Joined: 18 Jun 2004
Posts: 3842
Location: Queensland near Brisbane
Has friction drive been successful in a feather? I am thinking of attaching a 2" wheel to a drill and friction driving the wheels that will touch the floor. Would it work reliably for an event or will it wear down and slip too quickly? _________________ So even the rain that falls isn't actually going to fill our dams and our river systems
I think the closes has been nick with his inverted rollers. They have the advantage of the weight of the robot pushing them into the other wheels.
In theory it should work but not sure how well particularly with a lot of the fine dust and crap that ends up on the floor. Really only one way to find out. Maybe a little test platform? _________________ Steven Martin
Twisted Constructions
http://www.botbitz.com
Tue Nov 10, 2015 12:19 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
The small secondary wheels work fairly well, the only problem is their small contact patch leads to more wheel spins than the regular large wheels. The main thing I learned is to have a pressure adjustment; if the main wheels wear down even a small amount, the small wheels start slipping. as long as you check and adjust the wheels for slip, you should do fine _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Tue Nov 10, 2015 5:36 pm
Philip Experienced Roboteer
Joined: 18 Jun 2004
Posts: 3842
Location: Queensland near Brisbane
Thanks. I went back looking in Nick's thread for when he first put his small inversion wheels into his robot. It was about 60 pages back! A prolific thread with so much of interest.
2" wheels driving 3" wheels with adjustable positioning might be the ticket. _________________ So even the rain that falls isn't actually going to fill our dams and our river systems
Tue Nov 10, 2015 6:53 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
'only' 60 pages? I need to build more!
A 2" wheel will likely work much better. I used an M8 bolt as an axle and am now thinking an M10 or larger would have been better. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Tue Nov 10, 2015 7:02 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
"The force is strong in this one"
I was weighing parts today when I noticed something really strange with my electronic scales. When they are turned on, they register zero grams. As soon as I move to put something on the scales, they start registering up to 6 grams
before
anything touches the top of the scales!
Doing a little experimentation:
Placing my hand right beside the scale has no effect, the scale only changes when my hand to something connected to it is directly above the scale .
Dangling ferrous or magnetic objects above the scale has no effect.
Holding any kind of conductive object over the scales has an effect, but only if I am touching a conductive part. IE holding a screwdriver by the handle doesn't register, but holding the tip of the screwdriver does register on the scale.
A cat standing over the scale doesn't register (that wasn't a planned test )
So what's going on? I seem to be generating an electrical field that is being picked up by the load cell in the scale, which is pretty weird! _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Last edited by Nick on Mon Dec 07, 2015 5:04 pm; edited 1 time in total
Those are very sensitive and the amplifying board doesn't make it better.
If those parts ain't perfectly shielded, any inductance induced currents will change the results.
It's one of the PITA's I have at work. one of the machines has troubles with this since it was put into production.
The 11 simular machines doesn't suffer at all, but this one is biting my ass since 2003.
And I don't get permission to strip the electrical system to the bone as it will decommission the machine for a month.(if I have to do it on my own. I'm no electrician)
Mon Dec 07, 2015 4:26 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
So I'm not becoming a Jedi? . The scale used not to do this, it must be breaking down. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon Dec 07, 2015 5:35 pm
maddox
Joined: 21 Dec 2006
Posts: 786
Location: Belgium
It seems you ain't becoming a jedi, sith or black hole.
Mon Dec 07, 2015 5:43 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
LOL, that's a shame, I was looking forward to force-choking bots at the UK championships. Back to plan B; just smashing them with Mr Mangle and Decimator. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon Dec 07, 2015 6:33 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
Plan-B is a trademarked and wholly owned robot name ;-P _________________ Mechanical engineers build weapons, civil engineers build targets
Mon Dec 07, 2015 9:50 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Option B - I meant to say option B. Now please don't sue over IP rights _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Mon Dec 07, 2015 10:33 pm
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Shortening motor leads:
Does anyone have a tip on stripping ALL the insulation off the multiple strands of wire in motor leads?
I am having problems with overly long leads on out-runner motors and need to shorten them. All the manufacturers say to never cut their leads, but there has to be a way to do it properly. _________________ Australian 2015 Featherweight champion
UK 2016 Gladiator champion
Sun Jan 31, 2016 6:49 am
maddox
Joined: 21 Dec 2006
Posts: 786
Location: Belgium
The main thing is to keep the length/resistance of the 3 leads/windings equal.
All the rest is just covering all bases.
Sun Jan 31, 2016 8:47 am
Glen Experienced Roboteer
Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect
Should be no problem shortening the leads eletrically, Only lengthening them.
Getting the enamel off is a pain the ass on some motors. Acetone and brake cleaner don't strip it off as some suggest in my experience. I was just burning it with a pencil torch then touching the ends with steel wool.
I've heard you can sit the wire bundle on an aspirin tablet and solder over that to remove the enamel. Never got the chance to try it -
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum