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Some problems with motor height!
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bytraper



Joined: 31 Oct 2005
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Some problems with motor height!

Anybody know of a motor that puts out similar torque/speed as the nichi ra motors but in a lower profile?

The current problem I have is the shell of the bot is 80mm in height and the motor height is about 80mm from top to bottom, and then i need to put a toothed sprocket on it which blows it way out... Need something about 60mm (can have a greater circumfrence) with similar specs? (motor has to be vertical not horizontal)

Any suggestions?

Post Sun Jan 27, 2008 10:49 am 
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Nick
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Glen and Angus had wide, flat fan motors that might be around 60mm high. They looked a bit like Short EV Warrior motors but I don't know what cars they came out of.
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Post Sun Jan 27, 2008 12:56 pm 
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Glen
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i have some of those insanely flat (30mm) ones from the older plan b but they are a bit fragile, and the ev style motors are probably a bit taller than 70 but are big on power.
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Post Sun Jan 27, 2008 12:59 pm 
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Nick
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The pancake fan motors are the flattest U can get, but down on power compared to the nichi ra motor. They are easy to find at PnP too.
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Post Sun Jan 27, 2008 1:34 pm 
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bytraper



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Thanks guys, there has to be another solution Smile I just cant find it lol!!

Post Sun Jan 27, 2008 1:39 pm 
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Nick
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What size is the weapon? You could do fine with the pancake motor if the weapon is not too heavy or the motor is geared down right. On the other hand, you might think about going to a brushless outrunner motor.
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Post Sun Jan 27, 2008 1:46 pm 
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bytraper



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Hey Nick!
Whats new with Jolt? that and rapture are the bots Im a little worried about going up against Smile

Weapon is a 5.4kg ring spinner... out of bisalloy
400mm x80mm x 6mm

The motor is right on the borderline as it is...

Its just going to be too big... I have the wheels at 90mm which is 5mm protrusion each side. but i dont want the gears poking out lol.

Cheers!

Post Sun Jan 27, 2008 3:32 pm 
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Rotwang
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http://www.jayair.com.au/SearchByProductType.aspx


Select electric motors and go from there.
Smile

These part numbers work at Bursons or Repco
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Post Sun Jan 27, 2008 3:50 pm 
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Valen
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5.4kg is probably too much for a pancake motor.
Plan-B used one, if you can find some old videos you can see its spinup time.
Although they love voltage, you can probably run a pancake at 48v without too much trouble. Perhaps add a fan.
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Post Sun Jan 27, 2008 3:53 pm 
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Nick
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I would need some more details to figure out the kinetic energy of the disk, but at 400mm and 5.4 kgs, the Nichi Ra motor is going to get really hot driving the disk - I definitely wouldn't use anything less powerful.

Jolt is waiting for a rebuild and will be back later in the year. I am almost finished with Scissorhands, which is basically Jolt flipped upside down. Between Scissorhands and Rapture, other bots are in for a hard time this year!
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Post Sun Jan 27, 2008 4:05 pm 
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Nick
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Hey Jake, what was the max voltage you ran them at without destroying the pancakes? I never finished my dual magnet version of the pancake motor, but its performance @ 12v was interesting and at +30V it would be excellent for low height bots - perhaps its time for some further testing...
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Post Sun Jan 27, 2008 4:09 pm 
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Valen
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i think we hit around 30 or so
i believe we were running 24v with a 7 or so v booster on it
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Post Sun Jan 27, 2008 5:58 pm 
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Nick
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I am definitely not an electrical engineer, but the trial motor I made with two magnet plates to increase the flux density gave the motor a much lower RPM and increased torque - I think that generally means more efficiency too. Upping the voltage would bring the motor back to a useful RPM at a really handy power output - gear it down a little and it might prove to be a winner for low hight bots. I also worked out a neat & compact way to mount a pulley on the end of the shaft; it places the pulley right down at the motor casing.

Taking that to the extreme, a pancake motor with suitably large brushes and NIB magnets would totally rock! The Thingap motors used the same technology in a small diameter, high RPM design to get 600W - a pancake version would give lower RPM at higher torque and be ideal for bots. Sigh, back to reality...
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Post Sun Jan 27, 2008 6:22 pm 
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bytraper



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Hmmm... modding a motor isnt out of the question... maybe modding a pancake motor could be viable...?

I can always get variable sized brushes from our own brand (spg) motors...

Nick how far away is Sissorhands?

Post Sun Jan 27, 2008 6:36 pm 
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Glen
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not to mention those pancake motors have a horrible tendancy to delaminate the armature if it hits the magnets. even with shaft support i think it would still flex the plate and wreck it.
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Post Sun Jan 27, 2008 7:26 pm 
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