V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

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Bernard19
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by Bernard19 »

A new problem.
My insulated piston block is working fine. It is transferred and positioned in the Bati parent block. I tried to add the shaft to the piston block but now when I integrate it into the parent block, there are 2 superimposed shafts. I give up this way. The tree belongs to the flyweight block which is the son of the parent block.
My problem is the following: How to realize the rotation of the shaft with the piston block.
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Bernard19
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by Bernard19 »

Hi,
It's really powerful Assembly4.
I had trouble understanding and as usual, by dint of trying things we find. The solution was however before my eyes in the views of the first page of this post.
Now I think I have understood the system of combination of movements. As mentioned, there are several ways to operate these mechanisms.
This tool is amazing. Thank you for your encouragement and your support in this discovery of Assembly 4. My assembly is not finished, the biggest remains in my eyes: the screws ;) .

I offer you this video made with the ASM4 tool.
How do you upload a video to the forum? url youtube
https://drive.google.com/file/d/1PFlyXu ... sp=sharing
A+
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ppemawm
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by ppemawm »

Bernard19 wrote: Sun May 14, 2023 8:19 am Thank you for your encouragement and your support in this discovery of Assembly 4. My assembly is not finished, the biggest remains in my eyes: the screws.
Well, thanks, but you have done all the hard work. This project was especially difficult for a beginner. You now have nearly all of the Asembly4 tools at your command for your next project. Well done. Perseverance was key.

Assembly4 fasteners are the easiest but somewhat tedious part of the assembly since there are so many. It will take some practice. I like to include them in each sub-assembly as I create them. The most annoying part about Assembly4 fasteners is that you have to remember the ASME or ISO designations since there is no visual clue as to how they look. You can add the Fasteners workbench toolbars to Assembly4 for a visual aid. If you use the Fasteners toolbar to add fasteners you will have to drag and drop the fasteners into the assembly Model and then use the Assembly4 Edit Placement of Part button to insert them into the assembly at their proper LCS or Hole Axis.
Bernard19 wrote: Sun May 14, 2023 8:19 am How do you upload a video to the forum?
I have a YouTube (YT) account which allows you to to upload a video and create a link which can be inserted in a post reply using the video button. I am sure there are probably better ways than YT.
"It is a poor workman who blames his tools..." ;)
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Bernard19
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by Bernard19 »

Sorry to bother you, I have a movement coordination problem. The elements of the crankshaft rotate at the same speed on the other hand for the intake and exhaust valves it is different. (1 turn = 360°for ASM4_animate) It would take an opening at 90° and a closing at 135° for the admission and the exhaust between 125° and 180°. Intake valve lift is 4.5mm for ASM4_Animate. I don't see how to make between the two. Is it a complex formula or a setting in the animation window?
Thanks you
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ppemawm
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by ppemawm »

Bernard19 wrote: Mon May 15, 2023 8:14 am It would take an opening at 90° and a closing at 135° for the admission... Is it a complex formula or a setting in the animation window?
This can be handled by a conditional expression https://wiki.freecad.org/Expressions#Co ... xpressions or what I like to call an "event scheduler" for those mechanisms that have intermittent motion.

The independent variable is rotation. The valve lift variable must be defined in terms of the rotation in an expression. There are two events: open and close. This will require a "nested" conditional. In the expression check for one condition and if true check for the next condition--

rotation>=90? (rotation<=135?4.5:0) :0

Create a similar expression for the exhaust valve variable.

For another example of an Assembly4 "event scheduler" using conditionals see also viewtopic.php?t=70869
"It is a poor workman who blames his tools..." ;)
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Bernard19
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by Bernard19 »

Hi,
Thank you for the link fot the conditionnal expression. Very instructive but it will take time to make the most of it but at least now I know it exists.
It's like the "if function" in Excel.
(rotation>=90?(rotation<=135?4.5:0):0) -Ok
The intake valve is coordinated with the rotation of the frame.
I will attack the exhaust valve and fasteners.
I don't know if other people have embarked on this adventure, but I discovered the power of ASM4 and a great Professor.
Thanks
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Bernard19
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by Bernard19 »

For my last block, (weights), I can't add the screws.
What could be the cause of an impossibility to create Hole Axis and to associate a screw on a body?
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by ppemawm »

Bernard19 wrote: Tue May 16, 2023 5:34 pm What could be the cause of an impossibility to create Hole Axis and to associate a screw on a body?
Difficult to say much without more details about what you are trying to do or the file itself. It is generally a rather straight forward process in my experience.
"It is a poor workman who blames his tools..." ;)
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Bernard19
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by Bernard19 »

ppemawm wrote: Tue May 16, 2023 11:31 pm Difficult to say much without more details about what you are trying to do or the file itself
I have put some screws (47 - 58) but not all. It's impossible for 65 - 66 - 67 !!!
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ppemawm
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Re: V0.21 PartDesign/Assembly4 V0.12.4--Atkinson Differential Engine--Update

Post by ppemawm »

Bernard19 wrote: Fri May 19, 2023 2:23 pm I have put some screws (47 - 58) but not all. It's impossible for 65 - 66 - 67 !!!
You have a good start but need to finish the bodies before assembly:

65 add a hole axis in 19 govenor
66 add four holes and hole axes* in 64 flywheel
67 add a hole axis in 15 ignition cam

* or add a hole and axis then use polar pattern in PartDesign and circular (polar) array in Assembly4
"It is a poor workman who blames his tools..." ;)
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