Welcome, Guest. Please Login
SLINGING.ORG
 
Home Help Search Login


Pages: 1 2 3 4 5 
Send Topic Print
Roboslinger! (Read 2056 times)
RS
Descens
***
Offline


Slinging Rocks!

Posts: 165
Re: Roboslinger!
Reply #30 - Apr 18th, 2018 at 3:31pm
 
just use a centrifuge....shouldn't be too hard to fix up a throwing system to it.  u could control more variables that way=speed, acceleration, ect..
Back to top
 
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #31 - Apr 19th, 2018 at 12:49am
 
Sarosh wrote on Apr 18th, 2018 at 12:26pm:
I'm curious, have you already thought of experiments to conduct?  I would like to hear some examples.
what variables will be eliminated by the robot?


I would love to hear ideas. I personally want to do some accuracy experiments with a precision timed release mechanism and do some apples-apples comparisons of different sling designs. A vertical trebuchet would work for those experiments but CA is right about not being able to replicate sidearm throws on a treb.
Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #32 - Apr 19th, 2018 at 12:56am
 
@CA: a 4-DOF robot arm is pretty hard to build correctly on a budget.   In particular, the backlash on budget servos and gear boxes would make it hard to get repeatable results, and the system would be heavy too compared to a treb. It’s probably better to buy a $20k industrial arm rather than build my own if that was the way we wanted to go.

Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #33 - Apr 19th, 2018 at 1:12am
 
rcoon8865 wrote on Apr 18th, 2018 at 1:10pm:
Hello.
I'm new to slinging.org. I used to sling as a kid in the
70's-80's and picked it up again a couple of years ago. I
mostly enjoy throwing for distance. Does anyone have
any videos showing or demonstrating sling styles for distance.
thank you.


Hi coon, there are quite a few threads on distance throwing and different styles on this forum. I would recommend looking at the FAQ and maybe doing a keyword search. The roboslinger topic isn’t the best place to discuss your question.
Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
Curious Aardvark
past-administrator
*****
Offline


Taller than the average
Dwarf

Posts: 13965
Midlands England
Gender: male
Re: Roboslinger!
Reply #34 - Apr 19th, 2018 at 6:27am
 
Quote:
It’s probably better to buy a $20k industrial arm

that confirms it - you are made of money Smiley

At the end of the day it does depend what you actually want to test.

With a treb you can only really test forces at release, and effect of release points and methods.

pretty limited.

Don't see the problem with a robotic arm, plus it would be way more fun to build Smiley
Back to top
 

Do All things with Honour and Generosity: Regret Nothing, Envy None, Apologise Seldom and Bow your head to No One  - works for me Smiley
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #35 - Apr 19th, 2018 at 8:57am
 
Curious Aardvark wrote on Apr 19th, 2018 at 6:27am:
Quote:
It’s probably better to buy a $20k industrial arm

that confirms it - you are made of money Smiley

At the end of the day it does depend what you actually want to test.

With a treb you can only really test forces at release, and effect of release points and methods.

pretty limited.

Don't see the problem with a robotic arm, plus it would be way more fun to build Smiley


Ha! Not quite made of money. If I were, I wouldn’t need to be resourceful Smiley
It might be fun to build one, but it would not satisfy the current project. My point is that industrial arms are so hard to build from scratch that drumming up $20k would probably be easier. That definitely doesn’t mean it’s easy to just buy a robot (unless Morphy has a few gold plated emerald encrusted parangs to sell too).
Any robot arm that stands a chance at the performance we would need would at least cost thousands in parts cost alone. You can buy some robotic arms in the $10-20k range that would perform better and wouldn’t take years to finish building. Even those are not likely to give the performance we would want.

The other problem with electric motors is that they perform best under one specific load. That’s why you need to change gears to get a wider range of performance from a motor, but I’ve never seen a robotic arm with variable transmissions at the joints. Electric motors are a terrible surrogate for a human arm which can activate more or fewer muscle fibers at any time and transition smoothly between high strength and high speed motions while maintaining precision control the whole time. 

I would love to be proven wrong. It may be possible to get the performance we want on a budget, but I am not qualified to do that myself... at least not by building a robotic arm.

On a related note, Boston Dynamics did some impressive throwing experiments with an arm on a 4-legged robot, but it was using its whole body for the throw and the robot cost millions of dollars:

https://m.youtube.com/watch?v=-q7RsdxE76k
Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
Morphy
Slinging.org Moderator
*****
Offline


Checkmate

Posts: 8239
Re: Roboslinger!
Reply #36 - Apr 19th, 2018 at 10:47am
 
If we are looking at vertical throws we would most likely be replicating the Apache throw. Might I suggest you include that in the slow motion capture?

The thing with the figure 8 is the sling isn't just traveling vertical. It's coming from the opposite shoulder side from the sling. So there is some sideways momentum in play.
Back to top
 
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #37 - Apr 19th, 2018 at 1:06pm
 
I did the capture yesterday. I’m not great at Apache, but I did try it. I will try to post some animations as soon as I get the data back. Might take a week or two for me to have anything to show.

The vertical-only design is fairly limiting, which is why I only said that should be our first iteration. We can always make it more complicated later, but a vertical treb will help get us started more quickly. One thing I’ve been thinking about is putting the sling on the outside of the trebuchet struts instead of between two vertical supports. That way we could add a side-swinging component to the trebuchet arm later on without a structural redesign.   I’ll post a concept sketch when I get a chance.
Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #38 - Apr 19th, 2018 at 1:19pm
 
FYI, I did three sets of four styles in the mocap:
Underhand, Apache-ish, sidearm, and figure-8

Once I get the animations together, you can all debate whether I put the right labels on the four styles I used and whether the form was good or bad Smiley




Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
Curious Aardvark
past-administrator
*****
Offline


Taller than the average
Dwarf

Posts: 13965
Midlands England
Gender: male
Re: Roboslinger!
Reply #39 - Apr 20th, 2018 at 3:14pm
 
that'll be very interesting to see.

You could add 'things' to the end of the treb arm that could simulate different arm movements.

Kind of like rubber powered, joints that just fire with the main trigger.

Could get some interesting and consistent swings like that.

I'm definitely not talking industrial robot arms. Or the things on thingiverse really as they're all designed the same way as a conventional arm.

One designed specifically as a slinger would be quite different.
I haven't seen any home made robot arms that use metal 'bones'.

Give me a while to think about it and I could easily design the physical side of it. Just don't know the first thing about programming and electronics.

I guarentee it wouldn't look pretty. But I come from the ducktape and string school of building stuff.
If it works - it doesn't have to be a work or art Smiley
   
Back to top
 

Do All things with Honour and Generosity: Regret Nothing, Envy None, Apologise Seldom and Bow your head to No One  - works for me Smiley
 
IP Logged
 
Al Paca
Tiro
**
Offline


Slinging Rocks!

Posts: 48
Melbourne, Australia
Gender: male
Re: Roboslinger!
Reply #40 - Apr 23rd, 2018 at 3:36pm
 
I discovered slinging as a distraction from my trebuchet experiments. You may want to look at Leonard Vance's projects on YT especially the "Murlin" trebuchet. A five arm highly efficient machine. You may find that significant research has already been done in this area by a number of individuals and educational centres.

Back to top
 
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #41 - Apr 23rd, 2018 at 8:20pm
 
Al Paca wrote on Apr 23rd, 2018 at 3:36pm:
I discovered slinging as a distraction from my trebuchet experiments. You may want to look at Leonard Vance's projects on YT especially the "Murlin" trebuchet. A five arm highly efficient machine. You may find that significant research has already been done in this area by a number of individuals and educational centres.



Thanks AP!  I’ll check that out.
Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
NooneOfConsequence
Slinging.org Moderator
*****
Offline



Posts: 2993
Texas
Re: Roboslinger!
Reply #42 - Apr 23rd, 2018 at 9:42pm
 
Very interesting treb vid! Thanks for the tip Al Paca!  It definitely gives me some ideas for simulating a human throw too.

For reference, here’s the most informative video on the murlin:

https://youtu.be/K7mB5iftarQ
Back to top
 

“My final hour is at hand. We face an enemy more numerous and cunning than the world has yet seen. Remember your training, and do not fear the hordes of Judas. I, without sin, shall cast the first stone. That will be your sign to attack! But you shall not fight this unholy enemy with stones. No! RAZOR GLANDES!  Aim for the eyes! May the Lord have mercy, for we shall show none!“  -Jesus the Noodler
 
IP Logged
 
Al Paca
Tiro
**
Offline


Slinging Rocks!

Posts: 48
Melbourne, Australia
Gender: male
Re: Roboslinger!
Reply #43 - Apr 24th, 2018 at 3:34am
 
Thanks very much. Great vid
Back to top
 
 
IP Logged
 
Mersa
Interfector Viris Spurii
*****
Offline


Druid

Posts: 2615
Australia
Gender: male
Re: Roboslinger!
Reply #44 - Apr 24th, 2018 at 5:02am
 
Very impressive but how do we apply this to slinging?
Back to top
 

Razor glandes, Aim for the eyes!!!
 
IP Logged
 
Pages: 1 2 3 4 5 
Send Topic Print
(Moderators: Rat Man, joe_meadmaker, woodssj)