Telekinesis - FW Horizontal Spinner

Hey all!

Haven’t posted on the forum in a while so thought I’d make a diary for my new full combat featherweight. Since there aren’t many about nowadays I decided to do a horizontal spinner, should be fun.

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It’s also an “undercutter”, meaning the blade is very close to the floor with the aim to avoid armour and kill some wheels. To do this I decided to use a single bulkhead (this is two layers of 4mm Hardox and a 14mm aluminium piece at the front, supporting a 20mm thick shoulder bolt that holds the disc on and is held by a nut the other side of the bulkhead that is locked in place. Bit of trial and error may be needed here depending on how the design holds up to impacts with the shaft being only supported on one side, we’ll see.

Inner components are fairly standard, going to be a 5S lipo powering two 550 brushed motors for drive, through one of Rory’s new speed controllers, and a pretty beefy inrunner connected to a right angle gearbox with a second pulley stage powering the weapon.

The parts for the chassis, armour and disc are all water cut from 4mm Hardox, 10mm Hardox, as well as 4mm, 10mm and 20mm aluminium that slot and bolt together, these should make for a pretty strong chassis which can hopefully both give and take some pretty big impacts.

Few pics of the parts that I have so far, mostly from K-cut as well as a lovely hub for the disc that was CNC’d.

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More progress to come soon...

Cheers

Excellent looking CAD! I have a real fondness for undercutters, they are under rated and could do very well against the current flipper bots.

Is the 4mm Hardox top plate the unique "structure" part holding the disc??
If so, a "small" vertical hit on the disc will bend the front structure.

If it got a direct hit from a drum on the front of the bulkhead it might bend it a bit, but it will still be pretty stiff and reinforced further down where it matters and that also means getting past the disc infront

Hey all!

Managed to get the robot mostly finished and get a drive/spin test in at Manchester last weekend.

Build process I don't really have pics of but it went pretty smoothly...

Managed to scavenge together two fully functional Neptune gearboxes even though Ellis hasn't currently got them in stock, from Ellis himself as well as Giles being really helpful by giving up a slightly broken one from his feather..Really nice gearboxes I must say.
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Got the welded side armour pieces from Dave at the event too (thanks Dave!), need to do a bit of tweaking to make these fit onto the body a bit better as I didn't allow clearance/tolerance for taper etc from the cutting process resulting in the body not fitting together quite as perfect as in the CAD.
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Some pictures of the completed robot minus the side armour, with the anti-vert bar and normal disc on.
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And here is a youtube vid of the first time the robot was on the ground and the first time the weapon was spun, I was pretty nervous it would self destruct!

https://www.youtube.com/watch?v=D5r4LlHDbQY

Mostly went ok, with a few minor issues that I will overcome pretty easily.

Thats all for now, thanks for reading :)

Hey all, been a while

Telekinesis fought at Insomnia 61 UK FW Champs weekend before last so time for an update :)

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These fancy renders show the upgrades it got since I tested it at Manchester and Guildford.
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When I fully assembled the robot with the armour for the first time the day before the event, I realised the blue wheel hubs were sticking out more than I planned and fouling on the hardox wheel guards, so I bodged together a set of thinner colson ones and pressed in an aluminium bore on each, these were held on with an M6 grub screw to the gearbox shafts, not ideal but it seemed to work ok.

https://www.youtube.com/watch?v=bLzrzJ-BLLc

This was the weapon and drive test done after tech check at the event, all seems ok so far! One issue appeared when I hit the wall in an attempt to slow the weapon down after I had turned it off, the bushing between the bevel gear and the weapon motor shaft had slipped on the impact, which was never an ideal solution and something I have plans to upgrade to a custom 8mm keyed shaft in future, I originally thought the grub screw had sheared but thankfully the bushing slip was fixed by Adrian kindly using his epoxy to fill the gaps and strengthen it, which went on to last for the next 2 days of fights.

First fight was a 1v1 against Scruffy, I should have used the disc for this fight really but thought the bar, although being lower energy, would be a quicker spin up and be more reliable.

https://www.youtube.com/watch?v=pYaL8Trckq8

Attachment 7201 Some damage to Scruffy's forks, one of which I now have as a souvenir :) It also sheared base plate bolts and cut his wheels which was always the idea with the robot, even though I felt quite bad about it

Next fight was against Utopia and Gerty, this fight went well until my link came out, which I will fix with a better connector and link cover for next time.

https://www.youtube.com/watch?v=sUqq_mnTKwM

Attachment 7202 Lots of glancing blows on Utopia's well angled wedge.

The next fight was against 722, which I knew wouldn't be an easy fight but was hoping it would be an entertaining one either way. The fight turned out pretty quick, as my link came out again, along with the gearbox seizing as the main shaft bearings popped out the gearbox on an impact. He also took off one of my side wheelguards, shearing the 5 m6 bolts holding it on, new armour with better mounting in future!

https://www.youtube.com/watch?v=9SKmeHUDzxc

The fourth and final qualifier match was against Neon, another undercutter, and Hatchet. I knew this one wasn't going to be pretty either way

https://www.youtube.com/watch?v=MR5c...AjbKfg&index=3

Neon outdrove me and got one of my wheels pretty early on, from then on I was on the backfoot, he managed to also hit my base plate and shatter the polycarbonate holding the battery in, and sheared some bolts holding the drive in place, resulting in gruesome looking by the end of the fight! This hit also lost tension for the weapon, moving the mounting plate on the bottom of the robot. Did manage to hit his pulley at some point though, not quite sure when.

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This put me out of the competition on 8 points. At the time I thought the robot might have been a write off but it turned out to be quite easily reassembled with replacing a few sheared bolts, so I signed up for the annihilator.

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Made a new hdpe base plate to hold the battery in, the rest was held in ok by the aluminium underneath.

The annihilator was against Equinox, Hatchet, Mr Mangle, Mantis, Omega and Come here and say that again. The first 3 fights were very quick, all ending with Equinox OOTAing other robots, which let me stay back and stay in without doing much at all. For the first two fights the weapon hardly worked with the motor gear coming loose from the shaft again, so finally had time to fix this for the third round, which was a frantic rush but just about worked out.

The fourth Annihilator fight was sadly the last one for me, as I instantly span up and had a head on hit with Equinox, which killed one of the 550 drive motors and eventually deemed me immobile.

Video of the fight and small bit of damage to Equinox's drum from the impact.

https://www.youtube.com/watch?v=lrVPhHMEZy8

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I went on to have one more whiteboard with the robot but the gearbox had issues from the start, siezing up once again after one or two hits, meaning the robot never really hit something at full power with the disc which was a shame, but overall the robot worked pretty well and with reliability and robustness improved, should be fun to use again next time!

Telekinesis at the end of the event:
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Improvement Ideas:
-New gearbox to fix the issues with it, making the transmission for the weapon a lot more reliable.

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The threads mounting the box went by the end of the event, probably because the gearbox was relatively soft aluminium (6082) and there wasn't enough material for them - this will need a redesign. The motor could do with a custom 8mm keyed shaft to remove the middle man, being the bushing, to mount the gear to it better. Angle grinder gears should be more efficient than bevel gears for the high RPM of the gearbox too.

-3536 NTM drive motors on the drive, to increase the drive speed from 7mph which seemed a bit sluggish, to around 14mph for more bite and to make the robot more effective in bigger arenas, they will also save weight for other upgrades.

-New side armour, either redesigned out of hardox to be mounted better, or out of HDPE/aluminium which will absorb more impact and be less likely to bend/break.

-General strengthening to all the motors and the chassis in the robot. I'd like to add back support on all three motors.

-Taper roller bearings in the weapon.
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Overall the weapon set up I was very happy with, especially the shoulder bolt for the disc, that didn't bend like I thought it might. Though the deep groove bearings are both crunchy and were most likely acting as bushings rather than bearings for the last few fights. Hopefully with the right preloading from shim washers, taper roller bearings will be stronger in future.

Thats all for now, cheers :)

On further diagnosise it appears the weapon hub I thought was ok, is definitely not ok!
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This was once a press fit

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This will have to be remachined and slightly redesigned out of 7075 aluminium rather than 6082 in future :)

Great event report Andy, that weapon hub took a real beating! You might consider 2024 rather than 7075 for the hub; its not quite a strong but it is also much less brittle and less likely to crack. Either way, just thickening up the wall and particularly the rim around the bearings will fix that bearing problem.