On Sat, May 4, 2024 at 05:44 PM, WAM wrote:
That's how I did it:
toggle quoted message Show quoted text
Aha!? I thought I had seen something similar but couldn't remember where. I like your swarf shield, that's something that still needs to be done.? The portion behind my bracket is easy but the front part is a different story.? I want something like a shield rather than a brush or felt pad since I went to a lot of trouble to reduce the friction as much as possible. What type/brand of DRO did you use?? I'm assuming its frictional drag is low enough to not cause a problem like mine.
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Very elegant solutions gentleman!
Ryan
On May 4, 2024 at 5:44?PM -0400, WAM <ajawam2@...>, wrote:
That's how I did it:
https://www.ajawamnet.com/ajawam3/swarf/DSCN2848.JPG
https://www.ajawamnet.com/ajawam3/swarf/lathetopassylg.gif
On 5/4/2024 4:30 PM, Mark Kimball via groups.io wrote:
Some time back I started working on a DRO scheme for my lathe cross slide.? There's not a lot of room on top so many of the approaches I saw had one disadvantage or another.? As a result I came up with a scheme to put the DRO underneath the lathe and used a "C" shaped piece to transfer the cross slide motion beneath the lathe.? I had an iGaging DRO for the purpose because I bought two when I was working on my Z axis DRO setup, so I already had what I needed.? Or so I thought.
Unfortunately, the iGaging design uses a sliding contact with a fairly strong spring, which required a fair amount of force to overcome.? DRO mounting schemes that put the mounting system inline with the sensor aren't affected by this, but my C shaped piece would deflect under the force enough to cause about a .005" error.? I tried several ways to stiffen up the system but that was about the best I could manage.
So I decided to modify my DRO to reduce the amount of force needed to move the rule through the sensor.? This involved making a replacement base out of aluminum and replacing the sliding contact with bearings.? I used aluminum because the rule MUST be connected to the sensor's internal ground in order to work correctly.
My first iteration used flanged bearings because the rule needed to be constrained on two of its axes, but the flanges rubbed on the rule too much, which caused erratic variations in the force needed to slide the rule back and forth.? So I replaced the flanged bearings with conventional ones -- but then had to add bearings to the bottom and top assemblies to constrain the rule on its vertical axis.
At this point I debated on whether it really was worthwhile to continue my attempt to use an iGaging DRO, but since I already had a fair amount of time invested in this thing I forged on.? This is known as the "sunk cost" syndrome, and I admit to falling victim to it.
So after buying more bearings and? spending more machining time on the base (and 3D printing a cover, also with bearing pockets) I got this:
The top photo shows the scale, sensor, aluminum base and printed cover.? The side bearings are 3x10mm and the top/bottom are 3x6.
And here are photos of the mounting scheme:
I used a "T" extrusion in an attempt to stiffen up my "C" assembly but it didn't improve things much.? The 3D printed stuff was done with an older Ender 3 I bought from a friend.? This is the first project I've used it for.? The pieces were designed using openSCAD.? Not shown:? all the pieces that had something wrong with them :).
The scale passes through a slot I milled in the vertical piece.
At first the (re) assembled DRO had a terrible EMI problem.? I added some shielding on the back of the sensor board, which helped a teensy bit.? It turns out that the main problem was the spacing between the bottom of the sensor board and scale.? I had used some 3mm brass washers to make sure the board didn't rub against the scale, but that turned out to be a mistake.? I removed them and suddenly the noise problem disappeared.? The board still isn't rubbing so that was a solution without a problem.? I was sure that the DRO would misbehave once it was installed and the motor controller was turned on, but so far so good.
I checked the DRO vs the dial and they are very close.? That was a big unknown, since I wasn't sure if the spacing between the scale and sensor board would affect the readings.
Lipstick on a pig?? Well, probably.? If I had known what I was going to encounter along the way I think I would have just bit the bullet and found myself a DRO that would work right out of the box....
Attachments:
Base cover sensor.JPG: /g/7x12MiniLathe/attachment/119497/
Scale.JPG: /g/7x12MiniLathe/attachment/119497/1
Mounting assembly front.JPG: /g/7x12MiniLathe/attachment/119497/2
Mounting assembly rear view.JPG: /g/7x12MiniLathe/attachment/119497/3
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That's how I did it:
toggle quoted message
Show quoted text
On 5/4/2024 4:30 PM, Mark Kimball via groups.io wrote: Some time back I started working on a DRO scheme for my lathe cross slide.? There's not a lot of room on top so many of the approaches I saw had one disadvantage or another.? As a result I came up with a scheme to put the DRO underneath the lathe and used a "C" shaped piece to transfer the cross slide motion beneath the lathe.? I had an iGaging DRO for the purpose because I bought two when I was working on my Z axis DRO setup, so I already had what I needed.? Or so I thought.
Unfortunately, the iGaging design uses a sliding contact with a fairly strong spring, which required a fair amount of force to overcome.? DRO mounting schemes that put the mounting system inline with the sensor aren't affected by this, but my C shaped piece would deflect under the force enough to cause about a .005" error.? I tried several ways to stiffen up the system but that was about the best I could manage.
So I decided to modify my DRO to reduce the amount of force needed to move the rule through the sensor.? This involved making a replacement base out of aluminum and replacing the sliding contact with bearings.? I used aluminum because the rule MUST be connected to the sensor's internal ground in order to work correctly.
My first iteration used flanged bearings because the rule needed to be constrained on two of its axes, but the flanges rubbed on the rule too much, which caused erratic variations in the force needed to slide the rule back and forth.? So I replaced the flanged bearings with conventional ones -- but then had to add bearings to the bottom and top assemblies to constrain the rule on its vertical axis.
At this point I debated on whether it really was worthwhile to continue my attempt to use an iGaging DRO, but since I already had a fair amount of time invested in this thing I forged on.? This is known as the "sunk cost" syndrome, and I admit to falling victim to it.
So after buying more bearings and? spending more machining time on the base (and 3D printing a cover, also with bearing pockets) I got this:
The top photo shows the scale, sensor, aluminum base and printed cover.? The side bearings are 3x10mm and the top/bottom are 3x6.
And here are photos of the mounting scheme:
I used a "T" extrusion in an attempt to stiffen up my "C" assembly but it didn't improve things much.? The 3D printed stuff was done with an older Ender 3 I bought from a friend.? This is the first project I've used it for.? The pieces were designed using openSCAD.? Not shown:? all the pieces that had something wrong with them :).
The scale passes through a slot I milled in the vertical piece.
At first the (re) assembled DRO had a terrible EMI problem.? I added some shielding on the back of the sensor board, which helped a teensy bit.? It turns out that the main problem was the spacing between the bottom of the sensor board and scale.? I had used some 3mm brass washers to make sure the board didn't rub against the scale, but that turned out to be a mistake.? I removed them and suddenly the noise problem disappeared.? The board still isn't rubbing so that was a solution without a problem.? I was sure that the DRO would misbehave once it was installed and the motor controller was turned on, but so far so good.
I checked the DRO vs the dial and they are very close.? That was a big unknown, since I wasn't sure if the spacing between the scale and sensor board would affect the readings.
Lipstick on a pig?? Well, probably.? If I had known what I was going to encounter along the way I think I would have just bit the bullet and found myself a DRO that would work right out of the box....
Attachments:
Base cover sensor.JPG: /g/7x12MiniLathe/attachment/119497/
Scale.JPG: /g/7x12MiniLathe/attachment/119497/1
Mounting assembly front.JPG: /g/7x12MiniLathe/attachment/119497/2
Mounting assembly rear view.JPG: /g/7x12MiniLathe/attachment/119497/3
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Some time back I started working on a DRO scheme for my lathe cross slide.? There's not a lot of room on top so many of the approaches I saw had one disadvantage or another.? As a result I came up with a scheme to put the DRO underneath the lathe and used a "C" shaped piece to transfer the cross slide motion beneath the lathe.? I had an iGaging DRO for the purpose because I bought two when I was working on my Z axis DRO setup, so I already had what I needed.? Or so I thought. Unfortunately, the iGaging design uses a sliding contact with a fairly strong spring, which required a fair amount of force to overcome.? DRO mounting schemes that put the mounting system inline with the sensor aren't affected by this, but my C shaped piece would deflect under the force enough to cause about a .005" error.? I tried several ways to stiffen up the system but that was about the best I could manage. So I decided to modify my DRO to reduce the amount of force needed to move the rule through the sensor.? This involved making a replacement base out of aluminum and replacing the sliding contact with bearings.? I used aluminum because the rule MUST be connected to the sensor's internal ground in order to work correctly. My first iteration used flanged bearings because the rule needed to be constrained on two of its axes, but the flanges rubbed on the rule too much, which caused erratic variations in the force needed to slide the rule back and forth.? So I replaced the flanged bearings with conventional ones -- but then had to add bearings to the bottom and top assemblies to constrain the rule on its vertical axis. At this point I debated on whether it really was worthwhile to continue my attempt to use an iGaging DRO, but since I already had a fair amount of time invested in this thing I forged on.? This is known as the "sunk cost" syndrome, and I admit to falling victim to it. So after buying more bearings and? spending more machining time on the base (and 3D printing a cover, also with bearing pockets) I got this:   The top photo shows the scale, sensor, aluminum base and printed cover.? The side bearings are 3x10mm and the top/bottom are 3x6. And here are photos of the mounting scheme:   I used a "T" extrusion in an attempt to stiffen up my "C" assembly but it didn't improve things much.? The 3D printed stuff was done with an older Ender 3 I bought from a friend.? This is the first project I've used it for.? The pieces were designed using openSCAD.? Not shown:? all the pieces that had something wrong with them :).? The scale passes through a slot I milled in the vertical piece. At first the (re) assembled DRO had a terrible EMI problem.? I added some shielding on the back of the sensor board, which helped a teensy bit.? It turns out that the main problem was the spacing between the bottom of the sensor board and scale.? I had used some 3mm brass washers to make sure the board didn't rub against the scale, but that turned out to be a mistake.? I removed them and suddenly the noise problem disappeared.? The board still isn't rubbing so that was a solution without a problem.? I was sure that the DRO would misbehave once it was installed and the motor controller was turned on, but so far so good. I checked the DRO vs the dial and they are very close.? That was a big unknown, since I wasn't sure if the spacing between the scale and sensor board would affect the readings. Lipstick on a pig?? Well, probably.? If I had known what I was going to encounter along the way I think I would have just bit the bullet and found myself a DRO that would work right out of the box....
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Re: Mini lathe motor temperature
You right about taking heavy cuts at low speed on mini lathe. The gauge is on there so do not have problem.??
Have a photo of the (spindle crank)?
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On Fri, May 3, 2024 at 12:26 AM, Miket_NYC wrote:
Why should a minilathe motor be getting extremely hot in the first place? Mine never does. These machines aren't made for heavy use and cuts should be light. On the rare occasions that I've taken heavy cuts, I use a spindle crank.
?
Mike Taglieri?
105¡ãC sounds rather suspiciously (or perhaps not that suspiciously) like the lower temperature limit on most magnet wire used in motor coils.
?
Gets hot, the enamel melts and the coil shorts out.? If you¡¯ve spent enough time around motors or transformers you know the smell.? That 105¡ãC is basically the maximum temperature for the motor coils, if you let it get anywhere near that you¡¯re asking for trouble.?
?
You can get magnet wire with better heat rating, up to about 250¡ãC, but you don¡¯t see that much.? That¡¯s what the class of a motor means, better insulation.? Thoe old rule of if it¡¯s too hot to touch, it¡¯s too hot is well worth following.
?
The other reason for keeping the heat down is the magnets.? Won¡¯t bother the typical old-school mini-lathe motors, but newer motors (eg brushless) with neodymium magnets need to be kept cool as they start losing magnetism at around 80¡ãC.
?
Tony
?
?
?
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:
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Re: Mini lathe motor temperature
Your welcome.?
It is probably lesser problem if you know before the gets to hot.?
?
It some of problems I read about mini lathes for years.?
Dave?
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On Fri, May 3, 2024 at 01:04 AM, DAVID WILLIAMS wrote:
Dear All, Many thanks for the motor info. David from across the Pond.
?
On 3 May 2024, at 08:26, Miket_NYC <mctaglieri@...> wrote:
Why should a minilathe motor be getting extremely hot in the first place? Mine never does. These machines aren't made for heavy use and cuts should be light. On the rare occasions that I've taken heavy cuts, I use a spindle crank.
?
Mike Taglieri?
105¡ãC sounds rather suspiciously (or perhaps not that suspiciously) like the lower temperature limit on most magnet wire used in motor coils.
?
Gets hot, the enamel melts and the coil shorts out.? If you¡¯ve spent enough time around motors or transformers you know the smell.? That 105¡ãC is basically the maximum temperature for the motor coils, if you let it get anywhere near that you¡¯re asking for trouble.?
?
You can get magnet wire with better heat rating, up to about 250¡ãC, but you don¡¯t see that much.? That¡¯s what the class of a motor means, better insulation.? Thoe old rule of if it¡¯s too hot to touch, it¡¯s too hot is well worth following.
?
The other reason for keeping the heat down is the magnets.? Won¡¯t bother the typical old-school mini-lathe motors, but newer motors (eg brushless) with neodymium magnets need to be kept cool as they start losing magnetism at around 80¡ãC.
?
Tony
?
?
?
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:
?
?
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Re: Mini lathe motor temperature
I was going add a fan in November.? After thinking about the heat I need to know what heat is and someway to know if cooling fail.?
Also you do all your machining at 2,000 rpm.?
?I even thinking of indicator light.?
I need to know before anything happens like I do on my truck.?
Dave?
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On Fri, May 3, 2024 at 07:51 AM, ram50v8efi wrote:
Dave, I am wondering.... Have you been running the motor at less than full speed? The cooling on these is typically based on the motor running at full speed so the fan can move enough air to maintain somewhat reasonable cooling. If you find you are running the lathe slower then I would recommend either an increased reduction belt drive (so the motor can run faster whilst keeping the spindle speed lower) and/or a separate cooling fan for the motor.?
On my first heavily modified mini I added a cover to the rear of the motor and attached some light flexible hose (Hoover vac hose) that is attached to a small squirrel cage blower with a bit of filter media on the blower inlet. This keeps the motor cooler and also keeps swarf from being taken in the motor.
Just my thoughts, Cheers
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Re: Mini lathe motor temperature
Dave, I am wondering.... Have you been running the motor at less than full speed? The cooling on these is typically based on the motor running at full speed so the fan can move enough air to maintain somewhat reasonable cooling. If you find you are running the lathe slower then I would recommend either an increased reduction belt drive (so the motor can run faster whilst keeping the spindle speed lower) and/or a separate cooling fan for the motor.?
On my first heavily modified mini I added a cover to the rear of the motor and attached some light flexible hose (Hoover vac hose) that is attached to a small squirrel cage blower with a bit of filter media on the blower inlet. This keeps the motor cooler and also keeps swarf from being taken in the motor.
Just my thoughts, Cheers
|
Re: Mini lathe motor temperature
Dear All, Many thanks for the motor info. David from across the Pond.
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Show quoted text
On 3 May 2024, at 08:26, Miket_NYC <mctaglieri@...> wrote:
? Why should a minilathe motor be getting extremely hot in the first place? Mine never does. These machines aren't made for heavy use and cuts should be light. On the rare occasions that I've taken heavy cuts, I use a spindle crank.
Mike Taglieri? 105¡ãC sounds rather suspiciously (or perhaps not that suspiciously) like the lower temperature limit on most magnet wire used in motor coils. ? Gets hot, the enamel melts and the coil shorts out.? If you¡¯ve spent enough time around motors or transformers you know the smell.? That 105¡ãC is basically the maximum temperature for the motor coils, if you let it get anywhere near that you¡¯re asking for trouble.? ? You can get magnet wire with better heat rating, up to about 250¡ãC, but you don¡¯t see that much.? That¡¯s what the class of a motor means, better insulation.? Thoe old rule of if it¡¯s too hot to touch, it¡¯s too hot is well worth following. ? The other reason for keeping the heat down is the magnets.? Won¡¯t bother the typical old-school mini-lathe motors, but newer motors (eg brushless) with neodymium magnets need to be kept cool as they start losing magnetism at around 80¡ãC. ? Tony ? ? ? 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:
|
Re: Mini lathe motor temperature
Why should a minilathe motor be getting extremely hot in the first place? Mine never does. These machines aren't made for heavy use and cuts should be light. On the rare occasions that I've taken heavy cuts, I use a spindle crank.
Mike Taglieri?
105¡ãC sounds rather suspiciously (or perhaps not that suspiciously) like the lower temperature limit on most magnet wire used in motor coils. ? Gets hot, the enamel melts and the coil shorts out.? If you¡¯ve spent enough time around motors or transformers you know the smell.? That 105¡ãC is basically the maximum temperature for the motor coils, if you let it get anywhere near that you¡¯re asking for trouble.? ? You can get magnet wire with better heat rating, up to about 250¡ãC, but you don¡¯t see that much.? That¡¯s what the class of a motor means, better insulation.? Thoe old rule of if it¡¯s too hot to touch, it¡¯s too hot is well worth following. ? The other reason for keeping the heat down is the magnets.? Won¡¯t bother the typical old-school mini-lathe motors, but newer motors (eg brushless) with neodymium magnets need to be kept cool as they start losing magnetism at around 80¡ãC. ? Tony ? ? ? 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:
|
Re: Mini lathe motor temperature
105¡ãC sounds rather suspiciously (or perhaps not that suspiciously) like the lower temperature limit on most magnet wire used in motor coils. ? Gets hot, the enamel melts and the coil shorts out.? If you¡¯ve spent enough time around motors or transformers you know the smell.? That 105¡ãC is basically the maximum temperature for the motor coils, if you let it get anywhere near that you¡¯re asking for trouble.? ? You can get magnet wire with better heat rating, up to about 250¡ãC, but you don¡¯t see that much.? That¡¯s what the class of a motor means, better insulation.? Thoe old rule of if it¡¯s too hot to touch, it¡¯s too hot is well worth following. ? The other reason for keeping the heat down is the magnets.? Won¡¯t bother the typical old-school mini-lathe motors, but newer motors (eg brushless) with neodymium magnets need to be kept cool as they start losing magnetism at around 80¡ãC. ? Tony ? ?
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From: [email protected] <[email protected]> On Behalf Of davesmith1800 via groups.io
Sent: Wednesday, 1 May 2024 6:37 AM
To: [email protected]
Subject: [7x12MiniLathe] Mini lathe motor temperature? 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:
|
Re: Mini lathe motor temperature
Here the finished install.? 1) The first shows the the blue is heat shink tube with a sealer to protect the tubing left a little coil on the outside if gauge needs to be removed.? 2) The second? Shows the Capillary blub on the motor using HVAC Aluminum tape. Tape goes over 284¡ãF [140¡ãC] 3) The last photo photo shows read to go. It tilled se see better as run lathe Dave?   
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Re: Mini lathe motor temperature
I have fans.
I was more interested in know what real temperature is before something happens.??
If ot is big problem I will add a fan. But still keep the temperature gauge just case the fan fails?
It like car water temperature you know what temperature before you see smoke coming out of the hood.??
Dave?
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On Tue, Apr 30, 2024 at 04:34 PM, mike allen wrote:
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:
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/
20240430_111809.jpg: /g/7x12MiniLathe/attachment/119482/1
20240430_122140.jpg: /g/7x12MiniLathe/attachment/119482/2
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Re: Mini lathe motor temperature
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:
toggle quoted message
Show quoted text
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/
20240430_111809.jpg: /g/7x12MiniLathe/attachment/119482/1
20240430_122140.jpg: /g/7x12MiniLathe/attachment/119482/2
|
Re: Mini lathe motor temperature
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?
toggle quoted message
Show quoted text
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/
20240430_111809.jpg: /g/7x12MiniLathe/attachment/119482/1
20240430_122140.jpg: /g/7x12MiniLathe/attachment/119482/2
|
Re: Mini lathe motor temperature
Thermal images of the LMS motor? -
toggle quoted message
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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
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20240429_111501.jpg: /g/7x12MiniLathe/attachment/119482/
20240430_111809.jpg: /g/7x12MiniLathe/attachment/119482/1
20240430_122140.jpg: /g/7x12MiniLathe/attachment/119482/2
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Re: Mini lathe motor temperature
FYI?
If motor is over 145¡ãF [63¡ãC] do not touch it will burn.
So can be burn at a lower temperature and some can go above.
Dave?
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Mini lathe motor temperature
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?   
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Re: Using wood for mini-lathe and mini-mill accessories
 This is my last solution, for a specific job. A big clamp keeps it stable. 150 cm around.
Johannes ? Lavoll. ? ? ? ? ? ? ?
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On 28 Apr 2024, at 18:25, Roy via groups.io <roylowenthal@...> wrote:
?I've had good results with wooden accessories made out of Baltic Birch plywood. The real Baltic Birch has thinner layers than construction grade plywood + they're all birch. It's a bit pricy, but, worth it for maximum strength & stability
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Roy
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Re: Using wood for mini-lathe and mini-mill accessories
I've had good results with wooden accessories made out of Baltic Birch plywood. The real Baltic Birch has thinner layers than construction grade plywood + they're all birch. It's a bit pricy, but, worth it for maximum strength & stability
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Roy
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davesmith1800
ram50v8efi
Johannes