How to assemble a grinder with your own hands: drawings, connection diagrams, detailed step-by-step instructions.
1. OVERVIEW.
The grinder is built according to the classical scheme on a frame made of steel sheet 10 mm thick. All elements of the broach and stops are attached to it, and the AIR 71 motor, with a power of 750 W and a rotation speed of 2850 rpm.
In my workshop, this belt sander will do the sanding, sculpting, and fitting of parts for new DIY projects.
The machine turned out to be exactly what I needed, but it provides for the possibility of an upgrade (by replacing the motor and pulley and using crossbars) and for more serious work, for example, making knives blades not one-time, but serially.
You've already seen its performance and vibration tests. The tension roller - "barrel" holds the tape evenly and accurately, and the problem with the "runaway" of the tape under heavy load is solved (according to your recommendations) by installing a stiffer spring. Now this is the spring of the brake pads of the Gazelle car, and during processing you can safely apply force to the part, the tape no longer moves.

2. DEVICE. All drawings and diagrams can be paused and photographed, or a screenshot of the screen can be taken and printed. You can leave a request in the comments, I will send them to you by mail for free. Subscribe to stay connected. For all the technical documentation, I thank from the bottom of my heart my subscriber Vladimir Rudakov, he did a tremendous job of both 2 and 3D visualizations, so that we have not only simple diagrams that are understandable to everyone, but also serious drawings that can be given even for serious production.
a) FRAME. When choosing the thickness, I agreed with the audience, who suggested a 10 mm sheet. This avoids welding when installing stiffeners and fixing elements. The thickness of the sheet allows you to reliably and accurately fix the axes of the moving elements and cut the M6 ​​thread directly into the end. Refusal from welding is, above all, due to geometrical requirements, because the geometry is influenced by changes in dimensions as a result of thermal action (the metal "leads" during welding). It was possible to achieve the perpendicularity of the axes by fixing the tap for the start of the thread in the chuck of the drilling machine. But if there is no drill, there are other methods of precise threading.
b) The standard feet are screwed into the MOTOR SUPPORT SQUARE. After adjustments to ensure that all four legs and the frame are simultaneously supported on the surface, the legs are secured with locknuts.
c) ROCKER ARM. It swings on a 10 mm axis. Tighten the axle bolt to a snug fit and in this position fix it with a lock nut so that the rocker arm moves without play. Adequate contact area and pendulum extension of the idler roller is ensured by using a set of suitable washers. In the version proposed by Vladimir, the pressure rocker is lengthened to replace the tape, less effort is required.
d) PENDULUM allows you to change the angle of the idler roller by adjusting the position of the belt. Adjustment is carried out with a spring-loaded M6 bolt. In this case, the further the bolt is from the pendulum axis, the more accurate the adjustment will be. The pendulum in the bracket swings on an axis from the M5 screw. It is very important to drill all three holes as accurately as possible. Of course, with some experience, it is not difficult to do this without a drilling machine, but with a machine it is certainly more convenient.
e) ROLLERS, BUSHINGS, AND PULLEY ordered from a turner. A 95 mm diameter pulley provides a belt speed of about 14 m / s, which is quite enough for my needs. Of course, ideally, the turner also needs to order the roller axles, but I got by with the standard 10x80 screws with a thread length of 24, choosing from them those on which the bearing sat most tightly.
f) SUPPORT TABLE. I have it installed like this. This height is convenient for me, but if you want to use a larger processing area, the shape of the table arm will need to be changed, then the table will lower. It is very convenient to use a standard nut of an angle grinder - a grinder - as a table mounting flange. Through the holes of the nut, the screws are screwed directly into the table using a paste - a retainer, and the flange itself (nut of the angle grinder) is locked on the M 14 hairpin with a nut with the edges that have been ground off (so as not to interfere with the screw heads).
g) THE STANDING PLATE, together with the bracket, is fixed to the frame in a position that allows the use of a 6 - 10 mm thick ceramic plate. The lining, according to your advice, was glued on liquid nails with the help of clamps.
h) ELECTRICITY. The three-phase motor is connected according to the "delta" scheme using a working 50 mKF and a starting 100 mKF capacitors.
3. ASSEMBLY of all assemblies is carried out using Grover split washers, locknuts or paste - lock.