.ipt to .dwg export problems

[Squawk]

I'm a noob, but with help from people on this forum and other peoples Q&A I was able to make a foam inlay for in a case.

Then I devided the foam inlay in 4 layers and made a new part from those.

So far, so good..

The last step was to export the top of those 4 layers as .dwg files so that they could be cut out by a machine.

I made a new sketch on the top surface of each layer and used 'projected geometry' to draw all the planned cuts in this new sketch. I have to adjust the thickness of some of the foam cutouts and glue it back in to make different levels of depth in one level. So there are more planned cuts than just lines on the top of the sketch.

Either way, I could do it and ended up with 4 .dwg files (one for each layer) with all the lines on them that needed to be cut.

After all the work, and finally being my projects turn to be cut, the water cutter wrote me the message that the .dwg files were no good, because: they consisted out of points and non-joined lines. The different lines didn't seem to be connected..

I have since googled, experimented and lord knows what. But couldn't both see what he meant and neither find any solution to the problem.

I hope I could explain my problem well enough for you all to understand and really hope that there is a solution for this.

Thanks in advance for all te help!

Squawk

(Attached is the .ipt file of the top layer and the .dwg file I made from it.)

[ampster401]

judging by your description (I did not examine your files), you might be doing too much work by creating unneeded sketches - assuming your part files are made to scale and already include all cut out features (as they should)

1. Separate out each layer into it's own part file.

2. Using those part files, create a drawing of each layer, just providing the top view on each drawing.  There should be no need to sketch anything else here, all details should have already been incorporated into your solid model.

3. Then save those out as "AutoCAD .dwg" files.

4. Open those in Acad, and confirm the patterns are good for cnc/plasma/laser/water cutter work by running the pedit command for example on the geometry, converting everything into polylines and then use the Join option within the pedit command, and perhaps relocating the geometry so that the lower left corner resides at, on or near 0,0 (sometimes that's needed)

5. If needed, you could move the geometry over to required layers that the water cutter needs to see at this stage.

By running the Join command within the pedit command, that will ensure all end points are connected as they should be and not be separated by a gap.

HTH

[Squawk]

Hello HTH, thank you for your help!

Ok, this is until where I can get..

1. Separate out each layer into it's own part file.

-> Done. I have 1 big foam inlay of 17 cm devided into 4 layers (4, 4, 4, and 5 cm)

2. Using those part files, create a drawing of each layer, just providing the top view on each drawing.  There should be no need to sketch anything else here, all details should have already been incorporated into your solid model.

-> Yes, all the details are incorporated into the solid model (each foam layer, see picture attached). But how can I create a drawing of the top each layer without making that drawing in a new sketch? 

Best regards,

Squawk

 

[Squawk]

Is this what you meant with "create a drawing"?

Then how would I remove the inner dotted outline of the case? (The .ipt part file is tapered a bit, I need only the cut of the top, or widest part, of the .ipt part file.)

[Squawk]

2. Using those part files, create a drawing of each layer, just providing the top view on each drawing.  There should be no need to sketch anything else here, all details should have already been incorporated into your solid model.

-> Done! (I think..) I made a drawing from it (as in the yellow picture above here) and saved it as a AutoCAD .dwg file. Then I opened it up (in AutoCAD Mechanical) and deleted those dotted lines (small tapered shape of the case outline).

3. Then save those out as "AutoCAD .dwg" files.

-> Done! So I now have a 2D AutoCAD .dwg file of my part.

4. Open those in Acad, and confirm the patterns are good for cnc/plasma/laser/water cutter work by running the pedit command for example on the geometry, converting everything into polylines and then use the Join option within the pedit command, and perhaps relocating the geometry so that the lower left corner resides at, on or near 0,0 (sometimes that's needed)

-> Going step by step, I have to google this cause I have no idea what you're even talking about.. (sorry.. :-s)

[ampster401]

Ok, it sounds like you made it as far as realizing you do not have to create a sketch just so it shows up in the drawing.  Simply placing a Top "Base" view of each layer on their own individual drawing will automatically produce what you were sketching manually.

As for your statement; "Then how would I remove the inner dotted outline of the case? (The .ipt part file is tapered a bit, I need only the cut of the top, or widest part, of the .ipt part file.)"

If I understand correctly, you can easily remove or erase portions of any pattern you do not need from the AutoCAD side of this process.  I would recommend doing this in Acad and not Inventor.  So just delete the dotted line portion which will leave you with a profile of the foam shape without the tapered edge.

I believe the pedit command is in AutoCAD Mechanical.  Come back to this thread if you have any questions about what to do in Acad Mech.

Step #4 I mentioned above was just a rough generalization of some of the common things I've done in the past to confirm a cnc pattern was valid and I've sort of gotten accustom to checking all the time when sending anything to cnc/plasma/water jet/etc - to avoid what happened to you...or at least try to avoid by doing all of that!

"HTH" stands for "Hope This Helps"

Steve

[Squawk]

Hello Steve,

Thanks again for your help!

Ok, off topic, but now I know 'HTH' is not your alias.. lol..

Well, I've been able to figure out and complete step 1 to 3.

And in tthe process of doing step 4. There are 2 things I don't understand still..

Could you look at this screenshot:

1. You see I've made, and joined, a polyline of this outlay where the crosshair is at. But as you can see, not all the lines are joined. There are 2 round lines and a cakepiece on the left bottom that are not included.

How can I include those?

2. Is it nessesary to 'join' all polylines? Or is it also ok to just make the lines into polylines without joining them (like the round circle in the slightly middle left of the screenshot)?

HYCH

(Hope You Can Help.. ;-))

[blair]

It sounds like you are trying to get your IPT model to be cut by a CNC waterjet machine. Just RMB on the face of the part and select Export Face. This will get you the DXF of the face which you can then import into the software to cut your foam.

[mcgyvr]

I highly doubt they are going to be doing "pocket milling" with a waterjet..

Each layer must be cut completely through the material.. 

So your layers are incorrect from the start based on the first image I saw.

[Squawk]

Thanks for your reply!

The layers are not incorrect.

The idea is to cut on all the lines. This indeed goes through and through. But the foam will keep being pressed into it's larger body.

After all the lines are cut, I will push the idividual parts out. some will be made thinner and glued back in on the lower layer.

This will create the possibility to have thinner walls between the compartiments (not possible with CNC) but still be able to make various levels.

It is therefor essential that all the cuts are made, not just the ones on the face, but also the ones deeper down the surface of the foam layer.

Hence my initial try to use projected geometry on a new sketch and export that to a .dwg file.

Now, thanks to Steve, I was able to do it quicker and directly make a drawing from the part (containing all the cut lines) and saving that into a .dwg file.

I only had to edit the tapered slimmer section of the foam that follows the case (since the case is somewhat tapered).

Now I'm in the process of turning all the lines of that .dwg CAD file into polylines, so the watercutter can load them into his machine.

[Squawk]

I hope you guys can bear with me.. I'm almost done! 🙂

Ok, I've managed to have all the parts inside the foam converted to polylines, also the part I was asking about a few posts ago.

The only thing I can't convert though, is the case shape (outside line) of the drawing.

Both selecting a whole area as selecting all the individual lines will not turn and join the outside into 1 polyline.

when trying so individually convert a curve to a polyline, I get this message:

(For clearity, I've attached the full image to this message.)

Is this the reason I can't select all of them at once?

And what do I fill in here?

Thanks for any help!

[Curtis_Waguespack]

Hi Squawk,

The red curves in this image shows splines. You can likely just delete them and draw in arcs to get past this. Or at least this is what I do when I encounter the same issue. But there might be a better way.

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

[ampster401]

for an even quicker solution to creating the individual .dwg files, I'd use Blair's suggestion to right-click on a face and choose Export face.  That will help you next time.  I've been out of production use of Inventor for so long now that some of these things are new to me as well.

Some plasma /cnc/systems need to have everything changed over to polylines, some do not.  When I created patterns over 10 yrs ago it was a requirement on that particular plasma cutter.

But changing everything over to polylines and then using the Join command within pedit just basically allows you to confirm the patterns are good and there are no gaps and the pattern will go from "start to finish" without any interuptions.

Judging by your last screenshot, it appears as if you have already gone past the "Specify a precision" portion at least once and are now back in it.  I believe the specify a precision prompt has to do with an allowable gap, hopefully someone else can confirm that.

I've grabbed a copy of the last dwg file you've attached to this thread and will open it up and inspect for a bit then come back with questions and/or suggestions.

I think someone else mentioned you won't be able to cut "pockets" with a water cutter, so what may need to be done is you'll need more individual patterns than what you currently have possibly.

[Squawk]

Thanks Curtis,

But what is a 'spline'? Is it bad to have one in your drawing?

Best regards,

Squawk

[Squawk]

Thanks Steve,

I will await your comments after viewing my .dwg file. Really appreciate it! 🙂

And yes that is correct. Those pockets need to be cut through and through.

I will modify the cutouts to make levels (pockets) and glue them back in (glued to the side and the other lower foam layers).

Best regards,

Squawk

[ampster401]

splines can be nasty when considered for using for cnc/plasma, etc as it's made up of many nodes or points, usually too much for for what ever system they are being used to cut something with.  I'd guess there may not be a cnc system out there that can work with splines as most of the time when patterns containing splines are used they are sent back to be redone.

Besides what Curtis mentioned on the splines (they should be converted to polylines - redraw them as suggested since they are just arcs/corners and do not have to "be exact") I'd look into most of the areas I've highlighted in red below, and perhaps areas nearby those red areas (to determine what the pattern should really be like in those areas).  Those areas need to be researched as to how you'd expect those cuts to happen and not have anything fall out, ie, this may be an area where you determine you need yet another individual pattern to get those cutouts or shapes as you expect.

Edit, I see you have replied already and are aware of those pockets.  Go ahead then and edit the existing pattern to what you believe will be the final edit then load it up here so we can take a look and hopefully stop any questions or having it rejected by the water cutter operator.

[Squawk]

Thank you for your reply and your time Steve!

I made what you have turned into red lines as seperate (connected) polylines. Except the ones that share the main body (left top and left bottom).

Because the cutter let me know they can make a "cut cake" cutout where the cake is divided into parts from the centre to the edge of the cake circle.

So he should be able to make just 'line' cuts starting on a point shared by a contineous polyline.

All the parts you turned red have been made polylines.

My present problem.. ehh.. challenge, are the lines Curtis turned red.

I cannot make the outerline defining the case dimensions as a contineous polyline.

And my skill of AutoCAD (which is less than in inventor) is not so good that I can just delete those curves and redraw them..

I tried but the result was very strange.

Somebody posted this, but I can't get follow the same actions:

https://forums.autodesk.com/t5/autocad-2010-2011-2012/problems-joining-polylines-together/m-p/335248...

[Curtis_Waguespack]

Hi Squawk,

I'm short on time, so here are a couple of quick tips:

You can select everything in the drawing and then Press CTRL + 1 on the keyboard to bring up the Properties Pallet. This will allow you to find the Splines and Elispes (I didn't mention the elispes earlier, but they will not convert to a Polyline either.) Then you can use the color menu to change the color to see them stand out from the rest.

To create the arcs you can just trace over the splines using the ARC command, by choosing the Start point, Mid Point, End point:

http://docs.autodesk.com/ACD/2010/ENU/AutoCAD%202010%20User%20Documentation/index.html?url=WS1a91938...

https://www.youtube.com/watch?v=lIpWVYj4Mvo

Attached is a version of your DXF with the outer Polyline created.

I hope this helps.
Best of luck to you in all of your Inventor AutoCAD pursuits,
Curtis
http://inventortrenches.blogspot.com

[Squawk]

Thank you for your extensive tips and suggestions!

I have to get up again in 7 1/2 hours for work again, so I should hit the sack, but it will be the first thing I will try and look at when I come back!

Many thanks!

Squawk

[Squawk]

Curtis, I'm getting so close to being able to finish this myself, but I have 3 questions..

1.

I managed to do the arc thing. From the youtube video I figured out why I initially got such strange results. It works a bit different from Inventor.

I had to use the 'start - end - radius' option of the arc feature, because the 3-point didn't give me the correct result. 3-Point would have been the logical choice in Inventor..

However, since I can't just draw the arc's in 'nowhere', I have to overdraw it on the original lines. This way they are identical.

The only thing is, how do I delete the original line under the newly drawed line without/instead of deleting the newly drawed line?

2.

And also, why if I draw such an arc (or any line) in AutoCAD, will it not automatically be a polyline?

3.

How do I turn the circle in a polyline?