It's a good example of why ya should have a few old computer fans
in yer inventory .
animal
On 4/30/24 3:56 PM, davesmith1800
wrote:
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50% of motors running full speed the bearings will only last
20,000 hour but the coil last a lot longer dust is next problem.??
But biggest reason failed of a motor running lower speed is over
heating. The fan is not running fast enough to cool the motor.?
This because cutting low speed under heavy load.? This is our
problem on mini lathes.
The speed is 100 rpm and the fan turns slowly.?
If turning at 2,000 rpm the fan is doing? a great job of
cooling.??
I have seen 30 hp DC motors on machine tools. They add a very
large fan for cooling.?
It hard to put a good cooling fan in a tight spot.?
Dave?
On Tue, Apr 30, 2024 at 02:28 PM, WAM wrote:
Thermal images of the LMS motor? -
On 4/30/2024 4:36 PM, davesmith1800 via groups.io wrote:
After researching of motors are 221¡ãF [105¡ãC] after
that the life is shortened.
The outside temperature is about? 60¡ãF to 70¡ãF? [15 to 20¡ãC ]
less the coil temperature.? So if outside is could be wend the
coil is? 221¡ãF [105¡ãC] the outside is between? 151¡ãF and 161¡ãF
[85 an 90¡ãC].
On my gauge I set the red mark at 80¡ãC and 105¡ãC.
If I see gets never red it time to let motor cool down and
gives little to finish the cut.
The Capillary is attached by HVAC Aluminum tape , max
temperature is 145 ¡ãC at this point the motor is toast
Dave
Attachments:
20240429_111501.jpg: /g/7x12MiniLathe/attachment/119482/0
20240430_111809.jpg: /g/7x12MiniLathe/attachment/119482/1
20240430_122140.jpg: /g/7x12MiniLathe/attachment/119482/2
