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I wondered if someone could point me in the right direction to a site that sells the pulleys and belts people are using that fit on the brushless motors n stuff. The end goal is a beetle egg beater. I have main shaft n bearings etc sorted just need pulleys and a belt. Specifically that will fit most of the small in runners on hobbyking.
I use Beltingonline.com for pretty much all things transmission. For beetle scale weapons I'd suggest 6 or 9mm wide HTD3 timing belts/pulleys. You can get them to machine the bore, fit setscrews or keyways as needed (at additional cost).
Beaters are nice, I kinda wish I didn't sell mine. +1 for belting online
It was maybe a good idea to sell it as it's got a massive, Flatulence-sized weak spot, which I have taken advantage of on numerous occasions now :P
https://www.youtube.com/watch?v=Ikt03sRxOCc
That's fantastic thankyou! Which servo do you use in flatulence? Would it be possible to see a picture of the insides?
Hi Dave, the servo was the biggest one that was available on GiantCod/GiantShark at the time I bought it (~2011). I think it only cost me £15 and was rated at 20kg/cm. GS is no longer in business but there will be other servos out there of equivalent size and power, no doubt somewhere on HobbyKing.
I've got a couple of pictures of the insides of Flatulence but I'm just about to head out so will post them once I'm back. If you're planning on being at the November Iron Games final I'll have it there too so you'll be welcome to have a nosey in about it.
Ok cool no worries :)
This is probably the simplest picture of the insides, taken a few years ago. The massive servo sits on its long end, with the horn connected directly to one of the lifting arms. I then bolted a piece of HDPE to the opposite side of the servo (effectively its bottom) with an M6 bolt protruding and I use this as a pivot point for the other lifting arm support.
http://i31.photobucket.com/albums/c3...m/DSCN6327.jpg
As I said, the servo is rated at 20kg/cm, so over the full length of the arm, it's not actually got a huge amount of power on the end of the flipper but it's enough to tip other robots over if the angles are right.
The drive motors here were some of the MFA 15:1 motors, but I found them to be quite slow and underpowered so I changed to the 1000rpm motors that everyone uses and it was a big improvement. The battery in the picture is an old nicad pack from a drill, but I've since changed that to a lipo.
This is a more up-to-date picture of the insides, although still with the old motors:
http://i31.photobucket.com/albums/c3...ps36d6a14e.jpg
The lipo is mounted underneath the radio receiver, just held down with a polycarb clamp. The bit right at the front is the BEC, as the ones on the drive ESCs weren't powerful enough. Incidentally the drive ESC are Botbitz 10A ones and they're located in the back corners, along with the wiring loom.
God that's brilliant!!!
Here's something that you might be interested in if you're considering a lifter http://www.hobbyking.co.uk/hobbyking...arehouse_.html
It's rated for the same as Flatulence's servo (20kg) and is relatively cheap, It's actually the servo i'll be using for my champs entry this year. For the price it seems rude not to give it a try.
I have the aluminium version on my Truggy and though slower as advertized it is a good servo. I don't know how well the plastic housing will stand up to that torque though.
God that's awesome can you run it straight from the receiver?
You probably could but your BEC might struggle to run your drive and that, you can get a separate BEC or just run it straight from a 2s Lipo like i am, neither will be that expensive.
I can recommend this monster: http://www.hobbyking.com/hobbyking/s...arehouse_.html
These are what power the pay-to-drive Kinematic Events lifters/flippers. Cheap and seemingly solid. You will need a separate BEC capable of 5a or more to power it or others.
I was looking at one of those but it seemed a bit slow, I've driven your pay to drive robots a fair bit and the flippers are actually rather quick, i believe you used springs to help them along though? which is something i can't really do in my design.
I did, but those were for self-righting aid. The flipper didn't really change speed with the springs (maybe fractionally). The servos were at essentially 1:1 to the flipper, so on the ~80deg range that's barely 0.3s from end to end. Still fairly snappy.
Also the springs were actually very simple in the end. A pair of torsion springs from small pound-shop plastic grips, in-line with the flipper pivot. They just float there. This can work for 4-bars and rear-hinged designs too - a terrible picture.
Yep. The one in Flatulence is running straight from the receiver, although the receiver is powered by the separate BEC that I mentioned. And as Sam said, you could also run it directly off the battery if you're using a 2-cell lipo or battery of similar voltage.Quote:
Originally Posted by daveimi
Oh cool ok . giving the receiver its own power seems like the easiest way to power the beefy servo.
A small thread high jacking here sorry.
Looking at pulleys for both ants and beetles is technobots and beltingonline the way to go or do people here lathe their own and sell to other roboteers? Or is that just too much hassle and expensive anyway?