Modifying JHack's servobed and cover for easy mounting and removal: part 2

I was able to finish a rough draft of the new screwed down cover last night and printed it this morning.  Here is the print with support material.

Oddly, when I peeled support material off of it, one corner of the front screw-down tab was warped.  I'm not all sure why that happened.

I decided to make the guides an integral part of the cover so that there would not be a lot of gluing and messing about with the assembly.

Printing the JHack simple servo bed

Jhack's derivative of the simple servo bed seems to be an improvement over the original simple servo bed that Gael posted recently.  It is certainly simpler to mount servos in it.  It is, however, fragile, in a few places and it isn't obvious how you attach it to the forearm shell save using glue. The same can be said for the cover over the servos that fits on top of the bed.  Once glued down, it would seem to me that you'd have to tear the while forearm apart if a servo failed.  I'm probably going to try to modify that while I'm waiting for the rest of my HK15298B servos to arrive.

The simple servo bed was a touch too big for my UP! Pro 3D printer so I had to tilt 45 degrees on the vertical to fit into my print volume.  Given the height of the resulting print, I had to use the stable support option which took a lot of filament to make the support and a lot of extra print time.  You can see the finished print here.

The extent of the support structure needed is quite clear.

You can get an idea of the nature of the paper-thin support structure in this pic of the support structure being removed.

While the removal of the support structure looks like a formidable task, as a practical matter it took less than ten minutes to clean it from the print.

The cover, not pictured, required a similar support structure.  It was considerably more fragile than the bed and required greater care in removal from the support structure.  I was able to do that successfully, however.

Seating the new, larger leadscrew in the bicep

Gael quite rightly suspected that the new, stronger lead screw I developed for the bicep would clash when it tried to seat in the recess in bottom of the RotGear.  Raising the hole that the thrust collar axis seats in by 11.5 mm sorted that problem out quite prettily.

Here you can see the revised HighArmSide part that supports the thrust collar.  I've overlaid the revised design over the old.  As you can see the new mounting hole has been moved upward a bit.  I simply plugged the old hole and cut a new one in the STL file.

Here is the forearm at full extension.

Contracting the forearm towards the bicep at the elbow.

Fully contracted, the lead screw slides into the recess in the bottom of the RotGear which allows the bicep to rotate in a perpendicular plane to its axis.

A closer view.

Removing RotGear you can see the lead screw seated where the recess in the bottom of the RotGear is.

A closer look.

Kinect Progress 13-02-23

This morning, I got a note from the UP 3D printer people that they wanted to do a Skype video session to put my printer right.  I thought they meant right then, but was wrong, apparently.  While the new extruder heater block helped matters it didn't fix my UP.

In the meantime, I worked on the Kinect motion capture task.  I have it capturing the upper torso, head and arms and transferring it to a disk file.  My programme is very crude.  I simply identify the joints and put the coordinates in a list box.  Surprisingly, my PC and Visual Basic 2010 is able to keep up with the 30 frames/second that the Kinect does that process at with no effort whatsoever.  After I record a session, I simply save the XML formatted information to a file.

My next task is to restrict the saved output to the left upper torso, shoulder and arm and to covert the cartesian coordinates to joint specific coordinate systems which match the kinematics that Gael has designed into the Inmoov arm.

Left arm of Inmoov robot complete

Printing an assembly for the left torso, shoulder, bicep, forearm, wrist and hand is complete.

Front view of left torso assembly, shoulder, bicep and base of forearm.

Detail of rear view of upper torso and shoulder.

Left arm raised.

Forearm flexed.

Forearm extended.

Detail of lead screw and collar controlling the left shoulder.

The Hitech HS-805BB servos that drive the torso and arm kinematics are on order.

Printing Gael Langevin's Inmoov Robot

Andreas Maryanto and I have been working on animatronic hands for some time now with Andreas' Dexhand project streets ahead of my own efforts.  About a year ago, I happened across a printed hand done by hairygael {Gael Langevin} in Thingiverse.  It was interesting enough that I printed a copy of it, but at that time Gael had not got very far with the design, so I neglected to follow his subsequent progress.

Big mistake!  About a week ago I discovered that Gael's modest beginnings had subsequently blossomed into a full fledged animatronic robot upper half.

I was both shocked and completely entranced by what Gael had accomplished in so short a time.  Gael was kind enough to make his print files open source, so I immediately began a campaign to print a copy of his robot.  Using his files, I have so far managed to print out a copy of his Inmoov robot's left arm.

I apologise for the poor quality of the pictures.  My own camera was lost a few months ago when my son's car was broken into in Seattle and I have been remiss in replacing it even though his insurance company was quite prompt in reimbursing him for the loses.

At the moment, I have not tried to install servomotors but have concentrated on understanding how the many pieces go together.  I shall be buying the torso, shoulder, bicep and wrist servos in the next week or two.