Creating a hole from a "Bolts" created SHS

[Laurie Hartley]

I am having great difficulty in creating a hole on two opposite sides and ends of an SHS that I created using the "BOLTS" Macro. I am still a novice using FreeCad but have had some success creating holes, pockets and pads with other parts but this one has got me stumped.

I have attached the file. I am trying to cut a circular profile starting 32.5mm from each end and on two opposite sides SHS.

I have been trying using the Part Design workbench.

Help with were I am going wrong and the workflow would be greatly appreciated.

OS: Windows 8.1
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13541 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 9948ee4f1570df9216862a79705afb367b2c6ffb
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)

[Bance]

You need to drag and drop the extruded section into the body, this will create a base feature that can be pocketed.
You will also need to modify your sketch since it has open vertices....
See included file.

HTH Steve

[Laurie Hartley]

Thanks Steve - I will follow your instructions and post the outcome

[Laurie Hartley]

So far so good - progress - see attached file. Just got to do the same on the other end now!

[chrisb]

What is SHS?

[Laurie Hartley]

Chris - SHS is an abbreviation for Square Hollow Section - a steel product that comes in many cross section sizes, wall thicknesses, and lengths. Here is a link to a product information brochure.

http://www.austubemills.com.au/uploads/ ... _Apr18.pdf

[chrisb]

Thanks, I had googled it, but doing so in germany I got plenty of explanations of which none made any sense.

[Laurie Hartley]

As promised here is my completed part. I really appreciate your advice Steve (Bance). It saved me hours of going round in circles.

[chrisb]

This has nothing to do with the topic, but allow me some comments on your sketching. I had a look at "end profile":

- You almost never need dimensions of 0. Use constraints such as vertical or horizontal or point-on-object or tangency instead
- You should prefer geometric constraints in favor of dimensions
- Have a second look at your sketch if equal dimensions occur, also exact halves of dimensions are suspect

Furthermore there is a bug in the solver which makes it assume that your sketch is fully constrained, which in fact it isn't. The leftmost vertical line can be moved freeely in horizontal direction. (I should add that I don't have a2plus installed.)

ping

I could change your old version containing 7 dimensions (where one more was missing) and 15 constraints ...

Bildschirmfoto 2019-06-20 um 08.42.51.png (20.16 KiB) Viewed 1567 times

... to a sketch using only 3 dimensions and 12 constraints:

Bildschirmfoto 2019-06-20 um 08.47.03.png (15.08 KiB) Viewed 1567 times

[chrisb]

And here is one more: Instead of repeating the sketch construction you could have used a Mirror pattern. That would have been even easier, if you had positioned your object symmetric to the origin.