Any fast method to solve 7x7x7 centers?

[robertjurgen]

Currently my time for 7x7x7 centers is like 25 minutes (terrible). What I do is build 3x3 squares, then match the tredges like you do the edges (matching then replacing, then breaking them up). Then I match those up with the 3x3 block centers to make 5x5 centers.
This method feels very slow and I was wondering what fast speedcubers do to solve the centers on a 7x7x7.

 

[ianini]

I use 1x5 columns and the centers are done in 4 minutes, so I guess it's fast.

 

[Cyrus C.]

You can also spiral outwards.

 

[LNZ]

I use a mix of 1x5 blocks and rectangle blocks (where I can get one) to do the centres.

When I was praticing the 7x7 alot, I could do all 6 centres in about 9 to 11 minutes. And I had a PB of 28:30.

For the last two centres, I get as close as possible to solving them my row swaps and then use commutators to finish off the remaining few cubies.

 

[rahulkadukar]

Look at qqwref's tutorial on center building and of course practise as much as possible. I was getting around 8 mins but am now able to do the centers Sub 4 quite easily

 

[~Phoenix Death~]

Use K4...?

 

[trying-to-speedcube...]

Seriously guys, sub-4 centers is not hard. Whatever method you use. My centers are about 2:40 and I average about 5 minutes for the whole solve, which isn't really that good. Anyway, to the point, I make a 3x3 block, then expand that to a 3x4, while I pair up the next 3 centers, I try to look for a corner which is easy to attach, so I can expand the 3x4 to 4x4. If I can't, I expand to 3x5. Then I expand to 4x5 with either a 1x5 row or a 1x4 row, that depends. Then I finish off with a 1x5 block.

5 1x5 rows: 239 moves
3x3-3x4-3x5/4x4-4x5-5x5: 215 moves

It doesn't really look like there's much of a difference, but smaller steps make it easier to look ahead, so that's what I do (although I do recommend using 1x5 rows for the last 2 centers).