The idea of this mounting plate, is to assist the anti-fouling blades with difficult long wet grass, or old dry vines that the anti-fouling blades can not cope with. Most Australian’s would probably give their eye teeth, to have this problem, but for those of us fortunate enough to live in a high rainfall area, it can be a big problem as you can see by the photo below.
Another problem we face in wet areas, is vine infestation that can smother trees and when they die and dry out they are as tough as wire as you can see by this photo below.
As the blade developed to tackle more and more challenging conditions, I found that the anti-fouling blades could not cope with some of these conditions. Below was my first attempt in 2014, to develop an anti-fouling shield to work with the anti-fouling blades. This shield worked well for a while, but after a while this 3mm steel plate was bent up by grasses and weeds being forced between the shield and blade.
Five year later, I thought I would have another go with a shield, as part of developing a better heavy-duty guard. But like the first shield, it worked well to start with, until the shield was forced upwards about 5mm. I guess that if tree roots can split rock, pushing 1.6mm steel out of the way, is easy.
I then thought I would take a different approach, by replacing the Honda blade bolting plate with a new plate, that would direct weeds into the anti-fouling blade to be chewed up, instead of trying to direct them up and over the gear head.
Below you can see anti-fouling bolting plate, fitted to the gear head and because of the inward taper that forces vines down into the anti-fouling blades for chewing up.
This actually worked very well, until it came to the dreaded vines which slowly wedged between the bottom of the guard and the mounting plate. This didn’t stop the brush cutter, but it did cause enough friction to rob a lot of power to the cutting head.
I then thought I would add a shield to the mix and this worked really well. Cutting down this long and wet grass with no issues. Meaning no stopping to untangle long grass tangled around the gear head. To give you an idea of the length of this grass, that is a standard height star picket on the far right of the photo below.
But when it came to those infernal vines, the shape and flywheel momentum of the mounting plate sucked in and stalled the brush cutter before you could blink.
I then machined the mounting plate in the reverse direction, so that the dry vines would not overwhelm the anti-fouling blades.
This modification worked fairly well, but over time a few vines forced the shield upwards (see wear to the aluminium gear head in the photo below) and as the gap increased more and more vines would get wedged under. As with an earlier version, this added friction that resulted in loss of power.
Below is another shield design, that would hopefully prevent vines getting wedge under and forcing the shield up.
Below is a dead vine-covered sapling, that was cut and shredded up in just under 10 minutes, without ever stalling the brush cutter once. I can remember a time when such a feat would take over an hour, with most of that time stopping to unwind the vines from around the gear head.
But after shredding up several of these dead vine-covered saplings, the shield was again forced up, resulting in vines getting wedged under the shield and creating drag.
Below you can see how the shield was forced up, reducing any benefit the shield originally offered.
Below is the next version that I will try, this will have a deep reverse thread machined into it, to wind the vines up and over the gear head and prevent my dreaded vine problem.
This works really well and will be the next Honda upgrade I will be offering. But it will not be for everyone, as like everything in life, it come with advantages and some disadvantages.
The First Advantage, is the time saving clearing away long wet grass and the dreaded vines. So that I never have to stop and clear away a stalled gear head again.
The Second Advantage, is the flywheel effect that adds short-term extra cutting torque. In fact it briefly gives the extra torque of a much more powerful machine.
The First Disadvantage, is the weight and at 0.42kg it is a lot of extra weight to hang off the end of the brush cutter when you add that weight of a 0.9kg BrushDestructor blade. So this is really suited for those that will have the extra long shaft to help counter balance this weight.
The Second Disadvantage, is the price at around $195 Australian. Which is due to the type of steel, the intricate machining from a solid bar and the hardening process to make it very durable. I imagine only those with larger properties, or commercial operators, who have to deal with long wet or stringy grass or vines, will be interested in this upgrade at this price. I have been paying over twice that for the prototypes and personally I think that it is worth even that price.
I have place an order for the first run and hope to have stock, sometime in August 2019.