Cicatrix Build Diary

[RogueTwoRobots]

A couple of CADs to show what the plans are:





It's quite a cool way of working. The idea of interchangeability (is that even a word?!) certainly isn't new but this is probably the first machine in a while to actively do it in the featherweight class. Thankfully the first phase didn't fail at the NEC (impressive, considering I built it ) so will be good to see how it performs with the different setups.

[Anttazz]

I really should have posted the CADs on here shouldn't I... ahh well, they're here now

Phase one was a success really, even if it looked like a failure the concept didn't fail, just my driving and inability to listen to simple instruction .

Speaking of that, where can I get more of those screws Jamie? They're really soft, burst the head on a few of them and one of them I snapped in half right across the thread. Hopefully with that new drill bit i'll take care of new ones a bit better though.

[RogueTwoRobots]

I got them from Technobots:

http://www.technobotsonline.com/csk-hea ... 32995.html

Pretty cheap, you can get almost 200 for £5. But they are quite soft and will dislike you if you try to attack them with anything other than a pozi-3 bit. I'm looking at getting the same size but with socket heads for the Drumroll II chassis rebuild and for continuing the work on Carcinus.

Found 100 on eBay for £9 so a bit more expensive but they're a higher grade so should be a bit tougher:

http://cgi.ebay.co.uk/M6-X-30-COUNTERSU ... 1047wt_905

[typhoon_driver]

i bought a bunch of hex headed countersunk screws for the comp to replace the philips headed ones. Far better and far more difficult to chew the head. Get em cheap off of ebay.

o and throw a hex key in a cordless drill and you can take them out in seconds

[Anttazz]

Haven't updated in a while but will try to keep it brief.

Cicatrix now has its XXL in and will be testing that over the next few days, thats probably as far as I will go with that before RL Edinburgh but hopefully it will add a lot in terms of controllability and reliability compared to the mix of Scorpion and Electronize ESC I had running at the UK Champs

Decided to create a Daiske II, which had it first test today, possibly will get that running for Edinburgh. Was only running it at 7v, but should be on around 3 times that at Edinburgh and probably on bigger wheels. Took a wee video of it earlier.

http://s1214.photobucket.com/albums/cc4 ... -17-29.mp4

Looking forward to Edinburgh anyway and will hopefully be running 2 machines that are both useful and don't go on fire regularly

[harry hills]

very nice

[Anttazz]

Would I kill that Scorpion XL if I ran those motors at 24v do you think?

[psycho_fling]

whats the rating on the xl i cant remember

i think you have to clip a small connection if you run over 16.8v btw

[RogueTwoRobots]

Crap, just remembered you asked me that on Facebook and I completely forgot to reply

I don't think you'd kill the Scorpion XL, mainly because the speedo has current limiting built in. With my XL in Drumroll II, whenever I slammed the stick full forwards, the wheels would spin almost to full speed but then cut out, which I believe was the current limiting kicking in temporarily; I'd have to either then bring the stick back a little or ramp the speed up gradually to get around the issue (never was much of an issue in battle though).

So if you were to run the golds on 24V and they ended up drawing too much current, the motors would (should!) just cut out to protect the speedo.

One thing to possibly watch out for though is that the Scorpion's max input voltage is 28V, but a fully-charged 24V battery pack will be nearer to the 30V mark, so that might cause an issue. A similar thing happened to Gary using the Sabretooth. He was running two 18V drill motors at 24V and let the magic smoke out of two units before reverting to Electronizes. The increased current draw from the motors as a result of overvolting, as well as the high voltage of a fully-charged 24V pack were most likely the reasons for the failures.

[Anttazz]

I believe it is 12.5A per channel and the XXL is double that.

Yeah you do, I had it clipped when it was in Cicatrix at 19.2v then reconnected it for that test.

Haha no worries Jamie, I could try that combo I have set up in the video with the batteries from Cicatrix then, fully charged they are around 22.5v, and if it runs ok on that then I could just use the same type of batteries in both robots, which would be great.