Bonjour everyone, you remember Klaus?
Well it’s been so long I wouldn’t begrudge you if you had. It was a 4wd “hammer” “saw” with both of those words being used very generously. Ultimately it was one of more successful endeavours. Don’t get me wrong it still lost all its fights but it was a huge bucket of techniques I still use to this day. It was the catalyst for printing nylon chassis parts, for casting polyurethane tyres and generally having big silly fun.
The squat, power dense 4wd platform was very promising at being a simple and reliable machine with a few minor tweaks to the weapon system. Naturally it got abandoned for over a year then rejigged as an overhead saw with tracks.
My genius and tendency for self sabotage knows no bounds. To be completely fair, the thoughts originated for a newer MotherLoader but the potential for violence and the weapon style put it firmly into Klaus territory. It got close to being completed but never really clicked together to be a fully cohesive project for me. I’m super interested in revisiting this as I have done a lot of the legwork and have the parts.
Very recently I was cleaning out some boxes and found some old discs I had cut for a jolly - years back when I did such things. I think I was trying to emulate the VDD styles from the mid 00's that I really liked. 3 teeth, while lacking the bite of single tooth (hey, about a third as effective funnily enough!) they are great for looking cool and they let you stack a phenomenal MOI into a disc. These are 8mm thick and I feel the tooth profile is both aggressive and attractive. With these chunky nuggets in hand the brain juices really started flowing and before I knew it I had built:
KLAUS-293
Now I am not a huge fan of the spinner game anymore. I try to not come across holier than thou about it because I genuinely don’t think it’s wrong to build what you want. That’s kinda my whole deal. I make a few limp wristed snippy comments at the BattleBots level events and competitors where things morph unhindered into 4wd verts like an even more unsettling form of carcinisation. I try and wear my bias on my sleeve a little and not mask my intentions with fluff. This version of Klaus is my way of dipping a toe in while retaining my dippy little quirks.
Anyway, I made two verts. As I’ve enjoyed phrasing so far “does this mean I’m trying twice as hard or only tryharding half as much?” Answers on a double sided postcard.
God damn I love America from 1997-2007... well the robotics side at least...
I’m a very simple man with very clear sets of inspirations - Stance Stance Revolution is one (which itself comes from Counter Revolution. My word, it’s like poetry - it rhymes!) I was also tentatively inspired by Sunstroke, a dual disc horizontal that blew the backside out of Dear Mr Nips a couple months back.
Here was the first serious draft. The drive and proposed electronic system was transplanted from MotherLoader with the bluecap 25mm’s and a BBB dual esc. The tracks were from the overhead saw version of Klaus and the central motor was a 3538(?) NTM which was a veritable monster but was 1800kv. It was heavy, powerful and fast. Honestly before I got too bogged down in weight (spoiler alert) the speed was the killer as I was so limited on how small I could make the drive pulley.
To get the tip speed under the 250mph limits the driven pulley on the disc had to be enormous. This was a bit of a naff design as it just meant they are both heavy and a massive target!
I got to the point where I had made a bunch of revisions with the chassis. My new style of design is an initial sketch where I then derive every part from. It makes sweeping changes very easy and its a practice I need to keep going for sure. This lad is the first TPU frame I printed and you’ll notice the drive got a distinct upgrade too.
Width is weight and I was on a campaign to get this monstrosity as small as possible. The RB MARS are an amazing off the shelf solution. I bought a pair on launch but never had anything that would benefit until right now! In a typical turn of events about a week after I finally glopped these cracking little units into a robot Ranglebox goes on hiatus! At least these are bulletproof enough not to really need spares too often.
I also reneged on my “don’t buy anything” ethos and spend a whooping £12 on a 3530. This was a smaller, weaker and slower motor but that actually benefited me. I could power it properly from a beetle sized pack, I didn’t have to panic too much about ESC’s and the lower KV meant I could shrink the driven pulley down to much less of a weakness.
This was the moment I had got everything I wanted to into the robot and made the foolish mistake of plopping it on the scales.
1498g wow! Nice! 2 grams to spare!
What was decidedly less nice was I had to fit two lids, one 8mm shaft, a dozen bolts and screws, a weapon ESC and a switch into those two grams. Oh gee! How absolutely dreadful! That was what we in the trade call a big fucking problem. It had all the makings of being jolly bloody difficult to sort out! Theatrics aside, in all honesty it probably could be done with enough flesh cutting and titanium shafting, component swapping but that all started to look like either an expense, a compromise or an expensive compromise.
Luckily, because I am a slave to the whims of inspiration and generally completely awful I already have solved this problem. I had made several test beds to service an enormous horizontal that had a kilo of spinning mass and so had a lot of the necessary hardware to entertain an adhoc shuffler refit. See Ma, buyin' all them Chinese bearin's was worth it!
This was a little 3 cam offset leg that was really pretty low profile. There’s something exceptionally pleasing about 120deg spacing on this. Made really simple by the hex hub. I wanted my motion to be as smooth as possible and to properly fill out the space intended for the tracks I could fit 4 cams and 4 legs. Just working off the completely arbitrary premise that more legs equals a smoother ride. Mental simulations (daydreaming) said it would work.
There! You’d almost think I designed it like that. It was a really good fit for the first draft and the leg design didn’t actually change too much from #1
You can see how close it all is here. This is a 2mm offset on the cam which just rolls the leg profile around the space left for the track clearance.
With the PLA trials done I added in my geometry to cast the tread around and hit print! These were done in the same TPU as the chassis and were an abject failure. Way too soft and flexible - they looked the part though. I quickly reprinted them in nylon. The bearings are a really tight fit, but there are also screw holes around the bore with the idea you can use a flanged head as a mechanical retainer.
The ‘timing’ of the legs is done with the help of a 6mm MARS hub from Ranglebox. The 2x offset cams are through bolted together and put at their 90 degree spacing using the hub. The driven cams are just pinned together mirroring the driven ones. The bearings are 25*32*4mm and there’s a lot of them. Gobless AliExpress.
The driven cams run on Ranglebox nylon bushings - this works better than expected. I was stopped from using ball bearings by the PCD of any sensible screw pattern. I could use a needle roller but that’s expense that seems to not be completely essential for the moment. This is actually pretty fiddly to assemble the first time but it is okay to service if you make sure you remove it from the robot as one unit and don't immediately drop it. I can guarantee that is exactly what I will do when I'm in the pits under pressure however.
It’s a bit annoying but all 4 cams are unique - with that old style 3cam it was one part replicated. If I wasn’t retrofitting it I think it could go down to 2 or 3 parts.
I copied the model of the leg with the very moustache-y foot profile and just patterned them out in a shallow tray. I added some corner rads to make the silicone a little easier to remove and just printed it in one shot.
It wouldn’t be a Harry Post without a completely needless slab of silicone. I can’t help it, I just think they’re neat! With the silicone negative made I could then slot my legs in place and carefully pump them with 50a polyurethane and a smidgeon of orange pigment. It is a Klaus build after all!
This is the smallest and most delicate thing I’ve moulded and it’s the most stressful, difficult and wasteful. Because I only really need 2.5g of rubber per foot I don’t technically need that much but I’m making 100% extra just so I can get it into the syringe. You can’t reasonably pour these moulds either. The technique is to gently fill them with a syringe, backfilling them via the through holes in the leg. It’s satisfying watching vibrant orange bloom through the shape but not easy if you have the sausage fingers of a particularly dense Neanderthal and the dexterity to match.
And that brings us to the collection of ginger false moustaches that make up the shuffling element of the robot. You can see a rough test of the movement in this video
Unfortunately it's in Shorts format because I am a morally bankrupt slave to the online validation of strangers. Plus it marries up to my Boomeristic tendency to film in portrait. #content
So you can see here now relatively tight the mechanism sits in reality. You may call it an insulting lack of clearance but I say it’s an interesting and effective filling of usable space. The flanges are just ABS and with the M3 bolts running all the way through they keep the legs retained. There is a plate of armour that bolts to the chassis through the screw inserts.
A closer shot of the rest of the robot coming together. It has these TPU forks that are fractionally pressed into the ground by the elasticity of the material so that any frantic jiggling by the locomotion doesn’t pull them off the floor. This also shows the addition of the nylon brace which is there to make the robot look like an old bridge (please, call me Isambard Kingdom Hills) and more importantly stop the flexible nature of TPU from causing immediate and catastrophic damage the second it hits anything.
In case you needed some scale for Klaus-293 it’s much larger than a 50 pence piece but only slightly larger than Nips, sharing almost exactly the same footprint. Very different and incompatible vibes however. Nightmare blunt rotation.
Again, it just wouldn’t be me if there wasn’t an element of dyeing my fingertips a funny colour, alongside some nylon as a by-product.
The pulley and hub interlock with the spokes of the disc which means that the bolts (only 3*M4) aren’t taking all the shear load and it really helps from a quick alignment perspective. Does mean I'm slightly putting plastic nubs in shear along the layer lines but hey, don't think too hard about that - I sure didn't!
The assembly isn’t the sexiest or most interesting of affairs truth be told but it’s sort of an attempt at best practices within less than ideal constraints. There are two 8mm bearings, spaced out as far as possible but still having proper thrust bearings. They will run on a shoulder bolt that I can just torque the assembly down and get a really solid install. I had the ball bearings on hand but I had to splash out and grab the needle thrust washers. Strangely Amazon was the cheapest and easiest. What a depressing world we live in. I naturally sold my soul and spat on my principles for £4.79 and next day shipping.
Minus a gram or two for bolts that are the right length and that’s still a chunk of change for a weapon - and I’ve got two of em!
Now for the more eagle eyed readers, you may have noticed that both the discs are traditionally vertical. By which I mean they both spin upward in an uppercutting motion. This sort of makes the most sense to do but I have achieved this in a pretty horrible yet amusing way. I could have been clever and used additional pulleys or a gear driven drum to reverse the direction of one of the discs or just simply run one spinning down (& had a neat way of telling which end was the front!) but instead I decided to look back 100 years and pretend my robot was an overhead shaft driven factory.
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So that’s the guts of this little nugget. Reuse, recycle and so on. Some very well loved BBB brushless escs and a £3 genuine Bottom of the Barrel Borshless (different type of BBB) plane style ESC. Back in the day before drones ruled the skies, phat mosfet spammed plane escs were a completely legitimate way of controlling motors. Too dumb not to work is the theory I’m working on here.
Here it has been chopped and glopped together with a liberal application of heat shrink, zipties and several warcrimes against electrical engineering. It's nothing too exciting, the worst thing I did was backbreaking the capacitors and forcing them to sit upright. Good posture is paramount for efficient electronics. This bulk could be the fraction of the size but getting a proper or even smart ESC with programming options would have cost money. If it dies I have one complete unit as a spare and when that immolates I'll go spend more than £3 on electronics.
Well, there we have it. Some work still to go on, mostly detail oriented and tightening and testing but it’s all together. Not bad for a little low effort side quest to get me away from building real robots. I have picked up a few useful pointers with this build. Mostly tips and tricks for large TPU chassis blocks which I think is a good way to live my life going forward. It's so lazy but it feels so strong.
As stomach churning as it is to publicly state your own pride in a build I’m genuinely really happy with ole Klumpy here. It was a nice refresher into a lot of old habits and I can still try and trick myself into thinking I have an artistic flair. ( That’s ARTistic, people) For those wondering where the numerical component came from it's deceptively simple and highlights another niche interest of mine. Hm, maybe artistic was the wrong word after all.
It stems from the absoultely incredible chunk of engineering might, Bagger 293. Much like MotherLoader-T34 aped the clunky, simple nature of its Soviet namesake I tried to get some of the awe and structure of heavy German engineering into a little plastic clatterbox.
There’s still a lot of weight to play with so I’m guessing I’ll start beefing the lids and the side armour as a start but I’m kind of happy just to let it ride.
speaking of letting things ride
Sometimes it's not making noise? Excellent. Yes, for a small thing it creates a generous amount of noise pollution and with forward motion strictly as a secondary concern. I can properly get to grips with it when I get my transmitter back and can actually have the drive mixed to single stick. Right here and now I am doing my best with a pistol grip GT5 by pulling the trigger and turning the wheel at the same time. Flawless control I assure you. I have a tinymixer I could add in but I'd have to take it out when my i6 stops being bandied about by Yodel.
Now comes the question what do I actually do with this lump? I am dead set on Hard Nips being the next robot I compete with so it’s sort of going to get relegated to whiteboards which I don’t think is fair for this sort of robot. Already at a mobility disadvantage I feel it could hold it’s own in a 3 way melee but not against anything more serious. Just have to wait and see what the calendar looks like for the year and hope to get it wiggling it’s way out to something!
KLAUS-293
Weapon: Dual vertical spinner. 770g split over 2x 8mm hardox discs with a 238mph tip speed
Weapon Motor: Generic 3530 brushless motor 1100kv
Drive:2x Ranglebox MARS gearmotors powering a simple 4 leg cam based shuffler mechanism
Electronics: 2x BBB brushless drive ESC's, unbranded "40a" brushless plane style ESC & 4ch RX with a Fingertech switch (2.5mm UK compliant hex key)
Battery: 650mah 4S lipo
Chassis: 3d printed generic TPU with eSun Nylon used for pulleys, shuffler legs and chassis bracing. ABS and HDPE also used.
