Gap when joining onto a cylinder
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Gap when joining onto a cylinder
Hi,
I am new to FreeCAD and I'm currently practising by building models from part drawings I find on image search, I am currently trying to build this part
Version: 0.19
Everything was going well until I tried creating the joint between the two cylinders. I thought I could just expose some of the points from either cylinder and sketch the shape and pad it out like so:
However this leaves me with these gaps, what would be a better way to do this please?
Thanks for your help
I am new to FreeCAD and I'm currently practising by building models from part drawings I find on image search, I am currently trying to build this part
Version: 0.19
Everything was going well until I tried creating the joint between the two cylinders. I thought I could just expose some of the points from either cylinder and sketch the shape and pad it out like so:
However this leaves me with these gaps, what would be a better way to do this please?
Thanks for your help
Re: Gap when joining onto a cylinder
This sort of problem has come up on the forum previously as a challenge. Without going into any detail, it is geometrically impossible to create a smooth join just using simple flat surfaces as shown in your image.
Lots of ways to create overlaps and other joining techniques.
You need to decide how you want to deviate from simple planar surfaces.
Gene
Lots of ways to create overlaps and other joining techniques.
You need to decide how you want to deviate from simple planar surfaces.
Gene
Re: Gap when joining onto a cylinder
Just make it wider.
Re: Gap when joining onto a cylinder
I added some small rectangles and padded those out, I don't think it is the most elegant solution but it seems to have worked.
Could anyone point me to some techniques for creating smooth joins and overlaps please?
Could anyone point me to some techniques for creating smooth joins and overlaps please?
- Shalmeneser
- Veteran
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Re: Gap when joining onto a cylinder
- Attachments
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- JoinCylinder_SHALM.FCStd
- (180.59 KiB) Downloaded 18 times
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- Capture d’écran 2022-07-01 101159.jpg (76.99 KiB) Viewed 1242 times
[SOLVED] Re: Gap when joining onto a cylinder
Thanks @Shalmeneser for the inspiration!
Re: Gap when joining onto a cylinder
Here is a proposal with pretty much work in it, but you are rewarded with smooth transitions.
I kept the middle part as proposed by Shalmeneser, to keep the plane face on top. The gap closing part can of course be made smaller.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
Re: Gap when joining onto a cylinder
For comparison purposes is here a model which uses just a loft in the middle. Looks nicer on first sight, because it has less seams, but the top is a complicated curved face.
- Attachments
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- JoinCylinderLoftOnly_cb.FCStd
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A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
- papyblaise
- Veteran
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- Joined: Thu Jun 13, 2019 4:28 pm
- Location: France
Re: Gap when joining onto a cylinder
for fun, I'm redoing this exercise, but I stumbled on a bone: before (a long time ago) we could make the rays (marked red) ending in a point with the "filet" tool, we can't do it anymore today today, I had to use all my faculties to do this
and you
and you
- Attachments
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- fillets.JPG (29.55 KiB) Viewed 1181 times
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- fillets.FCStd
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Re: Gap when joining onto a cylinder
This is one of these cases where doing it with pencil is definitely easier
and permits quite a degree of "poetic licence" when drawing some edges
3D CAD doesn't understand fuzzy logic and wants precision
and permits quite a degree of "poetic licence" when drawing some edges
3D CAD doesn't understand fuzzy logic and wants precision