What the heck Weapon should i choose?!

What thickness are you running on your weapon around the edges? Compared to what you ran last year?

It still looks just a little undersized in the DWG but maybe thats just my eyes....

Drum thickness is .375, the teeth are... .75 across the top and .45 deep. That may change thou.

here are some designs we used in the past but I got to say that our design this year is a twin to your robot..Look at the frame design on the on robot witht the internals not done..... It is almost the same frame design as you have there and our drum for one of our designs is somewhat similiar to to your beater design

Lets see if I can add images now>>>>
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Old Drum
/Users/admin22/Desktop/100_0448.jpg

Sons Robot
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Ok maybe I cant add images yet??????????

Haha Signup for a Photobucket account.

www.photobucket.com, then host the images on there. Then copy the links for a message board into your post.

Answer the phone!

Oh great. I knew it was too quiet near me. I lost my ShamWOW! phone... argh...

To add images, use the "host an image button." It's in the same group of buttons as the one that looks like a film reel (opposite end of the row from Bold/Italic/Underline).

Not working.... Not gonna frustrate myself tonight...

I went crazy tonight. Just starting designing and designing and designing. Got a entire drum assembly up. (minus bolts and stuff to hold teeth on...)

And i have a different take on how to let it "roll"

It will have high sped bearings that are locked into the drum (pressed or using many set screws). It will then slide over the Steel/Ti/wahteverisstrongandwillmakeweight. The shaft is locked into the outer places with a 10-32 to keep it from moving radially or out. Might have to be steel so it will roll without much grinding and wearing down.

Add some spacers to keep the drum centered and thats a weapon! The rest of how the drum is pieced together is pretty self-explanatory. Keyed end caps bolted onto main drum. they are interchangeable.

Welp Mr Frisco im glad you pointed out how terrible of a driver I am haha
Steel Center was tough and i was anxious (at CalU is what im guessing you were talking about)
I know i shouldnt have tried hitting them when the spun butttttt i did lol and they angled "spikes" made it tougher to get a bite
I had never driven Aftershock before that and I can tell you it was ALOT different then shockwave and it had the smaller weapon motor in it at CalU

You seem to be on a possibly effective path

if you run needle bearings, then you need either a case hardened (or thru hardened) shaft or inner races on a Ti or whatever shaft.

Just keep in mind that 5/8 to 3/4" ID needle bearings have sped limits that are lower than equivalent standard ball bearings...but the support load is much better with the needles than they are generally lighter as well

Also, needle bearings can be obtained with seals, if that floats your boat.

having fun...???? or just out of control !!!!!!

keep us posted if you persue it

Cody: Didn't you guys run a 5/8" shaft and just a pair of ball bearings in shockwave???? just curious

Hmm i have a "okay" idea on how to hold those teeth in...

Click to enlarge




Countersunk screws go in the top, through the teeth, through the drum into a steel/ti threaded piece that is snug up against the inside of the drum.

Will gladly try any other ideas, or improvements to this.

Josh Raichel wrote:

Hmm i have a "okay" idea on how to hold those teeth in...

Click to enlarge




Countersunk screws go in the top, through the teeth, through the drum into a steel/ti threaded piece that is snug up against the inside of the drum.

Will gladly try any other ideas, or improvements to this.

You didn't notice the identical setup in the pic of Sting's drum???? lol

lolwut?

I only saw the pics of the outside. Nothing really detailed into the drum.... Hmm great minds i guess.

We used a similar nut bar on aftershock theyve worked great for us but we also had 2.
Shockwave.... yeah about thatttttttt.
I honestly cant remember what it had but im pretty sure it was 5/8" or needle bearing lol
your welcome for all the help

If you look at the end of the drum, you can see the Ti Nutbar thru the cutaway in the endcap.

My theory is that the nutbar should be wider than the blade, so if the blade is 1/2" wide, then the bar should be 5/8" , 3/4" or better...depending on weight

THickness should be at least 1.5 times the diameter of the screw that you will be using...So, 1/4" screws = 3/8" thick bar (minimum) for decent thread engagement...jmo and depending on weight.

Note that the cutouts in my end caps is so as to mount the outer blades right up to the end of the drum and keep a screw close as well..the cutout is a small point of imbalance On Sting it totals 2.3 grams (between both ends), which can be made up by using slightly longer screws in those nutbars.....If very high speed is disirable, then pay attention to those grams...your bot will shake like a leaf and may be undrivable if imbalance is present.

See the video of Sting vs Wallop (FINAL) ...after I lose the long center tooth, Sting is hopping around like a pogo stick...but was still effective enough to flip wallop over...lol

I'm sure you got thru this...but amperage draw from imbalance can be severe at higher r's

Cody Harris wrote:

We used a similar nut bar on aftershock theyve worked great for us but we also had 2.
Shockwave.... yeah about thatttttttt.
I honestly cant remember what it had but im pretty sure it was 5/8" or needle bearing lol
your welcome for all the help

I recall at nat's 2 years back, 5/8 shaft with ball bearings....you guys had trashed the motor....love those timing pullies...yawn

rj do you have a pic of Sting's weapon after it broke? like where it broke exactly?

i have 3/8" stuck in my head for a shaft with needle bearings

First robot with a nut bar to my knowledge was Solaris - it's an oooooold innovation (that works very well).

Ah Boreas is coming together quite nicely. This may actually be viable...

so far at almost 9pounds without the UHMW armour and electronics.

you should put the stator in the drum
solaris+corona what more could you ask for!

Josh Raichel wrote:

rj do you have a pic of Sting's weapon after it broke? like where it broke exactly?

All that happened is that the flat head grade 10.9 3mm screws broke, bent or stripped out of the alu.

When that happened , the blade key (in the alu) got smashed.

Since then, I helicoiled 4mm bolts and it was ok, but the bot was overweight....baaawaaa

I went to the beater, which was Ok, but against Ti, I bent a hard shaft, although weapon to weapon was fine...

I had already looked at going back to a drum with nutbars...thank you Cody and others.

You're on the right track in going with a wide low blade to start with.

Stings latest are .3 high and .375 wide on a thin walled drum with nutbars...as per the pic I posted.

I will stay with the center belt...(slightly better balance) and try 4 equal length blades. And I will use 4mm screws again...if it doesn't hold up, I think I have the weight for #10's....If that doesn't hold up, then I'll punt.

I believe that the MLEC bots are using 1/4" or 6mm screws and as many as possible, into nutbars as well, but I'm not sure....I could ask.....?