Instructions for BlockCAD

(Last updated: 2000-01-03)

As the program was made for my kids, there is not much text in it, you have to figure out the symbols instead.

You can build (small) constructions, using basic blocks, roof blocks, and some specialized pieces like windows and doors. You can choose the color of each piece (and change them later).

The primary method for building is with the mouse, selecting blocks from the block bar to the right, and placing them in the 3D view by left clicking. In the normal mode (Safe mode), every block is placed immediately on top of the location you are pointing at, and it is impossible to place blocks in the air, inside each other, and so on. The Safe Mode can be turned off from the 'gear' menu.

The top bar


Exit the program

Empty doc

Clear the drawing, warning if unsaved work

Open folder

Open a saved model or a sub-assembly


Save a complete model to a file on (hard)disk, or save selected blocks to a file (useful for sub-assemblies).


Select a part of the current view and save as a .BMP or .JPG file


Print a screen dump (simplistic)


Settings menu

Rounded arrows

Rotate the view


Studs on/off. Redraw is faster when studs are off.

Wire frame

Wire frame on/off. Naturally, redraw is faster with no surface rendering.


See through base plate (from bottom). You can look into a model from the bottom side.

Magnifying glasses

Zoom in/out


Redraw the screen. Might be necessary after playing with the Z-level cut off.


Cancel insert mode


Transparent blocks


Studded/Flat blocks


Choose any color

Question mark

About BlockCAD - here You can find my address, and who has helped me make BlockCAD better

The bottom bar

Brick from above

View from top. Does not affect the other angle.

Thin arrows

Select predefined view

Brick from front

View from front. Does not affect the other angle.


Restore view. The current view is saved together with the model in a file, and can always be restored.

Combobox with Normal/Half/Fine

Select the positioning increment. Normal means full studs, Half means half a stud, and Fine means 1/24 stud.

Scroll bar

Z-level cut off. Using this you can 'build' the model, by showing (or hiding) one level at a time. Also useful when you need to fix something after the model is done.

Base plate dimensions

Enter zero to eliminate the base plate. Click in the 'Thick' checkbox to make effective.

Thick/thin brick

Choose thick or thin base plate

The side bar

Colored squares

Left click to choose color for new blocks (Or for repainting already inserted blocks), right click to select background color.


Flip the pages with building blocks

Combo box with page names

Quick selection of piece selection page


Left click to select, right click to bring up the page/block edit menu.

Mouse commands - note: Ver. 1.5 switched the meaning of the first two!

Shift Left click

Select a block in the model for moving it. Be careful - when Safe Mode is active (Default), the clicked block is immediately placed on top of every other block at the same XY coordinates. Normally you should only select blocks in the uppermost layer.

Left Click

Select a block (or the whole group a block belongs to) without moving it. Another Left Click deselects the block/group again. More than one block/group can be selected.

Ctrl Left Click

Select/unselect only the block pointed at, regardless of any groupings

Ctrl Shift Left Click

Cut loose all the selected blocks. You can now move them all and place somewhere else.

Alt Shift Left Click

Copy all the selected blocks. You can now place as many copies of them as you like.

Right click

If you are currently placing a block: Turn the block or sub-assembly.

If you are not placing a block: Change the color of the block pointed at.

Control-Right click

Turn the indicated block 90 degrees.

Shift-Right drag

Rotate the model. Same as fat blue arrows on top.

Alt-Right click

Toggle the studs on the indicated block.

Keyboard commands


Delete all selected blocks (if any) if no current block, else delete the current block.


Delete the current block (if any). Same as clicking the Pointer button


Deselect all selected blocks.

Arrow keys

Move the current block one block increment in X or Y.

Shift-Arrow keys

Move the current block one stud increment in X or Y.

Insert key

Turn the current block 90 degrees.

Page up/down

Move the current block one block increment in Z (only when Safe Mode is off).

Shift-Page up/down

Move the current block one stud increment in Z (only when Safe Mode is off).


Place a block. Same as Left click.

F1 - F10

Corresponds to the View buttons in the bottom bar.


Page/block Edit menu (right click in the block selector)

Before you try any of these commands, it's highly recommended that you make a backup copy of BLOCKCAD.INI and the PARTS subdirectory. If anything goes wrong, you can always restore the original.

Advanced toolbox window

The upper part of this window is concerned with selected parts in the model - if nothing is selected, nothing will happen (hopefully).

So, first you select one or more blocks, and then you can use the commands in this window.

The lower part of the window acts on the model as a whole.

NOTE for Ldraw users: The step feature is in early beta right now, and has for the moment no connection with the '0 STEP' command in Ldraw. It will eventually.

If you click on the 'Edit Ldraw info' button, the window will be enlarged, and you have the possibility to edit the translation between BlockCAD and Ldraw. This is only useful for you if you have created a new block, and want to have it drawn correctly in Ldraw (In other words - 'keepa da handsa off', most of you).