relabel every geometry in BobCAM. This is very inefficient and there is no easy and fast way to do this and print this reference page out. It's advertised as running off the Windows platform so it's completely logical to assume it would at least save an objects file name from a windows pc. We cannot even make the file name appear over the geometry in order to take a screen shot for our map.

• Cannot merge multiple (the 3 or 4 pair of feet) .stl files at once

• The import/merge default file type is for only .bbd, so the drop down menu needs to switched to 'All' for every merge, since we use .stl files sculpted in Meshmixer. These little speed-bump interruptions to workflow are avoidable and really accumulate to our overall work time.

• Mouse lock issue - When selecting a geometry is it very finicky, not intuitive and rather annoying how this program clicks and locks on when moving geometry, then you need to click to unlock again and again.

• Translate and Rotate - need to switch between menus for each function

• Translate - We were sold based on BobCAM having the easy drag and drop feature but it's a misrepresentation to say BobCAM has drag and drop in the CAM. What we expressed we wanted would be similar to moving icons on a desktop: HoldClick, Drag(XY plane simultaneously), Release & Repeat. However when you select a geometry and start to move it in the stock the "Translate Amount" values are auto saved and auto applied to the next mouse click. The only way to stop this is to manually zero out every value before or after every single movement. Other wise when you select yournext geometry it automatically jump to overlap over the previous geometry. It is so much unneeded selecting, unselecting, menus and typing. Cody told us you cannot turn this feature off. I asked if we can pay to have the program modified and he said "No. BobCAM doesn't have a true drag and drop. We used to in a previous version but not now." Two very different stories from sales to the technical support team. A fluid movement pattern similar to Meshmixer (https://www.youtube.com/watch?v=hxGaiHa40So) would be ideal. 

• Rotate - These issues are similar to the "Translate" ones. If I need to rotate a foot to fit it in the stock it auto saves the rotation values and auto applies to the next mouse click (unless you manually go and manually zero it out). Also there is no way to easily rotate an object around its geometry centre. In "Translate" you can click the box for "Geometry Center" but not in rotate. Once again, not a true drag/drop/rotate and certainly not "Affordable and easy to use CAD-CAM" like advertised. A fluid movement pattern similar to Meshmixer/'moving the desktop icons' would be ideal.

• All the .stl files merge rotated with the Y and Z switched. It would be nice if we could have a feature to swap these on import (such as in Meshmixer) 

• There are no hotkeys for many of the these functions we use, need to manually select the majority of the different functions

• There is simply no printout (labelled map) of the geometries in the stock (automatically available to print)

• The CAM was advertised as follows "The increased programming automation and smarter toolsets equals fewer clicks and more efficient use of your time." This is not the case for our explicitly expressed intended usage.

Please see attached for 3 sample pairs of feet. They are in mm, from Meshmixer. Our stock we are starting off with is 12x24x2 inch (304.8x609.6x50.5 mm)

From my own research I have found a Potential 3D nesting add on: https://apps.autodesk.com/FUSION/en/Detail/Index?id=665011816067939988&appLang=en&os=Win64&_ga=2.103... But I'm not sure if this will work.

For a toolpath anything will do, however we have typically found good results doing a equidistant spiral pattern with a 0.1inch step from geometry centre outwards to the edge, then it continus straight down to near the bottom of the stock, so end Z level end point of 1.99 inches. We use a 0.5inch ball nose bit.

I haven't found any way of maybe an auto-labelled map of the stock, but I keep hearing Fusion360 is pretty customization, so I'm keeping my fingers crossed.

Can Fusion360 satisfy our criteria #1 and #2? If so could I see a demo of quickly accomplishing so, or sent a file etc? Any help would be most appreciated!

- Andrew

[Anonymous]

Yep, counting pixels the width stays the same (same amount of pixels appear smaller to the eye the higher the monitor's resolution...) Seems the side bar's width is always 70 pixels.

I added a platform detection. If the Python Shell window prints "Operation system: Windows" running the updated code (attached below) > In the output image the bar should be cropped off and the labels should be placed on the right position (although the zoom issue isn't fixed yet). Does that work for you so far?

[hfcandrew]

See attached. Yes it detects Windows. The menu bar is captured in the raw (on top) and is successfully cropped on the label view (bottom), the framing of it is good, appears to be successfully zooming and framing itself at the center of stock

So issues still to go are: Too much zoom (ideally the screen cap would be cropped at the printer bed), labels still shifted left, menus still appearing.

[Anonymous]

In the shell window there's a red error text hidden by the screenshot window. What does it say?

[hfcandrew]

I think it's an error from the file not being saved, only a temp one appears. Sorry I forgot to mention that issue. I have been getting some help also playing around with the script myself and we got that working on another modified version, see attached (geometryOutputWinAL.py).

See attached error code (Shell) and my directory setup after rebuilding mmAPI (directory setup). You'll see your 'Tool manager' in there as well! Thanks again for that piece of gold!

[hfcandrew · Accepted solution]

I can't believe it, but we are solved. The screen cap issue is difficult because parameters change depending on what version of windows you are on, your screen resolution and the current scale of your Meshmixer window. So we created code where you can change the stock,  a spread factor of the generated labels, offset shift, crop the captured image from Left, right, Top, Bottom, and scale the size of the font. See attached!

The parameter altering file is the "paramsWin.py"

Thank you for all your help!

[Anonymous]

Great to hear you've found a solution.

Meanwhile I found the way the brim around the printer is drawn (think so). Maybe that's of some help:

It takes 1% of the bigger dimension, then "ceil"s it ( e.g. all values > 1  and <= 2 become 2, all values > 2 and <= 3 become 3, all values > 3 and <= 4 become 4 a.s.o ), then multiplies it by 10.

Let's say the printer is: 200 x 310

one percent of bigger dimension = 3.1

ceiled value = 4

multiplied by 10 = 40

the outer rectangle of the drawn printer = 240 x 350

one brim's width on one side = 20

import math

max_Dim = 310

b_max_Dim = max_Dim + math.ceil(max_Dim * 0.01)*10

print "length of the brim: ", b_max_Dim 
# Result should be: 350

[Anonymous]

Hello Andrew, have you ever succeeded in doing a forefoot with meshmixer?

I try with the attracted function but it is not successful.

Do you have a trick to achieve it, it would avoid one more step after the milling.

Thank you for the video you posted making a half insole. I did it a little bit differently but it's always good to see other ways.

[hfcandrew]

I'm not sure what you mean, but I'm sure I have. Can you send me screen shot or zip and attach the .mix file