I am not seeing a reasonably direct way to do this in Alibre.

[JST]

This is using CAD in design, which I realize is contrary to the academic principles of using CAD, which is made for the purpose of documenting a design that is already fully defined. Well, get used to it, since CAD is a great design tool. But these issues come up.

I have a round part, think of a piece of pipe. (Unfortunately, I cannot show you the parts) It fits with other parts, and I need to locate two threaded screwholes in this pipe.

The holes are radial, and must align with two holes in a part that fits on the OD of the "pipe".

I do not have the exact numeric location of the holes angularly on the "pipe", they end up where they are when the part with the holes in it lines up with another feature in the assembly. The location is calculable, but it seems the long way around, it would take quite a while fiddle-farting with trigonometry to get the number, when Alibre knows it already.

Seems it should be easy, there are the parts, both together, the holes have centerlines, and I ought to be able to do it directly.

Is there an actual direct means?

I am not seeing a good way. I need a starting plane for the hole, but the angle of that plane is not exactly known, except that it is perpendicular to the existing axis. There is no way I see to start from a curved surface, and I cannot call for the hole to follow an axis, although that would clearly define its location.

It does not even seem to be possible to directly define a plane to be both perpendicular to an axis, and at a certain distance from a point, or an intersecting axis (the holes are radial, I have the axis, and I know the diameter of the pipe, but not the angle).

I have to measure the angle, and then establish a plane by a sequence of construction steps. That will not be exact, unless the angle is some non-repeating decimal with a reasonable number of digits. Ideally, an integer.

It seems that a CAD system ought to be able to make a hole follow an axis, and ought to be able to start on a curved surface of a simple type such as a cylindrical surface.

In that situation, all the information is actually known, but it seems as if the user has to extract it and then use it to separately establish reference geometry that reproduces the already existing actual model geometry.

 

[bigseb]

If I may: draw up a dummy of what you want to achieve. So much easier to follow...

 

[ChristianGa]

In Assembly, right click part in left navigation window and click "Show Reference Geometry".
Then in main naviggation on top, click "Measure", click any geometry (Axis) and you should get your numbers.

 

[NateLiquidGravity]

Not having any example to see I would say:
Edit the part in context of the assembly.
Insert an axis on the center of the hole.
Insert a point at the point you want to offset from.
Insert a plane using that axis and point.
Insert a plane offset from previous plane.

 

[JST]

Note that I am not saying it cannot be done. I am saying that there is no direct method, the methods involve construction of geometry to re-create what Alibre already "knows".

In Assembly, right click part in left navigation window and click "Show Reference Geometry".
Then in main naviggation on top, click "Measure", click any geometry (Axis) and you should get your numbers.

In the general case, the angle may turn out to be 23.857563629175843201 degrees, or some such, and entering it (limited to 6 places) will be "not exact enough for Alibre", even though it is way good enough for the most precise machining. So Alibre will tell you that the holes do not line up, and that you have an alignment error even though the holes are far more precisely located than any machining operation can be expected to produce them.

This is a common problem with Alibre.

Not having any example to see I would say:
Edit the part in context of the assembly.
Insert an axis on the center of the hole.
Insert a point at the point you want to offset from.
Insert a plane using that axis and point.
Insert a plane offset from previous plane.

Oddly, Alibre does not allow that operation. There is no insertion of a point at the intersection of a pair of axes.

If the center point is on a base plane, or any constructed plane then there is an axis and plane intersection, which is a valid definition and a point can be placed. So one must construct enough geometry to establish the reference, and then construct the starting plane for the hole, and finally make the hole. And repeat much of it for the second hole.

But, Alibre already has all the information actually needed to do the hole. There is the hole axis, and there is the starting surface (it is not a "plane").

The operation to produce a starting plane for a radial hole (the most common for cylindrical surfaces) in this case would be to insert a plane perpendicular to the axis, and tangent to the surface.

The tools to produce this exist, but are clumsy to use, particularly for multiple holes. On the other hand, Alibre can easily produce tangency, and perpendicularity.

This is a common enough need that it seems Alibre should have that facility.

 

[NateLiquidGravity]

I still don't see what could be improved unless you want Alibre to take a wild ass guess about where you want holes.

 

[JST]

I still don't see what could be improved unless you want Alibre to take a wild ass guess about where you want holes.

EH? say WHAT?

OK, we have an axis (in this case radial) through the surface of a cylinder. That gives a location in the universe down to exactly one dimension left, which is the depth of the hole..... I would like to have a hole along that axis, at that surface and a depth which I am happy to specify. The surface happens to be curved, and has no "start surface plane". I am asking Alibre to produce a starting surface plane at that intersection, and perpendicular to it, i.e. tangent to the surface, since the axis is radial.

That is essentially an added way to produce a new plane, using the intersection of a non-planar surface and an axis. We can already put a point at the intersection of a plane and an axis. And a point and axis can be used to produce a plane.

But that cannot be done with a cylindrical (non-planar) surface. It would be great to extend to a loft or other "imaginary" surface, but I'm OK with a cylindrical surface (or possibly a conical surface), because that is something that comes up a lot.

You can do this with a plain extrude cut in some cases (using through all), but the drilled hole tool is much more fussy about requiring a start surface.

I'd like to do this without having to measure the various distances and angles etc, copy down the results on a piece of paper, then enter those results in order to eventually construct the plane. When using a computer, writing down intermediate results and doing a lot of trig seems so, well inaccurate and 1700s-ish. Especially when the geometry is all laid out already in the model.*

The surface gives the location along the axis, the axis gives the precise location angle etc of the hole, and consequently of the needed start surface plane. I would have thought that nailed it down pretty well.

And you want more, claiming I want a wild ass guess as to location?

Perfect example of why I do not come around here much.

* This is likely a candidate for a script. I know as yet very little about scripts.

 

[HaroldL]

It took a while to understand your issue but when I tried to reproduce what you were describing I see what the issue is. Alibre doesn't show the reference geometry on the reference part (with the hole) to show when Editing In Place the part you want to add the hole to. It would be real nice it you could use ALL reference geometry from whatever part then you could reference the axis of the hole and maybe use Project to Sketch to position the new hole.

I seem to recall that in SolidWorks the Hole tool allows you to start a hole on a curved surface and it does let you reference other parts geometry a lot easier than Alibre. But SolidWorks is more advanced with its tools than Alibre, that's just the way it is. However I think I found a way around that limitation using the Boolean Subtract. (yeah, you can call this a workaround.)

So let's name the parts: Part A has a hole at some arbitrary angle. Part B is the part you need to create the hole in matching the angle in Part A. Part C will be used to create the hole in Part B

1. Starting with Part A make sure to add an axis to the hole.
2. Create Part C with a diameter of the required hole and length to match or greater than the diameter of Part B.
3. Open Part B and start the Boolean Subtract.
   
4. Select both Part A and Part C to insert into Part B and RMB Show Reference Geometry on both parts.
   
5. Constrain Part A to Part B in its assembled position allowing for the placement of the hole.
   
6. Constrain Part C to the axis in the hole of Part A and, if needed, offset the end from the Reference Plane for the hole in Part A.
7. Now Accept (Green check) the Boolean and the hole is created in Part B.

It ain't pretty but will this workaround get you what you need?

(This is an image of the sleeve (Part B) shown being edited in place.)

 

[NateLiquidGravity]

JST that workflow is probably more unique and specific to you than you think.
Should Alibre assume cut depth is based on starting at:
The point that the axis touches the surface?
The point that the diameter of the hole first touches the surface?
The point that the diameter of the hole last touches the surface?
Some other point based on the first part?

How will it be built? What precision will it be dimensioned to paper? What precision are the tools used to produce it. Even cnc milling has limits to it's precision.

 

[JST]

The logical answer to your very numerous questions is that Alibre is not supposed to assume anything. You are taking this as some sort of "new hole tool".

Nope.

Just want to use the "hole tool" in a more simple and user-friendly way. To not have to go through a long process of geometric construction to get the starting surfaces for a bunch of holes at different angles, when Alibre has the needed data already, but offers no tool to use it directly.

Alibre requires a plane to do the axis intersection to create a new plane, so you almost "need the result in order to get the result". If Alibre could put a plane perpendicular to an axis, and through a point on the designated surface, where the axis intersects it, so long as the surface is a simple form (cylindrical or potentially spherical, at least not a loft etc), then it would be much simpler and more exact to locate the hole.*

If you do this the hard way by building up axes and points and planes and then more planes at angles, establishing the plane tangent, so you can use the hole tool, then all the tools to answer your questions are present. You then do not need to ask those questions, they are not relevant.

Alibre has the data to produce a plane through the point of intersection that is designated by the user and perpendicular to the axis. We just cannot directly do that with the tools now present. A plane is required, but the plane is what is wanted.

Why would anyone want to do this? Holes in a piece of pipe or solid rod, for one thing. many holes at various angles. I do work for companies fabricating cell tower modifications , repairs, and extensions. There are mounting points all over them, for step bolts, accessories, and the like. Some require holes placed relative to other accessories, and the computations to locate the holes can get out of hand, but locating the hole from the model is easy, if the tools are provided. Otherwise it becomes a real mess of planes and axes, etc. Handrails are another case that can end up with holes at odd angles.

The number of reasons to want "drilled" holes or blind threaded holes at angles in cylindrical objects is rather large. And when using Alibre as a design tool, the amount of geometric construction to test out just one possible alternative for arrangement can get to be huge. The "tool", Alibre, actually begins to get in the way because of the cumbersome constructions needed.

Each particular case may have a unique solution that works just for it, so very specific examples are somewhat misleading, solutions proposed often exploit a particular detail of that individual case, showing "see how easy that is?", even though that may be the only case the "shortcut" works in. There is no "general case" tool for the job.

* the exactness is with regard to Alibre's internal use, not with regard to a machine tool and drawing. The 6 place accuracy is plenty for doing the drilling, too much in fact, but that imprecision can make Alibre complain that things are not exact when assembling the model.

Plus, it is silly to be taking notes of dimensions, and then having to input those numbers again, elsewhere in the program.

 

[NateLiquidGravity]

I don't get why Alibre can't put a point at the intersection of an axis and a non planar face. I thought it could. My mistake.

Maybe I'm just not understanding your ultimate goal for Alibre to create. You can do Holes thru multiple layers of parts now but they don't show up at the part level. Do you just basically want a way to have Assembly level Cuts and Holes be applied down to the parts level? This I think would be a great enhancement.

 

[HaroldL]

Just want to use the "hole tool" in a more simple and user-friendly way. ...
... If Alibre could put a plane perpendicular to an axis, and through a point on the designated surface, where the axis intersects it,

I agree that the Hole tool could do more to allow holes on curved/cylindrical surfaces. But without some major programming of the Hole tool it seems you are stuck with, what did you call "fiddle-farting", to figure out where the holes should be. I don't think you are asking too much but is it in Alibre's plan to add that functionality?

Is that something a script could accomplish while in an assembly? AND do you have models of the parts that will be assembled to the holes you need to create? Those parts/models would need to be present in the model for the script to reference - if it is at all possible.

And if you had models of the installed parts could you use the Boolean Subtract method I illustrated to create the holes, minus any clearances you would need to go back an create. You would have to accept the increase in file size too with the added Boolean parts.

Another "tool" that needs more options is the Insert Plane tool. Why for example can you not select a Reference plane, a cylindrical surface and an axis to insert a plane Tangent to the surface and at an angle to the reference plane in one operation. Now you first need to create a plane at an angle then you can create an offset plane tangent to the surface. Seems like it should be simpler.

This sounds like something that should be on Max's v23 Request thread, if it isn't already.

 

[JST]

The hole tool does not need to do it if a plane can be put on a cylindrical surface easily. That seems like a far easier programming job.

If that takes the axis plus a point, then a plane at the point, that's fine.

The present method , of getting dimensions and constructing the plane is a pain if there are many holes that are not on the same line.

The method of locating the point and then getting the plane is pretty general, because it works for a hole at ANY location or angle on the cylindrical surface. So it can be used to produce counterbored holes off the centerline, or the type used to join two sections if a flange is not allowed (think how a torpedo body is joined, although that is not the only application).

If you want to discuss the hole tool, for the counterbored holes, it would be good to locate the start plane (as an alternate) at the bolt head contact surface, defining the hole forward from that, and the counterbore "backward". In that way, one could do a counterbore in a cylindrical object in a nicer way, since the plane could be where you want the bolt head "under the surface", and the counterbore simply extends back through the curved cylindrical surface. Makes a hole that is off the centerline easy.

I won't demand that.

 

[bigseb]

If you want to discuss the hole tool, for the counterbored holes, it would be good to locate the start plane (as an alternate) at the bolt head contact surface, defining the hole forward from that, and the counterbore "backward". In that way, one could do a counterbore in a cylindrical object in a nicer way, since the plane could be where you want the bolt head "under the surface", and the counterbore simply extends back through the curved cylindrical surface. Makes a hole that is off the centerline easy.

This is a brilliant idea. Although I would like to see this as an added option, not replacing the current one.