The problem is more likely to be in the controller than the motor - motor problems usually keep the motor from running. (That's based on experience with brushed motors - I've got no experience with the newer brushless ones.)
On Fri, Jun 28, 2024 at 8:18?PM Roy via <roylowenthal=[email protected]> wrote:
Use the LMS troubleshooting guides:
?< >
The problem is more likely to be in the controller than the motor - motor problems usually keep the motor from running. (That's based on experience with brushed motors - I've got no experience with the newer brushless ones.)
Here is a 3D CAD file of your mini lathe. ? The link is for an online web-based viewer. ?If you have the full version of Fusion360, you’d have better tools to inspect the design (or even to build a minilathe from scratch.)
But even with the web view, you can rotate and zoom and EXPLODE the parts to see what is inside.
One good tool the the “model browser” (5th icon from the right. ? This puts up a list of parts and you can remove some of them. ? ?If you remove the case and covers you can see how the internal parts work. ? ? All the screws ?are in the model too so you can see how to remove the covers.
I did not create this file. ?I did clean it up a little. ? My use of it is to build a CNC conversion. ? The model is accurate enough to do virtual test fits of replacement parts.
On Jun 28, 2024, at 5:40?PM, Ralph Hulslander via groups.io <rhulslander@...> wrote:
Using the Guides is a good idea. Checking the brushes is a good idea.
Both of them take us back to my original question: "HOW TO INSPECT MOTOR"?
The Mini Lathe is probably very old, I have had it for 10 years, the previous owner probably 20 -30 years.
The motor is encased. How do I remove the cover?
On Fri, Jun 28, 2024 at 8:18?PM Roy via??<roylowenthal=[email protected]> wrote:
Use the LMS troubleshooting guides:
?<??>
The problem is more likely to be in the controller than the motor - motor problems usually keep the motor from running. (That's based on experience with brushed motors - I've got no experience with the newer brushless ones.)
I'm going to offer that you may have a
broken plastic gear inside the lathe.?
The klunky sound, sounds like a missing
tooth being engaged by the other gears' tooth, and finding nothing
there until the next tooth comes around, and they then hit point
to point.
.
To access the motor simply turn the
lathe around to the back side, like a record player, and the
cover, and then the motor are right there.
.
A possible 2nd option that happened to
me once was the motor mounting bolts vibrated loose. They are
behind/inside the electrical cover on the front side, bottom
right.
The motor was banging around loose, and
hanging at an angle, chewing on the belt a little bit.
In theory you can check the brushes by removing them through the holes in the motor cover and the lathe bed. In practice they never seem to line up with the holes. To view the motor you just need to remove the 2 screws at the top of the cover the power cord goes into. To remove the motor you also need to remove the 4 screws that secure the control panel to the head which allows you to disconnect the wires to the motor and see the 2 nuts that hold the motor in place. You probably will need to remove other parts to remove the nuts.
On Sat, Jun 29, 2024 at 7:44?AM paul mcclintic via <cannontandem=[email protected]> wrote:
In theory you can check the brushes by removing them through the holes in the motor cover and the lathe bed. In practice they never seem to line up with the holes. To view the motor you just need to remove the 2 screws at the top of the cover the power cord goes into. To remove the motor you also need to remove the 4 screws that secure the control panel to the head which allows you to disconnect the wires to the motor and see the 2 nuts that hold the motor in place. You probably will need to remove other parts to remove the nuts.
I have seen problem with lock rotors too. Does motor turn freely??
If brush problem like talked first part look for a dead bug. The old term get bugs out or debugging start with real bugs under contact and brushes. Now it is in electronic terms.
HEre’s an exploded diagram of a very similar one; this is pretty much how all the 7xNN lthes are built because they’re all the same design, with consmetic differences.
Also Ted Hansen’s book??has a section on removing and adjusting the motor
On Jun 28, 2024, at 5:40 PM, Ralph Hulslander via <rhulslander@...> wrote:
Using the Guides is a good idea. Checking the brushes is a good idea.
Both of them take us back to my original question: "HOW TO INSPECT MOTOR"?
The Mini Lathe is probably very old, I have had it for 10 years, the previous owner probably 20 -30 years.
The motor is encased. How do I remove the cover?
On Fri, Jun 28, 2024 at 8:18?PM Roy via <roylowenthal=[email protected]> wrote:
Use the LMS troubleshooting guides:
?< >
The problem is more likely to be in the controller than the motor - motor problems usually keep the motor from running. (That's based on experience with brushed motors - I've got no experience with the newer brushless ones.)
You spend a lot time looking and a little bug could have die. Thd other is over look is a losses screw just enough to test good but when? power is apply nothing.? I do not think a it is a losses screw on your lathe
Bugs was use for thousands of years for making Shellac.? He little clip from internet on using shellac fof electrical insulation.?
Shellac was used for fixing inductor, motor, generator and transformer windings. It was applied directly to single-layer windings in an alcohol solution
Dave?
On Fri, Jun 28, 2024 at 01:00 PM, Ralph Hulslander wrote:
My.motor.is.behaving.badly. How.do. I inspect the motor? Do I just flip it on its side to get to the? motor?
Attributed to Admiral Grace Hopper, early computer programmer and original developer of the COBOL programming language. (but probably not her, actually, since the term ‘bug’ had been in use since at least the late 19th century)
On Jun 29, 2024, at 8:50 AM, davesmith1800 via <davesmith1@...> wrote:
I have seen problem with lock rotors too. Does motor turn freely??
If brush problem like talked first part look for a dead bug. The old term get bugs out or debugging start with real bugs under contact and brushes. Now it is in electronic terms.
Dave?
On Fri, Jun 28, 2024 at 01:00 PM, Ralph Hulslander wrote:
My.motor.is.behaving.badly. How.do. I inspect the motor? Do I just flip it on its side to get to the? motor?
The bug story just might, maybe be relevant. ? As the story goes a big machine was broken. ?It was a computer but in those days computers still had moving mechanical parts and a moth got caught in the mechanism. ? At the time they thought it was funny because an actual real-life “bug” was the cause of the bug. ? Obviously, the term must have been in use, or it would not have been a joke. ? Hooper removed the moth and taped it to a sheet of paper and make some kind of informal display of it. ?I’ve seen photos of the dead moth tapped to the paper
I doubt there is an actual insect in the lathe causing the problem. ?Something has either come loose, broken or burned up.
To “debug” any problem with a complex machine there is a dumb way and a smarter way. ? Usually, the dumb way works. ?You simply replace parts more or less based on random hunches until the problem goes away. ?Your first hunch is usually correct and replacing the fuse fixes it.
The smarter way is called “divide and conquer”. ? First, you somehow cut the system in half and then figure out which half is NOT broken, the fault must be in the OTHER part. ?But where in the other part? ?Just do it again. ?Keep cutting the failed part into subparts and so on. ? It is usually hard to prove failure, but proving a part works is usually easy. ? (When a test shows a defect you always suspect that maybe it is an incorrect test method.) ?
The first cut I would make is to disconnect the motor’s power leads and test the motor with a DC power supply. (Old PC power supplies are worth keeping around) ?If it spins correctly the fault is not the motor or any of its parts like the brushes. ?If the motor works then then the fault is someplace between the motor power cable and the AC wall socket. ? The obvious place to cut again is to remove the AC cable from the controller PCB.
Using this process you can narrow down to (say) a single MOSFET component on the controller board.
As for how to take the lathe apart. ? The web-based view is only marginally OK. ? It is poor compared to a real copy of Fusion360, which is free for non-professional use and worth getting if you are into designing and building machinery. ?But you can see even in the web view where the cover is and how many screws hold it.
On Sat, Jun 29, 2024 at 08:53 PM, Chris Albertson wrote:
The bug story just might, maybe be relevant. ? As the story goes a big machine was broken. ?It was a computer but in those days computers still had moving mechanical parts and a moth got caught in the mechanism. ? At the time they thought it was funny because an actual real-life “bug” was the cause of the bug. ? Obviously, the term must have been in use, or it would not have been a joke. ? Hooper removed the moth and taped it to a sheet of paper and make some kind of informal display of it. ?I’ve seen photos of the dead moth tapped to the paper
?
I doubt there is an actual insect in the lathe causing the problem. ?Something has either come loose, broken or burned up.
?
To “debug” any problem with a complex machine there is a dumb way and a smarter way. ? Usually, the dumb way works. ?You simply replace parts more or less based on random hunches until the problem goes away. ?Your first hunch is usually correct and replacing the fuse fixes it.
?
The smarter way is called “divide and conquer”. ? First, you somehow cut the system in half and then figure out which half is NOT broken, the fault must be in the OTHER part. ?But where in the other part? ?Just do it again. ?Keep cutting the failed part into subparts and so on. ? It is usually hard to prove failure, but proving a part works is usually easy. ? (When a test shows a defect you always suspect that maybe it is an incorrect test method.) ?
?
The first cut I would make is to disconnect the motor’s power leads and test the motor with a DC power supply. (Old PC power supplies are worth keeping around) ?If it spins correctly the fault is not the motor or any of its parts like the brushes. ?If the motor works then then the fault is someplace between the motor power cable and the AC wall socket. ? The obvious place to cut again is to remove the AC cable from the controller PCB.
?
Using this process you can narrow down to (say) a single MOSFET component on the controller board.
?
As for how to take the lathe apart. ? The web-based view is only marginally OK. ? It is poor compared to a real copy of Fusion360, which is free for non-professional use and worth getting if you are into designing and building machinery. ?But you can see even in the web view where the cover is and how many screws hold it.
?
?
?
On Jun 29, 2024, at 5:40?PM, Ralph Hulslander via groups.io <rhulslander@...> wrote:
Do you mind if we stick with the subject of my post??If you want to start a new thread please do so.
?
Ralph
On Sat, Jun 29, 2024 at 8:01?PM Roy via <roylowenthal=[email protected]> wrote:
Here's a comprehensive article about shellac & many of its uses;