Author Topic: My most recent arms...  (Read 15822 times)

fkane123

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Re: My most recent arms...
« Reply #30 on: December 27, 2014, 07:04:47 PM »
Back to the original measurements you posted:

11" / 10" / 10" / 10.75"

If you remember, are those the lengths working from the claw backward, as pictured in the third photo? I tried these lengths using Bob's joints, but it resulted in arms that wouldn't fold up all the way. Either the latest joints are substantially different from the ones you used in 2011, or I assembled them in the wrong order... or maybe I'm not measuring from the correct points or something. I'm using those as the lengths of each plastruct segment, and then drilling screw holes 1/4" from each edge, then assembling as pictured here.

Would be good to hear from other builders as to the lengths they like to use too!




treadwell

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Re: My most recent arms...
« Reply #31 on: December 28, 2014, 02:03:13 AM »
Somehow I had in my head that the forearms were slightly shorter, but a quick look at reference doesn't agree. Where did I get that? Gary's booklet?

fkane123

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Re: My most recent arms...
« Reply #32 on: December 28, 2014, 05:52:11 AM »
Yeah, the Bot Building Booklet says to use 9 1/2" segments for both part of the forearm, and 10 1/2" for both parts of the... um... humerus, I guess. That does result in the wrist resting below the shoulder when folded up. My guess would be that the lengths varied over time on the show, and maybe those measurements were accurate at the point when the booklet was written.

Still, I've tried equal-length segments before, and they had a tendency to not stay parallel in operation. That's why I'd like to get these "new & improved" arm lengths working if possible.

Ron

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Re: My most recent arms...
« Reply #33 on: December 31, 2014, 01:15:27 AM »
I didn't use Bob's joints.  The joints I used in my example are from Lil' Monsters.

fkane123

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Re: My most recent arms...
« Reply #34 on: December 31, 2014, 08:46:56 AM »
Yeah, looking closely at your original photos, I think the Lil' Monsters elbow joint is wider than what Bob provides. That would explain it.

Here's how those measurements look with Bob's joints. Maybe you'll catch something I'm doing wrong, but I think they're designed to work best with the stated lengths in the Bot Builder's booklet. I've got some more plastruct coming in today so I'll give that a try.



fkane123

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Re: My most recent arms...
« Reply #35 on: December 31, 2014, 11:54:45 AM »
So, the measurements in the Bot Building Booklet didn't work out so hot either. Using Bob's joints, here are the plastruct lengths I settled on:

10.5" / 10" / 9.5" / 9.5"

As you can see this folds up nicely. I used foam tubing lengths of 8" and 7", which fit nicely and allow for the most movement. If using Bob's Fanny Grabber hand molds and shoulders, you'll want to use 3/8" Plastruct and not 1/4".

I think most people just buy entire arm assemblies from Bob and not just the joints like I did, but hopefully this will help someone out down the road.

This tries to match the look of the arm assembly in the Bot Building Booklet as closely as possible. You could however go for equal-length forearms and humerus by going with 10.5" / 10" / 10" / 10" instead.

Eyeballing it, they seem a little short in hindsight - I'd probably add an extra inch onto each segment if I did it again.

« Last Edit: December 31, 2014, 12:45:39 PM by fkane123 »

Ron

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Re: My most recent arms...
« Reply #36 on: January 02, 2015, 04:13:18 PM »
Nicely done!

rashielx

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Re: My most recent arms...
« Reply #37 on: January 14, 2015, 04:12:15 PM »
I trashed a set of joints... and... well... an arm as well. Where's the best place to get a set of joints? For that matter, is there a list of parts suppliers or certain people we can get parts from for the various bots?

sledge_riprock

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Re: My most recent arms...
« Reply #38 on: January 15, 2015, 08:30:08 AM »
To make the arms fold up correct with the foam in place the front three arm rods should be of equal length and and the back most rod 3/4" longer.  I use 3 - 9 1/2" and one 10 1/4" with 7 1/4" foam pieces on my Crow arms. No particular reason for this size. It just works for the height of my Crows on their bases. You can make them any size you want as long the rear one is 3/4" longer.

The original Wallace lamp rods are 13 1/2". Most off the shelf lamps are 14 1/2" or longer.

Ron

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Re: My most recent arms...
« Reply #39 on: January 16, 2015, 08:19:35 AM »
I've always shot for a "Movie era" length on the arms.  Those early season arms are just too gangly for my tastes. LOL

1984gojifan

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Re: My most recent arms...
« Reply #40 on: February 08, 2015, 07:44:36 PM »
I Personally prefer buying real adjustable lamps and salvaging them for crow joint to make him last longer, since I'll be taking him and Servo to Motor City Comic Con in May, For anyone who wants to buy real Crow type swing arm desk lamps, (keep in mind you'll have to either make or buy, scratch built wrist joints).

http://www.amazon.com/Alvin-G2540-B-Swing-Lamp-Black/dp/B001DNFLYS/ref=sr_1_1?ie=UTF8&qid=1423445188&sr=8-1&keywords=alvin+desk+lamp
"Watch out for snakes!"

1984gojifan

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Re: My most recent arms...
« Reply #41 on: February 15, 2015, 06:08:39 PM »
Got the Alvin Black desk lamp in the mail yesterday, now I can sleep a little easier now that Crow will last longer.

"Watch out for snakes!"

Gromilini

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Re: My most recent arms...
« Reply #42 on: October 18, 2015, 01:53:51 PM »
Hi Ron, I know it's a very old post, but is there a chance you could reload the pictures you posted on the first page of this thread? Many of them have gone away. I would especially love to see anything you have regarding connecting the grabby hand to the "guitar pick" wrist joint. Thanks!

Ron

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Re: My most recent arms...
« Reply #43 on: October 19, 2015, 09:15:15 AM »
Got those image links fixed...

katsu

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Re: My most recent arms...
« Reply #44 on: December 16, 2015, 06:10:07 PM »
I have an imposing question! Any chance for some scans or measurements for your joints? I've seen some various vague descriptions but I'd like numbers on a good looking set!