Subject:
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Re: Mr. Jeeves
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Newsgroups:
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lugnet.build.mecha
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Date:
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Wed, 21 Dec 2005 01:04:36 GMT
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Viewed:
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2403 times
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In lugnet.build.mecha, danny staple <orionrobots@gmail.com> wrote:
>
> Hi Eric,
> I have a habit of waking people up - not one for light conversation eh?
That was funny.
> On 20/12/05, Eric Sophie <mylegomaster@aol.com> wrote:
> > Good morning. (yawn) ahhh, yes, the Mana Cat, yes Manas.
> > http://www.brickshelf.com/cgi-bin/gallery.cgi?f=128009
> > Gah, coffe.
>
> Cool - although it didnt work out, it is definately a cool attempt. I
> like those boxes, there are only 3 channels you can use with them. I
> did at some point have a page on using them with the RCX, but for some
> reason I cannot find it (time to rebuild and repost it?) - I certainly
> know it can be done - and have done it myself. I do have a demo
> program to do it with NQC
> http://orionrobots.co.uk/tiki-list_file_gallery.php?galleryId=1
If the structure panned out, I knew the RCX and the Mana units could work
together so I had hoped to be able to control them more presicely using code or
the remote. I planned to look in to the technique to control them more
independantly.
> I am yet to post a design I started with manas that I never got to
> finish - it was a Jonny Number Five attempt (I am sure many builders
> have had a go at that one).
Oh nice!
> >
> > Um, ya, the Mana Cat was suxxor. Incorrect lower legs, trouble with the neck
> > area. Really hit some brick walls. hahaha brick walls. Slayer.
> >
> > I did walk away with some cool ideas, like the ankle return set up.
> > The same mechanism was used x4 for the spine, it allowed the Cat to bend
> > forward
> > and arch its back then return under the spring load.
> Cool - this is really the biomechanical stuff there.. Like I say -
> never stop learning. There is nothing wrong with having a go, at least
> you learned from it.
Yes, there were some cool things I liked, still I lost interest.
> >
> > It was wild when I used the controller. But really hard to control.
> > I reached the motor's stall load, and the fact that each Mana responded to the
> > controllers in weird ways.
> Hmm - how do you mean "weird ways"?
When the joints moved, the cat would lean and bend in interesting ways.
I mena if the fron lower left motor moved up, the Cat would tilt back, it was
like shifting a parallelagram or something, when you moved some limbs itwould
tilt towards the opposite way. Hard to explain. Some limbs needed to be moved
together to get the desired effect. Learning the dynamics of a quadra-ped was
interesting.
Same with the Mecha Cats, move one limb and it may not balance as might think.
> > No two positions were the same, like it had 16 differnt movements, really hard
> > to remember what was what.
> Maybe it would have been easier to get an RCX, and then use the RCX
> remote to talk to the RCX, and the RCX would then split up signals to
> go the manas - although I seem to remember that the RCX remote and the
> manas may not work together too well..
Right.
> >
> > One other thing that was tough was the size. Adding 10L axles to either side
> > of
> > the Mana units for the worm gear set ups made the legs really big.
> > That along with only a minimal amount of gear reduction made for additional
> > issues.
> I have experienced exactly that when building robot arms. Sometimes
> you have to think things through to make sure that the gearing at the
> end of your arm is not going to be too heavy to lift..
Torque and speed.
> >
> > Maybe I'll try again sometime. I rather get another pair and make an elongated
> > Hexapod design like the RG Mech.
> There have been some really amazing pneumatic hexapods appearing on
> .robotics. I would love to see some more efforts than span both these
> groups. I will repeat what I have said before - it was your Jama that
> actually got me lurking on .mecha eric.
Right on. I have always wanted to see other robotics builders blend the tech
with a skin or covering. We develope the technical aspects, now I'd like to see
them sheathed in an organic looking covering, or any covering at all.
> >
> > > The joints are all posable with worm gears arent they? I had a thought
> > > last night on a "compliant" worm gear based joint - which involved
> > > fixing the gear onto an axle, and allowing a housing assembly around
> > > the axle to move a little with a technic suspension - thus giving a
> > > joint a little compliance, which still springs back to the desired
> > > position when the force comes off. The alternative I had (which is a
> > > great deal more "human") was to use elastic-band tendons, and then
> > > have a set of two (or four using long pins) technic pulleys - either
> > > side of 2 pins - so a contraction would mean reeling in (winding up)
> > > the elastic band between the pulleys. The pulleys would probably be
> > > best driven by a high reduction system with a worm gear, and maybe a
> > > clutch to ensure that the thing stops before the band snaps. I may
> > > design an arm - and later a whole mech based on that...
> >
> > Wait I just woke up! Head hurts! Sleepy. Time for my morning run.
>
> Sorry - that was a bit of an intense databurst - I do that sometimes -
> it tends to get the "rabbit between headlights" look from people.
hahahahah.
> > Do you mean like this?
> > http://www.brickshelf.com/cgi-bin/gallery.cgi?i=1224292
> > That is a spring loaded return joint dealy.
> That was my initial concept, although now I have a bit of winter
> holiday, I am going to try my elastic band tendon idea - at first just
> with a poseable joint.
> <snip>
If you make a mock up, I'd really like to see it.
> > > I am always interested in socket/ball joints - and larger ones more
> > > so. Maybe we will see more of these in the coming lego mech series.
> > > Anyway - I think it looks good, thanks for posting them eric.
> >
> > The only issue is they can't hold any weight.
> > A Technic pin fits in to the socket, but easily comes out.
> > The 4 stud depression helped to secure the joint, but weight pressing down is
> > what really makes the set up work in the case of Mr. Krinkle and Mr. Jeeves.
>
> Fair enough - thanks for the heads up, I am still thinking of buying some.
By all means give it a try.
> >
> > I once tried an experiment to secure and bind the socket as a joint here in
> > the
> > Dancing Sun Power Suit, the result looked like the Mech was in traction!
> > hahahahha, I wanted to see if it could be done:
> >
> > http://www.brickshelf.com/cgi-bin/gallery.cgi?f=54980
> > see images:
> > ds-03-front.jpg and ds-04-rear.jpg
>
> Ah - now I am really thinking - I could take this idea, use the ball
> joints with the elastic bands, and then skin over it a bit with
> overlapping stuff to hide the joint itself. Thanks eric - I am now
> really inspired to go off and try and build this thing.. Once I have
> finished a few things that maybe a little project for me.
> <snip>
> > Have a good day!
> >
> > e
Hey cool, if you can over come some of the limitations I'll be the first in line
to congratulate you! Now you got me curious!
> Thanks eric, you too.
> --
> Danny Staple MBCS
> OrionRobots
> http://orionrobots.co.uk
> (Full contact details available through website)
Thanks Danny!
e
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Message is in Reply To:
 | | Re: Mr. Jeeves
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| Hi Eric, I have a habit of waking people up - not one for light conversation eh? (...) Cool - although it didnt work out, it is definately a cool attempt. I like those boxes, there are only 3 channels you can use with them. I did at some point have (...) (19 years ago, 20-Dec-05, to lugnet.build.mecha)
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