KV---A New robot from WM Robot Team

Don wrote:

rjw's right if u make it so u machine one tooth on each side of the drm it will spin faster than it already does

Not spin faster just change the tip speed

oh ok so is there less resistance ??

in theory you should see larger hits from a single tooth vs. a double....

Gotta test before you make changes...

In that video of KV and Belle Vernon you see a few things that Steve Learned...

Go right at the other bot from the start or spin up quick.... (Belle Vernon actually jumped the gun and nothing was said BUT you have to ready for that)

Never stop spinning your weapon, just lower the RPM's but never stop it completely.... (Steve actually stripped the set screw off in that match from trying to start it up too fast.... Plus on his stupid behalf put really small set screw in the weapon motor pulley 1/8" long) (I about lost it when I looked at the set screw after that)

Always check inverted driving.... (He never really checked how it drove inverted) (Needed more of a point on the frame where it met the floor)

Always clean the tires off before a match.... (we were slipping on the arena floor the whole time)

Compare that video to the Rumble where I basically reamed him a new one for not checking such things and gave him weapon speed 101)...

I was really dissapointed on how that bot actually did at finals....

I think all of it could have been avoided with a little more knowledge about getting a robot ready and what to do with a weapon of that speed..

I like RJ's points he said....

The staggered tooth never came to mind when designing it....

The weapon speed can be varied as we use throttle stick and that can help a lot for bite..

Steve had a bunch of problems right before Finals with the electronics... (2 Scorpions blown up 2 days before) which prevented him from driving and testing a lot of things...

Steve was getting his drivers license the day before Finals so any last minute testing was out of the question..

I think this bot will be a force to be reckoned with next year..

The speed and changes planned for it will make it even better...

I would put this up against any bot of any speed with some front wedge changes, the staggered teeth, a lot more know how and time to test by steve and a different outlook at ground clearance...

This was the first test we really had for this bot besides for a preliminary bout against Plum that was agreed upon before the match began...

A lot learned and a few changes and i think it will ready to go again....

I still like the UHMW though no bites and no real damage besides some scars on it...

At fast weapon speed no onecan really get a bite on it..

Really the only reason we got flipped was because Steve shut it off and did not keep the speed up....

He popped a battery in the fight before this and was very timid about letting it rip...

Being to timid always hurts you..

FRISCO

We've had the same set screw problems. We learned really quick to check every screw before every fight

That happened to us last year we had a set screw come lose and we lost drive to the weapon all together and it tore a slit rite through the belt so now we either use lots of locktite or a double locking set screw and our problem is solved

Last year our outrunner fell apart because we used the teeth of the belt and a sudden stop took the shaft out.

I know that I've said all this elsewhere, but let me try again...

1) If you're using set screws to hold a pulley on a shaft, a method that has worked since the 1930's in vibration/shock prone machinery, is to drill and tap 2 set screw holes at 90 degrees to each other (other angles can be used, but that is a subject for a different discussion).

Install set screws in the 2 holes in the normal fashion, but nthen grind the tips flat on 2 more set screws and install them on top of the first 2.

It's like using a jam nut.....even with NO loctite, properly tightened (and resist the temptation to overthighten), this actually does work very well.

The flat on the tip of the second set screw is so as to not crush the hex hole in the screw below it.

Back to the drum:

We need to not only read the Riobotz tutorial, but read it again and again until you understand the section on drums, tip speed, bot speed, etc.

KV's drum can be turned into a single staggered tooth by removing 1/2 the material from the outer ends of the existing teeth on one side and the inner half of the teeth on the other side .

The result is a staggered single tooth drum that is still balanced.

You will get twice the bite of your current design.

If you simply slow your drum down, you lose all the energy and even if you so get a bite, it won't have much KE behind it.

Ctown_ftw wrote:

Last year our outrunner fell apart because we used the teeth of the belt and a sudden stop took the shaft out.

That's why we invert our timing blts and use smooth pullies.....to make the whole setup slip = shock resistant.

skipper wrote:

Ctown_ftw wrote:

Last year our outrunner fell apart because we used the teeth of the belt and a sudden stop took the shaft out.

That's why we invert our timing blts and use smooth pullies.....to make the whole setup slip = shock resistant.

Quite

do you use any belt dressing to help get grip because for our prelims, we were thinking that exact idea of slippage and it ended up that it affected the perfomance of our weapon then helped

Don wrote:

skipper's right if u make it so u machine one tooth on each side of the drm it will spin faster than it already does

They don't need more speed, they need BITE at speed....the single tooth means that rather than hitting twice per revolution, they only hit once, so if the bots are moving towards each other, then there will be more engagement of the weapon teeth (bite)

Read and understand RIO...they have a chart with rpm, speed of bot, etc and you can see how a single tooth weapon can be spun much faster and still get bite....to a point

Bonus: single tooth drums make a cool noise when spun up to high speeds.

Believe me RJ I get it.....

Just didnt think of it when helping steve design his.....

Will be done for next year though...

Steve actually change to the double set screw idea for the rumble so he learned it there FINALLY....

It is funny when you make the kids learn for theirselves.....

It is always..... Why didnt you tell me that in the first place....

WELL I probably did and you were not listening or forgot...

There is a lot of weight of loose in KV's inner frame so Some S7 Front Ramps are in the works also..

I am still not changing the side UHMW though.... I am a believer..

Especially since we switched to 1/4 high temp UHMW.... Much sturdier and less shearing...

I am going to 3.5 inch diameter S7 with a new design with thinner walls for my son...

UNI UHMW Frame on this one and hollowed out to 1.5 lbs.

Also a wedge on back instead of square...

How thin do you think we can go with the solid S7 Drum before ripping it apart on impact...

My guess is 3/32???

And YA he (Rocco) will have a 3lb, and 15 lb bots next year.



FRISCO

hey the only time i said that you never told me to do something was when you told me i should have turned on the robot and drop it from like 3 feet before every match lol

and yah i understand what you mean with the single tooth design

Rick

My long winded reply got lost....

I would be leary of going much under 1/8" wall on a 12 or 15#. Remember also that S7 doesn't like sharp corners, etc....jmo

Also, nothing wrong with a tube with welded teeth....if done properly.

some cool pics

http://www.flickr.com/photos/botsiqswpa/5645554657/in/set-72157626433604117/
http://www.flickr.com/photos/botsiqswpa/5645555065/in/set-72157626433604117/

http://www.flickr.com/photos/botsiqswpa/5645555333/in/set-72157626433604117/
http://www.flickr.com/photos/botsiqswpa/5646118790/in/set-72157626433604117/
http://www.flickr.com/photos/botsiqswpa/5646111776/in/set-72157626433604117/
http://www.flickr.com/photos/botsiqswpa/5646111442/in/set-72157626433604117/http://www.flickr.com/photos/botsiqswpa/5646118582/in/set-72157626433604117/

heres some more
http://www.flickr.com/photos/botsiqswpa/5646111600/in/set-72157626433604117/http://www.flickr.com/photos/botsiqswpa/5645530659/in/set-72157626433604117/

Is that your screw on the floor under the robot?
http://www.flickr.com/photos/botsiqswpa/5645530913/in/set-72157626433604117/

not sure it doesnt look like anything is missing lol