Re: [DIYbio] open source syringe pump

Hi Nathan,

I've seen these pumps being used in protospace in utrecht and I've tried them against direct extrusion where the syringe is directly driven, not through a tube. The application in question is 3d printing, you just don't really get the precision, as you have to factor in the length of the tube, the bend, time delays etc. So for fixed dispensing of liquids, its good. As for retraction, again there is a delay and I have not found this to work so well. I think being able to shut off the tip of the syringe is the only way to stop drips, and I have a few ideas about that. :-)

On Thursday, September 25, 2014 10:24:15 AM UTC+1, John Griessen wrote:

On 09/24/2014 04:33 PM, Nathan McCorkle wrote:
> On Wed, Sep 24, 2014 at 10:43 AM, John Griessen <jo...@industromatic.com> wrote:
>> Meanwhile find a stepper with small light form, add a gear on its shaft,
>
> These are probably too small for most folks' needs:
> http://www.aliexpress.com/item/Treatment-2-phase-4-wire-stepper-motor-micro-screw-stepper-motor-stepper-motor-slide-slide/1111641517.html
>

Here's the type I was thinking of to drive a plastic rack (syringe handle pusher/puller):

http://www.aliexpress.com/item/20mm-2-phase-4-phase-hybrid-stepper-motor-6-wire-stepper-motor-micro-mini/1111628662.html


50 cents each in tens....and has a gear on it already!

A custom version might be available for that price in hundreds...