Hi, I'm new and playing with 3D STL file imports

[NCFatboy]

I've imported an STL file, fairly simple, a board designed in CAD and exported. The design itself poses a problem for the Aspire software when generating Rough or Finish toolpaths. The particular board I am trying to carve is a 2 sided carve in which a pocket carved on the top side of the board goes below a pocket carved on the bottom of the board (they are in different places, so they do not create a hole). With the zero plane being the divider of the top side and the bottom side, there is no level at which I can place the zero plane so that both pockets are carved to their appropriate depth. I know I can create a separate pocket path for one or the other to 'fix' the issue. Have any of you run into this issue can you solve it with Rough or Finish Paths? I have tried setting it to the bottom, but it cannot generate a bottom path because it has no depth. I can obviously do top side tool paths in one file, and bottom side tool paths in another file.

I've also found that the Rough and Finish toolpaths are not exactly correct to the STL file due to the way Aspire imports the STL.

[Rcnewcomb]

Can you post a picture of the STL so we have a better idea?

Also, is this really a 3D machining operation or could everything actually be cut using profile, pocket, and drilling toolpaths?

[TReischl]

I've also found that the Rough and Finish toolpaths are not exactly correct to the STL file due to the way Aspire imports the STL.

STL files are controlled by the software that creates them for the most part. Doing things with STL files is never going to be exact. Two problems, the first is that any surface in STL is defined as triangles. There are no triangles on a true sphere. If the software outputs it in low res (which some do thinking that folks only use their fantastic product) not much you can do with it. The second problem is that mapping those triangles to a grayscale bitmap (which is what Aspire uses) is going to result in some minute inaccuracies. Think "raster", and how a curve looks when it is blown up and the jaggies magically appear.

[NCFatboy]

I cannot post a image due to client confidentiality, it's not that complicated. Yes, I can do all of it with pockets, drilling and profile paths. That was not the point, I have a parametric CAD design that can render any type of file for machining, yes, STL is all faces, I understand that. My interest is in generating prototypes of a product that will eventually be manufactured via CNC with STEP files. Just exploring Aspire's ability for 3D or in this case 2 sided solid object automated toolpathing. Disappointed I suppose that Aspire cannot import STEP files and produce accurate vectors. Was just asking to see if I am missing something. The only other possibility is slicing the model, but I really don't want to assemble slices. Seems the 3D capability of Aspire is fairly limited and accuracy is questionable.

Has anyone actually used Rough and Finish paths to carve a piece and determined the accuracy of say, a 1/4" drilled hole or if there are 4 1/4" drilled holes, do they vary in size or are they consistent?

[Adrian]

There are many different factors that determine the accuracy. Aspire is pixel based so it's important to get as many pixels as possible into the model. If, for instance, you define the workspace as 8' x 4' and then import an STL that is 6" square you're wasting a massive amount of pixels and hence detail.

At the end of the day using 3D toolpaths to cut something that should be done with a drilling toolpath is going to be very slow and a compromise in accuracy. That isn't a failure of Aspire. Any CNC CAM software provider would tell you to use the appropriate toolpath strategy for the best results and a 3D toolpath isn't the best strategy for work like that.

[NCFatboy]

Thanks Adrian, I get that, but I'm more interested in the 3D toolpathing, shame that it doesn't import STEP. I am importing to the exact size board that the STL represents and the 3D pathing isn't very accurate even on the border of the board. It's close.

[Rcnewcomb]

I am importing to the exact size board that the STL represents and the 3D pathing isn't very accurate even on the border of the board. It's close.

I'm a big fan of Vectric software, but in my opinion it may not be the best tool for this application of taking an STL and using that for prototyping what is essentially something that is done more accurately with 2D toolpaths. You will find yourself constantly fighting errors that are introduced when:

• exporting to STL
  converting the STL to essentially a bitmap representation in Aspire
  toolpathing which is a raster patterns rather than following the actual contours of the design

As a consequence dimensions will be slightly off, and vertical walls will not be smooth. Is the customer is willing to see the prototypes as approximate and with those flaws?

Otherwise doing the prototypes using 2D toolpaths would be faster and more accurate, but that assumes the CAD work is done with 2D toolpathing in mind, and you may not have control over that part of the process.

A 3D printer for creating the prototypes might be another solution.

When the design is finalized will the parts be produced on a CNC? If so, how will you go about getting the 2D toolpaths to be able to do volume production?

[NCFatboy]

It's too large for 3D Printing. Yes, I agree with you on the toolpathing, the Vectric Toolpathing is useless for production. I will have to re-toolpath it from a STEP file and other software. Again, I am just experimenting with the Aspire 3D features and find it lacking. I was just asking to see if I was missing something. I do not see the 3D capabilities of Aspire as useful, especially with the time estimates for the Finish toolpath. Since I am new to Aspire, I was just trying to find out if my findings were correct or if an expert with Aspire could suggest solutions. I have already done the 2D toolpaths now so I am good to go with loading them up and making a prototype.

One more thing I discovered while making the toolpaths, is Aspire is fairly buggy with regards to tool usage on the Bitmap Height. The most annoying two things are the changing of the Bitmap Height rendering when selecting a portion of the image that I wanted to use as a guide. When choosing the line tool, the image changes and what I wanted to draw around disappeared. The second is that vector selecting when the vector is overlayed on the bitmap doesn't even come close to working correctly. Single left click doesn't select a vector. I can select an area of vectors by pulling a selection rectangle, but shift-click does not deselect a vector, it does nothing. Pulling a rectangle with shift does not deselect either, not if you pull from top left to bottom right. It only works if you pull from bottom right to top left. These make it very difficult to even utilize the 3D Model import as a guide to creating a close to accurate manual toolpath. I accomplished it by this means, but it was tedious and frustrating. There are many bug fixes needed when in 3D model rendering mode.

I appreciate the input guys, I was just trying to determine the usefulness of the 3D features (which I now find, at least for this application useless). It would have been easier to just import an rendered flat image of the design and work from that to draw the manual toolpaths considering the user interface bugs in 3D mode.

I would be interested to know what applications anyone has found in which the 3D features are useful.

John

[dealguy11]

Wow, that's a lot of incendiary and, frankly, incorrect statements in one post. I won't try to hit them all, but I'll point out that many people, including me, use Aspire for production work very successfully every day. If you refuse to use the tool as intended, then it doesn't follow that it is a useless tool.

A great example of this is the comment regarding how the image changes when you choose the line tool. This is not a bug, and it is controllable behavior by changing "Fading of non-selected bitmap" under Object Properties in the right-click menu for the component.

Same thing with your discussion of direction of selection when selecting vectors. Did you even look at the tutorials? Top left to bottom right selects vectors completely contained in the box. Bottom right to top left selects whatever the selection box touches.

The 3d features of Aspire are intended primarily for carving organic type models, not for the kind of machining you're apparently intending to do. For that kind of machining, 2d toolpaths are your best bet - they are faster and cleaner for that type of work.

[mtylerfl]

It appears John is still in the early learning stages. I too was surprised by the incorrect statements and conclusions made. Perhaps after watching the excellent tutorials and some more hands-on experience, this will change.

Too bad we cannot see the actual file and STL model he is importing. I'm sure many of us could be of more specific help. Unfortunately, we're somewhat "in the dark" and are forced to guess and respond in general terms that don't seem to help John much.

[LittleGreyMan]

It seems you are trying to produce a mechanical part with Aspire 3d toolpaths. Bad move, as Aspire is not intended for that. It will be fine if you use 2D toolpaths if it's a 2.5 D part as we can presume from your posts.

You even don't need Aspire for that, as it brings organic 3D design tools that won't be of any use. There are less pricey products in Vectric's products range.

You may use other CAM software that will produce a better 3D result because they offer other toolpaths types (as Z level finishing). But it will not produce efficient toolpath for 2.5D machining. It may be interesting if you are not concerned with the prototype machining time. In this case, 3D CAM will be a little quicker and safer than 2.5D CAM.

There are some CAM package that use automatic shape recognition on 3D shapes and generate 2.5D toolpaths for these shapes instead of 3D toolpaths.

But in no case you can pretend that Aspire is not a good software, or it is buggy, simply because you don't understand its behavior, didn't read the excellent manual nor watched the great video tutorials.

I'm in no way affiliated with Vectric, and I use several CAD and CAM systems. I can tell you Vectric products are very reliable and very good products to do the work they are designed for.

If you want to use a saw instead of a hammer, don't blame the saw if it doesn't suit your needs.

[mtylerfl]

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[mtylerfl]

Hi John,

Is it possible you could show us a screenshot of the part you are trying to make? Maybe you could get permission from your client and explain to him/her it's solely for the purpose of getting assistance with the making of this part.

I still feel like we are taking wild guesses as to what the best method will be to yield a high-quality prototype for your client. We just don't know for sure how to help, since we haven't seen exactly what you're making.

I don't want to be critical - I want to be able to offer good advice and assistance.

[martin54]

I understand that posting on a public forum is a problem for copyright/client confidentiality reasons but have you spoken with Vectric support about the problems you are encountering ?

The forum is mainly for user to user help & provides a good resource for most people but as Michael has said it is difficult when you don't know exactly how best to try & help. Contacting Vectric support in this instance is probably a much better idea.

One thing I have learnt through my job is that there is no such thing as a one size fits all software, it may be that Aspire is not the best option for your particular application but I would hardly say that means it is useless for 3D, I know a couple of guys through other forums I use that run production shops who run a range of different software, some very expensive. Which software they use depends entirely on the type of job they are doing. They both own & use Aspire BUT only for the type of job it is suited for

support@vectric.com

[Rcnewcomb]

I would be interested to know what applications anyone has found in which the 3D features are useful.

This is a fair question.

The 3D features are great for bas relief work for plaques, cabinets, signs, memorial containers, and fireplace mantels.