Lynxmotion Tech Support

Back to our roots. Uses the stronger HS-225MG servo rather than the HS-85. Max opening of 1.875".

_________________
Curiously enough, the only thing that went through the mind
of the bowl of petunias as it fell was "Oh no, not again."

James "Don't call me Jim" Frye
Lynxmotion, Inc
http://www.lynxmotion.com

Have you considered incorporating a microswitch or pressure switch into the jaw design?

I'm trying to work this out for a table-top 'bot that must find an object, capture it, and move it into a "goal".

Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

I'm planning some optional parts to add additional functionality. This is just getting the basic gripper back on the website. The options will come soon after that.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Good to see it back in the offerings! It is an interesting way to work the jaws. And of course the parallelogram action to keep the jaw faces parallel always attracted me as well.

I'm going to attempt to use a pair of pushrods to close my sheet-metal jaws for the table top bot. No way that I can see to work LM jaws into this 'bot. Your jaws reminded me that I won't get the parallel motion, at least with this rev.

Object is to be a block about 3.5" x 3.5" square, and perhaps 1.5" tall. OR, a cheese-shaped wedge about 4.5" long, and 3.5" wide. Any ideas for better jaws?

I'm planning to use some microswitches; both to detect when there is an object in the back of the jaws, and others to detect closure on the object.

Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

Our testing involves a pressure sensor. We are able to control the amount of force so the gripper can hold the object without heating up much. It's working great. Switches would be problematic as there is no way to detect how much work the servo is doing. You would have to incorporate some sort of spring to add some pressure before the switch closes.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

I like the pressure sensor idea. I've seen some low-pressure sensors, most are a bit bulky for my use.

The microswitches do come in various activation forces, for the switches at the rear of my jaws I finally got very light force switch. For the closure switches on the jaws themselves, higher force switches might be in order. or the springs you suggest. I'm also playing with using rubber surgical tubing to add some compliance.

Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

We're doing it like this.
http://www.lynxmotion.com/images/html/build129.htm

Here are some highlights.

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Ah! FSR's!

For some reason I was thinking of air pressure sensors, which I've wanted to use as force sensors on legs and jaws (hence the big and bulky comment).

I bought an FSR, but I haven't worked with it yet. Might be a solution for my jaws as well...

Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

Any thought to making jaws using the LPA parts?

Edit: LPA parts LPAGS-01

Something like this:



Needs a new LPF bracket, one that puts the centerline of the two gears inline with the axis of the R/C servo.

This one may be the next version of jaws on my Table Top 'Bot.

Shown here is an early version of jaws (grippers).



Needs to be able to grab a small block or piece of cheese.


Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

LPF?

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

Sorry. LPA parts, such as LPAGS-01 & LPA-1.

Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/

Ahh ok. This looks pretty cool. Will see what I can do. Thanks!

_________________
Jim Frye, the Robot Guy
http://www.lynxmotion.com
I've always tried to do my best...

My revised gripper (jaws):

Uses 4-bar linkage, with R/C servo driving LPA gears. Ball Bearing Hub under 2nd gear.

32 Pitch, 50 Tooth gears.

Left jaw at full extension, right jaw at mid position. Jaws are made from 1/16" aluminum, with a 2nd level to the jaws forward of the joint.

Any progress on your new jaw design?

Alan KM6VV

_________________
Visit:
http://groups.yahoo.com/group/SherlineCNC/
http://tech.groups.yahoo.com/group/HexapodRobotIK/