How to operate

Here you will find the most common instructions on how to operate your GMT grapple saw efficiently. Please check the user manual for more information.

If you are facing any problems during operation, please check the page "How to install" for most common installation and set-up problems. If the problem you are facing is still not solved, please do not hesitate to send us a short WhatsApp-video which shows the problem you are facing. We will come back to you as soon as possible.

Keep checking our website: This page will be updatet frequently based on new developments and frequently asked questions. If you have any, send us an email: info@gmt-equipment.com.

How does your grapple saw work

How to use your grapple saw in city areas

This video shows a great example on how to use your GMT grapple saw in city areas safe and efficient.

The first part of the video showing a tree felling job close to a house and a car. By moving the GMT grapple saw around the tree making cuts from various sides, you are able to control the felling direction to prevent damage. In this way tipping of tree branches is no issue anymore.

The second part of the video gives you a good overview how to approach a tree with the GMT grapple saw. Working from top to bottom; always keep the tree balanced.

 

How to warm up your GMT grapple saw

During winter conditions you might face some difficulties in operating your grapple saw due to thick oil. Warming up of the oil should help you to get started smoothly. 

Warming up your grapple saw by operate grapple open-functon 100% end rotate the machine for several minutes. Do NOT use grapple close and saw function!

(Saw function is only degisned for a single cut, not for continously running due to accumulator size.)

How to estimate weight of tree piece

The greatest danger involves underestimating the weight of the tree or branch being cut. Once it has been cut, the tree or branch becomes a suspended load that the machine has to support!

Besides the weight of the tree or branch, also take the constant weight of a possible jib and rotator with felling grapple into account.

To support the operator in determining if the diameter of the tree or branch to cut is not larger than Ø35 cm (Ø13,8”) for GMT035 or Ø50 cm (Ø19,7”) for GMT050 the following rule can be used: when the claws of the grapple are placed around the tree or branch and the claws are fully enclosing the wood the diameter is smaller than Ø35 cm (Ø13,8”) or Ø50 cm (Ø19,7”).

Afbeelding: grapple close

Below you will find a lifting reference table, containing the weights of certain lengths of various types of wood, in order to give you an idea of the weight of a tree or branch.

Attention! The values in table 1 are indications only. The load charts of the crane and carrying vehicle as well as the maximum allowed length of the hanging load are at all times decisive.

How to perform a multiple cut with your GMT grapple saw

Warning!! Always take maximum load into account before performing a multiple cut on bigger tree pieces.

It is possible to take bigger tree pieces by making a double or even a tripple cut. To do this you have to be able approach the tree from both sides to ensure a clean and complete cut. The second cut should be at the same height or a little bit higher to prevent saw from jamming. The maximum tree diameter possible with a double cut are:

Afbeelding: table double cut

This video is a perfect example on how to fell a tree safe and efficient, including performing a multiple cut (1:55).

 

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