http://www.wa4dsy.net/robot/drillmaster/index.html
TAKE THE CHUCK OFF FIRST!...So much easier.... and use the 5mm screw locking method not the O ring.
Printable View
http://www.wa4dsy.net/robot/drillmaster/index.html
TAKE THE CHUCK OFF FIRST!...So much easier.... and use the 5mm screw locking method not the O ring.
AAAAARGH! Thanks for the link, it's been very helpful thus far, but for some reason one of the drills decided to stick and managed to grind down the end of the grub screw completely :S The rest went fine... Any ideas for how I could salvage the gearbox or should I just buy another drill? I'm a bit sad that I've not managed to save it :'( :lol:
If you've got a drill bit that's up to it then drill out the head and then you'll be able to take the chuck off (I say 'up to it' as the screw is often very hard steel!) - once you're there you may be able to cut a new slot in the screw remains and attempt to remove it again.
Frustratingly it won't work because my drill bits are probably too soft.
I was considering either sawing into it to remove the head or just chucking the gearbox all together and then hope someone had a spare one! that or just buy another :( Bit late for my warrranty... :lol:
If its just one the grub screw can you not just use the other holes to lock the gearbox down?
WHY DID I SAY GRUB SCREW :'( The grub screws are fine, I meant the left handed screw that the shafts connected too. Oh bejeesus I am so sorry and I've only just realised.
:oops: :oops:
Ahhhhh I see, that makes more sense.
Those screws were quite tough to get out when I last did it if I remember right. After smashing the head a few times I just put as much force as I could on to the head of a screw and tried turning it, once you get the slightest bit of movement it comes off dead easy. Can probably do that more easily if you can get the drill in a vice or something similar.
This thing has literally no 'port' for the driver at all now. (what's the actual name for the head of a screw?) So that aint happening I'm afraid :( I have no more ideas. Really considering just buying another one.
Buy another complete drill or borrow a decent twist drill and remove/drill off the screw head.... DO NOT try cutting the chuck off.
Right, well I've now got all the money I need for this robot and then some, so I need to work out what I need to purchase since the whole graupner setup went to bust so I can put in orders.
I have four 18v drills which need to be powered by 18v batteries, but I can't find any at the moment nimh wise.
I've bought a dx5e controller which came with an ar600 reciever. I need an led + resister, power switch and wiring.
I'm going to sell my 8 125mm wheels as I don't feel that I am capable of placing nuts in them properly, and buy some 100mm blue wheels.
But I don't understand speed controllers, I mean I know how they work, I just don't understand what the max ampage etc. is talking about. Is that the maximum drain from the motor on the battery? Or is that the maximum ampage it'll let the motor drain?
Does anyone have a table on 18v drill motors, torque, drain etc?
I'm going to use a steel baseplate, and as an experiment use tufnol instead of hdpe since my grandfather can source it quite cheap, I think it's worth a try.
Urgh, it's all so confusing. There is so much to learn. :lol:
Thanks for all your help thus far guys :)
http://cgi.ebay.co.uk/9-6V-3700mAh-NiMH ... 33572d80baQuote:
I have four 18v drills which need to be powered by 18v batteries, but I can't find any at the moment nimh wise.
Two packs of these connected in series will give you 19.2V and a decent running time.
Technobots for the LED. They do 12V and 24V ones that contain internal resistors, so you can just connect it directly to your battery supply. If using the packs above at 19.2V, get a 24V LED. They also do a selection of sizes of silicone wire that you pay for by the metre. Relatively cheap too.Quote:
I need an led + resister, power switch and wiring.
For a power switch, just use a pair of Deans connectors and a small loop of wire. GiantCod has 10 pairs for £4, which is good value:
http://www.giantcod.co.uk/deans-style-u ... 03931.html
Without delving too much into physics, the equation for Power is Voltage x Current (P=IV). When you apply a voltage to a motor, the motor draws current (amps) from the source (aka a battery). This combination of volts and amps gives you power, which is visible to the eye in the form of the motor spinning. If you know the power rating of the motor, you can work out how much current it will draw when you apply a specific voltage to it. Rearranging P=IV to calculate current gives I=P/V.Quote:
But I don't understand speed controllers, I mean I know how they work, I just don't understand what the max ampage etc. is talking about. Is that the maximum drain from the motor on the battery? Or is that the maximum ampage it'll let the motor drain?
Taking a Bosch 35 motor as an example; the motor's maximum power output is 35W and you want to run it at 12V. The current (I) is power divided by voltage;
So 35/12 = 2.91
This means your motor will be drawing 2.91A when running at 12V.
However, this is only when the motor is at its most efficient, i.e. it is spinning at a constant speed without any load being exerted on it. If you attach a wheel to the spinning output shaft and then create resistance by, say, pressing the wheel against a surface, you are applying a greater load to the motor, and it has to draw more current in order to maintain the power output. So when your motors are in your robot, they will draw more current when you try to push another robot than they will if you are driving along unimpeded in a straight line. Your motors will also draw more current when accelerating from a standstill and when changing direction rapidly.
Often during these instances, the current draw can spike up quite high for short periods of time. A figure of 4x the normal current draw is a good estimate of what the motors can be drawing. So if your drill motor draws 10A under normal conditions, then it could be seeing as much as 40A when rapidly changing the motor from forwards to reverse.
So when it comes to choosing a speed controller, you need to pick one that will be able to handle the amount of current being drawn from the battery by your motors. I like to use 10A as a standard current draw for drill motors (although this varies between each motor and could either be more or less), so you want a speed controller than can take at least 10A continuous, with the ability to handle higher currents for short (1-2secs) periods of time.
It's best to over-spec the speed controller slightly so that it's not performing right on its limits all the time. With the 10A example, I would use a controller with a 15A continuous current handling capability. Most speed controllers can cope with the larger bursts of current for a limited time but if you pull the high (stall) currents through your controller for long periods, that tends to be when the magic smoke comes out.
http://architeuthis-dux.org/torquecalc.asp
One of the Banebots or Haborfreight setups should match your drills ...The amps pull may surprise you.
Ummm ...NOQuote:
Taking a Bosch 35 motor as an example; the motor's maximum power output is 35W and you want to run it at 12V. The current (I) is power divided by voltage;
So 35/12 = 2.91
This means your motor will be drawing 2.91A when running at 12V.
Nominal voltage 12 V
Nominal power 35 W
Nominal current 9 A
Maximum current 24 A
The 35 watts is nominal ( the power it can produce all day long without over heating ) and the efficiency at 35 watts OUTPUT is probably going to be around 30% ..meaning that your 2.91 amps is 30% of the actual amps consumed to give 35 watts OUTPUT ..you actually INPUT is 9 amps....with 6 amps being wasted as heat.
PEAK Watts is around 45 @ 12v.
http://www.boschmotorsandcontrols.co.uk ... /index.htm
http://www.boschmotorsandcontrols.co.uk ... nlinie.htm
Oh well, explains why I had so many resits at uni :lol:
Haha, thanks guys, I'll have a look on the weekend when I have time and hopefully buy a couple.
Wait, I can't actually work out the amps from my 18v motors because I don't have the watts? And with one speed controller controlling two motors on each side I'm looking at 300 quids worth of speed controller if I'm using the bosch sample, that can't be right? Or am I being thick and two motors doesn't effect current draw? Urgh, I hate not being able to learn this stuff at school.
Unfortunately doing the watts/volt = amps calculation doesn't give you a clear figure, beacuse no motor is perfect. Then there are different levels of draw for stall and nominal etc... And then over volting will increase the power of your motor and then your head explodes from it all!
I'm only just get my head round this now..
In short, if you can find a spec sheet for your motors (Google the product code) then that would give you the amperage's expected from your motor at stall, idle etc.....
Then put a fuse before your ESC rated at the maximum continuous current it can handle (or just below) so you don't destroy anything expensive.
And yes running 2 motors off your ESC connected in parallel will double the amp draw.
Just ordered a Sabertooth 25a dual, 6*8.4v batteries and a decent digital wall charger, should be decent for a 4*18v drill set up if my calculations were right
Does anyone have any 4*4 wiring diagrams? It would be extremely useful as I'm not sure which parts work best in series or parallel. Thanks!
Put your the motor's that are on the same side in parallel to give them full voltage.
Similar to the last diagram but without the servo and regulator shown here:
http://www.robotwars101.org/forum/vi...hp?f=10&t=1399
Looks good! Thanks.
I had my 6 8.4v batteries delivered. They all have Deans connections but I have a couple of problems with this, how do I go about connecting 3 in series for 25.2v and how do I then attach them to the other 3 to give 25.2v at 6600mAh?
The battery charger did not come with a deans converter either so that's going to cost me and extra fiver buying one. It looks like at this rate I won't have it ready for Worthing.
disconnect the wires, put a positive on one of the deans prong, then the negative to the next positive of a battery and so on till you have one negative left and put it on the other deans prong.
(sorry if it sounds confusing :lol: )
Hmmm, I can vaguely understand what you're describing, thanks Matt. :)
My Robochallenge wheels haven't arrived yet (even though they were meant to arrive on wednesday?) This is the second time products have been delivered late by them, has anyone else had this problem? Due to this I can't weigh out the internals properly as I don't have the wheels, would someone mind weighing out a pair of their 100mm blue wheels for me so that I have an idea of how much weight I have left for structure? Thanks!
It's pretty standard because Grant and James have other large projects on. I believe they are working on a big one for the gadget show atm.
Fair enough, I'm in pretty urgent need is the trouble as I'm building this week up at my grand fathers, I'll probably just make some cardboard mock ups to deal with it, I just need the weight of the things so I know what weight I have left!
Sorry for the double post but I can't find the LED+Resistor combos mentioned earlier in this thread, would anybody have some links to them?
199 gram for a blue 100mm with nut
per wheel :rofl:
Haha! Thanks a very much! :D Very helpful. Onwards with the building. I'm taking photos as I go so I'll have a build diary when I get back.
LED's:
http://www.technobotsonline.com/?subcat ... cts.search
Aaaah, I forgot about the technobots site, thanks!
The sabertooth 2*25 is confusing me, how exactly do I connect it to the reciever? Do I need to buy plugs seperately or do I configure it in a different way? The instructions on it are rather sparse.
you need to buy plugs seperatly.
look at the robot market place sabertooth 2x25 to look on how to set it up
Had a look and found a lead on technobots that looks suitable, ordered it too! Thanks.
Having trouble with weight, I have 7kg worth left for Chassis, and 100 cm by 300 cm area to fill. How do I go about solving this issue? All materials seem to dense, and I have no idea how to drop the weight of the internals considering they're already as low as they can be.
alot of foam :D
Sorry, I made that sound like I needed the volume filling, what I mean is, I have 7kg left and I have 100 by 300cm of armour that needs fitting and I don't know what would be viable materials at that weight, nor how I could reduce the current weight or size. I'm really at a stand still!
Edit: Solved the issue, I realised that I could reduce the weight, I'm ruddy tired and not thinking straight, sorry about that.
Are Trollied, Wasted, or Hammered available as Robot names, I haven't heard of them before but I thought I'd just check?
3m * 1m of armour? you could cover a heavyweight with that much :crazy:
Going by your dimensions and design on page 5 you should only need about 4000 sq cm of armour max not 30000
You're currently looking at 2-3 mm of hdpe or 1-2 mm of polycarbonate/cfrp/gfrp and probably nearer the lower end of those ranges so not the best armour.
I didn't notice either that I'd calculated 30000 cm sq :lol: (so tired)
After my new designs (Page 5 is quite outdated) I have 3800 cm sq to cover with armour, and according to http://www.jindalstainless.com/toolkit/ ... lator.html 15mm HDPE at high end HDPE standard at directplastics - 96 g/cm^3 (checked the density on their data sheets) equates to 5.5kg rounded? One of us has done wrong calculation, and chances are it's me.
Correct mass, missing a decimal point in the density though (0.96g/cm^3)
It's time to go to bed when you start designing robots with materials 6 times more dense than the sun as armour :uhoh: