Trimrite topmatewhy does it continually break the string no matter how carefully I wind it?

first guess is that you have installed it incorrectly
when winding on the string, it goes on in an anticlockwise direction so that it is point in the right direction for feeding out

when you are holding the spool on which you wind the string wind the string on in a anticlockwise direction
if it uses 2 strings ( one out of each side of the spool
wind in both strings together in the anticlockwise direction
that way , when you put the spool in the head and go to use it , the string is wound the right way to feed out and not get tangled

Pull the head off by turning the inner hub counter clockwise while holding the outer head still. Once the inner head pops out, turn it over and look for the string rotation arrow. If you can't find the string winding directional arrow, start the trimmer and determine shaft rotation direction (generally counter clockwise) and wind the string in the same direction as the head rotates when installed.
Pull about 5 arm lengths of string out of a string spool and cut it off. Place the inner trimmer head on an object that will hold it while you pull the string to even lengths through the winding hole (the support brackets of a pickup truck tail gate work well for holding the inner head while doing this).
Begin wrapping the string double wraps in the proper direction, laying them evenly and closely to the previous wrap, working it back and forth as the string begins to build up. Avoid crossing the string over itself more than necessary, the string can weld itself together if the strands cross to awkwardly. Once the string is wound, hold the head with one hand and slide the string through the outer head holes, avoid letting the string come unwrapped.
Carefully place the inner head down into the outer header. Avoid letting the string get caught between the inner and outer head. Once the heads are together lock the inner head onto the outer head by turning it and locking the round knobs into the outer head slots.
You can trim the string or let the trimmer guard do it. If the string doesn't feed it is either wound the wrong way, tangled between the inner/outer head or welded to itself.

Pull recoil and remove screw holding the string pulley. There's a spring behind it. Find where it hooks to the housing bend it to latch. This is what broke loose. Now wind it all into the designated spot. Attach string pulley and CAREFULLY put back together. Finally wind up insert rope and let it retract. This is a very difficult and frustrating job.

It sounds like you are winding the line in the wrong direction. You should wind the line in the opposite direction that the head spins during operation.

Good Luck!

Jim

LINE REPLACEMENT (Fig. 8) (For Reel EasyTM Head) Use 2.4mm monofilament string. Use original manufacturer's replacement string for best performance. n Stop the engine and disconnect the spark plug wire. n Cut one piece of string approximately 7.6m in length. n Rotate knob on string head until line on knob aligns with arrows on top of string head. n Insert one end of string into eyelet located on the side of the string head and push until string comes out through eyelet on the other side. Continue to push string through the string head until the middle section of the string is inside the string head and string outside the string head is evenly divided on each side. n Rotate the knob counterclockwise on the string head to wind the string. Wind the string until approximately 20cm remains protruding from the string head. INSTALLING STRING IN PRO CUT II STRING HEAD Use monofilament string between 2.4 mm and 2.7 mm diameter. Use original manufacturer's replacement string for best performance. n Stop the engine and disconnect the spark plug wire. n Gather two of the pre-cut lengths of trimmer line provided or cut two pieces of trimmer line, in 28 cm lengths. n Insert the strings into the slots located on the sides of the string head. String should be pushed in until approximately 2 cm protrudes from the holes on the top of the string head. n Remove old string by pulling it from the holes located on the top of the string head. http://www.screwfix.com/sfd/i/cat/pdfs/89/p4763889.pdf

It sounds like the sting is wound backwards. Try winding a short piece in the opposite direction. If it is backwards, it will be gone in a hurry.

Normally you leave string slack enough at the start so you can get 3 or 4 winds before it is at tension.

While winding, pull string sideways to keep gentle tension on the string.

They have cranks to speed up the winding process you caanbuy that are inexpensive.

Here is an excellent video of how to:

http://www.ehow.com/video_4396928_replace-strings-acoustic-guitar.html

Did the string break? Possible that the spring broke inside the housing, If so, then you will have to take it to a shop. I am in Largo Florida and can fix it. If you have a new string. Connect it to the right side of carriage then pull it through with a hook. Then wind up the spring clockwise several rotations then hook up the string and carefully and slowly let the spring take up the slack.

I’m happy to help further over the phone at https://www.6ya.com/expert/jayw_0e86fb055a7b73de

That's the problem; you're using light gauge guitar strings. Chances are that if you are not used to playing strings that light, you're fretting hand will hit the strings with more force than is neccesary to fret them, thereby forcing them out of tune. You can solve this problem by adding more winds around the string post (three or more winds should do it), or you can switch to a heavier gauge of string.

If they're true locking tuners, they should have a notch on the back of the gear housing that you turn with a nickel to engage the locking mechanism once tuning has been established.

Also; check the intonation of the guitar itself on an electronic tuner. If it tunes right but sounds out of tune when played, this is an intonation issue, and can be solved by adjusting a small set screw that moves the individual saddle back and forth in the tune-o-matic style bridge. You can check this by tuning the string to the correct note, then playing the same string at the 12th fret and checking it against your tuner. If it rings in true, you're fine, if it comes up flat or sharp, every note on the fretboard is going to be off by that much, and you'll have to adjust accordingly (turn the screw to the right to add length and lower a sharp note, turn the screw to the left to subtract length and raise a flat note, if I remember right).

Hope that helps.