Post battle analysis and repair

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All team death robots are now fully working again

That didn't take long! Glad to know PdR is up and running. I don't think I got chance to go all out with my driving this time around due to the miscellaneous issues it had last Dojo

[team death]

Sorry I couldn't get Piece de resistance working well on the day Adam and I noted

in your expression that you weren't happy driving an under par robot but the good

news it's fixed and better than before.

This gives me lots of time to tweak all the bots and work on the Mean Machine-

Note to self-Take along the welder to events in case of breakages

[team death]

The trouble with piece de resistance was...it just couldn't lift and although I tried various attempts to

rectify this including springs and shortening the lifting arm it was still disappointing.

So with my Corona virus free time and less distractions I have re -worked it once again.

Originally the motor was part of a bath mate lifter to help lift folk out of the bath and so

it should be capable of lifting 100kg so why cant it lift a featherweight robot?-here's why-

I removed the heavy duty reducing gear thinking it was overkill for what I needed and also

it was not easy to fit into my design but with more time on my hands it's now in the bot.

The arrow shows the original position of the lifting arm.....so the new position makes the

lifter very strong but not the quickest.

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[McMullet]

Nice! I'd always thought the "spatula" lacked the oomph it needed, this should work very well!

[Maxamuslead]

what ratio you think it using now ? i know lifters like bagherst used a 775 on 64:1 ratio (16:1 gearbox then a finel 4 to one)

[team death]

I can only guesstimate the ratio mark, I believe the motor splines might be 8 onto a inner gear of

70 and the outer gear is more of a 5 to 1 ratio so I don't know if you times those two numbers to

get the total ratio but if so.......70 divided by 8 = 8.75 x 5=43.75 to 1 .

The motor is much larger than you get in a linear actuator so I assume it's more powerful but I'm

not sure about that either.

[Ocracoke]

Yeah, you multiply the ratios of each stage to get the final output. The motor being larger doesn't always mean it is more powerful though again, you counter that with a higher gear ratio overall. What is the motor driving this?

[team death]

There are no specs on the motor lucy but it's almost identical to one in this link at a startlingly high

price!-It states it can lift 125 kg, I guess in the same set up as mine so I'm hopeful it will be strong

and I might get chance to try it tomorrow and take some pics.

I have tested the speed to full arc which is roughly half a revolution of the spindle at the arm end and

it takes 5 to 6 seconds so hopefully it could self right before been counted out .

This speed fits with that 44 to 1 ratio because I wouldn't think the motor would turn more than 4 or 500 rpm.

I'm pretty sure it's a 24 volt motor but I'm only running it at 16 volt at the moment.

https://mobilityhoistsandparts.co.uk...motor-complete

[Ocracoke]

Get it up to 24v (well, 22.2v nominal on 6S LiPo) and then see how it does then before changing the gearbox any further. Might just be that because it is under-powered that is the problem here.

[team death]

Thank's Lucy -When Adam and I first built this robot-It was called No Imagination then and it

had a split voltage system 16 for the drive and 24 for the lifter but the voltage seemed to seep

and gave 24 volts all round and I could not fathom the fault so I dropped it all to 16 but I

understand what you are saying and may go for 24 volt again which would truly make it

scary.

[Ocracoke]

I know the feeling. I had Azriel on 5S LiFe last year (16.5v nominal) which worked nicely but was underpowered in some regards. Now it is on 6S LiFe, it is much more powerful but I will need to set upper limits on the controller to make it controllable on the drive again.

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Thank's Lucy -When Adam and I first built this robot-It was called No Imagination

That had a rather tedious trip on the train with the large chunk of HDPE for it all, i'm glad its all gone to good use though.

[team death]

So it Work's-YaY Piece de resistance now has the power and that's just at 16 volts.

I had a look at the Transformer control box today that I got with the bath lift job lot and yes it is 24 volts.

My drive motors however are 14 volts so it could risk burnouts if I went for 24 volt through the entire

system but it would be as easy as swapping a battery and LED.

Here's some pics of piece de resistance lifting one of my other bots-Project Fear, there was just snag-

if I didn't foot the rear end of Piece de resistance it would up end PDR at the rear so I think it needs

a slight tweak at the pivot point or maybe some lightweight outriggers at the front.

I made a cowl out of fibreglass to cover the gears and it looks pretty neat.

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Front skis now fitted and it now lifts without up ending

[team death]

Another event- Robodojo in July and the inevitable repairs and analysis of what went wrong!.
July 12 event was the first after the Corona virus complications and Ian botwright has done well
and has a professional system in place for social distancing and virus hygiene.

For a sportman event I thought the reduced group of competitors were very tough cookies.

The arena has been slightly modified so you can't just be pushed off the sides and the slightly
anoying raised area is back in play but does not effect high ground clearance robots like mine.

My first fight- Piece de resistance v Bob 3 was an even match but I lost due to driver error.
fight 2anger UXB V mattock v iron clad 3 I managed to win with slightly smokey motor which
I thought might survive the next battle after half an hour cool time but it died half way through.
Even Piece de resistance managed to beat Mattock in the next round so I was pleased at this stage.

There were some very close judges decisions with Danger UXB so I was happy with it's performance
but then it met Hells Angel which I think was a battle royale and was a very close contest but the axe
on Hells angel managed to damage my fan on my ESC though it still worked.
Piece de resistance suffered a broken lifter after the weld came off and the motor/wheel came loose
from thee exhaust clamps I use and manged to twist the wires until they broke.
UXB went in for another fight which I thought I won but the ESC went crazy at the end and UXB
went slightly mad-big Thank's to Shane for grabbing a dangerously out of control machine.

A few wins over all but too many losses then I got chance to use my substitute Driller Queen which
Ian and Keith quite liked and Ian stated it had potential-though it lost due to the wheel unscrewing
itself.
Analysis :After all that work to make Piece de resistance lifter strong enough, it was slow in action
so I might return it to previous but run the whole system on 24 volts as suggested by Lucy to see
if that works.
List of Damage
Burnt out motor
broken ESC fan (hopefully its not whole esc)
wires pulled out of drive motor.
DSCN0364.jpgRSCN0370.jpgRSCN0371.JPG

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broken ESC fan (hopefully its not whole esc)

I have tested the Cytron ESCs without fans as I was curious if they really need the big and easy to break in our type of hobby fans, and the heatsink warms up, but it doesn't overheat excessively even with both fans disabled. I think the fans are a 'just in case' situation. I tested it whilst ramming a bot repeatedly into a solid unmoveable object so the motors would be drawing as much as they could, and it all was fine. If you can't fix it (although I suspect but cannot confirm right now, that they're just mini computer fans they've used, see: https://www.ebay.co.uk/sch/i.html?_f...r+fan&_sacat=0 for replacements of them)
I think you should be fine on just 1 of 2 fans if needs be though, at least in my experience, unfortunately silicon lottery means mileage may vary.

Glad to see you did well, although I guess that means I will miss you on the 26th, as I'll be at that sportsman event with my own FW for the first time.