This dispenser is inexpensive and small, expected to be used without syringe replace. Consider build separate one for each substance you plan to use (normal paste, low temp paste, flux).
| Name | Comment | |
|---|---|---|
| 1 | PCB & Components | Go to EasyEda project page and order both in couple of clicks. If you order PCB first, components second, then you will be able to join delivery and save some bucks. SMT stencil strongly advised, see note below. |
| 2 | 0.96" IPS Display | |
| 3 | Micro stepper motor | Other motors will need rework of 3d-printed supports. |
| 4 | Gearbox 1:300+ with long shaft | For max gear ratio select lowest RPM. |
| 5 | PVC transparent heat shrink tube 23mm | Display mount. |
| 6 | Double side foam tape, 15*1mm | Display mount. |
| 6 | 22 AWG wire | SMT stencil positioning & motor/syringe supports mount. |
| 7 | Heat shrink tube 35mm | Motor mount / electronics protection. |
| 8 | Cable ties 150-200mm | Syringe mount. 100mm enough for all syringes except 10cc. Width 2.5-3.0mm. |
| 9 | Silicone heat shrink tube 0.8mm, 1.0mm, 1.5mm | Needle caps, inner layer. |
| 10 | Heat shrink tube 1:4 with glue, 4mm | Needle caps, outer layer. |
| 11 | Joysick cap, 2mm | Optional, but recommended. |
| 12 | Syringes | 1cc recommended for soldering paste with max precision. 3cc - acceptable. 10cc - for fluxes when precision not critical, and for refill. |
| 13 | Needles | Needles choice from syringe set is too small. Buy separate set. |
| 14 | Micro USB silicon cable | Very soft cable strongly advised for convenience. |
Note. You are strongly advised to order SMT stencil for your PCB. That will add ~ 8$ in total to your order - good price for convenience. On placing stencil order at jlcpcb, select option "custom size", and define 30*130mm. Then stencil will be compact and light, with small delivery cost. You need top layer only. If you order SMT stencil, add this comment:
"Please make stencil with my paste layer directly. Make sure 2 TP rounds 0.7mm with X = 43.0 and X = 108.0 exist"
This sequence is for assembly with heat gun:
- Solder everything except buttons and LCD.
- Solder buttons manually.
- Wash PCB from flux.
- Solder LCD.
- Use IPA to accurately clean LCD soldering area. Or leave as is, if your flux is no-clean.
Warning. DON'T USE STRONG CLEANERS WITH LCD. It's not sealed, assembled with soft glue and will be damaged. That's why it's better to install it in last moment - you can clean PCB anyhow, but use IPA only with LCD.
Note. Here it's good idea to upload firmware and check display works, prior to continue (see instructions in next chapter).
Now mount LCD to PCB:
- Use double side foam tape. Stick to LCD first, then cut borders, then stick to PCB
- Fit heat shrink tube over that. You need 40mm of 23mm-wide tube. Center it over LCD, then shrink sides, front and back.
Don't worry about small air bubbles at screen surface, those will not affect image quality anyhow. It's possible to use special UV-activated glue for displays to avoid air gaps. But that does not worth efforts been spent.
Assembled PCB with power on:
You need VS Code to build and upload firmware. It's our choice, because it works on all operating systems and requires almost zero efforts to configure.
- Install VS Code. Then configure hardware if
needed:
- For Linux, add udev rules
- Clone this repo or download as zip archive and unpack somewhere.
- Open folder in VS Code AND after it suggests to install plugins - agree with everything. That should install PlatformIO and all required dependencies.
How to flash:
- Push joystick button and attach USB cable. It's important to push joystick before cable attached, to put device in programming mode.
- In VS Code menu select
Terminal->Run task->PlatformIO: Upload (hardware_usb)and wait until succeed. - Re-insert USB cable. You should see dispenser menu on display.
TBD
It's important to protect soldering paste from drying while not used. Here is simple recipe of needle caps. You will need 2 heat shrink tubes:
- Small silicone tube. They have small shrink ratio (1.7:1 only), so buy several sizes to fit all 0.8/1.0/1.5mm.
- Bigger tube, 4mm, with glue layer & 1:4 ratio.
First, shrink 10mm of silicone tube at needle edge. Then shrink 15-20mm of bigger tube and squeeze the end. Take off and cut the ends for accurate look. See result:
When dispenser ready, follow to User Manual.