OT: Brushless cordless drill less powerful or less efficient

[John Doe]

Is a brushless motor cordless drill likely to be less powerful or
less efficient when used in reverse? In other words... Would the
specifications of the drill likely not fully apply when it is being
used in reverse?

I have heard that ordinary brushed motor drills might be less
powerful when used in reverse.

Thanks.

 

[John Doe]

Here is a snippet of what appears to be some engineers talking about
the subject in 2001 (in this case, brushed motors)...

https://www.chiefdelphi.com/t/difference-in-forward-reverse-drill-motor-speed/35805/11

I just got a frantic message from my Johnson Electric contact. It
seems that he was wrong yesterday when he told me the motor was
not biased.

When he confirmed with his manufacturing sources in Hong Kong,
they told him that the magnets are oreinted 15 degrees with
respect to the brushes, making the motor performance
asymmetrical.

--

I wrote:

Is a brushless motor cordless drill likely to be less powerful or
less efficient when used in reverse? In other words... Would the
specifications of the drill likely not fully apply when it is being
used in reverse?

I have heard that ordinary brushed motor drills might be less
powerful when used in reverse.

Thanks.

 

[Jasen Betts]

On 2019-10-07, John Doe <always.look@message.header> wrote:

Is a brushless motor cordless drill likely to be less powerful or
less efficient when used in reverse? In other words... Would the
specifications of the drill likely not fully apply when it is being
used in reverse?

If it's got helical cut gears that's a possibility.



--
When I tried casting out nines I made a hash of it.

 

Jasen Betts <jasen@xnet.co.nz> wrote in news:qnhgr5$75u$1
@gonzo.revmaps.no-ip.org:

On 2019-10-07, John Doe <always.look@message.header> wrote:
Is a brushless motor cordless drill likely to be less powerful or
less efficient when used in reverse? In other words... Would the
specifications of the drill likely not fully apply when it is
being
used in reverse?

If it's got helical cut gears that's a possibility.

That also should not make a difference. If is designed to operate
in both directions (and they are), the gear face thrust presented to
both faces of the gear should also be managed properly and thus the
machine should run in both directions just fine. And gear face
thrust is the only thing about a helical toothed gear that would need
to be managed on both faces for bi-directional use.

There is no preferred direction on a gear simply because it has
helical cut teeth on it. As long as the faces have thrust washers,
it transfers power exactly the same in either direction. The problem
is that when they get predominately use in one direction, they "wear
in" on those gear tooth faces.

If properly 'worn in' in both directions, both sides of every tooth
gets worn in properly and operation is identical.

 

John Doe <always.look@message.header> wrote in news:qngfvc$r7f$1
@dont-email.me:

Is a brushless motor cordless drill likely to be less powerful or
less efficient when used in reverse? In other words... Would the
specifications of the drill likely not fully apply when it is being
used in reverse?

I have heard that ordinary brushed motor drills might be less
powerful when used in reverse.

Thanks.

Neither should show a difference. Brushed motor used alway in
forward *might* have the front edges of the commutator bars rounded,
which could very slightly affect certain elements forward and reverse
enough to call it a difference, but power shouldn't be one of them.
Usually just the sound it makes.

Gears also can get "worn in" (out actually)and display a 'preferred
direction' noisier in one than the other, and sometimes a bit of
power loss too if they were badly mismatched to start with.

 

[Lasse Langwadt Christense]

tirsdag den 8. oktober 2019 kl. 14.57.16 UTC+2 skrev DecadentLinux...@decadence.org:

John Doe <always.look@message.header> wrote in news:qngfvc$r7f$1
@dont-email.me:

Is a brushless motor cordless drill likely to be less powerful or
less efficient when used in reverse? In other words... Would the
specifications of the drill likely not fully apply when it is being
used in reverse?

I have heard that ordinary brushed motor drills might be less
powerful when used in reverse.

Thanks.


Neither should show a difference. Brushed motor used alway in
forward *might* have the front edges of the commutator bars rounded,
which could very slightly affect certain elements forward and reverse
enough to call it a difference, but power shouldn't be one of them.
Usually just the sound it makes.

the brushes/commutator timing with regards to the poles can be altered so
it runs different in one direction

a simplistic brushless controller could do the same with the hall sensors,
a smarter brushless controller will probably alter timing in software to
get the best performance at any speed/direction

 

Lasse Langwadt Christensen <langwadt@fonz.dk> wrote in
news:bff06796-4795-40dc-9817-d4d95f929348@googlegroups.com:

the brushes/commutator timing with regards to the poles can be
altered so it runs different in one direction

If it is designed to run in both directions, it will run the same
both ways.

If it was designed to run in only one direction, it may not run at
all in the other.