Hello, I've been lurking around these forums for about a month now trying to learn as much as I can before I order my Phlatprinter. I've already purchased all the electronics and software. All that is left is to finish the Opto-breakout board and order the printer. I'll be ordering a MKII the middle of August (Birthday present to myself). So to get ready I was trying to put somthing together in sketchup and export the Phlatcode to run in Mach3.
I saw the Phlatfoil and was inspired to make a 'universal' wing I could use over and over on different projects and I liked that it was a one piece built up structure. I've been using Rhino3d for years and so that's where I started, then exported a .dxf to sketchup. After cleaning up the curves I didn't find anything else wrong with it. I set some inside cutouts up and generated the phlatcode. In Mach3 they looked good. After adding some more cuts to the phlatcode (outside, and folds) the first inside cuts became lots of little separate cuts in Mach3. I tried 'ordering' them with the phlatscript and it worked as long as I didn't group them with anything else, or if they were the only things being generated inthe phlatcode. I'm assuming its something simple I'm missing. If someone could look at the Sketchup file and tell me if its something wrong in there, or something I'm doing (or not doing) wrong.




As I was posting these, I realized that I had cleared out all the cuts from the sketchup file, oops. Attached files SelfRibbedWing.skp (314.6 KB)Â

 

First of all, there can be alot of problem with importing dxf into sketchup. It's best when you start learning how to use the phlatscript, to not do that and draw you model in sketchup. You could just do a simply drawing to test things out. Say just one airfoil, a box and a fold line, to see if it works.

Without the cut lines, it's kind of hard to tell where your trouble is. You can try again and post when you get stuck.

I would have assumed it's the airfoil and holes, when you are referring to your 1st internal cuts. But how are you getting inside cut lines, without a surface. All openings should be filled ,for the phlatscript to work. Actually drawing the airfoil slot is probably not the way to go. If you look at Marks phatfoil drawing, it's just a single contour line. Also, why is there a line in the holes?

I am no expert. Just starting my MK2 build myself, so not a huge amount of plans experience. But just keep posting your progress and people will chime in to help.

-Kwok

 

First off all the inside cuts need faces. I have also notice when your centerlines go clear to an outside edge, you need to make them fold lines or your outside cuts get all boogered up.
Interesting design though. I messed with it a bit and found out you have to use a 1/16ths bit to make this cut work.
After I made the faces and posted the G-code it seems fine to me, I didn't set the order or group anything so it isn't optimized. Attached files SelfRibbedWing.cnc (28.2 KB)Â SelfRibbedWing.skp (764.7 KB)Â

 

I still have not found any strange things with importing the .DXF files I get out of rhino, if I select the Project to Plane option on the export dialog. Otherwise I've noticed a few lines not quite lining up.

I did have a surface for those inside cuts but when I removed the phlatscript lines I removed those too and forgot to add them back in. I also had originaly done a contor line and used the centerline tool for the airfoil 'ribs' to be cut out but started to experiment with a slot and a inside cut after haveing some trouble with the output. The circular holes came out fine as one complete cut each as long as I didn't group them. As soon as I grouped them they would be several separate cuts which was the main thing I didn't understand. The line in the holes is how I drew them. When importing the .DXF all the curves came out very 'coarse' so I redrew them all in SU7 so they would be smooth. The line was an easy way to get the center and radius of a circle.

The fold lines were shortened by the fold tool so they didn't go all the way to the edge, but when I reverted everthing back they went back to the full width.

My inside cuts still get all broken up if I group them with a centerline cut. That's still the thing I don't know why it's happening.

I did fix all my other problems. Some things I just figured out that I seemed to have missed when watching some of the tutorial is that
1: Centerline and Fold cuts go in the same direction that you drew the line (in the same order that you clicked the points for the line)
2: Centerline and Fold cuts are ordered in the phlatscript in the same order that you create them(unless you do grouping to change that order)
3: Outside and Inside cuts start at the first point of the last line that completed the surface.


By using those 3 bits of knowledge I redid the sketchup model and generated optimised phlatcode without grouping anything or editing the g-code in any way. I of course still can't cut it out to see if the whole thing can be put together but if someone else wants to try, I'll happily fix any problems they find with it. Once I know it works I'll put it up in the downloads section. Attached files SelfRibbedWing.cnc (23.4 KB)Â SelfRibbedWing.skp (681.5 KB)Â

 

Thanks so much for cutting that out, it makes it even harder to wait to order my own MkII. I can see that I need to add more material inbetween the fold lines that form the leading edge of the wing. That should help the skin line up better at the back edge. Looks to be about 1/2" off from the picture. Also it should make the leading edge a little more rounded. The reason the main spar doesn't sit all the way down to the bottom of the wing is because I was planning for a 1/4 carbon tube to go there. I have a whole bunch of those fro HC laying around and designed around that. Of course I could do it with two foam spars and no carbon tubes and it should still be very strong. I use the carbon tubes in other things so that I can make removable wing halves.
I did not know that about the v-tabs, but its an easy fix.
Hopefully when everything is adjusted to line up I'll be able to take same sketchup file and Skew the bottom and top half of the wing from the leading edge and make a swept back wing without haveing to change anything else. There's enough room on the sheet to get about a 22 degree sweep I think.

BTW, has anyone else had the problem with the grouped inside cuts not coming out right? I'll try making an example file and posting it now that I kinda understand when it's happening.

 

Ok, I stuck together an example of the problem I was having. The sketchup file contains a box with a circle and an arc in it. The box is an Outside cut, the circle an inside cut and the arc a centerline cut. I made two .cnc files from it, the first was with no grouping and the second all I did was group the inside and centerline cut. You can see in the phaltscript files that the inside cut is broken up when it gets grouped.

Attached files Grouped.cnc (1.6 KB)Â No_Group.cnc (1.2 KB)Â Test.skp (173.4 KB)Â

 

Not sure what is going on, but I can't duplicate your error. I see the difference (saw it jump around the circle during the sim) in your two cut files, but mine are fine. Same exact size, in fact, unless I messed up the test. You can have a look at my files:

Attached files My test_arc & circle grouped together.skp (23.8 KB)Â My test_arc & circle grouped.cnc (1.2 KB)Â My test_arc & circle ungrouped.cnc (1.2 KB)Â

 

I should have check you sketchup file, 1st. So I just did that and I don't have a problem with it, either. Am I understanding right, just group the arc and circle as a group?

 

yes, all I did after generating the No_Group file is group the cut lines for the circle and arc then generate the Grouped file.
All I selected were the cut lines, I didn't select the surface of the inside cut, could that have anything to do with it?

 

That might be it, because I selected everything with a box. Try my sketchup file and generate a cut file. It's already grouped that way.

 

Ok, after experimenting with it I have to select everything with the inside cut to get it to come out right when grouped. So that means the original outline, the original surface, the inside cut line and the surface it creates. It appears if I leave any of those out of the group it doesn't keep the cuts continuous. I guess it's getting a "start" point for the line from the parent object(the original circle outline) and is getting that start point tranfered through each of the child object untill it gets to the cut line. So if you remove any of the child object you break the chain and it doesn't know where to start and instead looks at them as a bunch of individual cuts. Of course I could be wrong.

Anyways, time to go back to getting that SelfRibbed wing adjusted to work right. BTW, I am assuming that the cut area is limited to 42" because the printer needs those extra 6" from the 4 foot sheet to hold on to. So I could use a longer safe cutting area if I specified taping an extension onto the foam sheet, right?

 

Yes, you are supposed to have infinite length in the long (X) direction.