Doing this or any mod may cause MakerTech original parts unusable. just thought i'd mention that.
My original servo died. bought a replacement that seemed to have issues of its own. i was able to find a solution though.
Power HD 20KG servo
they cost anywhere from $15-30. probably depending if its a knockoff or not. the ones i purchased cost about $23 from ebay. they come with a red or blue labeling on the servo.
They are not a direct replacement. modifications to both the mounting bracket and the servo itself were made. A needle file set from Harbor Freight can be had for about $5. I suggest the steel ones not the diamond ones as they do not work well on the plastic of the servo. though the diamond works well on the metal so having both sets are advantageous.
first filing the metal bracket is necessary for this to work. you'll need to file the upper and lower spans of the rectangle opening. try to file them evenly as it will make the hole alignment for mounting easier. try to use the file across the entire length of the span. a larger file would be ideal. personally i used a 9in. file. if you have one great if not needle files work fine. once you've filed the top and bottom spans of the opening some check it with the corner of the servo. if it doesn't fit repeat filing and checking the opening with the servo. once it fits through the entire length of the opening, move on to the sides. use the same filing process on the sides. you will get close to the holes since the servo has to be angled into the opening. this is fine, as there is still plenty metal to be structurally sound. next the holes on the servo are wider than the ones on the bracket. here i opted to file the plastic on the servo bringing the holes closer to the body of the servo allowing the screws to fit. use one of the round needle files to accomplish this. once it all fits you can mount the servo.
one thing you will notice from the pictures below of the servos i purchased(i purchased both). they have a female connector. as is the connector from the printer. so you will need some pin connectors. the link for them is below. i didn't link the people i bought my servos from as they were slow on the shipping side. other than that they were fine. anyway, the pin connectors can be cut to only the 3 pins needed.
a note. as i stated i bought both the blue and red labeled servos. i am currently using the red labeled one as it centered for the arm installation best. for me the blue one was off to a slight angle so when it actuated to one side it was a little loose and the other side it was very tight and the servo continuously tried actuating. felt this would eventually burn up the servo. it could most likely be fixed via adjusting the Angles in Marlin. but the red labeled one worked the best. though it too pushed one side continuously. i slightly bent the stop outward till the servo stopped trying to actuate in that direction.
i haven't tried doing any multi-filament prints other than the calibration printing. it worked fine during that so it would stand to reason there are no issues. with that i will be printing some in the future. if any issues arise i will post here with any fixes i implemented.
here are pictures of the servos i bought.
hope this helps someone. have a nice day