The wedge shaped indents probaly are the other side magnets .They are most likely conected in a magnetic circute to the front side magnet.
Fri Jan 14, 2005 12:28 pm
Nick Experienced Roboteer
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Not on my motors - the indents are just pressed into the case and there is nothing on the inside (no room either).
If the ring magnet has 8 poles, alternating N and S, then it should be possible to hack the back plate of a motor to make a new magnet front plate for a second motor. If you removed the brushes and cut out the axle to leave a central hole for the drive shaft, then the back plate would fit on the front of the motor. It would need to be rotated 45degrees so the poles lined up on both sides and there would have to be a spacer between the front and back covers to make up for the thickness of the extra ring magnet.
Does that sound at all possible? _________________ Australian 2015 Featherweight champion
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Fri Jan 14, 2005 12:44 pm
Valen Experienced Roboteer
Joined: 07 Jul 2004
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Location: Sydney
mmmm
possible bad news
doing more looking into things
back EMF increases with magentic feild strength.
IE, Torque output will increase, power probbly will too, but top speed will likley decrease.
not so much a problem for those using belt drives though ;-> _________________ Mechanical engineers build weapons, civil engineers build targets
Sat Jan 15, 2005 10:44 am
DumHed Experienced Roboteer
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that just means more advanced brush timing is needed _________________ The Engine Whisperer
- fixer of things
Sun Jan 16, 2005 2:33 am
Valen Experienced Roboteer
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dosent work like that
that will optomise speed for a given motor setup
if its generating 50% more backemf the timing wont do anything about that _________________ Mechanical engineers build weapons, civil engineers build targets
Sun Jan 16, 2005 8:51 am
Glen Experienced Roboteer
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well i got bored today and decided to take my old volvo fan motor (its made by bosch) apart to take a peek and heres some piccies.
^^ here is the top plate of the motor. its got a bearing pressed in there with a riveted on plate that holds it in. the bearing is open and has crap all through it so that was a problem.
^^ next we have the tasty bits. 3 huge magnets inside there and that thick steel case stops the magnetism getting out of the case unlike a fan motor. you can also see the brushes and choke coils ill talk about later.
^^ check those brushes out. there pretty big, well at least the biggest ive seen. more interesting though is that the brushes come upwards from the bottom instead of in from the sides. alot like the cm80 on the RMP. the entire brush housing is removable and there is some coils with a little rod magnet going through it for some noise reduction purpose FANCY.
^^ bottom of the armature showing the commutator. the brushes press UPWARDS on them.
i like the look of this motor alot and i want to have the shaft remade to just be 12mm thick all the way out and replace the bearings. the shaft looks to be held to the armature by a circlip only so i hope its removable.
Joined: 16 Jun 2004
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Location: Sydney, NSW
Who would have guessed that something good could come out of a Volvo? From those photos, it looks quite possible that the shaft could be replaced - there is a circlip on the Commutator side that could be removed and allow the shaft to be pressed out. With a decently long shaft, it would be an excellent motor. _________________ Australian 2015 Featherweight champion
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Tue Feb 15, 2005 5:45 pm
timmeh Experienced Roboteer
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U relise now im going to have to have a look in myn now lol _________________ Tim Team Reaper.
Tue Feb 15, 2005 5:47 pm
Glen Experienced Roboteer
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yeah that was my train of thought, a good 12mm thick shaft and 50mm long coming out of there would make it a damn fine item.
lol with the volvo bashing ! there some good stuff in those, auto windows, aerial actuators, mini wiper motors _________________ www.demon50s.com - Minimoto parts
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