New acorn Board and a few questions

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Bosco
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New acorn Board and a few questions

Post by Bosco »

Hello
I recently purchased the acorn board ,Did the benchtest and all went well so far. I've been do ing a lot of reading on the forums and they are very helpful, but I still have a few questions.

I try to give you as much info on what I have
Bulkman Cnc 3 Axis/ 4 Motor router - https://bulkman3d.com/knowledge-base/uc ... er-wiring/
Driver supply - 24V Mean Well LRS-350-24
TB6600 Stepper Driver
TB6600-Stepper-Motor-Driver-BM3D-v1.1.pdf
(708.64 KiB) Downloaded 69 times
Stepper motors -
23HD56001Y-21B.pdf
(130.41 KiB) Downloaded 73 times
VFD and Spindle -
HY01D523B-VFD-Manual.pdf
(12.13 MiB) Downloaded 68 times
Lead Screw TR8 2mm pitch

1. I downloaded all the schematics and was wondering which one to use the leadshine seems to be the one suggested not
sure which one there are more one and with everything i Have as far as the drivers and power supply is it possible
connect the step and drive to the screw terminal on the board or is the DB25 connector the best way?
2. I have The Drivers settings 4 Micro Steps 800 Pules/rev With the Dip Switches set ON,OFF,OFF,OFF,ON,OFF
is this the best settings for these motors?
3. what would be the advice for a main power switch once all is wired in a cabinet as far as ratings Voltage and amps

I am new at this and any advice would be appreciated
Thanks
Attachments
UC300 User Manual V2.pdf
(1.77 MiB) Downloaded 72 times
Richards
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Re: New acorn Board and a few questions

Post by Richards »

Question 1. Use the DB25 connector. You can use either Common Anode (Page 4 of the manual) if you use +5VDC as the stepper driver common, or you can use Common Cathode (Page 5 of the manual) and then use the DB25 ground signals as stepper driver common. I've used both Common Anode and Common Cathode with DM542 stepper drivers with excellent results.The DM542 driver is similar in ratings to your driver. NOTE: Do NOT connect the Enable signal. If it is active, it DISABLES the motors. If it is inactive or unconnected, the motors are enabled as soon as power is applied.

Question 2. You have set the motors to 800 steps per revolution and 3A current. The motors are rated at 2.8A. The driver has a 2.8A setting with switches S4, S5, and S6 set to OFF, OFF, ON. Also note that the motors have 2.3mH inductance. The maximum voltage for those motors is about 48VDC (SQRT(2.3) X 32 = 48.5VDC). You can find an excellent White Paper on the GeckoDrive.com web site that explains in detail the fundamentals of stepper motors and stepper drivers. A 24VDC driver power supply, like the one you have listed, will work just fine; however, a higher voltage power supply will allow faster jog rates. A rule of thumb is that the CURRENT mostly affects torque and VOLTAGE mostly affects speed. I use a 48VDC power supply with my DM542 drivers. A 36VDC power supply is a good compromise between speed and heat, but the 24VDC power supply that you have in your kit is good.

Question 3. I use a disconnect switch on my builds. I wire the switch with 120VAC, Neutral and Earth connected to terminals on the switch. That way, when I turn the switch OFF, all outside power is disconnected. There are two types of disconnects, DIN rail mounted and Door/Case mounted. I normally use the Door/Case style because it is easier to mount, requiring only a 22mm hole in the enclosure. The DIN rail mount style requires you to align the DIN rail mounted switch to the hole in the door. Tim Wilbourne on YouTube shows how he does that. I use disconnects from AutomationDirect.com (ML1-025-E-H03R ) or FactoryMation.com.

Good luck on your build. We're here to help.
-Mike Richards
Nigelo
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Re: New acorn Board and a few questions

Post by Nigelo »

Fully agree with Mike above although I would prefer setting steps / rev to 1600 for smoother operation. Remember to set Acorn to match this setting with whatever you decide.

If you do decide to increase the drive voltage for better performance, note that your driver has a max of 40vdc so cannot run the optimum 48vdc.

Hope this helps
"You can lead a horse to water but you cannot force it to drink"
Hope this helps
Nigel
Richards
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Re: New acorn Board and a few questions

Post by Richards »

The steps per revolution is a good point. The problem that I see with 1,600 steps per revolution is the loss of torque. The motors listed have a little less than 200 oz-in torque at standstill before current reduction kicks in and reduces holding torque to about 100 oz-in. That motor moves 1.8-degrees per full step or 200 steps per revolution. At 200 steps per revolution, the motor produces the greatest amount of torque possible per step. Sub-dividing the steps reduces the torque. The more micro-steps per full step, the lower the torque. I thought about recommending 1,600 steps per revolution, as is commonly done; but, after looking at the motor and the application, I decided to wait and see. If the motors stall under load, then we could discuss the need for gearing, for larger motors, or for changing the step rate.
-Mike Richards
Gary Campbell
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Re: New acorn Board and a few questions

Post by Gary Campbell »

There is a recommended minimum setting of 1600 steps per rev with Acorn
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Richards
Posts: 692
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Re: New acorn Board and a few questions

Post by Richards »

I don't want to start a war about micro-stepping. 1600 steps per revolution is ideal under normal circumstances, but, depending on the motors, the load and the power supply, 1600 steps per revolution might not work as expected. Let's take an example. Imagine that you're driving an old VW Beetle. You're on a stretch of level road. You've worked up through the gears and you're cruising along in 4th gear. The road starts to incline. The engine begins to labor. You have a choice. You can gear down or you can stall the engine. The stepper motors specified in this thread are similar to the VW engine. They are adequate when the operator knows their limitations and how to get around their limitations. Just as you cannot start driving a VW in 4th gear, sometimes you can't use the recommended micro-stepping because the motor can't "pull the load" when set to 1600 steps per revolution. There are ways to get around that. You can extend the ramp time to be longer than the default 0.5 second. You can set the motor to 400 steps per revolution or 800 steps per revolution. You can add a gearbox or belt-drive transmission. The adage that one size fits all only applies under almost ideal conditions. Knowing what each parameter does and what its limitations are lets the operator know when a simple parameter change can be a cheap alternative to adding a gearbox or a belt-drive when the motor keeps stalling.
-Mike Richards
Gary Campbell
Posts: 2164
Joined: Sat Nov 18, 2017 2:32 pm
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Re: New acorn Board and a few questions

Post by Gary Campbell »

Richards wrote: Mon Sep 27, 2021 11:02 am I don't want to start a war about micro-stepping. 1600 steps per revolution is ideal under normal circumstances, but, depending on the motors, the load and the power supply, 1600 steps per revolution might not work as expected. Let's take an example. Imagine that you're driving an old VW Beetle. You're on a stretch of level road. You've worked up through the gears and you're cruising along in 4th gear. The road starts to incline. The engine begins to labor. You have a choice. You can gear down or you can stall the engine. The stepper motors specified in this thread are similar to the VW engine. They are adequate when the operator knows their limitations and how to get around their limitations. Just as you cannot start driving a VW in 4th gear, sometimes you can't use the recommended micro-stepping because the motor can't "pull the load" when set to 1600 steps per revolution. There are ways to get around that. You can extend the ramp time to be longer than the default 0.5 second. You can set the motor to 400 steps per revolution or 800 steps per revolution. You can add a gearbox or belt-drive transmission. The adage that one size fits all only applies under almost ideal conditions. Knowing what each parameter does and what its limitations are lets the operator know when a simple parameter change can be a cheap alternative to adding a gearbox or a belt-drive when the motor keeps stalling.
Mike...
I agree completely. The torque reduction as each layer of microstepping is added is much more substantial than most DIY guys realize. Steppers are rated at (usually) full steps (sometimes half), zero rpm. Th reality is that the drivs are usually set to 50% idle current, so they seldom develop full torque when stopped. Then micro stepping is introduced reducing torque to under 20% at 1/8 (1600) under 10% if tenth (2000) is selected. That is the reason that a servo outputting 200 ozin continuous torque will kick the a$$ off a 900ozin stepper. Its because the 900ozin stepper is maxed out near 150ozin and the servo has 200 continuous and a peak 4-5 times that for a few seconds.

That said, The recommended minimum steps per rev setting still remains at 1600. This comes from Centroid. I use steppers with enough torque to be set at 3200 / rev on the stepper systems I design, (produced by others) but I prefer servos. Coincidentally, I set the ClearPaths to 3200 also, even the RNA models.
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Bosco
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Re: New acorn Board and a few questions

Post by Bosco »

Thank you for the replies
all the info was very helpful and got me on my way to motor travel and seems that the motor tuning has worked as well.
this forum and all the info is very helpful did a lot or reading on steppers may upgrade in future now knowing all the info.
have been looking at a subject on forum that I am unsure of and was wondering if it is possible to do, I have several 12v pc fans and was wondering how to incorporate them in the cabinet. not sure best way to connect them, can this be done?
thanks again
Richards
Posts: 692
Joined: Sun Sep 16, 2018 9:01 pm
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Re: New acorn Board and a few questions

Post by Richards »

I would suggest that you get some 24VDC case fans, such as the OD4010-24HSS from Mouser. They cost less than $6 each. You can run two 12'VDC *matched* fans connected in series from a 24VDC supply or you can add a 12VDC power supply. I wouldn't do either. At $6.00, I'd buy something that matches the other Acorn components instead of making the Acorn components match what you have on hand.
-Mike Richards
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