New drum design with a twist...literally

Here's a rendering of our latest goofball idea...the helical toothed drum...looking to improve aero a bit and this one looks promising. I'm thinking that besides possibly having less drag as compared to a straight tooth, the teeth may help promote a small vacuum or low pressure area that might also reduce drag from the other teeth coming around.

please feel free to boohoo or comment

2 questions

1) How will the aero be on this as compared to stadard straight teeth

2) How will this drum hit as compared to our previous straight tooth design

again this would be from a solid s7 round

note: no radii have yet been added bertween sides of teeth and round portion of drum...

thanks

Oh man that's badass. Awesome design. I don't know how it's going to hit, but it has a striking resemblance to an endmill. No that's not it. It's like an endmill with a small neck. I don't remember. Either way it looks awesome.

I don't think aerodynamics will be too much of a concern but if it's really bothering you, you could try Cosmos Floxpress and see how it'll be affecting the other teeth.

Can't wait to see it in action.

I know...if nothing else, it looks cool

I thought endmill as well...can you imagine ...high helix, low helix...the options are endless.

Paul from MLEC has decided to try his hand (again) at driving sot, so we came up with this in that he drives worse than me and I'm pretty bad.

We stand a better chance with a drum bot than the powered wedge...that needs someone good.

so we'll setup the 2 little bots as drums, 1 with straight tooth, which has proven to be finally a done deal and the other with something like this....

Should be taking them to Megacon March 14th for a test run...

btw: Kyle says it looks like a mud tire...might be good for the floor at moto...lol

mechanically, it should launch or deflect other bots off at an angle, plus maybe get a good bite on wedges, etc if we hit them with the pointy part.

Now that it seems that I have my cam software under control, this could start to get more interesting...or it cold be a dud....r&d baby...that's what I do....

no other comments???

Is everyone

a) not here
b) laughing
c) scared
d) totally confused
e) couldn't care less

Wait. So you rounded them? How the balls is that gonna hit/grab anything?

Our second battlebot we made, my first i helped design had radius (radiui?) on the outside of the teeth. Didnt grip poo even at slow speeds we were going.

Josh...wake up!!!

Not rounded , just kind of slight wrapping on a helix...did you not look at the picture?????

Like an endmill rather than a router bit...if that makes sense to you

So? i looked that it. And instead of a flat top of the tooth you have it rounded. when it spins it will create a circle of the part that sticks out the most. Which since you made the tops a radius, the top of the arc. It will grip less. TRUST ME. I have been here already. It will not grip as good as a flat top.

Give me a perfect side view and i can illustrate my point.

Josh Raichel wrote:

So? i looked that it. And instead of a flat top of the tooth you have it rounded. when it spins it will create a circle of the part that sticks out the most. Which since you made the tops a radius, the top of the arc. It will grip less. TRUST ME. I have been here already. It will not grip as good as a flat top.

Give me a perfect side view and i can illustrate my point.

I get you now...naw....the last drum had the same rounded top and did just fine...jmo

I know my dad and I definitely talked about something like this, we've just never had the means to do it. Leave it to you to not just talk about the crazy stuff lol. I can't wait to see this at megacon (which I WILL be attending).

on the mud tire thing i was comparing it directly to how a mud tire works, as it spins one way the tire (drum) grips to mud (air) pushing it out and away from the tire (drum) increasing traction(drag), the other way would draw mud (air) in and it will build up under (around) the tire (drum) causing a loss of traction (drag). on that though if you could create a vacuum around the drum even if it were just a slight difference in pressure like .25 psi wouldn't that mean that theres less cubic air around the drum to cause friction? just my rambling thoughts

I'd like to see it properly analysed, tweaked and then machined...

might make one or might not until I have the time to figure it all out....

Getting busy with other stuff.....

well I should have a pair of helical drums ready to rollin a day or so....the OD's (4th axis part) is almost done...just need to bore them out, test fit and heat treat.

Hope they work out...they look pretty cool....

interesting... it will put some serious loads on the frame of the robot...

Will Bales wrote:

interesting... it will put some serious loads on the frame of the robot...

I thought about that, but I don't know if anything can put more load on the frame that a horizontal hitting the side of a straight tooth...or the frame itself...so yes against verticals, there will be more load, but they'll feel it as well.

it could be a dud, but its worth the effort and somebody's got to do it.....

btw: ss hit It stings right in the same spot that caused Upchuck to come apart...well...It stings didn't come apart, fortunately.....a Ti guard held with 5 10-32's flew off...all the flat heads sheared right at the head.... that bot packs a mean punch