Engineered For Destruction 8 Tournament Recap

The Tournament

Arrival and Setup

For this tournament we were headed down to Nashville, Tennessee's Adventure Science Center. We ended up getting there around 10:00AM Saturday morning of the event. We unloaded the car, and moved inside to the room that the tournament was going to be hosted in. We got set up at our table and got the bot ready for weigh in.

Ready for a tournament!!!

The box was pretty cool, with a pit on one side and a free spinning disk in the middle. So when attempting to accelerate tangent to the disk, the disk will just spin out and cause you to not move where you are expecting to, or when driving over the disk it may create variable driving conditions that few drivers are used to.

The box we will be fighting in.

I compiled all the fights and the rumble together into one video. Below the video I have some comments and thoughts I had about each fight. Due to the size of the bracket there were a max of 4 fights for the day. Sorry for video quality of the rumble, we didn't have video stabilization on :(

Fight 1 Honeycomb vs Tweetle - Quarter Finals

Tweetle is an overhead saw bot with a wide base and aluminum scrapes on the front. However, I noticed early on that the center 2 forks actually ride up a bit above the ground, and I suspected if I just went head on with my wedge, I would most likely be able to get underneath him and knock him around and really control the fight. All goes pretty well and I end up winning this fight with no issues. Only thing to do is recharge the battery.

Fight 2 Honeycomb vs Pyramid of Death - Semi Finals

Pyramid of Death is exactly what it sounds like, a pyramid shaped robot that is very low to the ground on all sides, and on one side it actually has a ground scraping metal wedge. I figured that my wedge could get under it on the sides without the metal wedge, as they were not actually touching the ground. Additionally, the drive train for Pyramid of Death seems relatively powerful, but slow and lacking wheel traction, so I think if I can get to one of the sides I should be able to push POD around and really control the fight. It ends up going well, I end up getting tearing up his wedge a bit and close out the fight with a nasty hit which completely flips POD over and he gets counted out.

Fight 3 Honeycomb vs Tweetle Round 2 - Finals

Tweetle ends up making it all the way through the losers bracket and we end up meeting again in finals. Over all my plan going into this match was about the same. Part way through the match however, I break my mid plate which holds my two bearing plates the proper distance from each other so my weapon shaft doesn't fall out. The two bearing plates separate from each other enough for the weapon shaft to fall out. This renders my weapon useless for the rest of the match, and I lose this match to judges decision.

Fight 4 Honeycomb vs Tweetle Round 3 - Finals

Since I was undefeated for the day, Tweetle had to win 2 times since we were in a double elimination bracket. After the break in the lasts match I pressed the two halves together and wrapped duct tape around it so that it wouldn't come apart again. I think as long as I continue to use the 3D printed center part, I may continue to just tape it as these 3D printed parts are good with compressive forces, but are pretty weak under high tensile forces, shear, and shock. So maybe the tape will be good insurance that the two sides wont come apart in the future even if the mid-plate breaks like it did during fight 3. With the weapon fully working, I was able to get a lot of good hits off during this last match. Tweetle ends up driving into the pit after a while. This is the final round and I ended up winning the tournament 3-1.

3lbs Rumble

The remaining functional bots took it to the arena to bout it out for 5 minutes. During this shoot we forgot to turn on our image stabilization so during some refocusing of the camera it ended up being pretty shaky for the majority of the match. :(

The Recap

Just like last time I think I still have some of the same issues with just material properties. Currently, I am designing a new 3lbs robot, and when I go to have parts cut for the new bot, I might have some new parts cut for Honeycomb to make it more reliable.

I think I could also cut down the size of my battery to 850mah, 650mah, or possibly even lower. Currently, I'm running a 1000mah 3S battery which is definitely over-spec'd for this bot. I could probably up the power of this bot by cutting down to a 850mah or a 650mah, but up to 4 cell battery for higher weapon speeds. Need to do some rough calculations, but current estimate is I can definitely reduce to a 850mah battery, possibly the 650mah.

Overall, this was a really fun tournament that wasn't too far away, hope to make my way back for the next tournament hosted by MTRAS. (Also love coming down for the BBQ :P)

1st Place!!!

R&F Tournament Recap

This is pretty late, but I have been very buy with the start of the school year. Without wasting anymore time lets get into it. For this tournament me and RJ traveled to Wilkes-Barre, Pennsylvania. We left home about 10PM Friday evening, with plans on arriving there at about 8-9AM Saturday morning. Travel goes well without a hitch, and we end up arriving at around 8:30AM.

This tournament was hosted by Raymour and Flanigan furniture store, and they had the box set up in the middle of the Store, and it was the first thing you saw when walking in to the store. Very cool setup with a lot of couches and chairs surrounding the box for people to sit and watch the event.

The box setup in the main lobby of the store

When getting there, they had us move around back to their warehouse area which is where they had us set up pits.

I ended up wearing my old high school robotics shirt, represent.

Me rebuilding the weapon assembly for the 4th time that morning.

The first fight of the day was against Captain Doom. Captain doom had 5 ground scraping forks on the front of their bot and a powerful drive train that made them very difficult to bully around the box. Without my primary weapon this match was going to be near impossible to win due to their more powerful drive train and low ground clearance. At the end of the match however, we have a giant collision that ends up knocking something lose in Captain Doom and they are rendered immobile. We win the match and qualify for the round of 8.

Since Captain Doom was just a push bot, we didn't have any repairs to do outside of charging the batteries. This left us a lot of time to try and figure out why our weapon wasn't spinning up. Upon the recommendation of another builder (I can't recall who) we lowered the kv of our brushless motor and swapped from a 3200kv motor to a 1100kv motor.

Me rebuilding the weapon assembly yet again.

Finally ready, with the weapon working.

For the next match of the day, we were facing Mondo Bizarro. Mondo has a very nasty vertical spinner on the front, but a relatively weak drive train. So for this match I wanted to stay away from the front of his bot and get around to the sides and the back. However, this did not go quire as planned, and I took a lot of early hits that ultimately led to the failure of my weapon. This fight won me "Most Destroyed".

After it was all said and done, we were unable to continue on the day. We finished top 8 and got this cool gif.

cool gif

Overall Thoughts:

I think performance was pretty okay, but had issues with reliability off the bat. Below are a few thought on how to change the design and how to prepare for future competitions next calendar year.

• Remove all 3D printed parts from the design. They are pretty rigid, but tend to snap and break instead of losing chunks and chipping. Want to switch over to UHMW for the mid and back plate, or possibly 2 different materials. The logic being that the back is subjected to more hits, and the mid is subjected to more torque and sheer force as the different sides get hit. Will probably get completed after the November Tournament in Virginia.
• Make the permanent switch over to a lower kv motor. Maybe not 1100kv as that seems a little bit too low, but under 2000kv. However, all I have on hand are 1100kv, I'll see if I can find some 14-18 hundred kv motors before the next tournament. (Will probably get completed before the next competition in 2 weeks)
• Practice driving, I really shot myself in the foot not practicing driving more, with that being very apparent in the Mondo match.

Last Minute Changes and Other Notes

New Design Error Discoveries

When replacing the set screws for the wheel hubs, I noticed that the hole in the hub isn't actually lining up with the slots in the drive shaft and the set screws are actually sitting outside of the slot. So, I'm going to do a slight rearrangement of the wheel assembly to see if I can get the slots to line up with the set screw, and if not I'll grind the slot slightly wider to accommodate. I suspect that this was the reason why I lost so many wheels in my first competition, since the set screws weren't in the slots, any loosening of these screws would cause the wheels to come off with enough centripetal force.

Also related to the wheel assembly is that the mounting hubs are actually not screwed in all the way due to the short length of the screws used to screw it in. I believe at some point in the design process I changed the depth of the counter sink and never adjusted the screw size to accommodate for the new longer distance the screw has to reach to be fully threaded into the mounting hub. If I have the time I'm going to make my way over to the hardware store to get a 1/4" or 5/16" screw to replace the current 3/16". I didn't necessarily have issues with the hub ever coming lose in the last event, but better safe than sorry.

Additionally the teeth on the weapon are only held in place with zip ties working kind of like a shaft collar. I think I'm going to try and replace them with larger zip ties to get a more effective collar on the shaft, possibly add some sort of high friction item on it so that it really chokes the shaft and doesn't slide.

Update On Current Status

With the competition coming up in just a few short days, I'm getting down to the wire here. I still have to manufacture 1 more wedge, I don't think I'll need more than 2 for the whole weekend. However, if time allows I will try to cut out one more so that I can have a total of 3 for the weekend. I currently have only 1 extra back plate, but I'm not really worried about any of the bots at this event having the destructive power to destroy the plate outside of Silent Spring since most of them are wedge bots, or other vertical spinners.

All Hardware Came In: Time To Start The Final Build Before R&F

Yesterday evening the Blue Loctite, vice grips and brightly colored duct tape to mark my vice girps came in the mail. This morning I made my way over to Kleindorfer's hardware. They have consistently been a great help to help me find the hardware that I need, with fast and professional customer service. They helped me locate replacement screws for a few different applications around the bot which include...

• Wheel set screws - will lock
• Drive motor mount screws - will lock
• Shaft collar screws - will not be locked
• Weapon motor mount set screw - will lock

I was able to get most of them in a higher grade than what came with the parts originally to hopefully, when paired with Loctite, hold up better to repeated screwing.

Today I was also able to print out the outline for the new wedge, the new angle of the wedge even on paper is looking a lot better than what it used to and I will hopefully have it all cut out and ground down by Sunday.

Event and Rebuild Update

Events

Officially signed up for R&F Robot Fight 2019 (9/14/19) and Hill City Robot Combat 2019 (11/9/19). Was unable to sign up for NERC Franklin Institute 2019.

Rebuild

Currently: The bot is completely rebuilt, have run a weapon and drive test and everything seems to be working. Updated the circuit to allow myself to more easily turn off and on the bot (and make it compliant with safety protocol.

To Do: Cut and grind new wedge and backup wedge, buy stainless steel replacement screws for all set screws and shaft collars, buy loctite and apply to appropriate areas.

Inside Thoughts: Driving, Design, Competition Updates and More

While flying home, I had a lot of time to review a lot of the film more closely, and reflect more on things that went right and wrong in and out of the box at the last competition. I'll be splitting up the list by rough groupings of what the note has to do with.

Driving Technique and Bot Configurations:

• For the first couple matches I had the control toggle on on the controller, this toggle is designed to give finer movement and control of RC devices. As I quickly found out I was one of the quicker bots in the arena and should be leveraging that to my fullest advantage instead of trying to focus on the finer movement.
• Use speed to more effectively get around to other bots sides.
• Remove wedge for large vertical spinners with a wedge.

Weapon Management and Battery:

• From what I can tell the battery is over specd and is capable of running multiple matches without needing to be recharged/replaced. However this is only speculative and is based on 2 relatively short matches. Maybe cut back to a 750mah or 850mah to help cut weight and size. Will need to do actual math for this, ugh.
• Rev to higher rpm, with 4 weapon teeth I can afford it. Didn't seem to have any termal or reliability issues after removing that one tooth. Also didn't cog as much (only during a new dig match) as it did during pre-competition testing.
• Weapon reliably started up and reved quickly. Considering changing weapon gear to 18 or 22 teeth so that I can get a better ratio to hopefully solve any cogging that is still existent.

Things to Change/Improve/Redesign:

• Loctite, almost lost semi-finals to a lose drive motor, luckily it didn't come lose till the tail-end of the fight. Wheel set screws, weapon set screw, drive motor mount screws.
• Even out the grind on the drive motors key slot.
• Prep all my motors leading up to next event (luckily at this last event I didn't have any motors burn out) so that if one breaks I can actually change it.
• Lower wedge angle, and grind it more flush with the floor.
• Make sure wedge is actually touching the floor.

Things to buy:

• LOCTITE on drive motor mounts. All 6-32 screws seem to stay tight and probably don't need it. Maybe on set screw for wheel and weapon mount?
• Belt Sander to grind wedge better, (brownsville???) if not go to grainger or other tool supply store
• 3/16 steel setscrews for weapon hub.
• possibly new sized banebot hub?
• Switch out screws on shaft collars to stainless steel ones from the stripped crap screws that are on them now.

Event Update

Events that I am attempting to attend in the next couple of months leading into the new year are...

• R&F Robot Fight 2019 9-14-19
• NERC Franklin Institute 2019 10-5-19
• Hill City Robot Combat 2019 11-9-19

This may change based on class/project/test schedule this coming semester. Each event is about a month apart so that I have a break between tournaments to reprint, fix, and update design between events. Currently, I am registered for R&F and HCR, and will be attempting signup on Friday at 8PM est for the NERC event. I have been warned that the event will be very hard to get into and that the signup will fill up extremely fast, so I plan on being online and on top of it that day.

Design Improvement Ideas and Rough Thoughts

After this weekend and getting my first real driving practice with the bot with the weapon in full swing I have a lot of personal notes for ideas on how to improve the design before the next tournament in September (hopefully). First things first I want to cover pros and cons of the design that I saw this weekend.

Pros:

• reliable/rugged
• high potential damage
• very fast, seemed to be one of the top 2 fastest bots there in the weight division which has potential for a lot of out driving these drive motors are very well rounded and are probably actually over-sized for this weight division.
• lots of torque, won a few pushing matches 
• invertable, can drive upside down
• after reducing the weapon teeth from 5 to 4, I had a lot higher weapon reliability.

Cons:

• relatively high wedge clearance, wasn't winning wedge on wedge fights
• steep wedge, couldn't get people up the wedge due to the aggressive 45 degree angel
• difficult to open and close top of robot quickly
• need a main power switch that powers and unpowers the whole bot, opposed to the janky 5v eliminator workaround I had

Ideas for redesign:

1. Less steep wedge to allow bots to actually drive up it and into the weapon, lower the grade of the wedge by 33% and bring it down to 30 degrees instead of 45.
2. Better ground wedge, have it have a lot tighter ground clearance to allow me to win more of the battles for the low ground.
3. Possibly change wedge material to aluminum sheet? (not sure if weight will allow)
4. Redesign backplate of the robot since I abandoned the side armor in favor of a front wedge.
5. Use loctite to connect the drive motors with their mounting hubs, they tended to unscrew themselves after rougher matches and when the weapon was running for a long time, this connection should be almost permanent except for when a drive motor burns out. Actually had a drive motor twist its leads to crap after it came unscrewed during a match.
6. Add tolerances to the mounting holes in the backplate so that I don't have to sand it for 50 minutes every time I print a new one.
7. Possibly add a well for the nuts that attach the top and bottom plates to the frame, to hopefully decrease time it takes to remove and attach it.
8. Look into why the nut in the middle of the top plate keeps getting stripped and messed up. I've had to dremmel off the screw 3 times now. :( not fun.

Ohio State Fair Video

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Ohio State Fair Competition Recap

Yesterday, marked the completion of the first ever tournament Honeycomb has been a part of. We finished a proud 2nd place, and lost a hard fought match in the finals. Video to be edited and uploaded within the week so stay posted!!! Below are a few pics and our schedule from the day.

4:15AM

We had an early start to our day. We spent the morning getting ready for the day, grabbing breakfast, double checking that everything was packed away and that we weren't forgetting any important items that would be needed during the day.

5:15AM

We hit the road for our three and a half hour drive up to Columbus, Ohio.

9:00AM

We arrive at the Ohio State Fair, we get the bin unloaded from the car and meet up with Tad Douce, to receive further information and our entry passes upon arrival.

9:15AM

We make it to our pit area and start to unload and prepare the table for the day ahead.

Our table setup.

The battle box that we would be competing in for the day.

10:00AM

We go to safety inspection and initial weigh in. We pass safety inspection and, weigh in at 2lbs 15oz. We are good to go for the day.

Us after passing safety inspection. 😎

11:00AM

Driver meeting to review rules, regulations, and format. The format is set up so that we alternate between ant-weight (1 lbs bots) bracket, and beetleweight bracket (our division). During a match if 2 bots become immobilized at the same time by getting stuck on each other time will be paused and they will be unstuck from each other and the match will continue, there is a pit that opens on the far side of the arena partway through the match that gets announced 30 seconds before it gets opened. Double elimination bracket setup. Matches start for the day.

11:30AM

Our first match is against Sean V2. A wedge bot. We had a hard fight, but we ended up losing to them after they push us out of the ring after the pit door opens up. We are now in the losers bracket.

Sean V2

1:00PM

Due to technical difficulties from Wee Dotty-M, the other team, they were given till after lunch to repair their bot. We get in the box, and since they didn't have a wedge I quickly got underneath them and flipped them over. They then got counted out for an immobilization count. That's one win in the losers bracket!!!

1:15PM

Since we had a delayed match from before lunch played at 1:00PM, we ended up going straight into our next match at 1:15PM. We were against A new DIG. This bot has a 3" circle saw mounted to a brushless motor on the front of it and uses it to cut into other bots. We have some back and forth until I get a big hit and and flip him over. A new DIG is then counted out for immobilization count. That's 2 wins in the losers bracket!!!

  1:45 PM

Our next match is against Rebecca, a giant pan robot (image unavailable on buildersDB). On the front of Rebecca is a giant aluminum scoop, that is used to deflect blows, and other bots around. I quickly noticed that whenever he accelerated forward there was a small window of when his wedged popped up off the ground, and I was able to exploit that and continually get underneath his wedge for the rest of the match. I end up removing some pieces from him and win in a knockout. That is 3 wins in the losers bracket!!! Since we won the entire losers bracket, we are now entering into semi-finals with a rematch against Sean V2.

2:00PM

Semi-finals match, we are now in a rematch against Sean V2. For the first match I left the control switch on, a switch designed for model planes to allow for slower more precise movement, but for this one I knew that I had to be as fast as I could possibly be so I drove without for the duration of the match. There was a lot of back and forth during this match and he almost pushed me into the pit again, but with the increased speed I was consistantly getting around to his sides and biting his wheels up. The match went the full 3 minutes and under judges decision it went to me!!! We are now 4-1 on the day, going into finals, to contend for first place!!!

2:30PM

Finals match is upon us. We are fighting against H5N1, a vertical bar spinner. During the match for the first part of the match he gets a lot of large hits in on me and eventually rips off my wedge. After the wedge gets ripped off I get a large hit back on him flipping him over. However, he is still able to drive slowly upside down and is not counted out. I have to go back in for another hit because I am currently losing the match and my only hope is to hit him again. I hit him again, and he gets re-righted and continues to pummel me. I eventually get to a point where my entire back plate was destroyed, and I was missing a wheel on my left side. I decide to throw in the towel and tap out so that I can salvage my motors and escs for a rebuild. Congrats to H5N1 on the win!!!

3:00PM

Everything is all said and done, we finished in 2nd place!!! Super proud of how well we did, and I'm super excited to compete at more events in the future. 

Damage that we took from last fight...

• Lost front wedge
• Bent weapon axle
• Left wheel destroyed and removed
• Back plate destroyed
• Mid plate cracked
• Chain has a couple compromised links

All the electronics appear to be working correctly and at worst might need to be rewired. Overall this was an awesome day!!!

Redesign of Weapon Motor Mount

Due to poor design on my part, I've had to do a redesign of the weapon motor mount. I didn't have proper clearance around the weapon motor shaft and it was unable to spin up. I have since ordered some Aluminum Motor Mounts and plan on mounting them inside the chassis with this new piece that I designed.

Overall, I think this new piece should solve the issues. Potential issues with this part is it failing due to the force the motor exerts on it, however It has been designed to withstand a lot of force from the top plane inwards towards the center without having to rely too heavily on the screws that attach it to the chassis.

Parts Have Finished Being Fabricated

Pictured is a few of the pieces I had fabricated, everything else that was fabricated are just duplicates of the pieces already pictured. Top left is the drum pieces, top right are the side plates that mount the majority of the electronics, bottom left is the top plate, bottom right is the bottom plate.

I received the pieces back from TruFab on Tuesday. The parts came out beautifully all within the necessary tolerances for the other parts to press fit together with only some minor grinding. Currently doing a rough fitting of all the pieces and plan on rewiring once I see how much space I have to work with inside the bot.

When testing the weapon motor mount inside the bot, the component suffered failure in one of the mounting sockets, currently working on a redesign of the weapon motor mount and considering switching to this pre-made mount from Hobby King. However, this would require a redesign of some of the internal structures.

Final Fabrication Update

Side plates (left), drum pieces (top right), and the remains of the 4140 steel plate that the drum pieces were cut from (right)

I received an update email from TruFab this morning and attached was the image shown above. The side plates and drum pieces have been cut out.

It appears that what they have left is the side armor and top and bottom plates which will all be water-jet cut out of the 1/16" poly-carbonate, and the counter sinks in the side plates. Their machinist is out for the holiday so the counter sink work won't happen till either Friday or next week and the entire job is expected to be finished by mid next week. Super excited to get the parts and start the final build. There are some small adjustments that I will have to make in concerns to weight as the weight changed slightly due to the material change for the drum pieces. Possibly might have to go to 4 drum pieces instead of 5, additionally I want to design a front wedge/scoop using the Lexan to attach where the side armor will be attaching on the side plates to allow the bot to win battle for the low ground.

Final Fabrication

After doing some asking around, I ended up finding a local sponsor. Big thanks to TruFab Stainless here in Bloomington, Indiana. They have generously offered to donate their time to fabricate all parts that are needed for the robot.

I made my way up to Indianapolis the morning of 6/26/2019 to visit a couple stock metal and plastic businesses that I have been talking to. Ended up getting my 6061 Aluminum and 4140 Steel from Metal Supermarkets Indianapolis, and my 1/16" poly-carbonate sheet from Auburn Plastics & Rubber. Both of the supplier businesses had fantastic customer service and were very nice, would highly recommend either one for low volume orders of stock supplies.

After I finished picking up all of the stock I made my way back down to TruFab back in Bloomington. I got a chance to meet the staff and everyone was super friendly and taking in interest in the team, as promised I will make my way back over once I have the bot all finished to show them what's been going on. Once again, many thanks TruFab for their donation to the team.

Final Weight Estimation

With the CAD model completely finished, we were able to do a final estimated weigh in. All of the electronics have been wired and soldered, and could do with significant wire length shortening to cut even further weight. All weight is accounted for except for the spacers that will be used between each weapon tooth. Additionally, we counted out all of the hardware that will be needed to assemble the chassis and also added that to the weight. Currently, based on the current estimate the bot is 1.3 grams over weight, but we believe we can more than cut that with the re-wiring that will take place after fabrication. If absolutely needed we can go down to 4 weapon teeth instead of 5 which would cut 30 grams. Currently the weapon assembly makes up 20% of the weight, and will be able to spin up to ~8-10k rpm. We plan on probably not running weapon at full speed just because it's usually more effective to have a bigger bite.

This is the final bill of parts and their expected weights. Parts that do not have a volume and only a weight we weighed on a gram scale to get an accurate weight of the part with all of the wiring that is currently attached to them. We think we can significantly cut weight though as currently there is an excess of wires inside of the chassis.

Honeycomb 3.0

Rough Fitting, Weigh In, and Improvements to Make On Honeycomb 2.0

Rough Fitting

All of the main structural components finished printing on Thursday evening and were available for pickup on Friday morning. In the final design we plan on switching out the bottom, top, and side plates for 6061 aluminium and increasing the infill for the mid and back plate to 100%.

We did a rough fitting, not screwing in all screws, but just checking to see if parts and electronics are lining up the way that they should be and to check the clearance's of the holes.

The electronics look messy, but we plan on cutting down and re-soldering all the wires to appropriate lengths to cut weight and free up some of the clustered space in the internals.

Below is a list of components used in the build

Component	Name
Drive Motors	720 RPM Planetary Gear Motors
Weapon Motor	Turnigy 2836 Brushless 450-Size Heli Motor 3700kv
Drive ESC	Scorpion Mini ESC
Weapon ESC	Hobbywing X-Rotor ESC - 40amp
Battery	Turnigy Graphene 1000mAh 3S 75C Battery Pack

Weigh In

For the weigh in we went into Autodesk inventor and found the volume of all the custom parts (excluding the drum and side armor), then calculated the mass of the parts based on material density and the volume. We also had a scale to weight out all of the components IRL to account for their weight plus the weight of wires and connectors. In total the weight came out 1170 grams, which leaves about 200 grams for drum and side armor which isn't enough. This weight account for the bearings, shaft, gears, and shaft collars that will be used on the weapon assembly leaving the weight for only the drum.

Places to cut weight from:

1. Midplate, instead of a 8 way cross hatch, cut it down to 6 way (diagonals and vertical only). Cut down the material between the holes to mount the top and bottom plate.
2. Sideplate, instead of a 6 way cross hatch, cut it down to 4 way (diagonals only). Maybe, add some holes behind the bearing mount to cut more weight.
3. Backplate, instead of a 8 way cross hatch, cut it down to 6 ways (diagonals and vertical only). Cut down the material between the holes to mount the top and bottom plate.
4. Bottomplate, maybe double the honeycomb design to the bottom plate may present structural issues for mounting ESCs, battery, and radio receiver.
5. Electronics, clean up wire lengths to whats needed. Currently a lot of extra wires present in the build can probably cut 30+ grams.

Out of all the places to consider cutting weight my most hesitant place to cut weight from is the bottomplate and sideplate behind the bearing mounts as this might negatively effect structural integrity. We think the most drastic weight cut will be from the plating since those will be the largest amount of material removal.

We will also weight out all of the potential hardware that will be needed to hold the bot together (screws, nuts, washers, etc.) This weight will probably be even with any weight we cut with electronic's clean up

Improvements/Changes

1. Increase hole size for all 6-32 screws to a .144" clearance holes.
2. Move the centers for the top and bottom plate holes and mounts on the plate to be 5/32" instead of 1/8", idk why I didn't do this to start since a 6-32 nylock nut is 5/16" not 1/8" wide
3. Increase hole size for weapon motor mount to m3 clearance holes
4. Increase hole size for weapon motor shaft to clearance hole for a 3.17mm shaft
5. Increase hole size for drive motor shaft to clearance hole for a 4mm shaft
6. Taper the connection between the plates by 1-2 degrees to allow for easier slotting.
7. Change the tolerance on the shaft connection for the drum so that it is a close slide fit, not a interference fit.
8. Change the tolerance on the bearing mount to be a soft interference fit.
9. Add slot for weapon motor wires to clear to allow flush fit.

Fabrication of Honeycomb 2.0 Prototype

Once again to fabricate we used the IU 3D Print Lab. Currently we have the top, bottom, and side plates printed. The rest of the bot is currenlty on the printer and is set to finish up this Thursday around 8PM if I did my estimate correctly. This time we used the Ultimaker 3s instead of the makerbots, this allowed us to use dual extrusion to print some of the more intricate parts on the build.

This time true to form the top plate is now indeed Honeycomb.

The bottom plate finished up cleanly.

Don't know if you can see it here, but we had some issues with warping on the edges of the side plates. For prototyping this shouldn't really matter, but we wish it looked better :(

Redesign of Honeycomb 1.0

When approaching the redesign, there were a few things that we had to consider that we feel like we learned from our first design of this bot.

1. The clearance between my drive motors was just a little too close, so we wanted to widen the chassis by .25"
2. We originally had designed the weapon to be a dead shaft much like in the design of Radii V2 (http://hkim702.blogspot.com/2018/02/radii-v2.html). However, this presented a few issues especially when converting power from the weapon motor to the drum, so we decided to switch to a live shaft to allow the use of some VEX Pro motion items to more easily power the drum.
   
   Also, we have made the change to chain, such little is used we figured the reliability outweighs the added weight plus the team behind Radii made it clear that they had issues with belts and having consistent tensions fight to fight.
3. Due to the change in availability in Banebots t40 2-7/8" wheels (no longer in production) we had to make a change in the design to accommodate the 3" precision wheels from servocity which are about .2" wider than the banebot wheels. Additionally this also meant we had to make a change with the height of the skids that hold the weapon off the ground.
4. Added a new weapon motor mount to support the weapon motor more fully and still allow it to have proper clearance from the outer wall.
5. Increased the length of the chassis to accommodate all the electronics, after putting together the last version it quickly became apparent that there was not enough room in the design to accommodate the weapon motor and esc.

Prototype Fabrication of Honeycomb 1.0 and Review

For the first prototyping we used the IU Bloomington 3D print lab to fabricate my pieces. All the pieces for this round were fabricated on the MakerBot Replicator. Not pictured below are the top and bottom plates. The drum would be set on the 2 dead shafts on bearings and run via a belt through the notch in the mid plate support. This gave us the chance to put in all the electronics and see how it all fits together, and there definitely has to be some changes going into the next round of iteration being that everything was a little too cramped and could use a little more room within the chassis.

Honeycomb 1.0 Design

For the design of Honeycomb 1.0 a lot of inspiration was drawn from Radii V2 (http://hkim702.blogspot.com/2018/02/radii-v2.html). This was a tried and true drum spinner, and the authors of this blog made sure to highlight some of the issues that they had related to design and materials that they used in the fabrication of their robot.

Going into the design of Honeycomb 1.0 we're going to list the thoughts of some design aspects.

1. Interlocking outer chassis to improve strength and rigidity.
2. Outer wheel covers to protect from getting hit.
3. Invertible design.
4. Dead shaft to mount the weapon motor.
5. Easily replaceable outer layers that are designed to take a beating.
6. Have the side plates made from aluminum and the center plates 3d printed to cut weight while not sacrificing too much rigidity.