Can't cut a solid
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I am trying to model a wooden propeller for an rc airplane in Sketchup. I got my information from this link: http://www.nmine.com/propeller.htm. A person at this site made one in Solidworks.
I can do fine until I try to cut the hub. I covered the sections with Fredo6 Curviloft and closed the ends. Sketchup recognizes this as a solid. I have tried intersect with model. This leaves an open shell. Tried zorro. This crashes SU most of the time and when it doesn't it just leaves a mess. I have tried to subtract solids. Usually the propeller will go away and only the subtract is left.
The closest I have been is using the plugin "Trim and Keep". It looks pretty good when this is used. But it is not a solid any more. I run Fix Solids and it says 5000 things fixed 15 not fixed. I am then locked down.
I would appreciate any help with this problem. I have attached the model to show what I am talking about. The blocks laying around in the drawing are what I have been using to try to cut the propeller.
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Sketchup has trouble with small faces. Try scaling up your model by 100x, perform the trim operation, then scale back down.
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Worked!!
Thank you d12dozr.I scaled up to 100 and it still gave problems. I thought I was at a dead end again. I scaled the 100 up 10x more. Now I am at 1000. Tried the cut and it worked. Still ok after both side cuts. I thought surely I can get by with less than 1000. I then tried 200 and it worked. I made both side cuts and scaled back down. The prop was 5" tall and still showing to be a solid. I still have the top and bottom cuts to make but I feel certain it will work.
Thanks again.
Steve
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I wish I could figure out you want this cut. I use another plugin, hole in solids as a trimming or cutting. Would like to see if it worked but I don't know how you wish to make the cut.
Ken
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Ken,
I will try to explain the cut the best I can. If you look at the blocks laying around you will see a left hand and a right hand. If you put the 2 blocks together the arcs will be facing each other and together will make the complete side cuts. There is a line under the propeller blade. The airfoils to make up the blade was stacked on this line on their center of gravity. The line extended 5" up from the base. The way I am cutting is first place a center line on the block, the small section under the arc, then moving the blade and the line, using the end of the line at the base of the blade as the moving point, to the top of the center line that was just placed. This will embed part of the base of the blade in the block. The block might have to be widened a little to keep part of the base from sticking out. Then I use Trim and Keep to cut the base. If you look at the link above and see how it was done in Solidworks it will make much more sense. Both sides were cut in Solidworks but I'm cutting 1 at a time.
I am still not quite out of the woods yet. Every time I scale my part back down again it is so small I lose it out in space somewhere. I got to try to figure how to keep it in sight and get back to somewhere close 0,0,0.
Steve
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Here's how to make the scaling easy...
-start from your real-world scale
-draw a line exactly 1" long near 0,0,0
-Using the text tool, click the midpoint of the line so it says 1" then click in space. This marks the line so its easy to find and so you remember how long it is supposed to be.
-get the tape measure tool. Click one end of the 1" line, then the other. Type '200' and hit enter...sketchup will ask if you want to resize the model...say yes. Now the model is scaled up 200x.
-do your trim work
-get your tape measure tool, click one end of your 1" reference line (that is now 200" long), then click the other end and type '1' and hit enter...sketchup will ask if you want to resize the model...say yes. Now the model is back at the original scale, no muss, no fuss!Happy Sketching, and ask back here if you have any other q's!
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That's great d12dozr. I didn't know the tape measure could be used for scaling. I thought you had to use the scaling tool. I posted a reply about the same time you did that I had found out how to move precisely using absolute coordinates but apparently it didn't go. This way is much better.
Thanks again.
Steve
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For anyone who might be interested, I have attached a model with the finished propeller. Now if I had gcode for it I could cut it on my DIY CNC router.
Steve
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