Docs › RotoSpider manual › Reference

Questions people asked

Describes RotoSpider Web App 0.8.13 and Desktop 0.8.13 · checked 2026-09-13 D5

This page grows from the questions readers leave on the manual's pages. It starts with the questions asked while the manual was being written and checked against the app.

Is the rotation envelope really a sphere?

For the usual arm, where the arm tube's axis and the plates' axis meet at a right angle, yes: both rotations keep every point of a mold at one distance from the meeting point, so the reach of the rotating set is a ball, and a mold's height and its sideways reach share that one radius. The ball is the permitted reach, not the path a mold traces and not the shape of the oven. Machine makers publish exactly this on their mold-swing drawings, together with the separate mounting gap and usable width. The straight-arm page and the offset-arm page explain it and link the Association of Rotational Molders' machine chapter and a manufacturer's drawings.

I entered a smaller envelope than the spider and the app used the spider's size. Why?

The app takes the ball to be at least as big as the plate, since a plate that does not fit its own envelope is a contradiction in the data. It does not mean the machine has that room: correct the two numbers against the machine drawing. The straight-arm page says which is which.

The strip is orange and says PARTIAL, but every mold is placed.

You have kept a position that breaks a rule with one of the three allowances under the staging area. The arrangement is not treated as a layout until the warning under the switches is repaired, and it cannot be saved as one. The allowances page.

How do I move a mold from the upper spider to the lower one?

In the plan views. Tick 2D, then drag the mold from one plan into the other; the status line says Release to move the mold to this spider. The 3D scene keeps a mold on the plate it is on. The editing page.

Why does the machine list show a load for only one machine?

The Load column of the Machines list shows the result for the machine that is selected; the app lays out one arm at a time. Switch machines and read the strip each time, or open a second layout tab with the same Need for the other machine. The comparison page.

Save is greyed out.

Save needs a computed layout: type a Need first. It also refuses a layout that still carries a draft warning from an allowance. The files page.

My Need is not in the workbook.

Need belongs to the layout, not to the master data: it is saved in the layout file and starts at zero in a new layout. The workbook's MoldCount is how many of the mold you own. The Need page.

My CAD mold arrived lying on its side.

The suggested position is based on the mold row's dimensions, which do not identify the physical mounting face. In the import preview, change Face resting on the spider plate and Turn on the plate until the frame sits on its actual mounting face. Check the size line and preview, then press Use Shape. The import page.

Which CAD format and units?

A STEP file, any of the usual flavours, with solid bodies rather than surfaces, and the whole mold with its frame. Units are read from the file. The import page has the export path for each common CAD program.

Why is there no builder for a cylinder lying on its side?

The cylinder builder stands the mold upright; only the tapered cylinder offers Laid down. Enter a laid-down round mold as a tapered cylinder with the small end a millimetre smaller than the large one, or import its CAD file. The built shapes page.

The app accepted a spider Y offset of 0 and then refused to lay out.

Since 0.8.13 the arm grid refuses a spider Y offset of 0, as every layout already did, and keeps the saved value. A workbook from before that still holds 0 needs the real drop from the arm's axis to the plate's face entered and saved. The offset-arm page.

Does anything leave my computer?

Not on its own. The desktop app keeps everything on your machine: the workbook, the layout files, the recovery copies and the support bundles; a bundle goes out only when you export it and send it. The web app keeps its workspace in your browser and a share link carries the inputs inside the address itself. The share page and the support page.