The day I stop giving 100%, is the day I stop competing
Wed May 06, 2009 4:31 pm
Bort Experienced Roboteer
Joined: 15 Jun 2004
Posts: 696
Location: Sydney, NSW
I believe there was meant to be some open discussion about the robots in this class. Is that right?
Either way, its going to be a simple saw bot. Got a lot of stuff left over from retread and TWI.
What you got in store Angus? _________________ Farnsworth - "I hate these nerds. Just because I'm stupider than them they think they're smarter than me."
Wed May 06, 2009 6:44 pm
Rotwang Experienced Roboteer
Joined: 15 Jun 2004
Posts: 1589
Location: Vic
We already have our own version of this class Shreddy.
Different reason and aim though.
As Sean said our comp isn’t as destructive so no need for a beginners class and we have no spinner lightweights as an alternative for the spinnerphobics.
There is novelty bots where you can do whatever you like apart from the normal no glue, liquid etc provisos.
Bots like Laundry basket, Ghetto Blaster, Overdrive, and Little Mack, Pod. David’s walker etc.
They don’t have to fight, they can play soccer, tug of war whatever you like.
They act as fillers and entertain the crowd.
Gives you a chance to showcase something you have built. _________________ Satisfaction is proportional to effort and results.
Wed May 06, 2009 7:29 pm
dyrodium Experienced Roboteer
Joined: 24 Aug 2004
Posts: 6476
Location: Sydney
Ah, sounds good. Currently planned, it's a 4wd vertical spinner with tow balls for smashing idea is low speed but still fairly high KE to do some blunt damage and entertainment. _________________ ( •_•)
I was thinking about the weight limit.
For now im happy with a limit around the 20kg mark
After building a couple of bots previously even 15 kg is tough to stay at.
At this early stage i think being flexible on weight will encourage more interest
Mdf is very heavy.
If you plan on using red wheels you will have to watch your base thickness wheel diametre is small
If people want there robots cut send me the cutting list and ill cut them but i cant run a delivery and pickup service
16mm is the size i have most of so work around that.
If design becomes limited because of this ill look at getting in some other sheet thicknesses....thicknesses are 3mm,6mm,9mm,12mm,16mm,18mm,25mm,32mm.
But all 16mm is free of charge and will only be supplied cut to size.
2400x1200 sheets are available at $30 each uncut _________________ Photos - http://community.webshots.com/album/154092733uokpXC
Photos- http://community.webshots.com/album/166819552PDWWqP
Sat May 09, 2009 8:36 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Increasing the weight limit is a good idea, it could make a move to lightweights easier. If people use a lightweight rated drive train and a MDF rated weapon, its not so hard to test ideas out in the fun class, then swap the MDF for steel and a better weapon.
I plan to use the drive train from my lightweight flamethrower and make a one tooth spinning from the bar that broke on Jolt a few years ago. It will have a smaller tooth and a steel counterweight on the short side to balance it. Power will probably be a fan motor of some sort and top RPM something like 1,000 to 1,500 rpm. I figure it will have the sort of power we used about 3 or 4 years ago.
Since we are reviewing designs for this class, does that sound acceptable?
Sat May 09, 2009 9:53 am
Russell
Joined: 16 Aug 2004
Posts: 90
Location: Sydney
I have no problem with the weight being left for the moment till it works it self out. I have one I started when this discussion first started using a planB weapon and pancake motor with 12mm MDF and aluminum angel joiners. Must take some pic and put them up for comment.
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Sat May 09, 2009 3:35 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
Posts: 4436
Location: Sydney
Like I said I would be wary of increasing the weight.
If you do that you need to spend more money. You need scooter drives and IBC's rather than drills and scorpions.
Chris always wants to increase the weight, If you say 20kg, then you will want to make it 25 so you can put more SLA's in then 30 because they don't fit in the 25kg frame then 40 because now that you have 30 kg of frame it needs more battery to push it around.
The whole point of the thing is to build to the weight limit, not change the weight limit to build what you want.
a set of drills is ~$60
and that gets you drive and batteries enough for one of these things, If you use scooter motors your going to need alignment critical belt drives and things and an IBC to drive it, 2x the price of the scorpion. Then your going to need a decent battery pack to provide enough power. _________________ Mechanical engineers build weapons, civil engineers build targets
Sun May 10, 2009 9:19 pm
seanet1310
Joined: 08 Nov 2006
Posts: 1265
Location: Adelaide
punturer runs fine of a pair of 100w scooters and a scorpion XL but last i checked oatly dont sell the 100w scooter setup anymore anyway.
granted if you are talking scooter motors in the 200-300W range something more beafy then an xl may be needed.
That or if you want to over volt a 24v scooter you would quickly push the upper limit of the scoripons voltage wise _________________ Remember to trust me, I am an Engineer.
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
MDF bots are still totally experimental and its too early to make a call on the weight before we have a few built. As Chris said, MDF is very heavy, the strength to weight ratio is low and we might find that keeping to featherweight limits only allows totally feeble weapons, or that bots disintegrate too easily. We need a balance where weapons are effective but don't tear themselves out of their mounts every time.
Mon May 11, 2009 9:09 am
Knightrous Site Admin
Joined: 15 Jun 2004
Posts: 8511
Location: NSW
A nichi ra fan motor with a 300mm saw blade is going to be pretty effective weapon, and shouldn't explode out of it's mounts like a flywheel. _________________ https://www.halfdonethings.com/
Mon May 11, 2009 10:48 am
Nick Experienced Roboteer
Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW
Granted, a saw isn't as likely to destroy itself. On the other hand, we are aiming for "spectacular" damage and saws don't really deliver. Two sawbots grinding away at each other doesn't sound exciting to me.
This class of bots is still developing - we need tests as well as theories.
BTW: How to people feel about flame throwers in MDF bots? I just found some new parts that might let me shrink my LW size flame thrower down to about FW weight & size .
Mon May 11, 2009 11:08 am
DumHed Experienced Roboteer
Joined: 29 Jun 2004
Posts: 1219
Location: Sydney
I was thinking flame throwers are perfect for MDF bots _________________ The Engine Whisperer
- fixer of things
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