On Fri, Sep 24, 2021 at 03:06 PM, Jkle379184 wrote:
?I seem to recall that the power supplies
were commonly used to power LED lighting. Here is a
photo of the Motor that I used, the box that I put
the controls in and a crude wiring schematic. I
added switch position to bypass the sped control to
run full speed.
The power supplies are often quoted as being suitable
for LEDs, but you'd need a lot of LEDs to justify 24V
at 10A! Really they are general purpose power supplies
- use them for whatever you like.
The speed control you are using is one of the ones I
suggested for Oldtoolmaker.
On my power box I have two sockets for the motor - one
direct from the 24 V, the other from the speed
controller. The direct one has a forward/reverse
switch, but not the speed controlled connector.
Reversing the power while the motor is still spinning
is a good way to blow up the speed controller.
>>Measured full output speed of this motor was
3431 RPM. I drilled out the pulley to 8mm and it fit
the motor shaft perfectly.
The higher power motors run a bit slower than the
lower power ones. I got a little over 4000 rpm from my
130 W motor. Somewhere or other this is documented by
the motor suppliers. As said before, I got about 6000
rpm at the chuck at the highest speed setting on the
pulleys.
If my motor had had the longer shaft I would have
opened up the pulley. Since the shaft was too short I
made an extension at 6 mm and left the pulley alone. I
arranged to drive it by pins, more or less as in the
original, and held it on with an M4 screw, as per the
original.
>>Some photos of the motor end plate mods and
the "top Hat" for the mounting screw all done on the
Unimat.
You have the motor with the brushes at the back. This
makes it easy to add the extra fixing hole to the
front plate without worrying about screws getting
mixed up with the wiring. Note that to modify the
plain front pate it is not necessary to dismantle the
motor completely - it is simpler to just take the
front plate off.That way you don't have to disturb the
brushes, and fight the magnets when getting the
armature out, and in again. If the brushes are at the
front then it needs a bit of thought how to modify it
without shorting out the electrics. That's one reason
why I used an adaptor plate and left the motor alone.
The Unimat motor has two M5 screws at 42 mm spacing.
The DC motor has three M5 holes on a 42 mm circle, so
you only need to add one M5 hole to fit the DC motor
to the Unimat bracket. You might get away with tapping
it straight into the motor end plate, but adding this
reinforcement is a good idea.
I had a big BANG lock-up on my SL, and after that the
motor bearings were shot. If you take the motor apart
consider replacing the bearings with good quality ones
(SKF, NSK, FAG, etc.) while you have the chance. At
least measure them up so you know what size may be
needed in future. I've forgotten what they were, but
it wasn't hard to find replacements.
>>Photos of the motor taken apart, easy to do,
just two long screws. Put the end plate with the
brushes over the armature shaft first and then put
that into the stator tube when putting it back
together. The modified end plate with the top hat
epoxy glued in place, drilled out and test mounted to
the Unimat bracket.? And the last one is the unit up
and running. Notice the drive belt. Just a plain old
Buna white O ring, they are cheap and work great. ?I
drilled the pulley out to 8mm to fit the shaft. Then I
drilled the pulley for a small set screw to fit the
flat section of the armature shaft. All work was done
on one of my Unimats. You could do this first and then
when done replace the Unimat motor with the 24vdc
motor when done.
Jeff
Mainly covered in comments above. If you take the
motor fully apart mark the end cover positions with a
dab of paint or similar. It helps to get the screws
back through if the covers are properly aligned. If I
was doing it again I would also file a small point on
the long screws, as that would help to get them into
the tapped holes in the end cover.
In general, if I had this motor to work with, I would
have done the job very much the same way. As it was,
the motor I had was significantly different, so I did
things differently. If you can get a motor like this
one (regardless of power) with the brushes at the back
end and with a long shaft, it will be simpler. I would
still recommend the 130 W motor, as it gives a bit
more space around the working area, and it goes a
little faster, but these are not the most important
things. I haven't seen many motors with the longer
shaft. I reckon it would be worth spending some time
searching for that, and the brushes at the back end,
The wiring can be even simpler than shown. I think the
direct power option is good, but I couldn't tell you
why. My power box was more complicated as it allows
for a range of possible, but unknown, other uses. The
biggest problem, in my experience of such things, is
finding a good size box for everything. I still favour
a wooden base under the lathe with the electrics
inside, but that means you have to build it, so it
depends on your woodworking skills. I used a
commercial equipment box, but, along with the 24 V PSU
that probably cost more than the motor and speed
control combined. Fortunately someone in industry owed
me some money/a favour, so I didn't feel the cost!
Carl