spiral (or any other arbitrary) hole pattern

[Jasper]

I know how to create circular and linear hole patterns, but how would I create a hole pattern that follows a spiral? (and by that I mean a flat spiral - all holes start on the same plane)

Thanks,
PJ

 

[RocketNut]

Can you give us an examinable?

 

[Jasper]

can't post anything because I can't draw it. That's what I'm asking. A flat Archimedean spiral, in polar coord R = b(theta).

 

[KMoffett]

I have tried this technique to make a flat spiral: viewtopic.php?f=1&t=16410&p=101536&hilit=Flat+spiral#p101536
Without trying it, I suppose there would be a way of adding holes along the spiral at equal angles or equal distances. Though I have not tried it either, there is a way of using EXCEL spreadsheets to locate features.
Sorry I can't be more help.

Ken

 

[Lew_Merrick]

That's what I'm asking. A flat Archimedean spiral, in polar coord R = b(theta).

And how would you define the hole spacing along that spiral? This sounds like a job for WizoScript! You could calculate and place a series of Reference Points on your plane and then use the Coincident Point constraint to locate your holes. [Sorry, WizoScript does not (yet) have access to the Hole Tool.]

 

[bigseb]

I believe Moi can do this. Not at my PC right now so I can't confirm but I check and post back later...

 

[Jasper]

I believe Moi can do this. Not at my PC right now so I can't confirm but I check and post back later...

That would be great. I did turn to MoI out of desperation, and I was able to get a flat spiral (a polyline of some sort, not holes) ...but still trying to learn that interface and the sizing/manipulation of the spiral. Have not figured out how to get another shape, like the circles for holes, onto the spiral. I've never used MoI before so it's a slow go.

 

[Oldbelt]

KIS

Make a list with values and tap the result in.
The values can be calculated with Exel.

I do not understand why members of this board recommend use of other SW than Geomagic,
when the needed functionality is present.

 

[bigseb]

KIS

Make a list with values and tap the result in.
The values can be calculated with Exel.

I do not understand why members of this board recommend use of other SW than Geomagic,
when the needed functionality is present.

Not everyone uses Excel, Oldbelt. So that's not always an option. Secondly working out an XY co-ordinate for every single ppoint is time consuming, particularly when the guide curve changes. Its often just easier using another software to do that. Time is money, after all.

 

[TylerDurden]

Not too hard to do using GD and Inkscape, using the Pattern along Path extension. A spline is placed on a spiral path, the number of nodes can be preset on the spline and stretched to fit the spiral, or a set distance between nodes can be repeated to fit the spiral.



Arbitrary shapes are done in a similar fashion:


(Both of the above have 129 nodes.)

After the nodes are in the part workspace, holes can be set at each node using project to sketch and the hole tool.

Maybe not as fast and easy as other methods.

Edit: the figures in Inkscape are saved as DXF and opened in GD, copied from the drawing workspace into a sketch in the part workspace.

 

[JST]

So far the assumption has been that the holes are evenly spaced along the spiral.

Is that so? Or are they located by angle?

That would make a difference in how they are calculated.

 

[bemfarmer]

There are two Archimedean spiral scripts written for Moi.
The equations are fairly easy, so Excel could be used, or a WizoScript made, by those familiar with the latter two programs.
Polar coordinates are involved, and polar to Cartesian is easy.

- Brian

 

[Oldbelt]

Bigsep.
I used the form "Direct Entry" for Sketch points.
Polar / absolute values :distance and angle.
No need for cartesian input as Brian said.
Distance = a + b*Angle.
Simpel pocket calc. or exel.