New year new paintjob :);
http://i685.photobucket.com/albums/v...ps6e4148af.jpg
http://i685.photobucket.com/albums/v...ps26495bed.jpg
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New year new paintjob :);
http://i685.photobucket.com/albums/v...ps6e4148af.jpg
http://i685.photobucket.com/albums/v...ps26495bed.jpg
Thats awesome!!!!
A serious contender this year
Don't suppose there's any chance its not as vicious as it looks?
Are you open to bribes and match fixing lol.
Lol :)
Btw, what LED is that on the back, looks very bright
3mm super bright from maplins with an inline resistor to step voltage down to 5V
I am guessing that is from 6S down to 5V? Much easier at lower voltages. Doing it a 50.4V is harder... I have had to get a 5W rated resistor on order.
720 only runs 5 cell
Wow, punchy for 5S :-) Then again it its using an inrunner not an outrunner. How much did the drum weigh in the end?
In runner vs out runner makes no real difference in power at any voltage range. Just different rpm/torque characteristics
What does the brushless typically pull nowdays, Dave? You were peaking over 300a when you first tested this, I think? That's ~6kw on 5s, which sorta blows my mind.
300A on spool up on that low a voltage is likely getting super low efficiency. I'd expect the actual output at that range to be something like 3.5kw at most and the rest being burnt off in heat. As its hitting 300A for such a short time there's no real heat build up in the motor.
Yeah I figured it might be pulling that but actually turning a small amount into kinetic energy. Even at 50% efficiency that's more than my cheapo motor is rated for at peak total pull - will be interesting to see how the Hobbyking-level motors (and speedos) run this year.
Wasn't long ago a single s900 made for a respectable weapon motor, so I'm not worried about grunt, just reliability. Think they've improved a lot in the past 18 months.
What grant said... Most of it gets turned into heat, but as I generally only spinup 0-100% once or twice in a fight you can't really tell... After a 3min fight the brushless was still not much more than room temperature which amazed me.
Just seen this; http://www.fightingrobots.co.uk/cont...rweight-awards
Best driver - thanks to those who voted!
Well… a lot of people are doing updates thick and fast to there build diarys and flapping that there not ready so i thought id post where im at;
Got bored so took it all apart, re greased the gearbox's- messed about with the brushless motor a bit, and loctited everything and put cable ties around connectors etc;
http://i685.photobucket.com/albums/v...ps6ff77403.jpg
have a few people comment on how small 720 is… this is how… the electronics are very compact in the back;http://i685.photobucket.com/albums/v...ps1bd9385d.jpg
http://i685.photobucket.com/albums/v...psb40c6e6c.jpg
I noticed the amount of axe's signed up… decided to make a HDPE lid to go on top of the titanium just incase;http://i685.photobucket.com/albums/v...psd42a9656.jpg
Liked how the pits operation got compared to F1 style this year… i cant change the wheels in 3 seconds, but ive got a decent amount of spares this year… no spare chassis, but i presume john lear will have enough to go around on the day lol…also got a spare tz85 on its way from Aus which Nick kindly said he'd bring for me;http://i685.photobucket.com/albums/v...ps5b1ae775.jpg
current weight with the stainless wedges and the hdpe lid added is 13.57kg… 30g's to stick some foam in the top over the lipo, then just need to stick it all in the car….don't know how I'm going to fit it all in before next wednesday but ill try my best :)
How come you have so many spare wedges? They look like the last part that would break...
If the pits have to be run like an F1 race, are we getting F1 grid girls too? :)
He can change sets to get the drum even closer to the ground and in case they get chewed up my another spinner. Even if its just the leading edge that gets bent then they are useless. And because he can :-P
Nah they all started of the same height- although the nylon ones I had fitted last year are worn down and now the drum only has 1mm of ground clearance... I got 2 sets of stainless ones that I'm keeping back to fight wedge bots with, no point blunting them off against robots that don't even have a wedges :)
Lol :)Quote:
Originally Posted by overkill
720 didn't have the best luck this year, only really lost fights due to it breaking down which sucked…
the motors kept blowing for a few reasons.. the main one being the weapon has now improved alot… which when i get a big impact puts alot more shock through the robot- causing the lipo mount to flex into the drive motors and knock them out of align… so the lipo box will be going from 2mm rubbish ali upto 5mm T6 for next year…the thunderpower pack also failed causing the low voltage cut out to kick in, meaning next year im going to upgrade to optipower… which also saves weight and space inside the robot.
A new set of drive gearbox's are already half machined- these are basically beefed up Banebots units with rear motor supports (probably not needed- but i want belts and braces for next year) and im going to improve the gears inside to stop the output shafts pulling out.
The titanium drum did the job nicely packing a bigger punch and only suffered minor scuffs… and i couldn't fault the customised motor i made.
Once those issues are sorted out its just down to driving next year hopefully.
couple of clips from when it was running;
https://www.youtube.com/watch?v=4GpNhTz5zVQ
https://www.youtube.com/watch?v=8pgIkLvY26Y
If anyone caught 720 V little hitter feel free to post the link here :)
I think ~2mm titanium would be better than 5mm aluminium for the battery divider but either way, I would still use those guide screws you had in both the top & bottom panels.
The guide screw was just an on the day fix… which proved the plate moving was the issue… i think i will go for 2mm ti next year, combined with a smaller optipower lipo and more padding it should all work out nicely… ill weld a tab going the length of the base plate, and one on the lid to prevent the plate flexing forward… ill also be upgrading the lid to 3mm ti for next year.
Also i came up with an idea that callum has put into process for me to help strengthen the motors up, as it became apparent that the g-forces in the robot could also bend the motor front plates, as their pretty damn weak… he's nocked up some motor enforcement plates for me, and made a few spare sets if anyone is interested in purchasing some to fit the banebot p60's…he'll be selling them for £30 per motor… that includes a custom motor front plate to fit the gearbox, the rear motor retainer and all bolts etc to fit. PM me or him if your interested in a set.
http://i685.photobucket.com/albums/v...psc087e412.jpg
http://i685.photobucket.com/albums/v...ps7bf1eff8.jpg
Those look the deal! Would probably have a good market in the US.
That's excellent work, is it a whole new backplate on the P60? this would be just as useful on smaller motors - I regularly have 540 motors bend or work loose.
Yeah it's a totally new back half if the gearbox... don't see why it wouldn't work on a 500 size, the rear support plate might be slightly over sized though...
Forgot to mention the holes are M4... Not the dodgy American imperial size the p60 comes with as stock.
First set provisionally sold :) looks like these could be popular.
What size motors have you got on your P60s Dave?
RS775 18v... if anyone knows of a uk stockist of these motors id be glad to know... i recently emailed banebots asking if there still trading with no reply...
I emailed them as well to see if they knew when their 125mm 3/4" hex wheels would be back in stock and haven't had a reply yet either. They were definitely still trading as of February when I ordered my stuff, and were pretty prompt at dispatching it too.
I'm planning on ordering some new 775s when I get paid mid-May. Will give you a shout beforehand if you want to tag any on the order to combine shipping/import costs.
They are totally hopeless at customer service; I have emailed them in the past and they have always been slow to reply or don't reply at all. I wouldn't read too much in to the slow reply.
Thing that worried me was Grant tried to make an order from them months before the champs and it still hasnt been processed... I might give them a try, If you do make an order jamie stick me down for;
8 off Wheels - http://banebots.com/pc/WHB-HS6-398/T80P-394BO-HS6
4 off motors - http://banebots.com/pc/MOTOR-BRUSH/M7-RS775-18
1 off hub - http://banebots.com/pc/WHB-HM-HS6-S4/T80H-SS42
6 off snap rings - http://banebots.com/pc/WHB-ACC/TA-R6
Let me know the total Jamie and ill send you the funds before you do the order :)
Attachment 4533
It does feel like that a lot of the time...
Let me know if you are doing an order too Jamie. I need some more motors and might even get another pair of gearbox's for this lifter I have planned. Seems we will only save on postage though as we will mainly be stung on import.
I know a german one. Cheap as hell and various flavours of 775 size motors.Quote:
Originally Posted by Mouldy
http://www.pollin.de/shop/p/OTk4OTg4...ommotoren.html
Is that direct from Banebots, can't see any 775 options on RMP except this at 14.4v
http://www.robotmarketplace.com/prod...MAGNUM775.html
i pressume this is the closest tim? http://www.pollin.de/shop/dt/Mzk0OTg...C785LP_ES.html
Banebots version;
http://banebots.com/pc/MOTOR-BRUSH/M7-RS775-18
they the same fitment, speed and power?
ehm, no. Pollin one has 10.5 krpm at 18v while Banebots has 19.5 krpm.
Although the motor is only rated at 14.4v max, i think the closest is http://www.pollin.de/shop/dt/MTc0OTg...C785LP_HS.html.
All the 18v rated motors at pollin have around 10 krpm at 18v.
Ah, you see, that's where the site is wrong! Look at the datasheet. This is why my machine couldn't drive properly, when using the now discontinued 885. Easy thing to miss, eh? The stats they show on their selling page are the stats for the motor at max efficiency, but you'll see in the datasheet they are actually 20k no load. The 785LG_EF is probably the closest to the RS775 18v, with 500w@max efficiency (18v), but the issue is it doesn't have tabs, just wires already installed that look a bit small.
Did your motors still work ok though? Or did you have to change them?Quote:
Originally Posted by Ellis
Had to run them at 40% rates to protect the speedos, meaning it was completely powerless. Eventually burnt out the two motors in the bot as well as the spare, at which point Mark from the Nippers did a magic trick and pulled out two same-size-but-completely-unrelated 30v motors, the spares for LH3. Used those at full rates for the rest of the event and Yeovil. Was still kinda powerless and after about 60 seconds it'd simply not turn, but it got there, just! Thanks again Mark!Quote:
Originally Posted by Max
on topic: I tried to buy from pollin.de last year and their customer service was just short of awful, but the 885s I got were the real deal, total powerhouses (to be geared for 30+mph and still be able to drive the bot at 40% rates with 2" tyres - pretty impressive). I'd expect any of the 700 series motors they sell to also be pretty good.
Did try giving Banebots a call in their working day - just went to voicemail