How to set up belt tension

I am way on my way to completing my D-Bot variant and have just threaded the GT2 belts, attached one end of each to the X carriage and was about to attach the other ends when it dawned on me that I didn't have a clue how tight they should be and indeed how to adjust the belts after some use?

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They should be tight enough to not have slop when moving back and forth.

They should not be so tight they rip your carriage in half.

By industry guides:

I would not use longest or shortest span.

Lock down carrige(s) while tensioning

Quote
cozmicray
By industry guides:

I would not use longest or shortest span.

Lock down carrige(s) while tensioning


[attachment 76834 Belt_deflection.jpg]

[attachment 76835 Belt_force.jpg]

Very strange numbers. You know we are in the 21° century

Just use a portable small scale with a hook.
You attach it to an unfastened idler pulley and pull till you read the tension value then fasten it. If the two belts strand are //, a value of 26N is fine (13N per strand is good for a 6mm wide GT2). If not //, just pull in the direction that bisects the angle formed by the strands. The force you will have to reach is 26N x cosine (angle/2).
It is accurate enough.
In our case, it is more convenient than to use the deflection method and better with long belts.

Edited 4 time(s). Last edit at 04/27/2016 12:20AM by MKSA.