SYR32 Dual
A double shaft Nema 17 stepper with a FLYN17-5 flywheel turns a H20 GH17 pinion that drives a H20 GHI32M8 internal herringbone gear at a 17:32 gear ratio. The GHI32M8 gear transfers stepper power to an M8 screw that engages an M8 square nut embedded into a syringe plunger drive clamp made out of two [SYR32P syringe plunger clamp half] (https://github.com/firepick/FirePump/blob/master/STL/SYR32P.stl) parts.
The flange of the 32mm OD Medint 60ml syringe body is held in place by snap-in syringe clamp SYR32B. The Luer lock tip is held securely by slide-on syringe tip clamp SYR32T.
For operator protection, you should also mount the X80CVR gear cover over the H20 gears, which might otherwise catch and trap hair, clothing or fingers, etc.
- 20x60x400mm extrusion with 6mm slots
- 8x22x7mm 608 skate bearings (2)
- Teflon tape (as used for plumbing) for snug M8 fit within dual bearings
- NEMA17 dual-shaft stepper motor 1.5A (1)
- M8x140mm fully threaded bolt (1)
- M8 square nut (1)
- M8 nut to lock M8 bolt into bearings--snug but not tight (2)
- M8 washer between GHI32M8 and 608 bearing
- M5x10mm screw (6)
- M5x12mm screw (2)
- M5x16mm screw (2)
- M5 extrusion nuts (10)
- M3 set screw (3)
- M3x6mm screw (4)
- M3x20mm screw (3)
- M3 nut (6)
- FLYN17-5 flywheel
- X60N17 stepper mount
- GH17 pinion gear
- GHI32 internal herringbone load gear
- [SYR32P syringe plunger clamp half] (https://github.com/firepick/FirePump/blob/master/STL/SYR32P.stl) (2)
- SYR32B syringe body clamp
- SYR32T syringe tip holder
Lubrication affects pump performance:
- M8 Screw apply grease
- Syringe since syringes are typically single-use disposable, they will degrade rapidly and become unusably sticky even when lubricated
- Gears the gears run fine without lubrication
Many options exist for control and power. Here's an example of a working combination:
- 12V power
- DRV8824 stepper driver
- FireStep
- Arduino Due
- FireMC
Adjust the stepper driver VREF to limit current so that components do not overheat. In particular, keep steppers below 135F when running or when idle by reducing VREF.