elobire's build thread

[zoll]

Re: elobire's build thread

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

[elobire]

Re: elobire's build thread

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.

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.

[elobire]

Re: elobire's build thread

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.

[froggy]

Re: elobire's build thread

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

[elobire]

Re: elobire's build thread

just tested my reciever, its definatly broke. contacting giantcod to find out if they can send a replacement.

[team_orr]

Re: elobire's build thread

http://www.youtube.com/watch?v=mRdMt_xINvM

[elobire]

Re: elobire's build thread

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.

[zoll]

Re: elobire's build thread

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?

[elobire]

Re: elobire's build thread

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.

[elobire]

Re: elobire's build thread

just ran a quick test on the axe:
http://www.youtube.com/watch?v=Swl3dAEEnxw

[team_orr]

Re: elobire's build thread

looks really good so far , the frame looks a bit on the large side though

[RogueTwoRobots]

Re: elobire's build thread

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.

[elobire]

Re: elobire's build thread

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.

[RogueTwoRobots]

Re: elobire's build thread

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.

[elobire]

Re: elobire's build thread

Look forward to seeing the new video then with the lighter axe.
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.
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.