Team Kaizen - Shu!

[Ocracoke]

Well as it so happens, I've ordered fairly long bolts to screw the wheels into the hubs so they'll stick out like Boudicca spikes on a chariot.

[Albear]

Heres an idea, you can get spiked wheel nuts for cars or spiked valve caps if they fit your bolts and really make it look like a chariot lol

[Ocracoke]

Hahahaa! I may end up simply sharpening the bolts themselves if it comes to it.

Finally got around to weighing Shu! - weighs 863g at the moment so that is a worry off my mind. In the middle of making the rest of the bodywork/chassis which will likely add another 300g making 1.163kg roughly. So looks like the HDPE forks may yet make it.

[Ocracoke]

So this evening, I've finally got a top on Shu! with some dowel. I still need to fabricate the sides so at the moment, it looks a bit like a table to me. I've also started reorganising the internals so with any luck, the counterbalancing effect of the LiFePO4 batteries will help to keep the robot on the ground whilst the lifting arm does it thing.

I know it can self right with the 67:1 motor (first robot of Team Kaizen to be able to do so) but the wheels look... wrong now. I may, weight permitting, steal a set from The Honey Badger and see how well they go.

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[Ocracoke]

The internals are now reorganised, power lights added to both the drive and weapon circuits and rear panel added. The side panels are fabricated but need a bit more fettling before they'll go on. I think the front and top panels will be clear polycarbonate now rather than the grey PVC I am currently using - I've managed to salvage some from a house move I've assisted with recently.

I also added a set of forks to the front of Shu! to help counterbalance the weight and they do appear to have a effect. The robot can now throw 600g over itself without too much fuss. I tried a overweight stand-in of a robot as well (probably nearing 2kg) and Shu! overbalanced again so I think the arm being shorter and a little fatter would probably be of use here.

[Deathly Hallows]

How much run time are you getting from those batteries? Are you still using two 1500mAh? - I have a feeling I may have underestimated the battery in EK'W. I have only planned a single 1300mAh battery! But thought I should comfortably get 10 minutes run time. I posted my info on 4th December if I made an error (would not be surprised)please let me know -

"Checked my peak load calculations too. The drive motor stall is 4.9A and weapon only 2.19A surprisingly, so 12A total. Peak load is then low and easily managed by even a small 700 mAh rated just 20C, but I want more run time and a cushion.
With the available mass I can fit a bigger battery. The Zippy Compact units have a low mass and a 1300mAh 3S should give me 11 minutes at full power, so in the real world much more and many battles. It's a bit of a squeeze to fit the battery, perhaps I will need to angle it to allow access to the leads. I don't think I will really know best way to squeeze it in until the bots assembled."

[Ocracoke]

Yeah, I am still using the 2x 3S 1.5ah 9.9v LiFe batteries. The 12v drive motors in Shu! are probably undersized for the Beetleweight class as the stall amperage is 1.2A, so 2.4A for the pair of them. The 12v weapon motor as currently fitted has a 5A stall.

With your figures, though I claim to be no expert here, should be fine if you bear in mind a standard round is 3 minutes. However, whilst there is more to break in a separate circuit system that Shu! uses and uses more weight, the advantage is that if either circuit is broken, the other one will still work and less strain on the batteries as a whole. Single battery setups save weight but it is more of a drain on the battery that is there.

I am sure there is some mathematical calculation to work out the minimum run time with everything running all the time but really, the best way I found is to simply try it. For example, The Honey Badger's 2x 6.6v 2.1ah 30/40c LiFe batteries will last two 3 minute rounds in the Featherweight category before they need charging and that is with it running around everywhere.

[Ocracoke]

Finally found a bit of time to focus on getting the armour on Shu!. A session with the Dremel and the side panels are cut and fitted. It still needs front panels but I've got the PVC for that so will look to add them during the week. I also decided on fitting a clear top rather than the PVC top but the only plastic I have is scrap Arcylic from a old computer case so... yeah... might bring along the PVC top to Bristol as well :P

Sorted out the wheel hubs as well as the American 4-40 screws arrived. I had to ditch the bigger wheels as they had a curve in them which made drilling straight (without a pillar drill) impossible. The hubs aren't quite on square but they'll do for now and can be addressed nearer the event. I think the smaller wheels look fairly comical now but my wife, who's going to be operating Shu! at the event, says they are about the right size.

Also found time to rewire the speed controller so at least it goes back and forwards on the controller correctly.

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Weight wise, we are at 1067 grams, so I've no concerns about weight any more, therefore the things to do are:

• Make the removable link hole+cover
• Make the removable links
• Properly wire in the power LEDs
• Fit the front armour
• Paint it

[Ocracoke]

Did a bit of a wiring job on Shu! today and now the removable links and LED power lights are now done. The top lid needs a little bit of modification to add the gaps for them but they are as good done now. I also fitted the front armour and added something to protect the front top edges.

This, in effect, means Shu! is now ready for the UWE Beetle Brawl! There are some rough edges I want to sort out, possibly replace the wooden dowls for PVC rods and, of course, paint the robot but in effect, the robot is now ready to rock and roll.

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[Ocracoke]

So since the last post, I've replaced the wooden dowls with PVC rods, making this the first robot I've ever made not to feature wood in its final build. I've also added a couple of supporting rods to hold the batteries in position in the body and to reinforce the shell as a whole. Weights in at 1.3kg now.

Once painted, that is effectively it for the build and then the UWE brawl and then hopefully Burgess Hill if there is a BW event running there.

[Ocracoke]

The top and front panels are now painted along with a locking pin added for the arm. The lifting arm motor has been changed from a 67:1 motor to a 131:1 motor, which should mean a bit more oomph behind the lift. All it has to do now is not break during the UWE brawl... :P

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Not sure, after painting it, it looks like a Shubunkin (https://en.wikipedia.org/wiki/Shubunkin)... but you'll know which robot you are looking at

[Albear]

looking good! Love the theme! You should put google eyes on the side lol

[Ocracoke]

hahahah, I have a swathe of googly eyes from The Honey Badger of different sizes. I'll be sure to fit some on.

The Sabretooth controller has developed a odd twitch in that when you turn the transmitter on, one of the drive motors twitches momentarily and then works normally. Rather than risk it through tech check at the brawl, I am going to replace the controller with different controller + mixer and see how it works afterwards. If I can get the Sabretooth working properly again, I'll recycle it into my antweight.

[Ocracoke]

Well, here we are folks. If you count the build as starting from the 1st of November (which was when the original prototype was binned), it has been 72 days and with the panels now painted up and little details sorted, Shu! 1.0 is finished.

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The issue with the speed controller rumbles on but I can confirm it is not the speed controller. The new speed controllers and mixer arrived this morning and I wired them in this evening but the problem persisted, so this is more likely an issue with the motor itself or the wiring thereto. A bit more disassembly required but with a bit of luck, it shouldn't be an issue at UWE.

[Ocracoke]

OK, I am dim, it was the auto calibrate setting causing the twitch. Turned it off and now seems to be behaving normally apart from all the controls being backwards!