Mini Heat Gun

## Actual picture
![image.png]
## Then let's talk about the selection and picture of the hardware.
Fan: 3010 brushless fan rated voltage 3.7V (in fact, this fan has other rated voltages, such as 9V12V, but if it works at the rated voltage, the wind speed is too small, so it is manually "overclocked". Hahaha. The fan problem will be compared in a video on a certain website.)

![image.png]
Fan driver: A4950 (I use this driver because I have a lot of this chip and don't want to spend extra money to buy other ones). In addition, the PWM frequency required by this driver is measured to be 500hz and 1Khz, which is good. If it is 10khz, the fan will not rotate.

Control: STM32F103c8T6 (same, I have a lot of this minimum system hahaha)

Display: 0.91OLED (the long screen display UI is very friendly), just use 20mm long pins to pad it.
![image.png]
Interaction: Buttons (same, need to use very long buttons, I use 22mm, actual measurement as long as it is greater than 20!)

Temperature sensor: NTC thermistor, I chose 10K3950, it is best to find one that can withstand high temperatures, and the heat gun does not require high temperature accuracy, it is more convenient when writing programs.

Ceramic heating tube/heating wire: This problem is still being solved. The resistance of the heating tube is too low, which will cause the driver to short-circuit. Change the solution later.
![image.png] The ceramic heating tube solution is PASS, because there is no suitable one. If you need suitable parameters, you need to customize it, which is very troublesome, and the cost goes up. Today I changed the heating wire solution. See the picture below. Regarding the determination of the length of the heating wire, I am still doing experiments. I found that after the heating wire is heated and burned red, it will not be hot if there is a little wind blowing... It seems that a short one is needed.
In addition, if the heating wire is placed in the stainless steel air outlet, you need to pad some insulating high-temperature resistant tape inside the air outlet, otherwise I am afraid of short circuit. In addition, the position of the NTC resistor at the air outlet also needs to be tested, otherwise it will be too far away and the temperature measurement will be inaccurate. . . (scratching head.jpg)
![image.png] ![827f58ef6e1ef08a9c3275f0637d44e.jpg]
Air outlet: You can go to the shopping website and search for "stainless steel reducer", and then find some small air outlets. I feel that this one is still too big, so I'll just go with it. (In addition, for the connection between the air outlet and the 3D printing material, it is recommended that you draw the diameter about 1mm larger when drawing the shell, and then go online to buy high-temperature resistant glass fiber tape and stuff the stainless steel tube into the nylon tube.)
![image.png]
Shell: I drew it myself, and I need high-temperature resistant materials. I went to LiChuang 3D Monkey to find nylon materials. The official said that it can withstand high temperatures of about 170 degrees. The total cost is about 150 yuan. The shell file will be shared
![image.png] There is nothing else. I will update it later if I think of anything.

In addition, the current test video is in the attachment, you can take a look.

The code is not yet complete, I have also uploaded it for your reference.
If you have any opinions and ideas, please feel free to communicate in the comment area, I will take a look at them one by one and reply to you!