Need suggestions on how I can make this part (similar to washer)

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openBrain
Posts: 629
Joined: Fri Nov 09, 2018 5:38 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby openBrain » Wed Apr 17, 2019 8:04 am

intufreecad wrote:
Wed Apr 17, 2019 1:44 am
Hello everyone,
Hi intufreecad, welcome here. :)
I think the solutions with sketches are very elegant. But there is also another way, working only with part workbench and draft workbench.
Why say "But ... also" ? Better say "And ... still" :lol:
Very nice example of CSG using Part WB. I could have extrude my sketch out of a body with the Part Extrude and say I used Part WB, but IMHO it won't be the real sense of it. Your example definitely is. ;)
Hmmm... Are you French ? (Looks like most CSG modelers are) :lol:
The power of freecad makes that even such solutions stay parametric.
Here we could discuss the meaning of "parametric". But yes, your model is tunable. :-)
YeeP
Posts: 29
Joined: Sun Oct 22, 2017 11:25 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby YeeP » Wed Apr 17, 2019 2:09 pm

openBrain - If I were to try and modify your latest drawing to fit my needed sizes, should I just start by redefining the radius constraints on all of the circles in the sketch?

I was hoping to get the drawing to the table owner today so any suggestions on how I could resize it the correct way would be much appreciated.


Thank you!
Ryan
kisolre
Posts: 424
Joined: Wed Nov 21, 2018 1:13 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby kisolre » Wed Apr 17, 2019 2:23 pm

Here is a file with the dimensions you provided.
Attachments
washer_OB_diameter dimensioned.FCStd
(26.6 KiB) Downloaded 1 time
YeeP
Posts: 29
Joined: Sun Oct 22, 2017 11:25 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby YeeP » Wed Apr 17, 2019 2:50 pm

kisolre - thank you so much. I really feel like this is cheating for me and I need to force myself to learn. Could you point me toward topics I should look for instruction on that would help me build this?

On my list:
fillet definition
constraint dependencies


anything else? Also, is there a quick way to have the diameter/radius shown when you select a circle in sketch? In looking at the latest file you made I have no idea what the sizes of these circles are.
YeeP
Posts: 29
Joined: Sun Oct 22, 2017 11:25 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby YeeP » Wed Apr 17, 2019 3:11 pm

@kisolre & @openBrain, here is a file that I have been trying to modify the sketch. I am having constraint issues and am unsure how to solve them.
Inside of Sketcher, I have selected the Element '3-Circle' and tried to put a radius constraint on it (is there a better way to just sizing the circles or is this correct?). I tried to set the radius constraint to 2.1875 ", but I get an error stating "Invalid constraint index: 98". A similar issue happens when I try to adjust "Constraint 82". I wanted that to be 0.75". Can you explain to me what I should be doing to make these adjustments without causing problems in the drawing?


Thank you.
washer_Y1.FCStd
(33.76 KiB) Not downloaded yet
YeeP
Posts: 29
Joined: Sun Oct 22, 2017 11:25 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby YeeP » Wed Apr 17, 2019 3:11 pm

@kisolre & @openBrain, here is a file that I have been trying to modify the sketch. I am having constraint issues and am unsure how to solve them.
Inside of Sketcher, I have selected the Element '3-Circle' and tried to put a radius constraint on it (is there a better way to just sizing the circles or is this correct?). I tried to set the radius constraint to 2.1875 ", but I get an error stating "Invalid constraint index: 98". A similar issue happens when I try to adjust "Constraint 82". I wanted that to be 0.75". Can you explain to me what I should be doing to make these adjustments without causing problems in the drawing?


Thank you.
washer_Y1.FCStd
(33.76 KiB) Downloaded 1 time
kisolre
Posts: 424
Joined: Wed Nov 21, 2018 1:13 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby kisolre » Wed Apr 17, 2019 4:03 pm

The radial/diametral dimensions are created horizontaly by default and in those concentric circles they are cramped ot top of each other:
.
Radius_Diameter dimension.JPG
Radius_Diameter dimension.JPG (49.77 KiB) Viewed 49 times
.
As with all dimension constraints you can select their numbers and move them to suitable place:
.
Radius_Diameter dimension_moved.JPG
Radius_Diameter dimension_moved.JPG (57.54 KiB) Viewed 49 times
.
YeeP wrote:
Wed Apr 17, 2019 3:11 pm
I get an error stating "Invalid constraint index: 98"
This usually happens when the thing that you are trying to dimension is already fully constrained. If the circle has its radius constrained and you try to add another radius constraint it will be refused. Double clicking the existing constraint will open a dialog to change its value.
YeeP
Posts: 29
Joined: Sun Oct 22, 2017 11:25 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby YeeP » Wed Apr 17, 2019 4:17 pm

kisolre wrote:
Wed Apr 17, 2019 4:03 pm
This usually happens when the thing that you are trying to dimension is already fully constrained. If the circle has its radius constrained and you try to add another radius constraint it will be refused. Double clicking the existing constraint will open a dialog to change its value.
This is exactly what I did (dialog box).

I have Constraint82 highlighted, double click it, modify the length from 0.4000 in to 0.750 in. Error. I am thinking that this constraint has another that depends on it being at this measurement, and that is why I get the error. Is there a way to organize your constraints based on their dependencies? (Sorry if I am using the wrong terminology).
freecad1.png
freecad1.png (54.15 KiB) Viewed 46 times
freecad2.png
freecad2.png (30.17 KiB) Viewed 46 times
freecad3.png
freecad3.png (7.94 KiB) Viewed 46 times
kisolre
Posts: 424
Joined: Wed Nov 21, 2018 1:13 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby kisolre » Wed Apr 17, 2019 4:39 pm

The problem is that the fillet is too big for that width. Here I changed that constraint to driven (measures the distance instead of setting it) and you can see that the maximal value is around 0.58" so setting it to 0.7" will not be possible:
.
Constraint.gif
Constraint.gif (596.51 KiB) Viewed 42 times
.
You need to first set the fillet arcs radius, then the big circles and finally those widths.
YeeP
Posts: 29
Joined: Sun Oct 22, 2017 11:25 pm

Re: Need suggestions on how I can make this part (similar to washer)

Postby YeeP » Wed Apr 17, 2019 5:02 pm

kisolre wrote:
Wed Apr 17, 2019 4:39 pm
The problem is that the fillet is too big for that width. Here I changed that constraint to driven (measures the distance instead of setting it) and you can see that the maximal value is around 0.58" so setting it to 0.7" will not be possible:
<SNIP>
Thank you! What screen capture program did you use to make that gif? That was very helpful.