Assistance Please - CAD for a 3D Block??

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drmacro
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Re: Assistance Please - CAD for a 3D Block??

Post by drmacro » Thu Nov 19, 2020 7:38 pm

A pad operation adds material in the shape of the sketch (in the first case the sketch has a hole so it adds in that shape, assuming the hole is meant to be a void).

if you already have a solid (you do) and you want the sketch to represent a hole in the solid, then you must remove a pocket...in the shape of a circle.

my first guess on your base solid error is the sketch is visible and you selected the sketch edge for the fillet, rather than the edge of the solid. (I'm on a phone, so can't check k your file...)
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CRMS
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Re: Assistance Please - CAD for a 3D Block??

Post by CRMS » Fri Nov 20, 2020 12:35 pm

I've got a block with 2 holes and fillets. Last night got 4 filleted edges, but rear end of Second cylinder wasn't a hole. In an stl viewer, the triangles went straight across the hole.
So, removed all the fillets, changed FR cylinder to 42 mm, as recommended in manual, to stick out at either end. And hole right through, confirmed in stl viewer.
Then couldn't get the fillets back on.
A few seconds/minute later just having Block at the top selected, they went on. And in the tree view the fillets are at the top under block, rather than under the last operation - FR12.5mm, which is where they were before. Which has a green blob on it - trawling through manual to find out what green blob means???
Exporting to stl, I'm running into "nothing selected". Seems that the last operation needs to be selected, rather than the xxxxBlock at the top, or even Body halfway down??
Seems that perhaps PC power has something to do with it - Miscrosoft Surface Laptop 3 i51035G7/8GB/256GB SSD

Have I missed anything??


20201120Block2.jpg
20201120Block2.jpg (114.29 KiB) Viewed 152 times
Quite a learning curve - and part is for a mast/boom gooseneck to be 3D printed in Nylon/Chopped Carbon Fibre filament. But now will try and reduce the volume to look more like the black block:

gooseneck block.jpg
gooseneck block.jpg (9.84 KiB) Viewed 152 times

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22988 (Git)
Build type: Release
Branch: master
Hash: cdc01cb20cfa74079c45b9dc2dab81e3248b2aa5
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
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Bance
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Re: Assistance Please - CAD for a 3D Block??

Post by Bance » Fri Nov 20, 2020 2:19 pm

What's wrong with the fillet in Part Design WB?

By the way I wouldn't rely on anything 3D printed to hold a boom to a mast, leastways not if I expected it to stay connected.
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CRMS
Posts: 27
Joined: Sat Nov 14, 2020 1:10 pm

Re: Assistance Please - CAD for a 3D Block??

Post by CRMS » Fri Nov 20, 2020 2:29 pm

>What's wrong with the fillet in Part Design WB?

I was in PDWB, I think, when I added the fillets:

The block is not for a sailing gooseneck. I've already got something made from NCCF and it is pretty tough.

20201120BlockPDWB.jpg
20201120BlockPDWB.jpg (109.58 KiB) Viewed 122 times
Bance
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Re: Assistance Please - CAD for a 3D Block??

Post by Bance » Fri Nov 20, 2020 2:41 pm

You clearly were not in PDWB, compare the two files.

Green marker shows the "TIP".
Bance
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Re: Assistance Please - CAD for a 3D Block??

Post by Bance » Fri Nov 20, 2020 3:06 pm

How about trying a revolve?
block.png
block.png (60.58 KiB) Viewed 89 times
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CRMS
Posts: 27
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Re: Assistance Please - CAD for a 3D Block??

Post by CRMS » Fri Nov 20, 2020 3:22 pm

>Revolve...

Looks well smart. I'll have a play.

>Green marker shows the "TIP".
And that appears to be the last feature added, which did make some sense, but the fillets were added after the FR12.5mm sketch??
The jpg doesn't show PDWB, but on the start WB there wasn't a fillet icon.
Bance
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Re: Assistance Please - CAD for a 3D Block??

Post by Bance » Fri Nov 20, 2020 3:48 pm

In the screenshot above it can be clearly seen that the fillets are outside of the body, and have the Part WB icon Image

and not the PDWB fillet icon. Image

I presume you know how to analyse an example file?
Dougl
Posts: 39
Joined: Thu Oct 01, 2020 6:08 pm

Re: Assistance Please - CAD for a 3D Block??

Post by Dougl » Fri Nov 20, 2020 5:06 pm

Bance wrote:
Fri Nov 20, 2020 3:06 pm
How about trying a revolve?

block.png
Why did you also pocket the holes when the holes were created already by the revolved sketch design?

PS, your posted example is much appreciated as it helps me work on snapping out of my tendency to think of 3D primitives first when I should be thinking in 2D profiles. I too would have approached this as the OP has and tried to work backwards to what you'd done so much more elegantly.
Doug
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Bance
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Location: London

Re: Assistance Please - CAD for a 3D Block??

Post by Bance » Fri Nov 20, 2020 5:17 pm

If you delete the pockets, you can see the reason.
It could be more elegant, there is no need for the datum line, since I needed to pocket anyway I'd have revolved solid and used one of the sketch lines as ref.
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