My bad guys. Been getting mixed up with a FW thread on the antweight forum where someone was talking about running their machine on 12V/18V :crazy:
So yeah, 24V relays will match with that motor
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My bad guys. Been getting mixed up with a FW thread on the antweight forum where someone was talking about running their machine on 12V/18V :crazy:
So yeah, 24V relays will match with that motor
no problem, i think il wait untill what i ordered has arrived (transmitter, sprocket) before buying everything else.
Hiya
I happen to have a ready made relay motor control box I used for my linear actuator on Cabrakan, and that was running 36v, but since I have no use for it you can have the whole thing for £10, probably won't cover the cost of the relays but this saves you a bit of time and effort doing it yourself
PM me if you're interested
cant seem to find anywhere that sells the scooter motor i want in the UK, does anyone know anywhere i can find one?
also would i be able to use a belt, as i already have a motor that has a belt sprocket, or would i be able to swap it to a chain sprocket?
-elobire
:rofl: :rofl:Quote:
Originally Posted by razerdave
Andy: Whats so funny ?
Is this the one that Geoff built at whitwick with the stuff people had lying around in their tool boxes? I really do like to see stuff get recycled over and over again.
Seriously though the relays are automotive relays (PCB type so they're smaller) and rated for 24V at 30A so should suit an axe motor just nicely.
You wouldn't buy the parts for a tenner so i'd go for it. Relays are from rapid and not much to replace if they fail.
http://www.rapidonline.com/Electronic-C ... ive+relays
Andy
Actually the one geoff put together from your relays got arced shut when it didn't failsafe, so I built a new one with the relays from Technobots. thats the one I sold.
Ouch, another one of those big smokey moments then. What is happening with Cabraken by the way, will we be seeing the new evolution soon?Quote:
Originally Posted by razerdave
Cabrakan 3 won't be seen until the later part of next year, its not going to be built in a hurry like the last one, and its going to have a REAL weapon on it.
the controll box came thismorning, tested it out and it seems to work perfectly. cant wait till i can finally get the weapon sorted, its taken me a year to get this far somehow.
I got mine from this ebay shop. I rang an ordered direct from him in the end, am sure I only paid £30 inc p&p in the end. Give the place a ring see what they can do for you
There's a 24V, 350W one on Technobots too, if that's the size and power you're looking for:
http://www.technobotsonline.com/motors/ ... otors.html
Seems to be a good range in that eBay shop too
thanks, i think il see what i can afford then decide what to buy.
does anyone know if i can change the sprocket on a scooter motor i already have but uses a belt sprocket. just looking on the ebay and i found some, but not sure if they fit?
http://stores.ebay.co.uk/Petrolscooter- ... 1140450014
sure u can change it, you have a welder if needs be
thanks, think il change it to save some money. im trying to make this build as low cost as possible.
would it be best to go for one with less or more teeth?
youll want to gear the motor down so the axes moves at a slower rate to motor youll need a smaller gear on motor and bigger on axe mech how big is up to you really
just got the basic design that i may be using modelled in blender:
http://i639.photobucket.com/albums/u...bire/robot.jpg
i also got the drive sprocket and the chain, just need to wait till friday so i have enough money to buy the driven sprocket.
also i may have broken my reciever, not sure yet may just be flat batteries.
Design looks cool but I dont think youve allowed room at the back for how big those motors are?
you mean the drill motors? im hoping to put them at the front, so i can have a narrow back and make it turn easier ( although i guess it will be hard to controll).Quote:
Originally Posted by zoll
im going to weigh all the stuff i got later, i have no idea how much weight i will have left for the body or the weapon.
Nah the scooter motor its quite tall, and if ur using sprockets it need to be inline with the gear on the axe, so you need to try and make some kinda protection for it as you have no soft return i.e your going be hitting yourself as hard as your hitting your target
thanks for the advice, il have a think about how to stop it smashing itself apart.Quote:
Originally Posted by zoll
done a inside view to show where i am putting everything. the boxes are batteries, couldnt be botered to add speed controllers and it doesnt need to be exact, and i may not even use this design.
http://i639.photobucket.com/albums/u...t-wiremesh.jpg
been trying out some new designs, i think i may go with this new one, depending if i will be able to built it.
on this one il have the wheels at the back, if their is enough room with the weapon motor their.
http://i639.photobucket.com/albums/u...botdesign2.jpg
Hey guys
I am the builder of Pure Evil now with jack orr
For the axe Mech. i used a scooter motor..with a ten tooth chain sprocket
and a 72 tooth chain sprocket on the axe shaft.
This gave a ration of approx 7:1 which worked great.
i also used a rubber roller which acted as a chain tensioner and a back recoil bar
look at his vid....but as he says the batt packs have seen much better days
Cheers froggy
just tested my reciever, its definatly broke. contacting giantcod to find out if they can send a replacement.
havnt updated the thread much in a while, even though most of it i have been asking questions.
so far all i need is the sprocket for the axe as well as a hammer, then im ready to build the robot. managed to break my scooter motor when welding the sprocket on, it doesnt seem to turn smoothly now, so i think il put it on the other motor and hope that doesnt break.
What you mean doesnt turn smoothly, sure you havent just welded it on wonky, or maybe batteries have discharged while you havent been using them?
i havnt tried it with the batteries yet, but when i spin the shaft with my hand it doesnt seems to move as smooth as it used to. the spocket is also wonky so im going to take it off whatever i do.
just ran a quick test on the axe:
http://www.youtube.com/watch?v=Swl3dAEEnxw
looks really good so far :proud: , the frame looks a bit on the large side though :?:
35 seconds of axe video, followed by two-and-a-half minutes of music and black screen? :P
Nice prototype. The axe head does look quite heavy but to get a bit more power out of it, remove the paint tin and let the axe swing through 180*, that will improve its performance.
Think of it as a segment of a spinning disc; the faster it spins, the more energy it will have. So the more travel your axe has, the more energy it can build up before impact.
the hammer i had on their was too heavy for me to use, so i replaced it with a small hatchet. it swings alot better now that its under half as heavy.
the paint tin was their because it couldnt lift the axe up.
also the frame was one i made just to test out the drive, i made it large because i didnt know how much room i needed for the axe.
going to start work on the frame this weekend, got a sheet of aluminium for the base just need to find some thinner stuff for the rest of it.
will post a video of the new axe tommorow.
Look forward to seeing the new video then with the lighter axe.
One thing to think about though, which may or may not be a problem; you said you needed the paint tin to support the axe because the motor couldn't lift it from all the way back?
That may pose a problem when it comes to self-righting. If the motor can't lift the axe when it's a heavy hammer, it's probably not going to be able to lift 13.6kg when you've been flipped and need to turn yourself back over.
What's your gearing ratio on the weapon? Were the batteries fully charged? And are you running the motor at the voltage it will be running when the robot is complete? It may be okay, because when self-righting, the arm will be acting as a lever turning the weight about the pivot point of the axe mechanism rather than lifting a weight at the far end of the lever when firing the axe as normal, but just something to check.
i dont know much about gear ratios, but i know that the driven sprocket has 68 teeth (il have to check) and the drive has 12 teeth.Quote:
Originally Posted by k_c_r
and i dont think the batteries where fully charged in the video, but they where not completely flat either. going to get new batteries as well, the ones i have are too heavy, i only bought them because i was low on money at the time.
That's a ratio of 5.6:1
Quite low I would have thought for an axe but it depends on what you've got to work with sprocket-wise I guess. Depending on sizes etc you could get quite a ratio increase by changing the 12 tooth sprocket to a 10 tooth (6.8:1) or 8 tooth (8.5:1) but that's just me thinking out loud really. If you're happy with how it performs though with the lighter head (by what you've said, the batteries seemed fine) then that's okay.
Don't worry too much about what I said regarding levers. Again that was me mainly thinking out loud; I'm not even sure if what I said was 100% right :crazy:
Quote:
Originally Posted by k_c_r
what you said helped me understand what im doing a bit more actually.
im quite happy how it performs at the moment, although the chain keeps coming off, but i think thats because my brother sprayed WD40 on the chain and sprocket, along with the chain being loose.
also im going to have to redesign my robot slightly and have the wheels on the outside. i think some of my designs where a bit hard to built anyway.
You definitely want to make sure the chain is properly tensioned - what sprang to mind when reading that was ORAC, which had either no tensioners at all or improperly tensioned chains, with the result that they both fell off against Killertron (and then a certain amount of fire ensued)
I think people have used skateboard wheels as tensioners before, or failing that just a small sprocket on a sprung arm would work.
got some images of the robot so far.
http://i639.photobucket.com/albums/u...e/PICT0037.jpg
http://i639.photobucket.com/albums/u...e/PICT0036.jpg
will post a video of the new axe when i upload it.
also their is a problem with the chain, for some reason the sprocket isnt straight, this is causing the chain to jam and be looser when the axe is back.
the chain has only came of once, but i think thats because its hitting the motor mount and knocking the chain off. the drive sprocket also came off so had to refix it.
also the motor doesnt seem to be able to lift enough to flip my robot if its flipped. so il eventually buy a new motor and axe (think the handles causing the problem). il also be able to get a motor with the sprocket on it, i think that may be causing a few problems.
just uploaded the video.
you can see how the chain has some problems, i think it may be caused by the axe handle which the sprocket is mounted to being thicker at one end than the other.
im considering changing the axe for a axe with just a spike at the end, anyone know if this would be better?
http://www.youtube.com/watch?v=rBIKSG9YY1M
EDIT:
was thinking of something like this for the axe:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... ink:top:en