bombay comet puzzle solution

The Bombay Comet Puzzle Solution by Dick Guertin

This puzzle comes with a solution sheet (2 sided) with lots of pictures of how the puzzle is assembled. Although a picture may be worth several words, the solution is complicated by the fact that it must be held in one hand while being assembled with the other. Also, it needs to be turned in different directions several times. What follows is a simple layered method building from the bottom up on a central spine held by the base.

There are many pieces labeled from A through L. There is only one A, the key to the puzzle, and one K, the central spine of the puzzle. There are 17 B's, all of which are the shortest pieces. A is like the B's except it has a double notch in the center. All pieces have notches; even K has a small notch in the center. A, B, C, D, and E have only a single center notch. F, G, H, and L have a center notch and also slots on either side of the notch. L has a double wide slot on each side of the notch, and F, G, H all have a single wide slot on each side of the notch. Notches always connect to slots. So when told to connect B to F, you would place the notch in B into one of the slots of F. Note that B, C, D and E are progressively longer; and F, G and H are progressively longer, and L is like G except for the width of the slots.

K, J1 and J2 have narrow notches, and the slots run the length on these pieces, excluding the cubes on the ends. These are the longest pieces. J1 and J2 have the same size notches, and K has a smaller notch. Otherwise, notches are basically just single wide slots.

Start by placing one end of K into the hole in the base. You must orient K so that its notch points to the right and its slot faces you. Now connect a B to the lot at the bottom of K. On top of B, connect F to K with slots facing up. Connect 2 B's to F, one in each slot of F. On top of F, stack G and then connect 2 C's to G. On top of G, stack H and then connect 2 D's to H. You can pre-assemble F, G and H with their wing pieces, and then slide the assemblies onto the stack so the F, G and H notches join with the K slot.

You now have a stack of pieces coming up K. On top of H, stack J1 with its slot facing up and its notch joined to K. With J2's slot side facing left, at right angles, place J2's notch onto J1 on the right side of K, and slide it left until its notch slides under K's notch. You now have the slot on K still facing you, the slot on J1 facing up, and the slot on J2 facing to your left. Place E's onto J1's slot on either side of J2 running in the same direction as J2. E's notches point down joining with J1's slot.

Lay the two L's on the table, slots facing up. Connect 2 C's on both sides of the center notch of L. Then connect 2 B's near the tips of L. You should build two such assemblies. Pinch the C's so you can pick up the L assemblies and orient L's notch down and the C's and B's vertical. Slip each assembly onto J1 on the left and right sides next to the E's. Build two F assemblies the same way using 2 B's. Place the F assemblies onto J1 to the right and left of the L assemblies. You are building out from the center of K. Finally, connect one B on the right end of J1 and the only A on the left end of J1. You should be able to rotate A along its long axis so that its cube tips point left. You should also be able to slide the F and L assemblies on the left side to the left, and also slide E on the left against L. This leaves a gap between J2 and E on the left.

Now build H, G and F assemblies. H gets 2 D's, G gets 2 C's, and F gets 2 B's. Pick them up keeping the wings horizontal, starting with H and 2 D's. Place this assembly on top of J1 by sliding it down through the gap created by the assemblies sitting on J1 (L's, F's). Place G's assembly on top of H, and F's assembly on top of G. The notch on each of these assemblies faces the slot on K. Finally, connect a B to the top of K's slot.

Turn the entire structure so A moves from being on the left to being in front of you (facing you). Stand 2 E's vertically, notches facing J2, and slide them into the gap between J2 and the horizontal E that is now closest to you. Slide one in from the left side and one from the right side. They should slide into the center of the structure on either side of K. Do the same with 2 D's, and 2 C's and finally 2 B's at the tips of J2. Turn the puzzle to place A on the left again. Push A to the right by grasping both tips of A. Neighboring assemblies to the right of A should move right pushing E to close the gap between E and J2. Rotate A along its long axis so the tips point right. This locks the puzzle into position.

Note that this is a much simpler procedure for assembling the puzzle than the one supplied by the manufacturer. To disassemble the puzzle, just do these instructions in reverse, starting with unlocking the puzzle with the A piece, and sliding E and neighboring assemblies left along J1. This opens the gap necessary to extract B, C, D, E vertical pieces along J2. The rest is easy, unstacking B, F, G, H assemblies, etc. Have fun!

Pictures of solution in progress.

Pictures are above the captions that describe them.

Picture1: F-2B, G-2C, H-2D assemblies (2 of each needed).

Picture2: F-2B, L-2B-2C assemblies (2 of each needed).

Picture3: B and F, G, H assemblies stacked up K.

Picture4: J1, J2, and 2E's added on top of H assembly.

Picture5: A and F, L assemblies (left), B and F, L assemblies (right). Note that left side is shifted left.

Picture6: H, G, F assemblies topped by B, stacked up K. Note the gap between E and J2.

Picture7: 2E, 2D, 2C, 2B vertically into gap between E and J2. Shift A through E right. Turn A to lock. (done).

Alternate Puzzles

The Bombay Comet has three spines (J1,J2 and K) that are each 11 units long. A unit is the size of the side of the square at the ends of the pieces. If you reduced the length of the spines to 9 units, you could build a 33 piece puzzle by leaving out: 4E, 2D, 2H, and 2L assemblies. That's a reduction of 18 pieces. If you reduce the length of the spines to 7 units, you could build a 19 piece puzzle by leaving out: 4D, 2C, 2G, and 2F assemblies. That's a reduction of 14 pieces. Finally, you could reduce the length of the spines to 5 units and build a 9 piece puzzle called Newton's Comet. All of these reduced versions require different pieces, but the assembly method is essentially the same for all of them.

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