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Messages - rumham

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1
Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: September 10, 2019, 03:41:22 pm »
Hello Robot Builders! Here's the build report for Rickety Cricket my 6lb gyro walking beetle

Build/Event Report
https://imgur.com/a/8MFkRu6



--Luke

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Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: March 18, 2019, 12:38:59 pm »
I have very limited experience, but have been pretty unimpressed with the maxAmps batteries. On a heavyweight project with a few of the Canadians we were running them at Robogames a couple years back and they failed way, way before their specs said they would.
Were you able to measure how much power you actually got out of them before they ran flat? I'll bet the peak current draw with the sad motor winding was pretty epic, but in normal use do you know how much it pulls?
-Zac

Hey Zac,

I actually wasnít able to use the MaxAmps batteries for the event; I accidently left them on the shuttle bus at the airport. Fortunately my buddy Pete had extra batteries for 60 Seconds of Glory that fit. These batteries were Turnigy Graphene 2200mAh 4S 45C. Running at 8S instead of 10S helped put the weapon in the 200mph range. During safety the tachometer said it was spinning at 205mph so we just had to bump the throttle down a tiny bit.

Iím not really sure how much current the weapon usually draws. I was surprised to learn that the Castle Talon 120 HV does not have data logging. But it draws a lot of current. My match with Crippling Depression lasted 47 seconds and the weapon spun up only three times. After that match the battery charger put in 750mah worth of capacity, so the batteries are way undersized.

Iím working on ways to reduce the current draw and or increase capacity without building a new frame. I have extra weight and width to spare but not length. Higher capacity batteries seem to all be around 130mm long and I just donít have room for that. Iím currently looking at the https://www.maxamps.com/lipo-2800-5s-18-5v-battery-pack as itís the highest capacity battery I can find thatís ~108mm long. Compared to what I was running at moto 2.8AH@10s should give me about 59 percent more watt hours of power. I would still have to keep the weapon spinning around 200mph for an apples to apples comparison. This still wouldnít be enough power to run three minutes hard but it would be better than what it currently is. Ideally I would rewind the weapon motor to a lower KV so at 10s input voltage it naturally spun the weapon at 200mph (vs 300mph) but Iím not sure Iím ready to take on that project. I have a blown weapon motor so thereís not much to lose other than the time it takes to rewind the motor.

Iím also considering running the drive off its own battery. I think I can get another small battery and power switch to fit in the bot if I replace the massive drive VESCís with some hobbyking 80a ESC.

--Luke

3
Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: March 05, 2019, 03:20:29 pm »
Hey everyone. Here's the build report for Rum Ham XXX my featherweight that competed at Moto 2019.

Build/Event Report
https://imgur.com/a/UPk68bX



For more frequent updates like the team on Facebook.
https://www.facebook.com/SunnyRobotics/


--Luke

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Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: May 07, 2018, 11:18:59 am »
Machining the motor pattern into the disk is a great way to get a low-profile high torque transfer connection. I've considered something similar with an outrunner before but the can shape is so seemingly random between them (and even between runs) that I never pursued it. I like the way you built in some potential adjustment for the variation.
-Zac

This motor pattern was a lot trickier to reproduce than old style. I have to thank Brandon Wiebe for providing the motor model we used for the new weapons. For the old disk I found the motor files on grabcad.com .
--Luke

5
Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: May 04, 2018, 01:21:16 pm »
Here is my Robogames 2018 update for 'Rum Ham' the 3lb undercutter.

Build report:
https://imgur.com/a/ycipMwR

Disk machining video:
https://www.youtube.com/watch?v=Sbn0RFelWXA


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Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: March 12, 2018, 05:34:22 pm »
As you scale the design up you might have to go to some pretty serious chain to make it work. While I enjoy such projects more than most people, I do have to ask if you think all that chain/pulley/bearing stuff works out to be more efficient than a secondary clamping motor for the claw. Especially as you scale up I think it will be diminishing returns pretty fast.

Thanks for the kind words Zac! I'm going to try and keep just one motor for the lifting and clamping for larger builds, mostly for the coolness factor. I like all the gears and pulleys required to make it work even if it's not the most practical.

--Luke

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Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: March 07, 2018, 04:49:10 pm »
Here is my build report for Bird Law my plastic ant I took to Motorama 2018

Build report:
https://imgur.com/a/YNWrk

Videos:
https://www.youtube.com/watch?v=Qjwwdo41_rQ&list=PLIkQKO7gRmwOvs8guNn66k913Ze-D1YDs


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Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: January 17, 2018, 10:39:35 am »
Are you coming to Motorama this year? I'm really interested in seeing this bot if you are. I'm really interested in building an undercutter.

I will be at Motorama this year but I wont be bringing the undercutter. I don't expect to have it finished by then. It should be finished for Robogames. For Motorama I'm just bringing my prototype plastic ant 'bird law'. It should make for great cannon fodder.


9
Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: January 16, 2018, 12:42:36 pm »
Phew those are some thin cross sections.  Keep us posted on how they hold up.

-Kyle

Fingers crossed.
The ant weapons look the way they do because I had very little space left on the S7 stock before waterjet. Two of ant weapons were actually cut out of the space in between the spokes of the disk. The disk design resulted from the need to save weight. I really wanted to use 3/8 material but making a disk weigh less than one pound at 7.5'' was really difficult. The result was a really skinny disk with two spokes. The two spokes did however allowed me to make more ant weapons so that was a plus. Will the ant weapons and beetle disk break? Maybe; but I can always fall back on the bar for the beetle. I don't think the bar is going to break.

10
Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: January 15, 2018, 11:48:21 am »
Parts back from water jet. 3 ant weapons and 3 beetle weapons. all 3/8 S7. The ant weapons will be for a yet to be designed pizza slicer clone. The beetle weapons will be for the new rum ham. I still need to CNC machine the NTM v2 motor housing shape into the beetle weapons before heat treating.


 

11
Progress Reports / Re: Team Thrasher / Sunny Robotics
« on: January 15, 2018, 11:25:46 am »
Very cool. Has it fought any midcutters? The design is a little closer to the first undercutter I ever saw in person (http://www.lazytd.com/rc/rcg/hworf2.jpg) than the more common designs you see these days. Seemed nice and reliable in that video.

-Zac

I haven't fought any midcutters or even traditional horizontal spinners yet. The limited weapon reach would likely put me at a disadvantage. This design has however proven to do really well agents non wedge vertical spinners and drum bots.   

12
Progress Reports / Re: Team Thrasher
« on: November 02, 2017, 05:16:54 pm »
Here is an update for RumHam XL. These are the changes I made for AVC 2017.

Build report:
https://imgur.com/a/UqyLP

Best fight from AVC:
https://youtu.be/Xi-mzxQBKis



13
Progress Reports / Re: Team Thrasher
« on: October 26, 2017, 06:29:29 pm »
Here is the build report of 'The Undisputed Champion' my 30lb flame throwing powerwheels!

Build report:
https://imgur.com/a/Cr7WB

Videos:
https://www.youtube.com/playlist?list=PLIkQKO7gRmwN4_VrNRBQLdgyK1lbG6UGW


14
Progress Reports / Re: Team Thrasher
« on: June 22, 2017, 01:46:34 pm »
Thanks Zac. I'm a big fan of your robots, especially Magneato.

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Progress Reports / Team Thrasher / Sunny Robotics
« on: June 02, 2017, 04:44:30 pm »
Hello,

Linked below is a brief history of my team and the build report of Rum Ham XL my 3lb bot.

Build report:
http://imgur.com/a/zp6S3

Videos:
https://www.youtube.com/watch?v=CoaTV_VJ8OU&list=PLIkQKO7gRmwM8emBHAa74N7Ib6dMKEibX




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