This section is more or less obsolete, but if you have an old type cube with screws, you can use this information
A cube with screws e.g. Rubik's Hungary version Rubik's Studio cube
Silicone spray NOT pertrol based! Just 100% silicone. *WARNING* do not use silicone spray on just all your puzzles. Some puzzles have paper stickers, lik many of the Rubik's Oddzon versions with the new Rubiks's logo. Silicone will damage the paper stickers.
Bold scalpel knife or kitchen knife
Disassemble position, rotate face 45° degrees, and push the two bottom cubies down with one thumb and lift the edge with your other thumb. You may need some force. I do not recommend to use a screwdriver for this.
If you have a logo, you can protect it with with some clear PVC sticker aganst damaged and against the silicone spray.
Disassemble the cube, clean the cube with a dry towel if needed, dust etc must be removed
Remove center caps with a bold knife (I prefer a scalpel knife) on the axle.
As an option you can disassemble the cube and adjust the springs, grind or sand down the spring end flat. This prevents major wear of the center cubie.
Dissemble the cube and clean the cube with a dry towel
Lubricate with silicone spray every piece, you can arrange the pieces like below. Only apply silicone on the outside of the cubies, before lubriacate "polish" and clean the cubies a bit with a dry cloth. *NOTE* do not apply silicone spray in the centerpiece or on the screw end!
This is a fast way to spray all the pieces, spray rotate the corners three then spray the edges let it dry for a minute or two, turn over and spray again if needed, let is dry forthree to ten minutes. Wipe off the lubricant of the faces (and possibly on the stickers) a bit but let it on the extensions.
Quick Method for lubrication (use this for maintenance): Leave one edge out. Lubricate with silicone spray in the open hole. Only apply silicone in the inside not on the outside. Assemble the edge and let the silicone dry.
Play with the cube for 1-3 hours, repeat from step 5 if it does not turn correct. If you see more dust in the center piece as usual, compared to other centerpieces, you should check the spring. carefully sand down the ends of the springs with a nail file so that is it less sharp and don't scratch into the center piece plastic.
As an option you can glue the tip of the screw, this prevents the screw unwind. Normalluy only needed for old type cube that are already used.
Please note only apply super glue on the screw end! Wipe of excessive glue, it should be dry when you insert the screw in the center piece. Never put glue directly in the centerpiece or on the kernel.
Tune the screw tension, pull the centers apart of opposite sites, if the screw tension is evenly they should have the same space (about 1mm)
Assemble the cube. And adjust the screws a bit if needed if the faces do not feel evenly
Turn in the cube, do regular movement sequence like (F2 R2 B2 L2) x6 on each side, it must be turned for a while (1-3 hours).
Remove center caps on the axle and fine tune all screws, for the old type caps, you can fixed the center caps by making dents on the inside of the center caps (method by Peter Jansen) Use a hammer and make dents, hold the hammer in an angle.
Modify screw as option
An other idea by Simon Page is improvement is file down the thread on about the top 10mm of the screw, this will prevents the spring jamming or snagging against the screw (see image). The advantage is that the centre cubies move very smoothly along their 1mm or so of travel, plus the screw thread doesn't enlarge the hole at the bottom of the centre cubie with use. The downside is that it does take a while to do!
As alternative to file down the screw you can also fill the top end with fast harden epoxy. Fast harden two compound epoxy can be found in autoshops, but they might call it liquid metal. I used permanent repair (BISON). I addition you can spray some silicone on the epoxy part. The result is very noticeable, if you compare it to a normal screw spring set on the kernel with the center piece only. Please note I did not fully test all of this during long speedcubing, but I expect that this should prevent major wear of the center piece and prevent the center piece coming lose. So in short you speedcube will hold longer and run smoother! After some mails from Simon Page, a good idea to prevent major wear of the internal center piece is the use of a small metal washer. A M2 metal washer fits, but you have to drill the hole a bit larger or you may use the washers of the spring set of cube4you (not the screws)