10 replies to this topic

[havlicek]

This one started out as a late model Mura...very similar to the RJR once you start whittling.  In addition to cutting out the can, the sides got turned down and the top and bottom milled.  For the arm, I did another H12, this time wound conventionally.

[team burrito]

back in the day, we used to cut out the sides of the can to let the magnets 'air out'. this took out the torque & increased the RPM's, in theory at least.

[havlicek]

back in the day, we used to cut out the sides of the can to let the magnets 'air out'. this took out the torque & increased the RPM's, in theory at least.

 

Hi Russ,

     I actually thought about putting *2-holes on each side as a little "Mura" reference. 

[team burrito]

i was talking about a little bigger...

[havlicek]

I figured as much

[Jairus]

"Wireframe" motor can.
At what point does the strength and alignment evaporate?

[havlicek]

"Wireframe" motor can.
At what point does the strength and alignment evaporate?

 

 

I worry about all that too Jairus.  *IF* the magnets are solidly epoxied into the can, they can make up for a lot of weakness at the can sides.  The bearing strap is a whole other deal though, and you quickly get into trouble hacking that up.  The top and bottom of the can don't mean all that much as far as strength, even in a full "strap" type can, the end bell (*if all four screws are used) restrengthens the whole deal.

[zipper]

>>The bearing strap is a whole other deal though, and you quickly get into trouble hacking that up>>  Well, done and suffered... Long time ago we butchered Koford Feathers removing several grams from the can. They were fast and gave a good handling - until a crash bent the bearing strap.

[havlicek]

>>The bearing strap is a whole other deal though, and you quickly get into trouble hacking that up>>  Well, done and suffered... Long time ago we butchered Koford Feathers removing several grams from the can. They were fast and gave a good handling - until a crash bent the bearing strap.

 

 

Both the ProSlot and JK minicans come from the factory kinda weak back there Pekka.  I figure they wanted to save "us" from messing with the cans and weakening them, so they engineered the weakness into them for us. 

[Jairus]

Seems like one could cut the whole top off a motor and thus lowering the C.G.
4 screws and a bearing, as long as the magnets are glued in with something to glue to.... 
Weight down low makes sense.

[havlicek]

Seems like one could cut the whole top off a motor and thus lowering the C.G.
4 screws and a bearing, as long as the magnets are glued in with something to glue to.... 
Weight down low makes sense.

 

With stronger and stronger magnets, the can is really only there as a way to hold all the motor bits in alignment.   Some can/magnet combinations benefit from the can's effect on the permanent magnet's field strength, so how much can-hacking is OK kinda depends.  Another thing to consider when hacking-up motors is that the magnets are where a lot of the motor's weight comes from, and magnets don't have to be long, tall and thick to be strong...even ceramics.  Think about the relatively strong little ceramics in "fk" sized motors.  These routinely measure as strong or stronger than the old Arcos.  I've put them in C-cans, and they work fine.  Then too, I recently did a couple of C cans with the magnets honed way out to .580 when Dave Parotta clued me in about using .560" arms in them...ballistic.

There are so many combinations, and "formulas" for putting together motors other than just what's "out there", it's kind of mind boggling.  Great fun the screw around with these things!