Thank you for the details!ppemawm wrote: ↑Tue Jul 24, 2018 9:18 pm
The drawing shows two, one larger half outer helix, and a smaller inner helix on different centerlines. The wrap of the inner helix was adjusted to align the horizontal pad with the valve cap, the horizontal pad was trimmed at the valve cap centerline, and finally, a quarter revolve around the cap finished it off. Not as tricky as it may appear.
V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #6
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Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
- tanderson69
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Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
I don't think you can do this in freecad but occt did make this variable blend.
- Attachments
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- rockerTA01.brep.zip
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Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
Feature request
- microelly2
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Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
I put the problem into my testcase collection.
I have to extend my face connect to cyclic nurbs to get a smooth connect.
https://forum.freecadweb.org/viewtopic. ... 10#p246470
The idea than is like in Blender: open two round holes in the cylinders and connect them by a nurbs tube.
I have to extend my face connect to cyclic nurbs to get a smooth connect.
https://forum.freecadweb.org/viewtopic. ... 10#p246470
The idea than is like in Blender: open two round holes in the cylinders and connect them by a nurbs tube.
Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
NormandC wrote: ↑Tue Jul 24, 2018 7:04 pm Unfortunately, this sweep is not perfect. The rear is not perfectly straight. Just to find out, I placed a large cube tangent to both cylinders and made a Part Cut.
You can see where the sweep was exceeding the line, the cut generated two planar faces (in grey).
I solved these two things that were bugging me.
I changed the AdditiveLoft for an AdditivePipe, no good reason, I just wanted to have a planar face underneath so a refine would work with the other faces (Loft never creates planar faces between sections). I know, it's silly since this planar face is going to get consumed by the mirror! For the second AdditivePipe, the solution to making it straight at the rear was ridiculously simple: rather than use the front arc as path, use the rear straight edge. Duh!
To make the fillets succeed, I had to sacrifice tangency of all the ends between the cylinders. In the master sketch, I made the circle 0.01mm smaller in radius.
Now I have a mirrored model entirely made in PartDesign. And it has a smaller file size.
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- ppemawm_exhaust_rocking_lever_test_nc2.fcstd
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Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
Thanks NormandC for the follow-up.
I must say that every time I read one of your posts I learn something new.
One question, why use datum planes in this example if you can attach the sketches in the same manner?
Note: The 3 mm fillet fails on Recompute in my version which is a bit behind the latest.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.13983 (Git)
Build type: Release
Branch: master
Hash: 8f1c6f77c090ae7d9c2bfd4f18811083b01a3eb2
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)
"It is a poor workman who blames his tools..."
Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
Ah, for convenience, mostly. I haven't found a way to directly attach a new sketch to anything else but a plane. So without using a datum plane, I'd have to first create a new sketch on a plane, close it then edit its attachment mode, and finally go back to sketch editing mode. It's a hassle.
I'm not surprised. Before adding the Mirrored feature, I tested fillets first; I couldn't make a 3mm fillet there successfully, the highest it would go was 2.9.
After the Mirrored, the 3mm fillet worked, and I ran with it... Should have checked. OCC's fillets are sure finicky.
I worked in 0.17.13522 on Ubuntu, on which OCC was recently upgraded to 7.3.0. I don't know if it could be related.
Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
Totally agree but do not like the idea of all the extra baggage of datum planes if not needed, especially in a project of this size.
What I have been doing (after about 500+ sketches you can do it in your sleep):
Create sketch.
Select any plane.
Slow double click Okay button. This opens and closes the sketch.
Open the map mode in the Property Panel.
Set attachment mode and offset.
Reopen sketch.
It's a hassle, indeed.
"It is a poor workman who blames his tools..."
Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #2
I understand completely! I only did a 550KB part, not a 116MB mammoth assembly!
Just tested with the 0.17.13522 AppImage, which is based on OCC 7.2.0. After a recompute, same as you, the 3mm Fillet feature breaks. The biggest value it will accept is 2.90mm.
With OCC 7.3.0, no problem recomputing; but 3.2mm is the highest possible value, over that the Fillet fails.
OS: Ubuntu 18.04.1 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13528 (Git)
Build type: None
Branch: releases/FreeCAD-0-17
Hash: 5c3f7bf8ec51e2c7187789f7edba71a7aa82a88b
Python version: 2.7.15rc1
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: French/Canada (fr_CA)
Re: V0.18 Challenge--Clerget 9B Aero Engine--UPDATE #3
The engine proper is finally beginning to come together. All of the major subassemblies are now complete with the exception of the remaining accessories (oil/air pumps and magnetos). The last assembly to be completed were the reciprocating components: piston assembly, master connecting rod, and the slave rods. These were all quite straight forward except for some filleting of the master/slave rods which I simply could not model with a valid solid.
A few screenshots of the recent progress with some brief comments:
.
The file has grown to 133 Mb, 646 Sketches, and 191 Bodies, but performance is still adequate. No crashes, stable as can be. The only problem with such a large file is the (~4 min) required for autosave every 15 minutes and during some random recomputes triggered somehow. Perhaps someone could come up with a way to make this an incremental save? Then again, who else would want to have everything in one file?
Now, on to the accessories which I may put in a separate file due to their complexity. Stay tuned for more updates.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.13983 (Git)
Build type: Release
Branch: master
Hash: 8f1c6f77c090ae7d9c2bfd4f18811083b01a3eb2
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)
A few screenshots of the recent progress with some brief comments:
.
The file has grown to 133 Mb, 646 Sketches, and 191 Bodies, but performance is still adequate. No crashes, stable as can be. The only problem with such a large file is the (~4 min) required for autosave every 15 minutes and during some random recomputes triggered somehow. Perhaps someone could come up with a way to make this an incremental save? Then again, who else would want to have everything in one file?
Now, on to the accessories which I may put in a separate file due to their complexity. Stay tuned for more updates.
OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.18.13983 (Git)
Build type: Release
Branch: master
Hash: 8f1c6f77c090ae7d9c2bfd4f18811083b01a3eb2
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)
"It is a poor workman who blames his tools..."