How to make a wall chaser from a grinder with your own hands
A professional wall chaser is an excellent assistant for an electrician-installer: high speed of work, reliable protection and minimum dust. Its only drawback is its high price, which can be bypassed by a self-made chasing cutter - a nozzle for a grinder, which gives about the same cutting performance.
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How a wall chaser works
To understand how to assemble a homemade wall chaser from a grinder, you need to know how a factory-created device works. Its main parts are a powerful electric motor, on the shaft of which two concrete discs are mounted. The distance between them is adjusted with nuts. Additional, but no less important, components are a protective cover, which also acts as a dust collector, and an adjustment bar, which determines the depth of the groove.
The required cutting depth is set, a vacuum cleaner is connected, and now you just need to use a chasing cutter along the markings drawn on the wall, after which a nozzle used for chasing walls (popularly called a "shovel") is put on the puncher and concrete is knocked out from the inside of the cut.
If you use a grinder instead of a wall chaser
From the design, it is clear that in the extreme case, the machine for making strobes can be replaced with an ordinary grinder - put a disc on it on concrete and make the necessary cuts in two passes. They really do this if one small strobe is needed, but practice and multiple reviews show that the dust after such a strobe will settle for a long time, which can stall all work.
If it is necessary to grind several grooves, the loss of time will be significant, and if such work is performed at regular intervals, then the method becomes ineffective. Other disadvantages of this method are the inability to maintain the same dimensions of the edges of the groove and their depth. This cannot be called a significant drawback, but sometimes it is fraught with a piece of the wall falling off when hollowing out the core of the groove.
If the length of the mounting shaft allows, then two discs on concrete can be put on the grinder at once, and then the strobe will be cut in one go. Even if you do not touch on the issue of safety, then less dust will not and it will settle at the same speed. As a result, the gain in time will turn out to be insignificant, and the injury risk increases by an order of magnitude.
How to turn a grinder into a wall chaser
To make a full-fledged wall chaser from a grinder with your own hands, you need to solve two questions:
- Dust removal. This is the primary problem - without its solution, further modernization is pointless.
- Placement on a shaft designed for one disc, two circles on concrete. In this case, the design must be reliable and ensure a strictly perpendicular position of the circles to the cutting plane - the slightest skew at 3000 or more rpm is, at best, jamming and failure of the gearbox or engine.
Manufacturing of a protective casing
By and large, this part makes a homemade wall chaser out of the angle grinder - such a nozzle for a grinder replaces the standard protection installed on the device, completely hiding a part of the circle that is not immersed in the wall. There should be no question how to make the fasteners - they are simply copied from the factory part.
The protective and dust-collecting casing is a flattened cylinder cut off from the side, in which there is a branch pipe for connecting a hose from a vacuum cleaner (you can use a construction one, and if you make a cyclone filter, then a regular household one).
The height of the cylinder is made sufficient to accommodate two discs at the required distance from each other. To make it, you need two iron semicircular plates and a strip of steel that will hold them together. The strip is bent, welded to the rounded parts of the plates and the base of the casing is ready.
Depending on the fasteners of the factory protection, in the plate that will adjoin the body of the grinder, in addition to the slot for the shaft, holes for bolts are made, or a clamp clamp is welded.
Cutting depth adjustment
The part of the casing that solves this problem is at the same time a guide for the wall chaser - if you attach wheels to it, then the device will easily move along the wall along them.
It is made in the "L" or "T" -shaped form - the lower part of the "letter" is drawn from two corners that are attached to the upper part of the protective casing so that the lower part can freely rise and fall, which will allow you to adjust how much the discs will look out of -under the casing. It is easiest to fix in a given position using a bolted connection or a stop.
Additionally, sidewalls are welded on the base of the guide so that dust, no matter how the depth of cut is adjusted, does not fly out from under the casing.
The upper part of the "letter" is needed for stability - the wheels are installed on it for smooth movement of the wall chaser along the wall.
Installation of two discs on the shaft
It is extremely rare that the factory shaft of a grinder is of sufficient length, which will allow two circles to be immediately fixed on it. There are two logical ways out of this position - to grind a new shaft or make a nut that would clamp the first circle and hold the second. For a number of reasons, the second solution is more profitable:
- No need to disassemble the grinder.
- If the device fails, then you can purchase another and simply rearrange the nut on it.
- It is technically easier to carve a nut than a shaft that connects to a gearbox.
- The nut is machined together with the sleeve.
The discs are put on in the following order:
- The first disc is installed on the grinder shaft.
- On top of it lies the sleeve and on it - the second circle.
- The nut is threaded through the upper disc, bushing and tightened by pressing the first disc and clamping the second between itself and the bushing.
The whole structure is clearly shown in the video:
Features of working with a homemade wall chaser
The internal structure of the factory wall chaser is somewhat different from the grinder - it is designed for one single task, is simplified as much as possible and requires higher quality components. The force on the grinder shaft is transmitted through the bevel gear and everything is designed for cleaning surfaces and cutting iron.
The forces arising when cutting a groove quickly destroy the gearbox and bearings. This is facilitated by the double load on the components of the mechanism and the fact that the second disc is not located at the design place, which means that the force is transmitted at a different angle.
In any case, the cost of a wall chaser is an order of magnitude higher than that of a grinder and it is often easier to buy a new angle grinder than one furrow cutter. But this should not interfere with the observance of simple recommendations that will prolong the life of a home-made wall chaser made from a grinder:
- It is necessary to ensure that the instrument does not overheat and, if possible, give it a rest as often as possible.
- It also does not hurt to evaluate how much faster working with two disks than one. The adjustable cutting depth guard provides dust protection and relatively straight grooves even when making two parallel cuts. If the extra movement along the wall with a single-disc wall chaser extends its service life, then it may be worthwhile to limit yourself to this option.
As a result, a do-it-yourself wall chaser, well-made, works no worse than the original factory, but there is a risk of quickly destroying the grinder, which is taken as its basis. If you have to cut grooves often, then it is better to purchase your own furrow cutter, designed specifically for grooving walls, and a grinder converted for a groove cutter is more suitable for periodic work.
