Speedcubing

Speedcubing, also referred to as speedsolving, is a competitive mind sport centered around the rapid solving of various combination puzzles. The most prominent puzzle in this category is the 3×3×3 puzzle, commonly known as the Rubik's Cube. Participants in this sport are called "speedcubers" (or simply "cubers"), who focus specifically on solving these puzzles at high speeds to get low clock times. The essential aspect of solving these puzzles typically involves executing a series of predefined algorithms in a particular sequence with eidetic prediction and finger tricks.

A speedcubing competition

Competitive speedcubing is predominantly overseen by the World Cube Association (WCA), which officially recognizes 17 distinct speedcubing events. These events encompass a range of puzzles, including N×N×N puzzles of sizes ranging from 2×2×2 to 7×7×7 and other puzzle forms such as the Pyraminx, Megaminx, Skewb, Square-1, and Rubik's Clock. Additionally, specialized formats such as 3×3, 4×4, and 5×5 blindfolded, 3×3 one-handed, 3×3 Fewest Moves Challenge, and 3×3 multi-blind are also regulated and hosted in competitions.

As of October 2024, the world record for the fastest single solve of a Rubik's cube in a competitive setting stands at 3.13 seconds. This record was achieved by Max Park at the Pride in Long Beach 2023 event on June 11, 2023. Additionally, Yiheng Wang set the record for the average time of five solves in the 3×3×3 category with 4.09 seconds at Xuzhou Open 2024 on September 21, 2024. Speedcubing participants are predominantly under the age of 20, and numerous countries organize international competitions throughout the year. The widespread popularity of the Rubik's Cube has led to an abundance of online resources, including guides and techniques, aimed at assisting individuals in solving the puzzle.

History

An original Rubik's Cube from 1980 in Hungary.

The Rubik's Cube was invented on May 19, 1974, by Hungarian professor of architecture Ernő Rubik (born July 13, 1944). In 1979, Rubik partnered with Ideal Toy Company to garner widespread international interest in the cube. On June 5, 1982, the first world championship of speedcubing was held in Budapest, Hungary. Nineteen people competed in the event, and the American Minh Thai won with a single solve time of 22.95 seconds, which was, at the time, the fastest Rubik's Cube solve ever recorded. Other attendees include Jessica Fridrich and Lars Petrus, both of whom later contributed to the development of new solving methods and of the speedcubing community. The Rubik's Cube waned in popularity after 1983, as there were no official competitions held, but with the advent of the Internet, online websites began to surface to discuss the cube. With these websites facilitating the renewed popularity of the cube, a new generation of speedcubers arose.

Those prominent in the online speedsolving community, such as Ron van Bruchem, Tyson Mao, Chris Hardwick, and Ton Dennenbroek, eventually wanted to create an organization where cubers from around the world could meet and compete. In 2003, they organized a championship in Toronto, Ontario, followed by another competition in the Netherlands later that same year. This revival of competition sparked a new wave of organized speedcubing events, which included regular national and international competitions. There were twelve competitions in 2004, 58 more from 2005 to 2006, over 100 in 2008, and over 1150 in 2018. Since Budapest's 1982 competition, there have been nine further World Championships traditionally held every other year. This new wave of speedcubing competitions has been and still is organized by the World Cube Association (WCA).

Since the rise of speedcubing's popularity, numerous entrepreneurial ventures have been founded specializing in making or selling speedcubes, creating competition between these brands and Rubik's. Dozens of cube manufacturers, such as GANCube, MoYu, YJ, and QiYi, have begun improving the cube's technology to allow for smoother turning and faster solving. This has helped to facilitate the eventual rise of the Rubik's Cube as not just a toy, but also a lucrative business.

World Cube Association

Main article: World Cube Association

See also: List of world records in speedcubing

The World Cube Association (WCA) is an organization which organizes speedcubing competitions and ratifies results. The WCA consists of the WCA Board, WCA Committee, and the WCA Council. The WCA Board is the head or leader of the entire WCA, and is responsible for fulfilling tasks not completed or done by the WCA Committee and WCA Council. The WCA Appeals Committee(WAC)is responsible for ensure right and fair decisions in accordance with the WCA Regulations. The WCA Committee is also responsible for reviewing and resolving appeals regarding the decisions of other WCA Staff members. The WCA Council is a special type of Team that serve as an advisory role to the WCA, and consist of community members, and not WCA Staff Members. These WCA Staff Members are part of a cubing community, which consist of organizers, who organize and manage cubing competitions, and delegates, who help in managing competitions and help competitors who are disoriented with the competition environment, and to decide whether a competitor’s solve should be penalized or not. WCA Regulations are required to be followed by competitors. WCA Regulations can be found on the official WCA website.

Methods

3×3×3

The standard 3x3x3 can be solved using several methods, not all of which are intended for or suited to speedcubing. The most commonly used methods for speedcubing are CFOP, Roux, and ZZ, which are generally considered to achieve the fastest times. The CFOP method is used by the majority of cubers and employs a layer-by-layer system with numerous algorithms for solving the final layer. Roux, the second most popular method, starts by forming a 3x2x1 block on either side of the cube and solves the middle layer last, using fewer algorithms. ZZ uses a unique step called Edge Orientation to improve the ergonomics of turning. Other notable methods include Petrus, which has been popular at times in the past; however, it is now considered sub-optimal to CFOP and Roux and was abandoned due to its unfavorable fingertricks.

Solving larger cubes, such as 4x4x4 and 5x5x5, is most often done by reducing them to 3x3x3 and solving them like so, while 2x2x2 can be solved with the same or similar methods as 3x3x3. However, specialized 2x2x2 methods are quicker, and are regarded as superior to 3x3x3 methods. These methods include Ortega, CLL, and the EG method (which can allow users to plan the entire solution during inspection).

CFOP

Main article: CFOP method

CFOP speedsolver in a speedcubing competition

The CFOP (abbreviation for Cross-F2L-OLL – PLL) method, also known as the Fridrich method after one of its inventors, Jessica Fridrich, who finished second in the 2003 Rubik's Cube World Championships, is the most commonly used method in speedcubing today. Its origins are credited to David Singmaster, who was one of the first to publish a layer-by-layer method of solving in 1980, and Guus Razoux Schultz, who built upon this and developed a more efficient system for the first two layers (F2L). Jessica Fridrich then finished developing the method and published it online in 1997, an event that was very influential in the revival of competitive speedcubing. The first step of the method is to solve a cross of edge pieces on the first layer. The remainder of the first layer and all of the second layer are then solved together in what is referred to as "corner-edge pairs," or slots. Finally, the last layer is solved in two steps – first, all of the pieces in the layer are oriented to form a solid color (but without the individual pieces always being in their correct places on the cube). This step is referred to as orientation and is usually performed with a single set of algorithms known as OLL (Orientation of the Last Layer). Then, all of those pieces are permuted to their correct spots. This is also usually performed as a single set of PLL (Permutation of the Last Layer) algorithms. OLL and PLL use 57 and 21 algorithms, respectively.

The CFOP method can be used as a less advanced method by dividing the steps into more steps, reducing the number of algorithms that need to be learned but sacrificing time. It is usually known as the beginner method or layer by layer (LBL). Most people start learning CFOP with 4LLL (Four-Look Last Layer), which is the less advanced, slower, and algorithm-reducing (from 78 algorithms to 16) way to learn CFOP. The 4 steps are divided into edge orientation, corner orientation, corner permutation, and edge permutation (which can be called EO, CO, CP, and EP). Later on, full OLL, which has 57 algorithms, and full PLL, which has 21 algorithms, can be learned. An average CFOP user that solves with full OLL and PLL, along with an efficient cross (which takes 8 moves at maximum) and efficient F2L (which takes almost 30 moves), consists of 55-60 moves, which means that it has a higher move count than Roux and ZZ. However, finger tricks and algorithms are more researched with CFOP than any other method, which explains why the majority of the fastest speedcubers use CFOP as their main speedcubing method.

The CFOP method is the most widely used speed-solving method. It is a more efficient version of the Layer-By-Layer method (also known as the beginner's method). It is very popular due to the vast amount of resources that teach and improve upon the CFOP method. Many top speedcubers, including two-time World Champion Feliks Zemdegs and world record holder Max Park, learn additional sets of algorithms for the last slot and layer, such as Corners of Last Layer (COLL), which orients and permutes the corners when the edges are oriented, or Winter Variation (also known as Valk Last Slot, or VLS), which finishes OLL while inserting the last pair, and ZBLL, which combines the solving processes of OLL corner orientation and PLL in only one algorithm, provided the last-layer edges are oriented.

Pseudoslotting is a technique that allows advanced CFOP solvers to be more creative with efficient solutions. It is an alternative method to F2L, where instead of creating and inserting pairs with matching colors, the bottom layer is intentionally misaligned to allow different pieces to be paired together. This provides more freedom while pairing pieces during F2L. Pseudoslotting is similar to another technique called keyhole in which the bottom layer is misaligned to allow a piece to be inserted independently of its solved counterpart. It is widely believed that Tymon Kolasiński (who holds the European record for a 3x3x3 single with 3.66 seconds) is the best speedcuber who uses pseudoslotting.

Roux

The Roux method was invented by French speedcuber Gilles Roux. The first step of the Roux method is to form a 3×2×1 block, usually placed in the lower portion of the left layer. The second step is creating another 3×2×1 on the opposite side, so each block shares a bottom color. The creation of these blocks is commonly known as "block-building". The remaining four corners are then solved using a set of algorithms known as CMLL (Corners of the Last Layer, without regard to the M-slice), which leaves six edges and four centers that are solved in the last step, L6E or LSE (Last Six Edges).

This method is not as dependent on algorithm memorization as the CFOP method since all but the third step is done with intuition as opposed to predefined sets of algorithms. Because of the frequent use of M moves, the Roux method can be performed without any rotations (unlike the CFOP method), which means it is easier to look ahead (solving pieces while at the same time looking for the solution to the next step) while solving. It is also considered one of the most efficient speedsolving methods, with its average move count being between 45 and 50 moves for experienced solvers. However, the Roux method of speedcubing has been criticized over the years because, unlike CFOP, ZZ, or Petrus, Roux requires M (middle layer) slices to solve LSE. Using M slice moves makes it harder to achieve higher TPS (turns per second) because the finger tricks are almost always flicks, but high TPS is achievable through training.

One of the users of this method, Kian Mansour, broke the one-handed (OH) world record average with a time of 9.54 seconds. Sean Patrick Villanueva is the first Roux user to achieve a sub-6 average of five in competition and is currently ranked twenty-sixth in the world by 3x3 average. He also podiumed in 3x3 at the WCA World Championship 2019 (2nd Place). On May 25, 2024, he broke the OH WR average with the largest margin in nearly 10 years, bringing it down from 8.62 to 8.09 seconds. He also broke the WR single with a 6.05 a few weeks later, though he lost this to Dhruva Sai Meruva, a CFOP one-hand solver on October 6, 2024.

ZZ

The ZZ method (short for "Zbigniew Zborowski") is a modern speedcubing method originally proposed by Zbigniew Zborowski in 2006, and built upon since. The method was designed specifically to achieve high turning speeds by focusing on movement ergonomics and is a combination of a block-building method and a layer-by-layer method. The initial pre-planned step is called EOCross and is the most distinctive hallmark of the ZZ method. It involves orienting all edges while placing the cross pieces. It is also common to build an EOLine, mainly used for one-handed solving, where all edges are oriented and only the front and back cross edges are placed. The next step solves the remaining first two layers using only left, right, top, and bottom face turns, one of the advantages of ZZ. On completion of the first two layers, the last layer's edges are all correctly oriented because of edge pre-orientation during EO. The last layer may be completed using a number of techniques, including those used in the CFOP method. An expert variant of this method, ZBLL (Zborowski-Bruchem Last Layer), allows the last layer to be completed in a single step with an average of just over 12 moves but requires a total of 493 algorithms to be learned. Due to the ergonomics of ZZ, rotating when solving will never be needed, unlike in the CFOP method. The ZZ method has fewer moves than CFOP, with ZZ averaging 53.5 compared to CFOP's 55–60 moves. Because ZZ uses EO, it is very move-efficient, and these techniques are sometimes used in FMC (Fewest Moves Challenge).

Corners-first methods

Corners-first methods involve solving the corners and then finishing the edges with slice turns. Corner-first solutions were common in the 1980s. It was used by the 1982 world champion Minh Thai. Currently, corner-first solutions are rarely used among speedsolvers. Dutch cuber Marc Waterman created a corners-first method in the cube craze and averaged 18 seconds in the mid-late 1980s.

Fewest Moves Challenge

At the highest level, there is typically not a standard method used for Fewest Moves solving. Rather, competitors attempt to solve the cube intuitively using solving techniques such as blockbuilding, Normal-Inverse-Scramble-Switch (NISS), commutator insertions, and Domino Reduction after its rise to popularity in 2019. Most solves use multiple of these techniques in order to generate a solution.

Blindfolded

In 2003, when the first blindfolded competitions were organized, world record solvers would use the 3OP (3-Cycle Orientation Permutation) Method, which orients and then permutes pieces using 3 cycles. As of today, methods such as 3-Style and M2 are among the fastest and most popular blind-solving methods. The Old Pochmann Method, which is a method that solves one piece at a time, is a method typically used by beginner blindsolvers. Blindfolded solvers use letter patterns to help memorize sequences of moves in order to solve the cube.

The lettering scheme that blindfolded solvers use is called the Speffz lettering scheme, and each sticker or individual color is given a letter. The letters are assigned starting with the top edge of the top face, going clockwise, and beginning with A. The top edge of the top face is A, the right edge is B, the bottom edge is C, and the left edge is D. The same process is done on the other sides in the order top, left, front, right, back, and bottom to get every edge lettered from A to X. The same process is applied to all of the corners, starting with the top left corner and going clockwise in the same face order. A cycle of piece swaps is then used with the letter E being used as a buffer location for corners and D commonly being used for edges in the Old Pochmann method. The current 3x3 average and single blindfolded world record holder is Tommy Cherry, from the United States.

Competitions

Speedcubing competitions have been held every year since 2003. The WCA was formed in 2004 to govern all official competitions. For a competition to be official, it must be approved by the WCA and follow the WCA regulations. Included in the regulations is the necessity of having one or more WCA delegate in attendance. A delegate's main role is to ensure all regulations are followed during the competition. Once the competition is finished, results are uploaded to the WCA website. Judges oversee the round. Delegates help the judge. Runners give the scrambled or solved cube to the competitor. A scrambler scrambles the cube.

Format

The majority of puzzle competitions are held using a trimmed mean of five. This involves the competitor executing five solves in the round in question, after which the fastest and slowest solves are disregarded and the mean of the remaining three is used. The 6×6×6 and 7×7×7 events are ranked by a straight mean of three—only three solves, none of which are disregarded. In 3×3×3 blindfolded and 3×3×3 fewest moves challenges, either a straight mean of 3 or the best of 3 is used, while 4×4×4 blindfolded, 5×5×5 blindfolded, and multiple blindfolded challenges are ranked using the best of 1, 2 or 3, depending on the competition.

When a round begins, competitors turn in the puzzle they will use. Puzzles are scrambled using a computer-generated scramble. In each round, five, three, or one (depending on the format mentioned above) scrambles are used. Every competitor in the round will receive each scramble once. Before starting a solution, a competitor has up to 15 seconds to inspect the puzzle (inspection is removed for blindfolded events). This is monitored by a judge with a stopwatch. Once the solution is complete, the judge records the time on the competitor's scorecard, which is signed by both. If the puzzle is unsolved and the timer is stopped, the time is recorded as "DNF" (Did Not Finish). There are also numerous reasons why the solver can receive a two-second addition to the solve time, such as a face being more than 45 degrees off or the competitor going over the allowed inspection time. A competitor can also receive an extra solution to replace the one just completed, for example in the case of a timer malfunction or a duplicate scramble.

The official timer used in competitions is the StackMat Gen 4 or Gen 5 timer, which was originally designed for sport stacking. This device has touch-sensitive pads that are triggered by the user lifting one or both of their hands to start the time and placing both their hands back on the pads after releasing the puzzle to stop the timer.

Only two WCA recognised events are not "speedsolving" events (i.e. are scored by means other than time taken for solves), these being: Fewest Moves Competition, or FMC, which is scored using the number of moves for a competitor's solution, with a lower number of moves being better, and multiple blindfold solving, or "multi-blind", where a competitor's score is calculated by subtracting the number of unsolved cubes from the number of solved cubes.

Official competitions are currently being held in several categories.

Category	Cube type
Speedsolving	2×2×2, 3×3×3, 4×4×4, 5×5×5, 6×6×6, 7×7×7
Blindfolded solving	3×3×3, 4×4×4, 5×5×5
Multiple blindfolded solving	3×3×3
One-handed solving	3×3×3
Solving in fewest moves	3×3×3

Speedsolvers solving Megaminxes at the 2011 Estonian Open

Competitions will often include events for speedsolving other puzzles as well, such as:

• Pyraminx, a pyramid-shaped puzzle.
• Megaminx, a twelve-sided dodecahedral puzzle solved similarly to a 3×3×3.
• Skewb, a cube-shaped puzzle added in 2014 as an official WCA event due to its growing popularity and the ease of its regulations.
• Square-1, a cubed puzzle that changes shape as it is solved
• Rubik's Clock, a double-sided circle-shaped puzzle with 9 clock faces on it that is considered solved when all clock hands are in the 12 o'clock position.

The following are no longer official events:

• 3×3×3 with Feet, 3×3×3 with Feet was removed from the list of official WCA events in 2020.
• Rubik's Magic, a folding puzzle with 8 connected tiles, Rubik's Magic was removed from the list of official WCA events in 2012.
• Rubik's Master Magic, a folding puzzle with 12 connected tiles, Rubik's Master Magic was removed from the list of official WCA events in 2012.
• Rainbow Cube, a cuboctahedron-shaped puzzle, the Rainbow Cube was removed from the list of official WCA events in 2007.
• Siamese Cube, two connected 3×3s, the Siamese Cube was removed from the list of official WCA events in 2007.
• 3×3 with No Inspection, 3×3 with No Inspection was removed from the list of official WCA events in 2006.

World Rubik's Cube Championships

The WCA organizes the Rubik's Cube World Championship as the main international competition once every two years. The latest championship was held in Incheon, South Korea from August 12 to 15 August 2023.

Championship	Year	Host	Date(s)	Nations	Competitors	Events	Winner (3x3)	Winning time(s)	Ref
I	1982	Budapest	5 June	19	19	1	Minh Thai	22.95 (Single)
II	2003	Toronto	23–24 August	15	88	13	Dan Knights	20.00 (Average)
III	2005	Lake Buena Vista	5–6 November	16	149	15	Jean Pons	15.10 (Average)
IV	2007	Budapest	5–7 October	28	214	17	Yu Nakajima	12.46 (Average)
V	2009	Düsseldorf	9–11 October	32	327	19	Breandan Vallance	10.74 (Average)
VI	2011	Bangkok	14–16 October	35	292	19	Michał Pleskowicz	8.65 (Average)
VII	2013	Las Vegas	26–28 July	35	580	17	Feliks Zemdegs	8.18 (Average)
VIII	2015	São Paulo	17–19 July	37	428	18	Feliks Zemdegs	7.56 (Average)
IX	2017	Paris	13–16 July	64	938	18	Max Park	6.85 (Average)
X	2019	Melbourne	11–14 July	52	833	18	Philipp Weyer	6.74 (Average)
XI	2021	Almere	Cancelled	—	—	17	—	—
XII	2023	Incheon	12–15 August	63	1187	17	Max Park	5.31 (Average)
XIII	2025	Seattle	3-6 July	TBA	2000	17	TBD	TBD

World Records

Main article: List of world records in speedcubing

Speedcubing world records ratified by the WCA.

Note: For averages of 5 solves, the best time and the worst time are dropped, and the mean of the remaining 3 solves is taken. For events where only 3 solves are done, the mean of all 3 is taken.

Event	Type	Result	Person	Competition (Date(s))	Result details (Min:Sec.100ths)
3×3×3	Single	3.13	Max Park	Pride in Long Beach 2023 (11 June)	—
	Average	4.09	Yiheng Wang (王艺衡)	Xuzhou Autumn 2024	3.83, (5.16), 4.55, (3.71), 3.88
2×2×2	Single	0.43	Teodor Zajder	Warsaw Cube Masters 2023 (5 November)	—
	Average	0.92	Zayn Khanani	New-Cumberland County 2024 (9 March)	0.84 / (2.69) / (0.71) / 1.04 / 0.88
4×4×4	Single	15.71	Max Park	Colorado Mountain Tour - Evergreen 2024 (8 June)	—
	Average	19.38	Max Park	Arizona Speedcubing Spring 2023 (19 March)	(17.60) / 18.49 / 19.37 / (23.80) / 20.28
5×5×5	Single	31.60	Tymon Kolasiński	DuPage Fall 2024 (28-29 September)	—
	Average	34.76	Max Park	Rubik’s WCA North American Championship 2024 (18-21 July)	(39.71) / 35.10 / 33.55 / 35.44 / (33.75)
6×6×6	Single	58.03	Max Park	CubingUSA Western Championship 2024 (2-4 August)	—
	Average	1:05.66	Max Park	CubingUSA Western Championship 2024 (2-4 August)	1:09.34 / 1:09.61 / 58.03
7×7×7	Single	1:34.15	Max Park	Rubik’s WCA North American Championship 2024 (18-21 July)	—
	Average	1:39.68	Max Park	Nub Open Yucaipa 2024 (20 April)	1:36.19 / 1:38.19 / 1:44.65
3×3×3 Blindfolded	Single	12.00	Tommy Cherry	Triton Tricubealon 2024 (11 February)	—
	Mean	14.05	Tommy Cherry	Rubik's WCA European Championship 2024 (25-28 July)	13.48 / 14.42 / 14.24
3×3×3 Fewest Moves	Single	16	Sebastiano Tronto	FMC 2019 (15–16 June)	—
			Aedan Bryant	Ashfield Summer Challenge 2024 (23 June)
			Levi Gibson
	Mean	20.00	Wong Chong Wen	FMC Johor Bahru 2023 (17 September)	20 / 21 / 19
				FMC West Melbourne 2024 (14 April)	23 / 18 / 19
3×3×3 One-Handed	Single	5.66	Dhruva Sai Meruva	Swiss Nationals 2024 (4-6 October)
	Average	8.09	Sean Patrick Villanueva	Quezon City Open II 2024 (25-26 May)	8.94 / (9.38) / 7.71 / (6.60) / 7.63
Rubik's Clock	Single	1.97	Brendyn Dunagan	La La Land 2024 (31 August-1 September)	—
	Average	2.39	Volodymyr Kapustianskyi	Grand Forks 2024 (14 September)	(2.96) / 2.46 / (2.24) / 2.29 / 2.43
Megaminx	Single	23.18	Leandro Martín López	Di Tella Inspira 2024 (13 April)	—
	Average	26.84	Leandro Martín López	Nacionales Argentinas 2023 (1-3 September)	(25.22) / 26.31 / 26.55 / 27.67 / (28.15)
Pyraminx	Single	0.73	Simon Kellum	Middleton Meetup Thursday 2023 (21 December)	—
	Average	1.27	Lingkun Jiang (姜凌坤)	Deqing Small Cubes Summer 2024 (25 August)	(1.43) / 1.22 / (1.18) / 1.21 / 1.39
Skewb	Single	0.75	Carter Kucala	Going Fast in Grandview 2024 (23 March)	—
	Average	1.52	Carter Kucala	CubingUSA Heartland Championship 2024 (7-9 June)	1.65 / 1.45 / (2.57) / (1.37) / 1.45
Square-1	Single	3.41	Ryan Pilat	Wichita Family ArtVenture 2024 (2 March)	—
	Average	4.81	Dylan Baumbach	Cube More in Ardmore 2024 (21 September)	(4.19) / 4.40 / 5.13 / 4.89 / (DNF)
4×4×4 Blindfolded	Single	51.96	Stanley Chapel	4BLD in a Madison Hall 2023 (28-29 January)	—
	Average	1:06.46	Stanley Chapel	PBQ and a Little Eggstra Oxford 2024 (30-31 March)	1:01.14 / 1:04.03 / 1:14.20
5×5×5 Blindfolded	Single	2:04.41	Stanley Chapel	Virginia Championship 2023 (10-12 November)	—
	Average	2:27.63	Stanley Chapel	Michigan Cubing Club Epsilon 2019 (14 December)	2:32.48 / 2:28.80 / 2:21.62
3×3×3 Multi-Blind	Single	62/65	Graham Siggins	Blind Is Back LA 2022 (26 June)	57:47

See also

• Rubik's Revenge
• Professor's Cube
• Magic Cube

External links

• Speedsolving.com
• Speedsolving.com Wiki
• Fridrich Method
• Roux Method
• ZZ Method
• Optimal solutions for the Rubik's Cube
• List of Rubik's Cube manufacturers