Hello, dear readers and homemade products!
When sharpening small tools, post-processing of small parts and cases, printed circuit boards, a grinding machine is often required. It is not entirely advisable to use a hand grinder or a grinding machine at home for these purposes.
In this article, Valery, the author of the YouTube channel “Valera Perinski”, will tell you how you can make a miniature orbital (disc) grinder.
This machine can be made quite simply at home.
Materials required for homemade products.
– Brushless Motor Speed Controller (BLDC)
– Motor from an Old Hard Drive
– 12V Power Supply
– Velcro tape
– Filament for 3D Printing
– Power Connector
– Heat shrink tubing, flexible silicone wire
– Amtech NC-559-ASM flux, Sanki 60/40 solder
– Two-component epoxy adhesive
– Silicone feet (plugs), screws, screws, dichloroethane
– Sponge sanding discs 50 mm
– Sanding discs 50 mm with Velcro.
Tools used by the author.
– Electric soldering iron with temperature control
– Non-contact digital laser tachometer DT-2234 ° C +
– Deburring knife
– Wire stripper
– “Third hand” with backlight
– 3D printer Ender-3X
– Stainless steel nippers, handicraft scalpel.
So, the heart of such a machine will be a brushless motor from an old hard disk. You can find them in abundance at the radio market flea market. In this case, the author uses a drive from a Samsung SP0411N hard drive.
The following brushless motor speed controller (BLDC) is used to control the motor .
The first step is to remove the connector pins from the board, the wires will be soldered directly. Excessive component legs are also nibbled off to fit the board into the case.
Three multi-colored wires are stripped, tinned, and soldered to three phase terminals on the engine.
Excess flux is immediately removed.
Models of parts for the case and disk can be downloaded from the following link, kindly provided by the author. There are also several versions of the converted models that are better suited for motors from other hard drives.
The wizard has printed them on a 3D-printer . If you do not have such a device yet, you can contact your friends, or find people engaged in 3D printing near you on the next site .
Wires are soldered to the power connector , and the open contacts are insulated with a heat shrink tube .
The wires from the engine are passed through a special hole in the bulkhead of the case, which separates the compartments for the engine and electronics. < br> holes in the case.
This engine model is fastened with only three screws.
Next, the power connector is screwed into place. Holes are also provided for the connector and potentiometer on the front panel of the case.
The compartment will be closed with such a cover for a couple of screws.
Now you can shorten the wires, strip them, and solder them to the board. To strip the wires, the master uses this stripper .
Three wires from the motor are soldered to the board outputs (U V W). The power wires are soldered to the Vcc and Gnd contacts respectively.
NC-559-ASM flux and Sanki 60/40 solder are used for soldering and tinning.
Wires are charged against the board. Now you need to connect the 12V power supply, and check the direction of rotation of the spindle. You can choose it at your discretion, and to change it is enough to swap any two of the three wires of the engine phases.
As you might have guessed, the engine speed is regulated by the rotation of the potentiometer.
Now you can screw on the lid.
For the device to be stable and not slide on the table, holes are provided in the bottom of the case for installing silicone cap legs .
The author cleans the outer edge of the printed disc with a special knife … As a result, there should be a very small gap between the edge of the disc and the case. This will reduce the amount of dust getting inside.
A piece of electrical tape is glued to the surface of the disc, and the author measures the revolutions using a digital laser tachometer . The maximum speed is just over 11 thousand per minute.
To be able to quickly change the sanding disc, you need Velcro tape .
The belt is cut into strips and they are seated end-to-end on the back of the sanding disc.
The disc is pressed against the strips, and through holes are punctured in them.
Based on the received marks, the master punches four holes in the Velcro.
Velcro squares are glued to the surface of the disc with two-component epoxy glue.
During the polymerization of the glue the parts are pressed by the load.
Now you can cut off excess Velcro with a sharp knife or scalpel.
To reduce vibrations, I would recommend do not install the motor in the housing immediately, but first stick the Velcro to it and fix it to the flange. After connecting the speed controller , start the disc rotation, and sand the outer edge of the disc with fine-grained sandpaper.
This will bring about a kind of turning, removing minor print defects, and balancing the disk.
Everything is ready, you can screw the disk.
50mm sanding discs are suitable for this device.
This is a miniature grinding machine made by the master. It easily handles sharpening scalpels and other small tools.
Thank you Valery for the design and details of a simple, miniature dish-shaped grinding machine.
Good mood everyone , good health, and interesting ideas!
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The author's video can be viewed here.
Hello, dear readers and homemade products!