Author Topic: Team Brain Damage  (Read 46412 times)

rcjunky

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Re: Team Brain Damage
« Reply #345 on: January 06, 2019, 01:38:34 am »
Thats fair.

From my vesc research (running on in my new sportsman to run 8s) those made by Maytech are the best, the hobbyking ones (what I went with) also seem good, I think its those sold by diyskateboards that are questionable at best. If ya need more firepower the vesc6 can handle more current and I think Maytech has something else either almost on the market or just hit the market (and they have a good name in all there big sensored type stuff) so thats another option if you have the space/weight. When I contacted them direct for pricing shipping is only about $25 so reasonable as well.

Sounds like Brian Nave is going to be distributing maytech as well now and can be reached on Facebook.
« Last Edit: January 06, 2019, 04:19:09 am by rcjunky »
Andrew Burghgraef
Canadian Carnage Robotics

rcjunky

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Re: Team Brain Damage
« Reply #346 on: January 06, 2019, 02:42:17 am »
The other esc option I totally forgot about is the brushless ragebridge. I think Pete cooked a couple as well but don't know if that was a software issue. Out of the box they're made for drive and I'm sure would be sad spinning a shell with full drag brake.
Andrew Burghgraef
Canadian Carnage Robotics

Team haciM

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Re: Team Brain Damage
« Reply #347 on: January 06, 2019, 09:10:45 pm »
If I remember correctly when I was talking to pete at avc he was still running the vesc, but he had troubles with a certain branfmd. The build is looking good. Thanks for taking the time to post everything.

zacodonnell

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Re: Team Brain Damage
« Reply #348 on: January 06, 2019, 09:16:18 pm »
Thanks to the suggestions here I'm looking at brushless rage (the smaller one) which has ratings very close to the ones on my motor. It fits well into the bot too. The other option is something like the Castle Edge HV120 which leaves a ton of headroom over what my system would produce and still fits in the bot. I like the castle for the data logging and I've been very happy with the ICE 100 I'm using in both bots for years. I'm thinking In-fight reversing may be more trouble than it's worth but I'll have to keep thinking about it. I still have a couple weeks until I have to commit, and I can run 8S with what I have on hand for initial testing.

-Zac

zacodonnell

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Re: Team Brain Damage
« Reply #349 on: January 10, 2019, 07:36:15 am »
More updates added to the album. I redesigned the base to add more shock compliance and optimized for 12S Lipo. I'm happy with how it came out. The drawings for the shell and the new frame all went out to the shop. Now I just need to do the wiring and the finish machining on some of the parts I'm making.

(last four pics)
https://imgur.com/a/5fndlb9

-Zac

zacodonnell

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Re: Team Brain Damage
« Reply #350 on: January 12, 2019, 06:01:47 pm »
I made some good progress today. I got the center shaft good to go except for the mounting screw holes. Those will wait until my aluminum order comes in (probably Monday) because I included a drawing of a dril guide with the rest of my laser cut parts. It helps all the holes line up, which makes spares easier. These screws go through a lot of layers so good alignment is important.

I also made the weapon motor pulley and the steel ring that goes on the weapon shaft. Both turned out pretty well. Next up will be the weapon roller axle and pulleys, then the roller hub/washer setup. Hoping to get to the axle tonight.

Pictures:
https://imgur.com/a/5fndlb9

-Zac

zacodonnell

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Re: Team Brain Damage
« Reply #351 on: January 12, 2019, 10:31:26 pm »
I got the weapon roller shaft and pulleys done this evening. I didn't get to the roller hub itself so that'll be tomorrow morning's project.  The belt is a little too loose so I'm going to play with the pulley and belt sizes and see if I can get it to be tighter.



Pictures:
https://imgur.com/a/5fndlb9

-Zac

BranYoung

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Re: Team Brain Damage
« Reply #352 on: January 13, 2019, 01:26:53 am »
So if I'm reading this right the weapon mount is mounted into the mid-plate via a nub and the bolt pattern? Are you hoping to distribute the load over such a wide area that it won't warp it? It just seems like a lot of force to put into one sheet.

It's looking good and I'm curious to see how it all works out! I'm making my own feather this year so we may meet in the ring.

zacodonnell

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Re: Team Brain Damage
« Reply #353 on: January 13, 2019, 10:06:51 am »
Yeah, it is a lot of force to put into a single sheet. I made the inside washer plate pretty big to offset it a little bit, but the reason I had to recut all the parts is that I was pushing the bolt pattern out as wide as possible specifically to offset the warping problem. While I agree it is an area of concern, I think this frame is significantly better suited for carrying that load than any other I've created.

The previous base, for example, still used a .125" 6061 plate as the bottom plate.  The lowest part of the shell was 3.25" away from the top of that plate. Attached to the base was a 4.25 x 3" footprint made up of two .5" thick rails working like standoffs. This setup never bent, even though at its strongest geometry (horizontally) it was 2.125" over and 3.25" up, a ratio of .65 : 1

The new base puts the supporting plate WAY closer to the load, only .25".  The washer plate that holds the center post in is 3" wide. So that means I have 1.5" over and .25" up, a ratio of 6:1. Add to that the fact that it only takes 2 degrees of deflection in the joint for the mid plate to skip off of the inner ring of the top and I don't think the aluminum will form a bend even when it does flex enough. I drew in places to add bolt heads that stick up around the edge to cut that deflection in half, but I may not bother.

What did happen on the last version on both copies of the base plate I used was that the weapon roller assembly was pushed down hard enough to warp the bottom plate and tilt the weapon motor downward. This eventually caused the shell to scrape on the back of the weapon motor (the highest point in the bot). The extra framing was mostly to combat that problem, and in the most recent iteration I added two additional standoffs to the weapon roller plate to help.

I look forward to seeing what you bring to the show. I don't think I've had to fight you before have I? I changed so many things on this bot from the last several versions that I'm sure some of my assumptions are wrong and will need to be tuned.

-Zac

rcjunky

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Re: Team Brain Damage
« Reply #354 on: January 13, 2019, 11:46:25 am »
to tension the belt a bit could you put a tiny little roller through the face tapped holes on the bearing blocks and gain a bit of belt wrap on the big pulley? Certainly not much space in there otherwise.

It looks like thers going to be a lot of new 30lb bots between the 2 classes which is excellent to see.
Andrew Burghgraef
Canadian Carnage Robotics

zacodonnell

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Re: Team Brain Damage
« Reply #355 on: January 13, 2019, 11:50:24 am »
My current leading idea is to put little plugs in the weapon motor mounting holes with offset screw holes in them. They'll be a little annoying to make, but since I was planning to have the motor free-float in those holes anyway it doesn't actually risk much to do it. Plan B is to just leave it and see how it goes, and Plan C is to order in a bigger weapon motor pulley, though a 22T 3mm HTD x 15mm wide pulley is something I haven't been able to find so far. I found a piece of steel pulley stock that I could use, but it's heavy and a pain to work with. It *would* work though.

I shall continue to experiment

-Zac

rcjunky

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Re: Team Brain Damage
« Reply #356 on: January 13, 2019, 11:46:53 pm »
in the future you could have like 3 sets of motor mounting holes to fine tune the tension as well.
Andrew Burghgraef
Canadian Carnage Robotics

zacodonnell

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Re: Team Brain Damage
« Reply #357 on: January 14, 2019, 09:55:07 pm »
Some more small updates last night. I got the weapon roller hub and washer done, and made a spare as well. I'm happy with how they came out and having two will make swapping rollers between fights easier if they are wearing fast. I won't know that until I get the shell and try it but it can't hurt to be ready.



Pictures:
https://imgur.com/a/5fndlb9

-Zac

zacodonnell

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Re: Team Brain Damage
« Reply #358 on: January 17, 2019, 09:18:42 pm »
Well... I finally got back into the shop. I've been busy with work stuff the last couple of days, and working on some event management stuff with the NERC crew. My batteries came in today so I decided to give them a quick check when I pulled them out. Turns out that was a good idea... a quarter of them appear to be damaged in some way.

Two of the packs have at least half of the cells at 2v or less. The third has three cells at 3.6-3.7v and one at 2.5v.  I admit, I haven't spent much time with lipo packs because I was trying to keep my bots eligible for Franklin... Are these packs junk? Is this a sign that I should ship the whole lot back and get different, potentially higher quality packs? What brands / sources would you guys recommend? I used ThunderPower for the ones in my 6lber and they have slow shipping, bad service, and the packs vary quite a bit from the sizes on their site. I'd like to steer clear of them if I can help it. I need 12 packs, so I don't want to pay a ridiculous amount per, but I'm willing to spend a little cash to get a quality product. Yes, I know, that's not what I did for these.... I'm already regretting it.

The packs I ordered are the Turnigy Nanotech 1300mah. They are 35mm x 33mm x 75mm @4S.  I can go as big as ~40mm x 36mm x 80mm without too much trouble. After that I start to run out of padding or have to fit them in around stuff a different way. I'm shooting for 70C, but could probably settle for 50-60C if I had to.
https://hobbyking.com/en_us/turnigy-nano-tech-1300mah-4s-70c-lipo-pack-xt60-hr-tech.html



-Zac

zacodonnell

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Re: Team Brain Damage
« Reply #359 on: January 17, 2019, 09:24:02 pm »
It's not a good sign when the battery has a "warranty return" barcode right on it. Seriously, what did I get myself into? Apparently they have so many batteries returned that they have a whole separate process for it.

-Zac