Blade adjustment is paramount to understand for successful long term cutting.
As a new blade dulls, you can continue to cut, however you may need to adjust the blade depth and force to match its current state. Occasionally, the blade tip will break off, you can visually check this, it should be a sharp point, please replace the blade if this occurs.
Bike Protection Film is a thick and ‘difficult’ material to cut, so we can take a process to set the plotter machine up correctly.
Step 1: Setting the blade force through bracketing
When considering blade forces look at it as a scale.
On the low end, the force is not high enough to cut through the film.
On the high end, the force is so high that is cuts through the film and the backing sheet.
On each end of the scale there is a ‘trigger’ point where we cross the threshold. We will start by finding these thresholds…
Ensure that your blade depth is enough that it would cut through the backing sheet, you should be able to see a good bit of the blade. Precision is not important at this time.
To confirm this, we will check the high threshold…
Set your plotter force to a ‘high’ number (this is specific to your plotter)… for example, on a GCC Expert 2 we use 180g.
Using the Super Cutter run a Test Cut. Check the result:
- If the plotter cut straight through the backing – reduce your force by a notch, in the case of the Expert 2 – 5g or 10g
- If the plotter did not cut straight through the backing – increase your force by a notch, in the case of the Expert 2 – 5g or 10g
Repeat this step as required until after a single notch change you get a change of result. IE If you were cutting through the backing sheet, then reduced the force by 5g and now it does not cut through the backing sheet. THIS IS YOUR UPPER THRESHOLD.
Next, we will check the lower threshold…
Set your plotter force to a ‘low’ number (this is specific to your plotter)… for example, on a GCC Expert 2 we use 90g.
Using the Super Cutter run a Test Cut. Check the result:
- If the plotter scored but not cut the film and you cannot remove it easily – increase your force by a notch, in the case of the Expert 2 – 5g or 10g
- If the plotter cut the film and you can remove it easily – reduce your force by a notch, in the case of the Expert 2 – 5g or 10g
Repeat this step as required until after a single notch change you get a change of result. IE If you were cutting through the film and could remove, then reduced the force by 5g and now it does not cut through the film enough to remove. THIS IS YOUR LOWER THRESHOLD.
We now have the upper and lower force thresholds. On the low side, we know that any force lower than this will not work as we will not be able to peel the pieces out. On the high side, we know that any force higher than this risks cutting through the backing sheet and jamming the machine.
We typically recommend choosing a cutting force that is roughly in the middle of these two numbers. You will be able to cut through the film with a small score on the backing sheet below. This force will allow you to continue cutting successfully for a while as your blade dulls.
Step 2: Setting the blade height through bracketing
The blade holder is a piece that not only holds the knife, but also allows you to ensure that you will not cut through the backing sheet or cause a bunch up of the film.
We can take a similar bracketing process to set our blade height to the threshold.
You can choose to bracket from high to low or vice versa. The reduce potential damage to the blade by cutting through the backing sheet, we prefer to bracket from low to high.
- Set your blade holders depth to very low (this means that when you spin the tip you will not be able to see much of the blade tip)
- Set your force in the Super Cutter to very high, a notch or two above the upper threshold (we know that at this pressure, the machine would cut through the backing sheet)
- Run a test cut.
Check the result…
- If the cut does not cut through the film and the backing sheet – increase the blade depth (show more the of the knife tip) by a notch
- If the cut goes through the film and the backing sheet – reduce the blade depth (show less the of the knife tip) by a notch
Once you have changed it by a notch to the point where you receive a different result, this is your blade depth threshold. We recommend notching the blade depth to be slightly less than this. This ensures that you will never cut through the backing sheet and cause a cut issue.
The perfect cut conditions are those that ensure that you cut through the material for easy weeding, have a slight scoring in the backing sheet, but never cut through the backing sheet completely.
Here is a video that includes details about blade depth setting