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Topic: uArm??An open source robot arm (Read 35 times) previous topic - next topic

teocreo

hi,the sequence of parts are ok,im use that bearing but i have that at home..
for connect the servo is very simple,make at ceter the rotation base,make at center the servo,insert the servo in the wood and apply the 4 screws....
for trasmitt the moviment from servo to robot,use the attachments servo round,with 6 hole,fix it at last round of wood(the item if fix the internal of bearing,and use 2 little screws to fix the plastic to wood.

all internal parts of wood(the round parts) are fix on the base with a glue and 3 screw from back,and,when we have insert a bearing,apply he last round parts and insert a very good screw on the centrer,but first make a "V" hole for head of screw but after up at this item you apply the plastic servo attachments..

very sorry for my bad english....

the external of bearing is fix in same system,first the hole little ,3 item with hole same measure of bearing and after the item with hole small,but this you insert on base first the bearing,after fix the bearing and after fix the rotational base of arm.

thanks a lot for interest of my project,if you have any question write me.

OldSalt1945

I had to give up on my lazy susan bearing and order a proper bearing.  It will be here Thursday.  I just couldn't figure out how to make it work reliably with all the slop in the fit.  Since my arm is 2x teocreo's arm, I had to get a bigger bearing.

http://www.ebay.com/itm/NEW-Ball-Bearing-6908RS-6908-RS-/281046194616?pt=BI_Heavy_Equipment_Parts&hash=item416fa899b8

I am hearing that there is some potential that the UArm project may become a scam.  I don't think that I will be placing an order until I see reliable shipping taking place.

After some re-reflection, I have determined that the base pivot mechanism works as follows:
Round discs 29mm are stacked to form a post.
The small 25mm disc is used to center the bearing on the post.
The last 29mm disc is placed on top of the bearing
   and the whole stack is screwed together with a 3mm flat-head machine bolt.
This captures the inner bearing race at the center and it centers the bearing on the post.

The rings with the 37mm openings are stacked.
The rings with the 33mm openings are added to the stack.
The bearing/post assembly is fitted into the 33mm opening.
One or more 37mm rings are placed over the bearing to capture the outer bearing race.

This has to arranged such that the servo horn just touches the top of the post when everything is assembled.

Then, attach the servo horn to the top of the post and screw the assembly to the robot arm base.

Then attach the post to the platform.  The shaft screw that holds the servo horn to the servo cannot be used, because you can't get to it.  Since it is between the servo and the post with little or no clearance, it won't work off, so it is not needed.

Done.

John
Always keep the shower curtain INSIDE the tub.

zoomkat

Somebody posted the below link on the kickstarter site. Good price with free shipping, but rather use paypal instead of credit card.

http://www.aliexpress.com/store/product/MG995-robotic-mechanic-arm-4-axis-stacker-servos-arduino-Control-Palletizing-Model-four-axis-w/213876_1639729152.html
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

Alex_Co



uArm? is a small Palletizing Robot refer to ABB PalletPack IRB 460. You can also use it as a robot arm and make a development of it to make more interesting applications.

In order to make it more flexible and easy driving, I have also designed two kinds of Chassis of the robot arm.
One is a simple 2WD car as you can see in the following picture.




Your arm is cool! It's very well done and now I was wondering if it could be used as a robotic "leg".
I mean, could someone program it so that it works like a leg?

I ask you this because I would want to use it to create a robotic leg (and a robotic arm like your) for a small project that I have in my mind.

OldSalt1945



Your arm is cool! It's very well done and now I was wondering if it could be used as a robotic "leg".
I mean, could someone program it so that it works like a leg?

I ask you this because I would want to use it to create a robotic leg (and a robotic arm like your) for a small project that I have in my mind.


Yes it is.  It is the robot arm that everyone has been posting about for the last 10 pages.  They have started a kickstarter program to get funding.  We are all waiting to see if they actually produce a product or just take the money and run.  They are currently offering the robot arm mechanical parts for $69 without servos and without electronics.  It is a good deal if they actually deliver on their promises.

https://www.kickstarter.com/projects/ufactory/uarm-put-a-miniature-industrial-robot-arm-on-your?ref=live

John
Always keep the shower curtain INSIDE the tub.

teocreo

hi John,you have make your robot ??
with the formulas .... ??

im very couriose to look the creation of other user,if my draw are ok for we..

OldSalt1945

#141
Apr 26, 2014, 02:54 am Last Edit: Apr 26, 2014, 03:50 am by OldSalt1945 Reason: 1

hi John,you have make your robot ??
with the formulas .... ??

im very couriose to look the creation of other user,if my draw are ok for we..


I have the robot arm completed, but not the base.  I created drawings for the base, but made a mistake.  I made the radius the diameter and everything that we burned on the laser cutter was twice as big as it was supposed to be.  Brain fart.

I will have to try again on Monday.

Always keep the shower curtain INSIDE the tub.

OldSalt1945

The other side.
Always keep the shower curtain INSIDE the tub.

Chagrin

I created drawings for the base, but made a mistake.  I made the radius the diameter and everything that we burned on the laser cutter was twice as big as it was supposed to be.  Brain fart.


Well, you know how it goes. When you make an omelet you need to break a few eggs.

zoomkat

Good photos. The servos seem somewhat small for the size of the arm. do they move the arm ok? I still think a simple temporary base could be made using the home depot lazy susan.
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

OldSalt1945

The lazy susan bearing has a lot of slop in it.  In trying to design something that would allow for that, I kept side-tracking myself.  (this, but that, and the other thing, but then again, although, etc., etc., endless loop).  I finally said to hell with it and ordered a proper bearing.  It was only $7.50 and 4 days shipping time.  Then I goofed up the drawing file and got parts that are too big.  Now I have to wait until after school Monday.

The servos are MG996R digital with 61 in/lb torque (ebay $5.50 free shipping on a slow boat from China).  The humerus is 9" the ulna 10.5".  At a 10" reach, it should be able to lift maybe 5# with friction, arm weight, etc. At full reach of 22" it might be able to lift the rear wheel of my truck or, perhaps a sheet of paper.  50/22 = about a couple of pounds, perhaps, maybe, on a good day with favorable winds.  When I get the new parts from the high school teacher, and hook it up to the Arduino, I will know fer shur.  Assuming no smoke escapes.

Breaking eggs for omlet.  Note the egg in the photo as a size reference.  When I get it working, I will see if I can bash the egg.  I have chickens.  I get the eggs for free, if I don't count the feed bills and equipment and all the other.........................

John

Always keep the shower curtain INSIDE the tub.

teocreo

Hi john,very good !!!
very big robot :-) 

amrovski

hi  :) i heard that  the cad drawings of the uarm would be released in  may, i've been looking for them every  where, but  i just can't find them, i need the drawings to create the base of the uarm, please can  some one help me  :smiley-sweat:

cr0sh

I wanted to let everybody know that one of my friends, who participated in the Kickstarter at a level to get a uArm kit - told me that he was contacted a couple of weeks ago by the developers of the uArm to get his information for shipping. This seems like good news; hopefully it means things are progressing with development, and that their lack of responses to inquiries (and here on this forum) means that they are just kicking butt to get orders fulfilled.
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

zoomkat


hi  :) i heard that  the cad drawings of the uarm would be released in  may, i've been looking for them every  where, but  i just can't find them, i need the drawings to create the base of the uarm, please can  some one help me  :smiley-sweat:


Below is a forum where you might ask questions. I previously posted a .pdf file that has ~full size drawings of arm parts that might be of use to you.

http://forum.ufactory.cc/
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

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