conundrum!

Conundrum (as it has been officially named) is 95% complete. The only remaining tasks are debugging and balancing the drum. Oh, and checking weight... haha which I haven't done in a while. I bet I'm way over... but the drum is slightly unbalanced so it vibrates around a bit... but it spins FAST.

I switched out one of the drive motors which was doing strange things, and the ESC I screwed up, so now it drives fine. It still is inconsistent as far as signal goes. It'll cut in and out, and stop spinning... I held it in the air with the drum spinning and "drove" it around and everything worked 100%. I put it on the ground (with a freshly charged battery) and i had it spinning around half for a little bit, tried driving and it didn't really like it and was kinda stuttery, then the drum stopped and drive came back 100%. When the drum is spinning the drive barely works. This is a battery issue, isn't it?

It is probably battery related....remember that those jst connectors and or your wire size may not be able to put the amps thru that you need...is anyhting getting hot???

btw: what's the drum weigh??

nothing's even close to getting hot... the drum weighs .34 lbs with bearings and endcaps.

I guess you need to try a battery with more juice

yeah. but i'm 505 grams.
time to drill some holes... we like drilling holes...

HURRAY FOR SPEED HOLES!!!!!!!!!!!!!

its prob gonna be alot of holes. See if theres any extra wire or other materials you could rid of.

Dan Curhan wrote:

yeah. but i'm 505 grams.
time to drill some holes... we like drilling holes...

Smallest gauge wire, no wire connectors (except battery), shave the drum, strip the battery pack down to 1 piece af large heat shrink , no switch, holes in wheels...it goes on and on

50 grams or so might be tough to do....that's one of the reasons why we went to 3 pounders....1 pound is a tough act, if you use any metal....lol

Good luck with it

edit:

1) drill the shaft...probably only good for a few grams tho
2) smaller flanges on drum pulley...turn em down probably 5 or 6 grams of fluff there
3) Hollow out weapon motor pulley....probably 10 grams of fluff there
4) take 10 or 15 thou off the whole frame od
5) Pocket the polycarb or use a thinner sheet

In my experience, you can lose more weight by removing metal on large diameters and by thinning out large sections by just a few thousandths...holes are not as effective. Do ALL the calculations for weight loss before even thinking of drilling holes

jmo

your shaft does look pretty beefy for a baby lol

yeahh i was definitely going to drill through the 3/8 7075 shaft with like 1/8 or maybe even 3/16...
and there's plenty of material for pocketing. Definitely the top piece. I don't think there's enough meat in the bottom to do anything with. My dad bought a woodruff key cutter that can pocket the sides of my frame (because he had to do it to his), so I'm probably going to do that. The front corner blocks have almost a 1/4 inch of extra material out front so that'll be the first to go...

i'll look at my weapon motor pulley, take down the flanges on the drum pulley (prob better for the belt anyways if there's any misalignment, though I made the weapon pulley wider to account for that...) and as a last LAST resort, do something with the drum.

so i've gotten conundrum down to 480 g. Still some work left. I also am getting closer to balancing the drum. I put it in the lathe and moved things around til the bearings spun concentrically... still need to figure out the weight distribution though...

You'll get there....I just did on my 3 lbs. drumbot named 'STING'

Happy 18th B-day!

I really hope that when my (currently 6 year old) son turns 18 that the thing he most wants to do on his birthday is FINISH A BATTLEBOT!!

Have an awesome one!