Still a newbie - having some issues with holes and pockets

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andy.wpg
Posts: 23
Joined: Sun Jun 05, 2022 1:43 am

Still a newbie - having some issues with holes and pockets

Post by andy.wpg »

Hi once again.

I'll start by saying - I'm learning. I'm getting farther and farther with things, and then hit a wall. I've searched the forum, and can't seem to find anything that describes my problem in a way that helps me.

I'm creating a part that is screwed to a two by four, and has a sliding part that holds the top of a wheelbarrow against the garage wall. At the bottom, a bracket holds it against the wall there. There will be a sliding part that is pulled down toward the ground by a spring in a pocket on the base.

I was able to create the profile I wanted using the YZ plane, to fully constrain it, and to extrude it to 127mm. I have holes running from one end to the other to hold end caps.

The problem comes in when I try to cut holes in the top face (highlighted in green in the picture below)
Freecad view.JPG
Freecad view.JPG (30.29 KiB) Viewed 1233 times
I need a couple of countersunk holes (4mm w/8X3.5mm countersink) and a channel for a spring to sit in. When I highlight one of those faces, and then click on hole in part design, I can adjust everything all I want, but no holes or pockets appear.
I've tried creating a new sketch, and put the holes on X-Y, and they show up on the underside of the model, but no matter what I do, I can't make a pocket or hole appear.

Of course, later, I'm going to have to figure out how to use this as a "template" for the slider's profile. Another round of searching will commence then.....

I know I'm not understanding something about the environment, or how FreeCAD accomplishes things, but I'm beating my head on the wall, and any helpful pointers in the right direction would be greatly appreciated.

Thanks,

Andy

OS: Windows 10 Version 2009
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24267 +148 (Git)
Build type: Release
Branch: Branch_0.19.4
Hash: 476ecf091941bead59b14e44afa6064d5a66afa3
Python version: 3.8.6+
Qt version: 5.15.2
Coin version: 4.0.1
OCC version: 7.5.3
Locale: English/Canada (en_CA)
Attachments
Top Lat(Base) - YZ Extrude.FCStd
(22.94 KiB) Downloaded 20 times
"I have noticed even people
who claim everything is predestined,
and that we can do nothing to change it,
look before they cross the road."

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NewJoker
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Re: Still a newbie - having some issues with holes and pockets

Post by NewJoker »

To make holes with this tool you need a sketch with circles located where the holes should be placed. Their size doesn't matter, just the location is important. Check the wiki page for the Hole tool: PartDesign Hole.
Last edited by NewJoker on Sun Aug 07, 2022 9:31 pm, edited 1 time in total.
Bance
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Re: Still a newbie - having some issues with holes and pockets

Post by Bance »

Make the sketch a 1/2 inch above the XY plane, then use the hole feature followed by a pattern.....
Snip macro screenshot-b144c0.png
Snip macro screenshot-b144c0.png (32.46 KiB) Viewed 1216 times
andy.wpg
Posts: 23
Joined: Sun Jun 05, 2022 1:43 am

Re: Still a newbie - having some issues with holes and pockets

Post by andy.wpg »

Bance wrote: Sun Aug 07, 2022 9:31 pm Make the sketch a 1/2 inch above the XY plane, then use the hole feature followed by a pattern.....
Thank you! I was thinking backwards about it. 🙂
I also rounded the "anti-twist" channels.
Onward and upward!

countersink.JPG
countersink.JPG (24.11 KiB) Viewed 1193 times
"I have noticed even people
who claim everything is predestined,
and that we can do nothing to change it,
look before they cross the road."

Stephen Hawking
Bance
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Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Still a newbie - having some issues with holes and pockets

Post by Bance »

If you give the 1/2 inch constraint a name, you can use it in an expression to make the following sketch parametric.....

To transfer the holes think about using shapebinders.
andy.wpg
Posts: 23
Joined: Sun Jun 05, 2022 1:43 am

Re: Still a newbie - having some issues with holes and pockets

Post by andy.wpg »

NewJoker wrote: Sun Aug 07, 2022 9:30 pm To make holes with this tool you need a sketch with circles located where the holes should be placed. Their size doesn't matter, just the location is important. Check the wiki page for the Hole tool: PartDesign Hole.
Thanks. Yours, combined with the other answer got me to the point where the relationship between the sketch, the model, and the tools is clearer.
After I got the holes, it was easy to create the spring pocket.

Andy
"I have noticed even people
who claim everything is predestined,
and that we can do nothing to change it,
look before they cross the road."

Stephen Hawking
andy.wpg
Posts: 23
Joined: Sun Jun 05, 2022 1:43 am

Re: Still a newbie - having some issues with holes and pockets

Post by andy.wpg »

Bance wrote: Sun Aug 07, 2022 10:03 pm If you give the 1/2 inch constraint a name, you can use it in an expression to make the following sketch parametric.....

To transfer the holes think about using shapebinders.
I get the naming constants thing now. It’s like defining I/O pin 2 on an arduino as “LED”. I address LED in the program, and if I change what pin it is defined to, every reference in the program is changed automatically.

Thanks!
"I have noticed even people
who claim everything is predestined,
and that we can do nothing to change it,
look before they cross the road."

Stephen Hawking
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Shalmeneser
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Re: Still a newbie - having some issues with holes and pockets

Post by Shalmeneser »

Your sketch is ... awfull :
* Don't repeat the same dimension : use geometrical constraint
* Do not try to do everything in ONE sketch : Keep it stupidly simple
Attachments
Capture d’écran 2022-08-08 021656.jpg
Capture d’écran 2022-08-08 021656.jpg (85.42 KiB) Viewed 1042 times
Top Lat(Base) - YZ Extrude_SHALM.FCStd
(40.89 KiB) Downloaded 18 times
Capture d’écran 2022-08-08 023519.jpg
Capture d’écran 2022-08-08 023519.jpg (47.76 KiB) Viewed 1042 times
andy.wpg
Posts: 23
Joined: Sun Jun 05, 2022 1:43 am

Re: Still a newbie - having some issues with holes and pockets

Post by andy.wpg »

Shalmeneser wrote: Mon Aug 08, 2022 12:36 am Your sketch is ... awfull :
* Don't repeat the same dimension : use geometrical constraint
* Do not try to do everything in ONE sketch : Keep it stupidly simple
Not surprised by your evaluation. I think one of my main problems is using constraints properly. I really have trouble figuring it out when I have a couple unconstrainded and am not sure how to proceed a lot of the time. Not sure what it’s complaining about.
"I have noticed even people
who claim everything is predestined,
and that we can do nothing to change it,
look before they cross the road."

Stephen Hawking
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Shalmeneser
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Re: Still a newbie - having some issues with holes and pockets

Post by Shalmeneser »

Look at the lecture in chrisb signature : https://forum.freecadweb.org/memberlist ... ile&u=5646

Try to begin with geometrical constraints :
* vertical, horizontal
* equality
* symmetry
* points on line
You can use construction lines (blue) to help you.

Moving lines, it must keeps its global form.

THEN dimension constraints :
* vertical, horizontal, radius
If you use twice the same value, do we need equality ?
Dimensionning regarding to the origin changes the color of the constrained lines.
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