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Author Topic: just bought a little baby cnc 280mm square davinci style thing  (Read 4023 times)

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Offline nobby

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Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #30 on: February 12, 2023, 03:15:10 PM »
ahh this machines power supply is a 24v unit
looking at the picture of the controller.
it appears then that the i/o for the step direction and limit switching must be stepped down to 5v

IF there is an option there for 12v
that would suggest the spindle is 12 volt dc?

so ts a 12v dc motor
IF it has a tacho generator, can I assume it will not work with the mach3?
thanks


Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #31 on: February 12, 2023, 03:37:21 PM »
Hi,
You have yet to identify the motor design. Its impossible to say whether its suitable for Mach3 until that question is answered.

Do some testing with a multimeter and determine what the motor is. The answer to other questions may then be apparent.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'

Offline nobby

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Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #32 on: February 12, 2023, 04:27:09 PM »
ohms x100
reads 400 ohms

i think
brown and white

Offline nobby

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Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #33 on: February 12, 2023, 04:33:07 PM »
ohms x100
tahc
500 ohms
Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #34 on: February 12, 2023, 04:47:36 PM »
Hi,
redo your first measurement. The resistance of the armature will be low, well lower than 10Ohm

Maybe try measuring between other combinations of wires, somewhere you must find a low resistance, be it the armature if its a brushed motor,
or a stator winding if it is brushless.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'

Offline nobby

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Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #35 on: February 12, 2023, 05:41:26 PM »
hello, pardon me from sounding stupid,
I just realised I need a controller for the spindle anyway?
the controller that came with the machine would have had it build in?
considering this machine is 25 years old
did brushless motors exist back then?


to recap

what do i actually want to go and get?

Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #36 on: February 12, 2023, 05:50:21 PM »
Hi,
questions like this are pointless until you confirm what sort of motor it is. The age suggests that this is a brushed DC
motor, but either its faulty, say the brushes worn out, which would explain the high resistance reading you are getting.
Until and unless you can find the armature resistance or equally low stator resistances its not going to run no matter what.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'

Offline nobby

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Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #37 on: February 13, 2023, 11:55:06 AM »
hello there
been looking at stuff.
the spindle motor is a maxon 35/6mm motor body
its mounting is 3 on a triangle
the output shaft i think is 6mm
this goes through a plum or blum coupling to the collet which is in a bearing of its own - real nice and sturdy and factory

I take it IF its a brushed dc motor with a tach its old school
so

maxon themselves make I would assume its modern equivalent in this ?

https://www.ebay.co.uk/itm/334307656880?hash=item4dd64a04b0:g:anUAAOSwD5BZa-XI&amdata=enc%3AAQAHAAAAoFJ2B9dudiAGgCBZwUiE3sJZFTj%2BHP7mSb6gdaZ9xEC6XYU8nC34rccipP5azMeOMx5p1NvJ1BbGtUBH%2FGTiw9mEbRNOk2X6JoQuhxfmBPQcYjm6Zcwvk0YfYZgsr7h%2F%2Bi90nLozUXPf%2B36eRvENX9W6KtkI6vof4l9VmM%2FzlBs0kxltbj3nFCJCRmL6kw3I4vpmxXR2ss2wmCdlZWSuXpw%3D%7Ctkp%3ABk9SR9Kl-bbJYQ




Maxon DC motor


Quick Information (Motor + Encoder)
Nominal Motor Voltage:                        42 V
Nominal Motor Power:                          90 W
Nominal Speed:                                   7560 rpm
Diameter (Motor):                                 35 mm
Length over all:                                    111 mm
Length encoder to motor mounting flange: 91.5 mm
Width at encoder:                                 45 mm
Motor shaft diameter:                             6 mm
Motor shaft length:                                18 mm
Encoder resolution at motor shaft:         1000 Counts / rotation = 4000 Increments / rotation
Encoder Voltage:                                  5 V
Encoder Channels:                               2 (A-B)
Original price in this configuration:         approx. 482 $
Cable length        ca. 250 mm
Comes with a complete cord set, including ferrite cores, combining motor and encoder contacts in one 8-pin plug.
Please tell me if you would like the cable to be removed.

PinOut Encoder
Pin 1: Gnd Enc
Pin 2: not connected
Pin 3: Channel A
Pin 4: Vcc Enc (5V)
Pin 5: Channel B

PinOut Plug
Pin 1: Motor (+)
Pin 2: Shield
Pin 3: Channel B
Pin 4: Vcc Enc (5V)
Pin 5: Channel A
Pin 6: Gnd Enc
Pin 7: Shield
Pin 8: Motor (-)


About Maxon DC motors
maxon DC motors are high-quality motors fitted with powerful permanent magnets. The ?heart? of the motor is the worldwide patented ironless rotor. For you, this means cutting-edge technology in compact, powerful and low inertia drives.

Application
This high quality DC motor with attached incremental encoder and high precision planetary drive can be used for various applications like:
 - Robotics
 - Arduino projects DIY
 - Home automation
 - Motion control
 - Speed control
 - Mechatronic systems
 - High torque, hiqh precision, low space application

Specifications - Motor
Maxon Art.-no.: 273754
Supply Voltage                                      42 V
Nominal power                                       90 Watt
No load speed                                       7560 rpm
No load current                                      92.9 mA
Nominal speed                                       6820 rpm
Nominal torque (max. continuous torque) 101 mNm
Nominal current (max. continuous current) 2.02 A
Stall torque                                            1080 mNm
Starting current                                      20.7 A
Max. efficiency                                      86 %

Characteristics
Terminal resistance                               2.03 Ohm
Terminal inductance                              0.62 mH
Torque constant                                    52.5 mNm/A
Speed constant                                     182 rpm/V
Speed / torque gradient                          7.05 rpm/mNm
Mechanical time constant                      5.35 ms
Rotor inertia                                          72.5 gcm2

Thermal data
Thermal resistance housing-ambient         6.2 K/W
Thermal resistance winding-housing          2 K/W
Thermal time constant winding                 30.2 s     
Thermal time constant motor                    644 s
Ambient temperature                               -30...+100 °C
Max. permissible winding temperature      +155 °C

Mechanical Data
Bearing Type                                           Ball bearings
Max. permissible speed                            12'000 rpm
Axial play                                                0.05 - 0.15 mm
Radial play                                              0.025 mm
Max. axial load (dynamic)                         5.6 N
Max. force for press fits (static)                 110 N
(static, shaft supported)                            1200 N
Max. radial loading                                   28 N, 5 mm from flange
Weight                                                    340 g

Other Specifications
Number of pole pairs                               1
Number of commutator segments             13
Direction of rotation                                 Clockwise (CW)
Number of autoclave cycles                     0


Specifications - Encoder
General information

Encoder Avago HEDS 5500 B11
Encoder type                                           Incremental Quadrature Encoder
Counts (Lines) per turn                             1000
Increments per turn                                  4000
Number of channels                                 2 (A B)
Line Driver                                               No
Index Signal                                            No
Max. speed                                             12'000 rpm
Shaft diameter                                         4 mm

Technical Data
Supply Voltage Vcc                                 5.0 V ± 10.0 %
Driver used logic                                      TTL
Min. angular acceleration                         250000 rad / s2
Output current per channel                       -10...5 mA
Signal rise time                                       180 ns
Measurement condition for signal rise time  CL = 25 pF, RL = 2.7 kOhm
Signal fall time                                        40 ns
Measurement condition for signal fall time  CL = 25 pF, RL = 2.7 kOhm
Phase shift                                             90 °e
Phase shift, inaccuracy                           45 °e
Index synchronised to AB                        Yes
Max. moment of inertia of code wheel       0.6 gcm2
Operating temperature                              -40...+100 °C
Orientation encoder to motor defined         -1.0°


I gather the encoder then wants 5v i/o = great
so do the limit switches I have !!!

which leads to
does the ess smoothstepper run 5v i/o

i.e. I need to buy another controller anyway - the other one can be used on the plasma table

so
buy that motor
buy an ess smoothstepper IF the i/o is 5v
refit the photo limit switches stock

run the drives 48v
use the same psu for the spindle

bobs your auntie

I need anotehr controller
less hassle with limit switching
up the spindle power
up the driver power






« Last Edit: February 13, 2023, 11:57:02 AM by nobby »
Re: just bought a little baby cnc 280mm square davinci style thing
« Reply #39 on: February 13, 2023, 12:58:02 PM »
Hi,
the two are not matched.

The photo of the motor is a brushed DC motor with an encoder fitted.
All that is required to run this motor is to hook up a DC power suppply....you don't need a driver at all. A variable voltage
supply would be nice if you want speed control, but mostly you'll run at full speed all the time. So just a power supply and a relay
to turn in on and off.

The driver you have pictured is for a brushless motor.
The drive is for a different kind of motor altogether.

What about the motor you have already got?
Did you get around to doing any of the measurements I suggested?

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'