Hey Guys
I am in the process of building a syringe pump similar to the one in the following post: panic.berkeley.edu/~ghe/DIY_SyringePump/ .However the linear actuator mentioned in the post i.e the L12 even with the highest specification is too fast for my needs.I need the actuator to move at a min of 1um/sec (if it can do 500um/sec that may suffice).Is there any way that I can modulate the speed of this Linear actuator to achieved the desired speed.
On a second note, I was attempting on making a linear actuator using a stepper motor and variety of gears on a rack and pinion mechanism to create the linear force (see attached Pic).What are your thoughts on the assembly of my home made syringe plunger.The modulation of the stepper motor will be done using a home made program and the schematics will be a derivative of the following: electronics-diy.com/stepper_motors.php
Finally do any of you guys know where in Canada I can order a gear rack.The closest option I can see is from servo city : servocity.com/html/gear_racks.html
I know this has been a long post guys, any insight you can offer to fix my problem will be highly appreciated.
Hey Coleman
Thanks for the prompt reply.I just have one question regarding the attachment of the L12 linear actuator to the DC controller.Will the DC controller enable microstepping or will it just slow the RPM of the linear actuator.
Welcome to the RobotShop Forum. You can use a DC motor controller to control the speed of the L12 linear actuator (ensure you have the right model), but 1um/s is really incredibly slow and accurate, as is 1/2mm/s. You would need to choose the highest gear ratio (210:1) which can provide 2.5mm/s (peak power) according to the L12 datasheet and reduce that by a factor of 5 using a motor controller. Note that friction will cause the speed to vary slightly since it will constantly be changing between kinetic and static.
The PQ12 may also be of interest because of its size. Check out the PQ12 datasheet. Last, one of the best ways to quickly reduce speed is to use a worm gear (this is not very efficient, but can achieve high ratios in one step). We can special order gears (including racks) from KHK Gear, and the quality is very good.
