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guerd87
Joined: 08 May 2010
Posts: 11
Location: Pakenham, VIC
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quote:
Originally posted by shreddy:
hey! great to see someone else keen for an event! I also note your interest in fbspinners
last I checked dick smiths and supercheapauto were both selling 18v drills for $40, which was what I got mine for.
also on the batteries, if you manage to find an efficient weapon motor as mine then capacity for a spinner should not be an issue, I only draw 800mAH out of my 2300maH batts in a 3 minute match.
hope to see you round
Thats really good efficiency, thought it would be alot higher then that
The FBS's seem great, but I think im going to go with a nice simple design first off to get used to the whole thing. If i had access to a lathe then it could be different but I dont right at this time Looking to get one start of next year or even as soon as tax time if the misses allows ^_^
So Shreddy, youve got a bot ready to go in VIC, want to gather up a few people that you know and get down for a run? Even if no one is ready to run yet maybe we could meetup sometime and chat, youre not too far away from me.
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Wed May 12, 2010 11:03 pm |
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Fish_in_a_Barrel
Joined: 30 Sep 2006
Posts: 673
Location: Perth, Western Australia
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quote:
Originally posted by shreddy:
...last I checked dick smiths and supercheapauto were both selling 18v drills for $40, which was what I got mine for...
Which is why everyone is leaning away from them. Back when they were $15 each, they were cost efficient to buy because they are low quality motors. Also they were 12V motors so to get more power (bang for buck) they could be overvolted to 18 or 24V (which is what people were running their weapon motors at anyways).
Starting with a motor that is twice the cost (at least) for the same power starts to lose it's attractiveness. Overvolting would require higher voltages (24V or 30V) which increases the size of the battery. However voltages that high tend to really start to cause excessive arcing at the brushes of the motor, shortening life.
For the extra cash ($40 drill vs. ~$75 gearbox + motor + opposing bearing) you get a drive which is supported at both sides, a better quality gearbox, easier to mount as is is square and your choice of motor and gearbox ratio.
If you can buy drills at a decent price (I wouldn't pay more than $30 for them) then they would be great for your first build, but as Brett said, the days of $15 drills are well and truly gone.
If your lucky someone may have some lying around from the early days from when they started, and have since moved on to more expensive options that they may be willing to sell you. I personally have given some away? or at least replaced some poorly threaded wheels and left handed screws to newbies, because we like to see the sport grow.
Otherwise I would recommend investing in the better drives that would last. On that note, I haven't played with anything but drills so I can't speak for the quality of the other options. _________________ They say that he crossed the fine line, from insanity to genius.
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Thu May 13, 2010 3:16 pm |
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guerd87
Joined: 08 May 2010
Posts: 11
Location: Pakenham, VIC
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There 2 x drills on ebay that im watching that are no reserve finishing in 3 days, will see how they go, Current bids are very low
Had a look through my motors I have here and have 2 x 200w Scooter motors, 1 x 300w Scooter motor and my mate has 2 in his shed I can have. They are either 100 or 120w Scooter motors. Hes unsure exactly what wattage they are but they are both the same, which is good.
Because of the type of bot I plan to build first off being a wedge/pusher type, I think ill go for the Scooter motors. I can save a bit of weight by using LiPO's over NICD or NIMH etc so hopefully wont go over weight. Ill benefit more from more speed and more power with this type of bot
Ive seen some scooter motors that have built in reduction units on them, But these ones dont. I will need to get some pulleys and use a toothed belt. Ive done some drawings of an adjustable motor mount with belt tensioner that I can cut out of HDPE on my CNC router. Should be able to fit different sized pulleys to fine tune the speed. My router will only handle HDPE, timber, Lexan etc, no alloy
Does anyone have any good starting pulley sizes I should be looking at first off with a 100w motor? I was thinking of just running the standard Scooter reduction, prob using a bit smaller wheel though will give a bit more torque.
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Thu May 13, 2010 5:01 pm |
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