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AssuredElectrical, Home Specialist
Category: Home Improvement
Satisfied Customers: 4241
Experience:  35 years home improvement
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My black and decker string on 18 v trimmer keeps breaking the

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My black and decker string on 18 v trimmer keeps breaking the string?

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Customer: replied 3 years ago.
Yes I can wait a week or so. Do you understand the question? This is the nylon string that cuts the grass on a Black and Decker 18 v trimmer. Don't know why mine keeps ripping off when I use it

Thank you for your continued patience. We will continue the search for a Professional for you.



Welcome. My name is XXXXX XXXXX would be glad to assist.

What Model number is XXXXX trimmer?

Where did you purchase the replacement string installed, and what size?

Is it breaking in the middle between the spool and guard or someplace else?

Are you just trimming grass and not against fencing etc?

Customer: replied 3 years ago.
Hi Tommy, this is a refurbished model that I bought on line last summer.I tcan't see a model number. I had to install the spool and the line is .065. It breaks in the middle of the spool and guard and the grass is not around any fences, wire or rocks. Thanks David
Thanks for the information.

The .065 is the most common on battery string trimmers, although there are some that use the .080 line.

Couple things to look at since it is breaking in the middle.

Usually that is a sign of poor quality found on after market string line or too small of string line.

Look at where the string comes out of the spool through the eyelet.

If there is a lot of open space (line is not filling the opening of the eyelet), then what happens, is the when the spool is rotating and then stops, it actually presses the line against the eyelet and starts to deform a bit. This happens with each start and stop and weakens the line, eventually breaking it in two.
Flexing extensively.

It may sound odd, but it happens often on spool replacements.
The trimmers do operate at a very high rpm and it is very powerful even though it is a battery operated one.

Inferior brands sometimes do the same even if the line is the proper size.

You can try a test, run the trimmer while trimming, do not let go of the switch and keep trimming until the string is worn down extensively.
At that point stop and start as you would to get the line to feed by centrifugal force and go through that step again.

Then, trim some grass using the start and stop method as we all do when trimming.

If the line tends to break on the standard start and stop and not on the more continuous cycles, then that does indicate one of the 2 cases posted on size and quality in my opinion

I had a similar situation and a good friend who owns a landscape company gave me the same information to help me cure my issue.

These are the most common reasons.
AssuredElectrical, Home Specialist
Category: Home Improvement
Satisfied Customers: 4241
Experience: 35 years home improvement
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