RoboSavvy Forum

robonova size and max. load capacity

2008-08-01T02:23:47+01:00

Putting two servo in parallel needs to be done with great care as otherwise each servo will try and move the other, both will get hot and probably fail. It might be a good idea to learn about torque and how servos work before going further.
David

Statistics: Posted by robots42 — Fri Aug 01, 2008 2:23 am

robonova size and max. load capacity

2008-07-19T10:56:26+01:00

the above pic was just an example.... can anyone tell me which servo is handling the most load? maybe i might just add 2 servos on that joint where the robonova will handle the most load after scaling the size... and will leave the other joints with 1 servo to leave more servos for other body parts...

thanks...

Statistics: Posted by vicong50 — Sat Jul 19, 2008 10:56 am

robonova size and max. load capacity

2008-07-18T22:53:34+01:00

so that is 20 servos for 2 legs !!!
Now you have to squeeze the rest of the body into 6 servos

Statistics: Posted by DirtyRoboto — Fri Jul 18, 2008 10:53 pm

robonova size and max. load capacity

2008-07-18T04:35:25+01:00

hi thanks for all the replies...

will it work if i install 2 servo motors per joint? example in the picture below...

the above pic is for 1 leg only....

can the robonova work with 2 servos per joint after i increase and scale the size bigger?

how can i program using roboscript for proper alignment?

thanks...

Statistics: Posted by vicong50 — Fri Jul 18, 2008 4:35 am

robonova size and max. load capacity

2008-07-15T19:51:55+01:00

As done by humans, move the arms infront of the body at it lifts. the arms should add extra weight to the duty direction of the servo and so reduce some of the stress.

This needs to be done after the robo has reached 45 deg angle. you might look at adding some weights to the robos hands to help.

Statistics: Posted by DirtyRoboto — Tue Jul 15, 2008 7:51 pm

robonova size and max. load capacity

2008-07-15T11:18:50+01:00

Thanks Badlands and DR, I now have highspeed, cool.

One further question if I may, I tried to make the ROBONOVA do sit ups, however in its modified form the top end is heavy.

So if I hold the legs and program the hip servos to lift the torso from horizontal they struggle to accomplish the move/slow/need light assistance.

The answer could be a simple one, in that they are not powerful enough, however I wondered whether I could alter the torque being applied within the program language?

Sorry, for what are probably simple programming questions.

I must say the Robonova through all of its mods and tests has been completely reliable, even with a fur body covering it!

Cheers guys

Photos and vid shortly.

Statistics: Posted by My Bear — Tue Jul 15, 2008 11:18 am

robonova size and max. load capacity

2008-07-15T00:24:42+01:00

As badlands says

HIGHSPEED SETON
(and also)
SPEED 15
(and another thing to help)
PTP SETOFF

The RN1 will not get lift-off but it can still move fast.

I really want to find out about the 3 crows, spider and wasp. What a cool combo.

Statistics: Posted by DirtyRoboto — Tue Jul 15, 2008 12:24 am

robonova size and max. load capacity

2008-07-14T15:33:42+01:00

In roboBASIC the highspeed command is HIGHSPEED SETON or HIGHSPEED SETOFF.

Statistics: Posted by badlands — Mon Jul 14, 2008 3:33 pm

robonova size and max. load capacity

2008-07-14T10:59:00+01:00

Hi DR

Yes I've written the pilot and have spent forever designing other characters, which unfortunately have to be hand control puppets until funds allow Robotic models as well.

The 'bear' is complete and with the aid of a hand puppet duplicate I can capture most moves/shots.

One command you might be able to help me with is one to make the servos react at 'highspeed'. I use robobasic and can alter the speed but I want the robonova to extend its legs in one super fast move to catapult him off the ground, however, when I type in HIGHSPEED it just highlights in yellow because I'm missing something or could this be the incorrect command anyway? I'm trying to achieve the fastest movement possible which the servos will allow, perhaps a servo move command?

Also cannot achieve as yet unassisted walking, can create a shuffle walk, but the second he tries to lift a foot off the ground, it all goes pear shaped, perhaps I'm trying to achieve the impossible?

I'll post a video once I've filmed a few more moves, It's surreal.

If completely successful I've then got a cat, three crows, a spider, a wasp! and a further bear to give the Robonova treatment to.

Cheers

Darren

Statistics: Posted by My Bear — Mon Jul 14, 2008 10:59 am

robonova size and max. load capacity

2008-07-13T19:35:29+01:00

yea I remember you had left out some WAIT commands a while back.
How is the project going by the way? have you put together any stories yet.

DR.

Statistics: Posted by DirtyRoboto — Sun Jul 13, 2008 7:35 pm

Scaling up

2008-07-13T17:34:27+01:00

I've re manufactured the torso and now have a robonova at 60cm high, i've also placed the robonova inside of a Teddy Bear!

I had to reduce the feet slightly to accommodate the Bear body, sounds like a recipe for disaster but stability is OK and no servo problems to date, although I feel its pushing the envelope a little.

Statistics: Posted by My Bear — Sun Jul 13, 2008 5:34 pm

robonova size and max. load capacity

2008-07-12T22:53:58+01:00

I am not sure about 1 metre but you can scale RN up to about 2 ft which is what I am looking at doing now i have 2 of them

Statistics: Posted by DirtyRoboto — Sat Jul 12, 2008 10:53 pm

robonova size and max. load capacity

2008-07-08T14:26:26+01:00

i currently have machines that can cut and bend the aluminum to the shape and design i need...

and i will use back the servos that comes with the robonova...

is it powerful enough?

what is a suitable size i can scale it without needing to change any servos?

thanks for any replies...

Statistics: Posted by vicong50 — Tue Jul 08, 2008 2:26 pm

robonova size and max. load capacity

2008-07-08T14:21:55+01:00

thanks for replies...

i was thinking of using the original items like the servos and boards, and fabricating my own metal brackets. I will use aluminium 1.5 - 2mm thickness and will anodize to get the colour effect.

what if i remove the laptop and just scale the robonova without adding additional items? would the current servos provided with the robonova work?

Statistics: Posted by vicong50 — Tue Jul 08, 2008 2:21 pm

robonova size and max. load capacity

2008-07-08T13:06:20+01:00

Scaling the Robonova is probably not a good start for a 1 Metre biped. Making it 3 times the size will also increase the weight by a large amount even before adding the additional load of the laptop. I would guess the total weight would end up at least 15Kilo compared to existing 1.5 Kilo even using light materials.

This would require servos with 30 times the torque. Speed might be reduced to compensate for part of that, but I guess you are still needing 10 times the torque of the existing servos and some additional gearing.

You may want to post your question more generally at the Lynxmotion site. You really need some help from someone already making 1Metre bipeds.

Statistics: Posted by i-Bot — Tue Jul 08, 2008 1:06 pm