Freecad 0.21.2

[WobblyHand]

@Ronno6 attached is a text file.  Edit the extension back to .FCStd.  Shows the basic steps.  Make the cylinder and dimension.  Then add subtractive features one by one.  I added a rectangular pocket, then a set of round holes.  Finally put a groove around it.  It's all nonsense, but shows the basic operations as you create an object (the Body) then either add stuff to it, or subtract.

[Ronno6]

The Adventures in Creation series is helping a lot.
But the narrator's voice is so law and mono tone that he puts me to sleep..

I have seen a bunch of things that do not relate to me project, put probably will in time....if I recognize them.

Lemme lay out a word scenario.

I want to draw a shaft, 26.4mm in dia and 30mm in length.
The shaft will have a key way along its full length down the linear axis on the side of the shaft.
This key way is 7.62mm wide, then, the tricky part: how to dimension the depth, as is should be dimensioned form the portion
of the arc that is now gone..... the depth from the circumference at the intersect point should be 3.445mm to the bottom of the key way,  or maybe 3.86mm to where the arc would be above the center of the key way...
If I draw this with the notched diameter on the x-y axis. then "pad" the keyed circle to 30mm, that oughta do it.

What would be the steps to design this keyed shaft?

[WobblyHand]

The Adventures in Creation series is helping a lot.
But the narrator's voice is so law and mono tone that he puts me to sleep..

I have seen a bunch of things that do not relate to me project, put probably will in time....if I recognize them.

Lemme lay out a word scenario.

I want to draw a shaft, 26.4mm in dia and 30mm in length.
The shaft will have a key way along its full length down the linear axis on the side of the shaft.
This key way is 7.62mm wide, then, the tricky part: how to dimension the depth, as is should be dimensioned form the portion
of the arc that is now gone..... the depth from the circumference at the intersect point should be 3.445mm to the bottom of the key way,  or maybe 3.86mm to where the arc would be above the center of the key way...
If I draw this with the notched diameter on the x-y axis. then "pad" the keyed circle to 30mm, that oughta do it.

What would be the steps to design this keyed shaft?

He's kind of slow at times, especially in the beginning, but his words are gold.  They will be important later.  You will be hard pressed to keep up in a few videos.

In every situation, there's probably 3 to 4 ways to do it.  None are more right than the other.  Some may be more convenient than others, however.

You can make the sketch for the pocket on one of several planes.  It could be sketched on the same plane as the circular face.  (The xy plane.)  Or a plane that is tangent to the radius of the circle.  (XZ plane, that is offset by the radius of the circle.). Either is fine.  It doesn't matter that the cylinder is cut away, you are not using the face of the axial surface as a reference.  You are using the radius of the circle as the reference dimension.  Since you know the radius, you position the furthest extent of the rectangular sketch at the radial distance.  That's it.  Then the width, etc, until all the constraints are set.  Then pocket.  Done.

Or you can work your buns off making a circle with a cut out in the sketch and padding that sketch.  Personally, I think that is the hard way.  At least for me, making the cylinder, and then adding a pocket is a lot easier, and takes a lot less time.  In the end, it's your choice.

[Ronno6]

I MIGHT actually understand that!
Now, to see if I can DO it...........

[WobblyHand]

I MIGHT actually understand that!
Now, to see if I can DO it...........

Show us a picture when you get it! 

[Ronno6]

I don't imagine that a hole running thru the diameter of a round.shaft can be 3D printed....

Have to be a secondary operation ?

[WobblyHand]

I don't imagine that a hole running thru the diameter of a round.shaft can be 3D printed....

Have to be a secondary operation ?

In general it will be a secondary operation, as a normal hole will sag.  I believe you can make holes with a ^ in them, that print relatively well.  Me, for just one's and twos, I just post drill the holes.  You do need to make sure when sliced that there's enough meat surrounding the hole to support a drill going through without going into your infill area.

But I have done horizontal holes.  With and without support.

[WobblyHand]

Let's see if I can attach a picture via a link.  The shape for a horizontal hole needs to be more like a tear drop, with the point facing upwards when printed.  Sagging will round the hole. 
https://img.facfox.com/imgs/2022/05/12/1dbfd7cfe2008bf2.png

[WobblyHand]

Here is a link to a FreeCAD forum post on how to construct the teardrop.  https://forum.freecad.org/viewtopic.php?t=82955
I've been too lazy to do this, but I may give it a try.  If you are trying to make parts for sale, it's worth printing correctly the first time without post processing.

[Ronno6]

I will have to make a fixture for drilling the hole.
It will be a bit tricky as IIRC the thru hole is not on the center line of the "shaft"

And, the dia at 1.040" (26.4mm) can't be bored into a holding block as I can't find a Forstner bit the
right size. I suppose I could chuck up a piece of aluminum plate and bore it on the lathe........

[WobblyHand]

I will have to make a fixture for drilling the hole.
It will be a bit tricky as IIRC the thru hole is not on the center line of the "shaft"

And, the dia at 1.040" (26.4mm) can't be bored into a holding block as I can't find a Forstner bit the
right size. I suppose I could chuck up a piece of aluminum plate and bore it on the lathe........

Print a fixture?
Drill a hole at 25.4mm then bore out the rest? 
Not sure what you are doing, exactly, so hard to make a recommendation.  Pictures help.

[Ronno6]

OK. Here you go.........
Disregard the screw and larger hole...

[WobblyHand]

@Ronno6 thanks for the pictures.  So are you trying to make this piece out of metal?  Is this a single piece or dual piece part?  Does the screw hold the piece on a rod? Is this basically the same piece you linked before?

I understand that you have a lathe.  Do you have a mill or drill press?  If drilling on a curved surface, I'd make a small flat spot to start the drill, with an 1/8" end mill and then drill through.  I'd use a drill press with a vise so things go smoother.  I'd hate to try hand drilling.

[Ronno6]

@Ronno6 thanks for the pictures.  So are you trying to make this piece out of metal?  Is this a single piece or dual piece part?  Does the screw hold the piece on a rod? Is this basically the same piece you linked before?

I understand that you have a lathe.  Do you have a mill or drill press?  If drilling on a curved surface, I'd make a small flat spot to start the drill, with an 1/8" end mill and then drill through.  I'd use a drill press with a vise so things go smoother.  I'd hate to try hand drilling.

i intend to 3D print using plastic.
The screw is a bleed port that will not be required.
Yes, it is the same part. This is the rear end of a Vortex gas spring.
They leak so often that I want to replace with another brand, but need to replicate the shape of this part,
only 10mm or so longer with some secondary operations to allow for a centering pocket for the replacement ram.
The clevis aspect of the part allows the trigger assembly to slide in and mates up with that shape on the rear block/safety assembly.
The larger dia. thru hole is a fill port that will not be needed.
So, the shape is all that I need to 3D print.

[Ronno6]

Is it necessary for any sketch to be fully constrained to be applied by pocket?

Certainly some dimensions will not be centered on an axis.......does this affect the constraint?

The large opening across the diameter of my part is not centered on the vertical axis, but cam be drawn that way,
If you consider a rectangular centered larger portion of that slot, then add a smaller one along the side of that slot to the step at the bottom corner.
I have to see how that measures out......

[WobblyHand]

Is it necessary for any sketch to be fully constrained to be applied by pocket?

Certainly some dimensions will not be centered on an axis.......does this affect the constraint?

The large opening across the diameter of my part is not centered on the vertical axis, but cam be drawn that way,
If you consider a rectangular centered larger portion of that slot, then add a smaller one along the side of that slot to the step at the bottom corner.
I have to see how that measures out......

You strictly speaking don't have to constrain your sketch, but I strongly suggest you should constrain it.  You do not have to have the sketch on an axis, it can be offset.  Just constrain the distance from the axis.  Why fully constrain?  So if you need to make a change, you know where you started from!  Or where to go back to.

You can have the center of a rectangle or circle or hexagon be anywhere - just tell sketcher where it is, via the constraints.  If you don't like it, you can always go back and edit the value.

You can pocket air, it just won't cut away from the body.  So to make a multi-step pocket, do the big one first, then the other one.  You can reference the pocket side from an axis, or a displacement from the axis, whatever is more natural to you.

[WobblyHand]

Here a circular sketch is not on the axis, but it's diameter and x and y coordinates are constrained.

[WobblyHand]

Solid model with hex pocket in part of it, with offset holes and chamfers.  The interface is significantly different.  Been learning how to do this as well.  Somethings are much better, others, well I liked it better the previous way.  Still pretty good.

[Ronno6]

If taken as 2 separate sketches to pocket, the wider,longer one would be on C/L.
The thinner, shorter one would be adjacent.......
I think that is the way to go.

[Ronno6]

I am becoming a bit more comfortable with working in the program.
My biggest problem comes when tools go missing from my tool bar..........like PAD and POCKET go away,
and I do not as yet understand how come they do that, or how to get them back........

Sometimes the SKETCH icon is gone............
I keep re-watching the early lessons and can't seem to translate them into use......