The harvest season is about to start again and all machines are being made ready. You are probably already busy preparing too. It is essential to check the knives in the cutter bar. We explain how you can check the cutter bar in three short steps and, if necessary, how to easily replace the knife sections.
Getting started: what to do?
Check the knife sections in three easy steps. All these steps entail a physical check and include the following.
Please note: always wear work gloves for your own safety.
- Check that all knife sections are attached.
It is important to check whether all knife sections are still tightly attached. This can be done by hand. Don't be afraid to pull quite hard to make sure that all knife sections are still attached tightly. Loose knife sections may cause a lot of damage. - Check that all knife sections are straight.
In this step you check whether all the knife sections of the cutter bar are still in a straight line and there are no bent knife sections. Stand the cutter bar upright and check whether all sections are in a straight line. - Check for broken knife sections
As a final step, you check whether all knife sections are still intact and that there are no broken sections.
If these three steps show that all knife sections are properly attached and straight and nothing is broken, the cutter bar will be able to function optimally again. Any broken sections must be replaced. Read here how you can do this quickly and easily.
Replacing the knife sections in the (finger) cutter bar
You have determined that the some sections need to be replaced and you have purchased the correct replacement knife sections. What should you do next?
- Position the cutter bar at the correct height for easy access and ensure that the bar is properly supported.
- Remove the complete knife.
- Check that all fingers on the cutter bar are in a straight line. Please note: most fingers are made of cast iron and are very fragile. So it is important to do this carefully.
- Replace broken and blunt knife sections on the cutter bar.
- Check that all sections are attached tightly.
- Place the knife back in the cutter bar.
- Finally, check whether there is enough play in the knife relative to the fingers.
How to attach the knife sections
To make sure that a new section is properly secured, it must be attached with rivets, or bolts, depending on the type.
There are two ways to attach a knife using rivets:
- With a rivet setter and rivet snap die
Locate the rivet through the knife section and knife back, then deform the tail of the rivet using the rivet setter until it is tight, the tail is then finished using the rivet snap die, to create a nice round head on the rivet - With a riveting machine
How to determine the length of the rivets
To determine the length of the required rivets, we look at the thickness of the knife, the thickness of the knife back and the space that must be left at the rivet to create a nice round cup after riveting. Usually, approximately 6 to 7 millimetres of extra space will help form a nice round cup. So if the knife back is 6 mm and the knives are 2 mm, a riveting length of 15 mm would suffice. When the knife back is 6 mm thick and the knives are 3 mm thick, a rivet with a length of 16 mm fits best.
Would you like more information?
View the knife sections in our online shop here. Not sure yet which knife or which rivets are most suitable for your cutter bar? We are ready to help you prepare properly, order the right (spare) parts and give advice: contact a Kramp specialist today.
View this page for additional information on the harvest season and all associated products.
