What motor for a parallel gripper kit?

I have a parallel gripper (https://www.amazon.com/Actobotics-Parallel-Gripper-Kit-A/dp/B00OP2V5OY/ref=sr_1_1?ie=UTF8&qid=1473285267&sr=8-1&keywords=parallel+gripper+kit)

and a servo motor (https://www.amazon.com/Hitec-31311S-HS-311-Standard-Universal/dp/B0006O3WVE/ref=pd_bxgy_147_img_2?ie=UTF8&psc=1&refRID=3HV5VN9HQSBC9K4N1183)

I wrote a little program to open the gripper for 10 seconds, then close it for 30 seconds. When the gripper is open, if I put anything between the gripper arms, when the close, they stop when they meet any resistance, and whatever I was expecting them to hold gets dropped.

I'm thinking the servo is not powerful enough (not enough torque?) But I also read somewhere not to hook up that particular servo to anything more than 5V.

So is this a power problem, the wrong motor, or maybe even bad code?

I'd like my gripper to grip stuff. :)

Compatible with standard size Hitec or Futaba servos (sold separately).

Which is what you've got. How strong did you think the grippers were? Have you thought about adding rubber jaws to it?

BTW: You do have adequate power supply for the servo? Arduino 5V rail is not adequate and inappropriate (you shouldn't share logic and motor supplies)

I have a N298N motor controller. Was going to try and hook that up to see if it helped.

But right now I am driving everything (all three wires) off the Arduino itself.

I thought a gripper would grip things. Right now, the servo stops closing when it meets resistance, so it doesn't really hold onto anything.

Thanks for the help! :)

An L298N is nothing to do with a servo. Do you have adequate (more than 1A) 6V power for the servo?

BTW a hobby servo is not technically a servomotor, that's something completely different: http://www.ebay.co.uk/itm/MDSKSBS056-23-LENZE-Servomotor-1-1KW-3800U-min-mit-Bremse-24V-/142082048836?hash=item2114c00344:g:ci0AAOSwKIpV~U~G

A hobby servo is a small servo-actuator or servo-mechanism, which incorporates a small motor in a feedback loop using a built-in controller.

A servomotor is a high torque motor with resolver or encoder used as a component in motion control systems, and comes separate from its control unit typically.

I'm using an AC/DC adapter that converts household current to 9V/1A.

You need 6V, not 9V