Pierce a band and judge it at the bore

WhereBlender’s top menu bar, File > Open, then File > Save As.

DoOpen p10-04-start.blend. Then choose File > Save As and give the file a name of your own, so that the start file stays clean.

You should seeOne plain ring band, seen from an angle: you look through its hole. The picture names its two round faces. The bore is the inside, against the finger. The outside is the face everyone sees.

It worked whenThe band is the only thing in the 3D view.

WhereThe sidebar at the right of the 3D view (press N with the pointer over the 3D view if it is shut), the CAD/CAM tab.

DoClick Flow in the section bar, the small word buttons at the top of the tab. Then click the words Flow on Surface once, to fold that panel.

You should seeThat panel shuts up to its title, and the Pattern Builder panel moves up, with Make Pattern in it, as in the picture.

It worked whenYou can read Make Pattern without scrolling.

WhereThe 3D view.

DoClick once on the top of the band.

You should seeAn orange outline round the band.

It worked whenThe outline stays when you move the pointer away.

WhereThe Pattern Builder panel.

DoPress Make Pattern.

You should seeHexagon posts stand on the band, and a long flat strip lies in front of it with the same posts on it. You need not pick a face on a band: the add-on finds its outside by itself. The blue marks and the word Done on the band are handles, for changing a number by dragging. You may click Done when they get in your way. The status bar at the very bottom counts the cells, “Made Pattern 1: 15 cells”, but its message fades. The panel’s first line gives the count too: it begins “15 cells, rib”, then names the rib on the outside face and on the smaller face, which is the bore. Under it a line, “fit closes the seam”, says how the cells fit round the ring. The seam is where the rows of cells meet as they go round the ring.

It worked whenPosts stand on the band, and the panel’s first line, under the words “Pattern 1”, begins “15 cells, rib”.

WhereThe Pattern Builder panel, under the family buttons.

DoRead the rows marked in the picture. Type nothing.

You should seeA band carries load, so the add-on chooses for it: Rib (mm) reads 0.800 and Thinnest Rib Allowed (mm) reads 0.600. It is the thinnest a rib may be for the add-on’s check to pass: it is not the band’s own thickness, which is 1.80. The line above that one says “Through the band: structural, least 0.60”.

It worked whenYou can find both rows, and you have typed neither number.

WhereThe Pattern Builder panel, the field Cell (mm).

DoClick the middle of the number once, type the new one, press Enter, and look down on the band. Go down the table.

You should seeTo look straight down, click the blue Z ball on the small coloured axes at the top right of the 3D view. The pictures below are all from straight above. Count the rows by eye: the pictures give the cells.

It worked whenCell (mm) reads 1.200, and 3 rows of posts stand across the band.

WhereThe Pattern Builder panel, near its foot. Scroll the sidebar with the mouse wheel if you cannot see the button.

DoPress Check Metal.

You should seeThe band looks just the same, and it is now the selected object. Scroll the sidebar up: the new sentence stands under Least Opening (mm), above the button you pressed, as in the picture. It reads “Thinnest metal between openings 0.80 mm inside, 1.23 mm outside; 0 places under the 0.60 minimum (structural)”. The panel says openings for holes.

It worked whenThe sentence says “0 places under the 0.60 minimum”.

WhereThe Pattern Builder panel, near its foot.

DoPress Make Real.

You should seeThe posts on the band become holes, as in the pictures. It takes a few seconds. The status bar’s message says what went: “Cut 123.8 mm3 from CJ_Shank_Flat_M (55 cells, 1.92 g saved)”. CJ_Shank_Flat_M is the band’s name. If the message has gone, the holes are proof enough.

It worked whenThe band has holes where the posts stood, and the status bar’s message begins “Cut 123.8 mm3”.

WhereThe 3D view.

DoOrbit round the band. Find one rib from the outside, then find the same rib from inside, on the bore.

You should seeThe same rib is narrower on the bore. You will not read these numbers on your own band: the picture cuts through it so that you can see both at once, 1.23 mm at the outside and 0.80 mm at the bore.

It worked whenYou can say which of the two numbers counts: the one at the bore.

WhereThe 3D view.

DoOrbit to look at the band from behind and below, as in the picture.

You should seePlain metal at the back of the ring, with no hole in it. You typed nothing to get this. The sizing area is the part of a ring a jeweller cuts and joins to change its size: it is the middle of this plain arc, and the add-on leaves more plain metal than that needs.

It worked whenThe holes stop well short of the bottom on both sides.

If it goes wrongThe guide and its posts stand in your way: orbit further round, to the side away from it. It is no part of the ring.

WhereThe 3D view, with the pointer over it.

DoPress Ctrl+S to save your copy.

You should seeThe guide stays in the file: this page does not clear up. It is no part of the ring.