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Re: Pulse in setup

Posted: Fri Mar 05, 2021 7:52 am
by Richards
Tell us about how you have mechanically connected the motors. Do you use ball screws, gears, rack and pinion? What resolution and speed do you need? For example, on my test bench, I have a 5mm ball screw. Each revolution of the motor shaft moves the axis 0.1969 inches. With the drive set to 200 steps per revolution, each step would move the axis ~0.001 inch. With the drive set to 400 steps per revolution, the axis would move ~0.0005 inches per step. Mechanically, that ball screw can't even repeat 0.0005 inches per step. Even at just 100,000 steps per second, if I set the drive to 400 steps per revolution, the axis would move 50 inches per second, which is much too fast for that ball screw.

What I've found with the Acorn, using ball screws that I can afford, is that the Acorn can easily produce many more steps per second than the mechanics of the machine can handle. The drives can be set to produce finer moves than the mechanics can handle. So, I have the best of all worlds. The Acorn is not limiting the mechanics of what I have in the drive chain.

Re: Pulse in setup

Posted: Fri Mar 05, 2021 11:05 am
by usinart
new report

Re: Pulse in setup

Posted: Fri Mar 05, 2021 1:22 pm
by usinart
And My screw as a pitch of 10 for the x and y .

Re: Pulse in setup

Posted: Mon Mar 08, 2021 7:34 pm
by cnckeith
ok.. the report.zip shows you have the overall turns ratio set to 12 turns per inch.

what kind of machine is this? photos. ballscrews or leadscrews? how did you determine the pitch of the screw? how are the axis motors connected to the machine ? direct drive or belt? if belt then what ratio?

what encoder steps per rev INPUT do you have set on the motor drive (or in the motor drive software)?
report shows you have Acorn set to 1600, the drive setting should match that!

always perform a bench test with motor disconnected from machine to verify that the steps per rev set in the wizard matches the steps per rev in the servo drive. marty has videos showing this. basically what you do is set the overall turns ratio to 1 turn per inch then command a 1" move
using MDI (G0 X1) and observed the motor shaft, it should turn 1 revolution. if not, you do not have steps per rev settings matching. do not proceed with other settings until you get this right otherwise you will just dig yourself a hole. :-))

Re: Pulse in setup

Posted: Thu Apr 01, 2021 10:13 am
by usinart
until that setup I tried to install a rotary axe with open loop drive set to 1600 step per rev. My axes are set up with the db25 . I plug my #4 rotary on the #8 #9 step dir . and the one of the com. By using the db25 plug did I have to do something special in the wizard. I have seen that is a section for the db25 should I do something there.
I

Re: Pulse in setup

Posted: Thu Apr 01, 2021 10:53 am
by martyscncgarage
usinaet wrote: Thu Apr 01, 2021 10:13 am until that setup I tried to install a rotary axe with open loop drive set to 1600 step per rev. My axes are set up with the db25 . I plug my #4 rotary on the #8 #9 step dir . and the one of the com. By using the db25 plug did I have to do something special in the wizard. I have seen that is a section for the db25 should I do something there.
I
Yes, go into the DB25 tab of the wizard and make sure Step and Direction Output output says DB25 at the top:
DB 25 Mapping Screen Shot.jpg

Re: Pulse in setup

Posted: Sat Apr 03, 2021 12:58 pm
by usinart
Hi Marty sorry no manual .
It a DM 556 Chinise drive . the drive is set to 1600 micro step on it , it a rotary axe A and the ration 4:1 , 1 is the motor gear.
It on the Cnc12 that i have trouble figuring it out .For now the drive is on green light is on . the rotary is lock not moving .
I played with the A + A- on the screen and nothing is moving.
What is the basic setup to go from ?
Thanks
Alain




https://photos.app.goo.gl/bTsU16J6G1sCd1Gm9

Re: Pulse in setup

Posted: Mon Apr 05, 2021 6:25 pm
by martyscncgarage
usinaet wrote: Sat Apr 03, 2021 12:58 pm Hi Marty sorry no manual .
It a DM 556 Chinise drive . the drive is set to 1600 micro step on it , it a rotary axe A and the ration 4:1 , 1 is the motor gear.
It on the Cnc12 that i have trouble figuring it out .For now the drive is on green light is on . the rotary is lock not moving .
I played with the A + A- on the screen and nothing is moving.
What is the basic setup to go from ?
Thanks
Alain




https://photos.app.goo.gl/bTsU16J6G1sCd1Gm9
Without a drive manual and its programming and terminal definitions you are likely out of luck.
Marty

Re: Pulse in setup

Posted: Tue Apr 06, 2021 10:23 am
by Richards
The DM556 manual is available on the Internet. I entered "DM556 manual" in Google to find it. Figure 9 of the manual that I'm looking at shows the connections required from the Acorn to the DM556.

You wrote: "I plug my #4 rotary on the #8 #9 step dir . and the one of the com." From what you wrote, I'm assuming that you connected DB25 pin 8 to the DM556 Pulse+ and DB25 pin 9 to the DM556 Dir+. You wrote that you used ONE common. You need to connect a DB25 COMMON pin to the DM556 Pulse- terminal and a DB25 COMMON pin to the DM556 Dir- terminal.

Normally, you DO NOT connect anything to the DM556 ENA+ and the DM556 ENA- terminals.

This is what happens if you connect the terminals as I've described: Inside the DM556 is a circuit that detects current. The circuit turns on when current flows through that circuit. When the Acorn sends a HIGH signal from its DB25 connector, the Acorn provides current to the DM556. The COMMON connection completes the path for the current. Acorn -> Pulse+ -> Common creates a complete path for the current. When connected this way, the Acorn SOURCES current to the DM556 driver.

The DM556 manual shows the a Controller connected to SINK current. The figure in the manual shows that you connect +5VDC to the Pulse+ and the Dir+ terminals. You connect the Acorn's step signal to the DM556's Pulse- terminal and the Acorn's direction signal to the DM556's Dir- terminal. Choose one method or the other. I have used both Sourcing and Sinking connects with some DM542 drivers. I clicked the Invert button in Wizard to get the proper polarity.

Here's what I would do. On the test bench, I would connect Acorn DB25 pin 8 to DM556 Pulse+. I would connect one of the Acorn DB25's Common pins (18-25) to the DM556 Pulse- terminal. I would NOT connect anything to the DM556 Dir pins or to the DM556 Ena pins. Use A+ and A- to move the motor. If the motor does not turn, then invert the signal in Wizard for the A axis. Without Dir connected, the motor will only turn in one direction. After you get the motor turning, then connect the Dir pins.

DM556.png

Re: Pulse in setup

Posted: Tue Apr 06, 2021 9:20 pm
by usinart
Hello Richard
I made the connection as you said but nothing works.
I'm sending pictures to see if you saw anything wrong.
I tried red with a spinning senx and then I changed it, nothing spins.
on your side the test bench said what?
Alain


https://photos.app.goo.gl/N4LxPsWhwECpqDcr7