Grabbot hand only opens

[steveg]

When I constructed the grabbot hand, before adding the motors for the wheels, I tried to rotate the claws by hand. I rotated the gears but they will only open the claws, and it jams when trying to reverse them. The pictures in the book are very dark and I had trouble interpreting them. Are ther any online photos that are clearer, or any ideas as to how to fix this.
Thanks

[Laurens200]

Hi Steve,

There may be an error in your contruction. For example, the knob wheels might have been aligned incorrectly. I think this causes the behaviour that you describe. Can you post a picture of your grabbot? Then I'll be able to help you better.

Laurens

[steveg]

I would be glad to send photos. Is it permitted to place here, or should I put them on Picassa or somewhere else?
Thanks

[Laurens200]

It is up to you where you want to post pictures. I think it is best that you attach them to your post here, so that readers with the same problem can see the possible solution.

You can attach the image(s) by clicking 'Additional Options' below the text window.

[steveg]

I uploaded the photos to:
http://picasaweb.google.com/lh/sredir?uname=steveg1009&target=ALBUM&id=5416015920720418769&authkey=Gv1sRgCMzxqJmj9ZCF6gE&invite=CIa_2cAP&feat=email

You can cut and paste into browser of choice. Photos were too large to put here on site. I thought that it would be easier to be seen here.
Thanks for the help.

[Laurens200]

Hi Steve,

I spotted the problem  . Both 4-by-2-hole-L-shaped-beams in your grabber are misaligned. As a result, the two knob gears do not stick together.

Carefully review the steps on page 310 to fix the problem. Please let me know if this helps. If you're unsure what I mean, let me know as well.

I'm sorry to hear the images are so dark. Aparently the darkness varies from copy to copy. In my book, chapter 9 is OK, but chapter 10 is dark.

I hope you'll enjoy the grabbot!
Laurens

[steveg]

Got it! Thanks.