Ould have thought that would be fine? That's sounds pretty sturdy!
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Ould have thought that would be fine? That's sounds pretty sturdy!
ill see how it goes. I'm leaning towards the flat wedge, is cheaper and i can put something into the wedge (steel bits) to stop things going straight over
Satanix is 5mm mild steel and that stands up to pretty much everything.
A lot of it is about how it's mounted though.
finally near-enough finished!
Just awaiting the botbitz 85A escs and a little bit of angle grinding on the wedge. Upgrades in future will include a further support under the wedge and real speed 900s. Will try and use the pistol grip TX system with the new ESCs as the electronizes would go full throttle on that system when the signal was lost.
The LED strips have turned out pretty good! Performed nicely at guildford other than small niggling issues which will get sorted. ESCheap 85a ESCs have now been fitted and are much better than the old electronizes.
Next set of improvements will be new side panels which will have a shoulder for the steel wedge and polycarb armour, a HDPE wedge at the back for when its flipped and possibly real speed 900s (although the replicas are more than adequate!). May also look into getting titanium axles.
Do the replicas run ok on 22v? Would they be ok running in 24v as a spinner motor?
yeah, had no issues. get a little warm but thats it. I'd say give it a go as they are only £12 delivered on ebay! only thing might be that they have less torque than the real ones so you may have to reflect this in the spinner drive ratio.
What gears did you use?
Modified 90t mod 1 spur and 12t pinion gears. All from technobots
Need a little advice if possible. I currently run a 2wd replica speed 900 wedge rambot, which is generally built from HDPE, but I'm flirting with the idea of resurrecting my 4wd four motor 22.2v rambot built entirely of 5mm steel. Not too sure whether to stick with HDPE speed 900 bot or go for a 4wd drill steel bot? Any guidance would be much appreciated!
Cheers
Dan
i used this website to calculate the weight of the the Armour for my 4wd that got 8mm steel round the sides but i had to use 3mm on the base and aluminium for the top plate to keep it in weight, and i just weighed the wheels motors etc and its about 12kg without the wepons
http://www.matweb.com/tools/weightcalculator.aspx
it was drill powered not speed 900
Size of wheels? 100mm?
120mm diameter with bicycle tread
I'd be amazed if normal drills would handle that. Ours destroy themselves with smaller wheels and lower voltage...
Very fast machine then.
Unless you got a strange set Speed 900 replica's. What size of axle did they have?
Sorry, my fault! The replica speed 900 bot runs 120mm wheels on a 12mm axle. The drill bot would use 75mm robo challenge wheels
I ment, what axle does the replica 900 have. There are 3 major types.
5mm, fast runners, ment for applications as battery-leafblowers and such.
6mm, speed 900 size.
6.35 - 1/4 Ment for car applications.
5mm output shaft. These are the replicas from ebay
Fast runners then. 12K rpm @12V
@22.2V those want to run 22.2K rpm. With a gearratio of 7.5-1 the theoretical topspeed should be 71km/h, given time.
Unfortunatly, it will be something about 35 km/u, and the motors will run half speed, drawing more amps. Don't close of the vent holes, and maybe adding a small fan to keep the air flowing trough the motors at all times.
These are the ones some others and I are using:
http://www.ebay.co.uk/itm/12-v-ELECTRIC ... 45f7de0c88
I'm just unsure which direction to take?!
That's yet another combination. The windings from a 900, and the axle of the fast-runner.
Oh well, that changes the entire calculation.
37 km/h tops. Perfectly useable. But I won't tape off the fan of the motor.
I think the trade off is going to be weaker motors for stronger armour, whereas at the moment it's strong and fast drive for slightly weaker armour
BonX uses 2 Speed 900 with 10-1 gearratio, Sidewinder speedo, and aboutish 24V in batteries.
Armor is 3.2mm Hardox all over, with internal bracing.
The four drill motors would be the gimson 18v versions, ran at 22.2v. From my guesstimates, the four drill motors would generally be slower but have much greater torque through their 36:1 gearbox, but again the replica speed 900s will have the opposite (faster drive, lower torque). Both systems would use two botbitz 85a controllers.
Had a new frame made up. 5mm thick sides and 3mm lids. all welded steel. 4wd drive with four 18v drill motors. ran at 22.2v through two botbitz 85a ESCs. Going to change the ratio in the gearboxes to 24:1 to get a little more speed. The wheel arches will glow red in the same way my old bot glowed green. Will probably end up selling the old HDPE speed 900 replica bot at some point.
Interesting, what weight is the bot currently?
12kg without lipo and electronics. Should easily be in weight
Should make for an interesting wire up! :?
Would be good if you met my cousin with Cicatrix, the machines are so similar it'd be good to see how they both got on against each other :)
That would be cool. If not, could just have a whiteboard battle.
The drive units have failed (totally!). I'm looking at the gimson GR2 units. Other than the expected work to make them fit, will they fit in the same space as an Argos unit with a robochallenge 75mm wheel? It's the length I'm concerned about as my bot is very compact (see the pic earlier in this post).
Cheers
Dan
yes their shorter
How have the drives failed? We have just bought a bunch of innards to make our drills 24:1...
Did the pins that hold the gears on the second stage (the 6:1 bit as against to the Gimson first stage which is 4:1) fall out/come loose?
If yes, that's a good thing (for me anyway, that's how all of our drills have failed to date), if you stripped the first stage of gears, that worries me, we just spent 65 quid on parts!
Yeah, the pins came loose. Put it all back together but didn't work, could hear it grinding when you turned the wheel. Did get a good amount of use out of them though. Will contact gimson robotics on Monday to get hold of all the parts I need.
Got a bit of an issue with the control as well but Mario helped me out with that. I think the thermal protection on the escs was kicking in as all the motors and ESCs were completely sealed. This then lead to the drive dying about 2 mins into the fight then being fine 5 mins later!
Ah, okay. We should be able to avoid that as we're also going to be running 18v motors, but at 5s. I don't see why they should fail, the setup will be running more or less within factory spec. It can only be better than our current setup where we blow something up in every fight!
And yes, I think the max rating for the tz85s is 24v so you're probably just nudging their limits after a few minutes of battle. I saw some of the footage and it certainly was running fast!
Also Ewan may be able to advise better, but if you intend to run 18v Gimsons on 6s then you're likely to run into this problem again. The pin setup is the same as that in the average drill, so the failures may well happen in the same way unless the load is dropped by upping motor v or lowering the battery v.
Keep us posted. :)
What wheel size are you using? 100mm wheels with 24:1 and 18 volts is really pushing every thing to its limits, should work, it's just for how long is the question. I'm doing every thing I can to keep every thing cool in my robot and I still don't think mines going to last very long.
If you can, buy some 24V fans from Technobots and fit one for each motor, the bigger the better. That might help them last longer. You could also bend some Heatsinks out of sheet copper and attached them to the motors with thermal paste.
We have a single 40mmx40mm fan on Binkys 160HV for the weapon. It has never got hot even in heavy testing! A bit of air circulation can do wonders :-)
I don't see how motors working at their designed voltage on 100mm wheels is pushing it, really... It's only like having 16:1 banebots gearboxes and smaller wheels, same end ratio I mean. Plus we have four, so the load is spread out. If you're referring to Robob, I believe he's using 75mm wheels.
Also the issue with Robob's setup isn't the motors overheating at all, which is our experience with overvolting 12v motors to 5s, it's the torque they produce as a result of overvolting that kills the gearboxes. I'd still be running 12v motors at 18.5 if there were suitable gearboxes that can take the stress. The motors do get warm, but nothing more than I'd expect, and the power you get out of them is awesome.
best give a bit of background!
im using 75mm wheels and the gearboxes are very old. the output shafts are the same ones ive been using in my drill powered bots since my first event at the O2 so they were due to fail at some point. I can imagine the overvolted motors and increased speed will have exacerbated the problem a bit! luckily the GR02s will fit in nicely so ive emailed Ewan to get hold of the necessary parts (i just need the housings really). All just in time for the championships!
Only issues ive got now is the suspected ESC thermal protection breakdowns which i think are solved by removing all the tape from the motors and unwrapping the ESCs from the foam that they were wrapped in and a strange problem with my DX6i which i think is due to the mixing. For example, when your go full forward and full left hoping to stop the left hand motors and let the right hand motors bring the bot around, the reverse happens and the right hand stops, left hand carries on and ends up going right?! As i say, i think its due to the mixing im using which is the built-in elevon/aileron mix with the following set-up in the youtube video below to get full throws: http://www.youtube.com/watch?v=6Ewa79_9Iq4 . Any help with that would be great!
You shouldn't really have any problems running 18V GR02's at 22.2V, it's only a 24% increase, though of course you should take care to ensure the motors are well ventilated and aren't allowed to stall (which usually only happens in combat robots if a wheel locks or gearbox fails).
One thing people often forget is that if you start with with a motor designed for a higher voltage then the current draw will be lower which will help reduce the amount of heat produced - for example running an 18V motor at 27V (1.5 x voltage) should be less prone to thermal failure than a 12V motor run at 18V.
Another thing to add is that I've not yet had any gear or pin failures reported for the GR02's (famous last words..). A large number of these types of failure with drills seem to be related to how well (or poorly) the output shaft of the gearbox is supported, so do make sure external bearing are used for overhanging loads.
Will send a reply in a few minutes Dan!