VV AFS Mod Concept

This is a concept for a VV mod with AFS. It uses a 20mm dia stepper motor to drive a M3x0.5 316 stainless leadscrew. The original seal from the 10ml syringe is fitted to a delrin 'nut' with M3 threaded bore. Hopefully the seal provides enough friction so that it doesn't rotate with the leadscrew and instead travels up/down the syringe. The injector is an off the shelf 15G canula with luer lock to the syringe that is epoxy glued into the 510 connector.

The mod will be powered by a 1700 mAh 7.4 volt Lipol. This battery will provide enough power to go through 10ml of juice before recharging and refilling. An onboard charger powered by a 2A 9V Plug Pak will recharge the unit in under 2 hours.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16742

One button and one RGB LED will be the only user interface. A long press on the button for normal vaping. One short press will inject a shot of juice. The LED will indicate the voltage (temperature?) by its colour. Blue will be 3V or so, red will be 6V. Voltages in between will be indicated by the colour spectrum from blue to red. 2 short presses of the button wil ramp the voltage up until the button is pressed again. 3 short presses will likewise ramp the voltage down.

To refill the syringe, a length of silicone tubing is attached from the injector into a bottle of juice. 4 short presses on the button will start the syringe driving backwards and drawing juice into the syringe. 5 short presses can be used to empty the syringe. Maybe morse codes would work better

This mod will be on the large side with overall dimensions of ~45x35x115 depending on the case it ends up in and maybe too big for a woodie

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Sweet youre designing it. Nice CAD! Will be watching with mucho interest

 

Acb, now I don't think you need any more mods just yet or you are going to have to get yourself a larger desk

 

always room for another mod

 

No, Richard is right. I am on a mod exile atm (the ones I have already ordered dont count)..

 

Still a couple of weeks away from finishing this but making good progress. The syringe seal still holds good air pressure with the leadscrew going through it so it should be fine with juice. Am expecting the stepper motor mid week and the circuit board a week later. Knocked up the wooden case this afternoon and it measures 44W x 39D x 132H. It's a bit on the large side but still easy enough to hold/use with one hand.

I'm thinking to go variable power rather than variable voltage for 2 reasons. The first is that different resistance atties can be used without changing voltage. Secondly I'd like to try.comto feeding the juice based on power given that the vapourisation rate is probably a function of attie power.

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nice work jonny, I looked at doing a lead screw feeder for a while but figured it was always going to be too long and a pain to fill.
Hope it works out for you.

 

Yeah it will take a few minutes to refill especially if I allow for the viscosity of VG at cooler temperatures but with 10ml capacity it will only need filling every few days. The easiest way to refill will be to upend a 30ml drip bottle onto the injector needle and select 'refill'. Since it's using a stepper motor the micro will know exactly how many steps are needed so there's no need to hand hold the filling process unless you want a stop at a lesser fill.

 

Still progressing this design. Directly driving the leadscrew with the stepper motor basically stuffs the motor be.comse it exceeds the motor's axial load rating by about 20 times but I was able to get about 20 fill/empty cycles before the motor started stalling. So decided to unload it with a spur gear since the motor already comes fitted with a pinion. Just waiting on samples of the gear so I can finish the motor/gear mount design. So at least another 6 weeks or so before I get a working proto.

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In the meantime the circuit board will arrive this week and I'm keen to load it and try out the variable power concept. I can probably squeeze this board into the tiny 2 x 18650 mod I posted last week.