Centroid Community CNC Support Forum

RKM,

The biggest mistake that I made was undersizing my servos. I have a PM25 which is smaller that now has 4.4 Nm servo for X & Y axis (replaced original motors about $500 mistake).

I would recommend that you find someone that has an operating PM30 and see what size motor they used. It is cheaper to learn from others mistakes, you will need the money for other tools.
Chuck

martyscncgarage wrote: ↑Tue Aug 18, 2020 11:13 am those should be ok.
You have a choice, DC supply or AC supply. AC supply you would just need the transformer.
48VDC should be fine, will affect your rapid speeds. Are you direct driving the ball screws?
Should be OK. More voltage, faster motor RPM. If direct driving, would be neglibible.
You might take a look at www.antekinc.com they have a large number of DC Toroidal power supplies.

Marty

not really looking for "ok"

the only supply i can find on steppersonline is : https://www.omc-stepperonline.com/switc ... 00-48.html
and this gives me the low end for my motors, they can do 48-100, and I'm just supplying the bare minimum in that spectrum.
so my question is what inches IPM could I achieve with this supply?

i am not at all familiar with toroidal power supplies.

thank you,
RKM

carbuthn wrote: ↑Tue Aug 18, 2020 11:45 am RKM,

The biggest mistake that I made was undersizing my servos. I have a PM25 which is smaller that now has 4.4 Nm servo for X & Y axis (replaced original motors about $500 mistake).

I would recommend that you find someone that has an operating PM30 and see what size motor they used. It is cheaper to learn from others mistakes, you will need the money for other tools.
Chuck

thank you, yeah the way it sounds i have my sizing down for my stepper motors,
this project may take a year to gather funds and parts as i go, or it may take 2mo depending on what cash i can get moved around for it.

How about Dual shaft steppers? so I can attach a hand wheel to do manual milling still.
is this an ok thing to do? the reason I ask is, doesn't the stepper turn into a generator when turned by hand and can "back feed" voltage to boards and fry them? or is there a setting to disengage the motors in the software so they aren't "active" and this wont happen?

thoughts on this would be super helpful

thank you,
RKM

If you turn steppers by hand, you loose your position information and your DROs will not update with the movement. The Acorn is an open loop controller.

RKM 3D Designs wrote: ↑Wed Aug 19, 2020 12:56 pm How about Dual shaft steppers? so I can attach a hand wheel to do manual milling still.
is this an ok thing to do? the reason I ask is, doesn't the stepper turn into a generator when turned by hand and can "back feed" voltage to boards and fry them? or is there a setting to disengage the motors in the software so they aren't "active" and this wont happen?

thoughts on this would be super helpful

thank you,
RKM

I think you will find if you buy the Wireless MPG, you will not need to turn "handwheels" and if you learn to use Intercon (Conversational programming) you will be able to do a lot with out CAD/CAM, but you will have to learn Feeds and Speeds for your machine, cutters and material.

tblough wrote: ↑Wed Aug 19, 2020 2:32 pm If you turn steppers by hand, you loose your position information and your DROs will not update with the movement. The Acorn is an open loop controller.

ok cool then no handwheels for me then.

martyscncgarage wrote:
I think you will find if you buy the Wireless MPG, you will not need to turn "handwheels" and if you learn to use Intercon (Conversational programming) you will be able to do a lot with out CAD/CAM, but you will have to learn Feeds and Speeds for your machine, cutters and material.

ok cool.

looks like im looking at these steppers and drivers. and 3 of these power supplies, since steppers online guys told me i need a power supply for each kit.
https://www.omc-stepperonline.com/ye-se ... river.html

https://www.omc-stepperonline.com/ye-se ... river.html

https://www.omc-stepperonline.com/350w- ... 50-60.html

is there any reason you anyone would say hell no dont buy these.

Many buy stepper on line. ME personally, I call hogwash on individual power supplies. I would never do that personally.
One good toroidal unregulated power supply properly sized would do.
Open Loop steppers are typically engineered about 20-30% over the torque needed for the typical machine. You don't have to do that with closed loop steppers or servos. When I refit. I try and stick with a similar rated motor that came off the machine.

YOU ARE RESPONSIBLE at the end of the day for making your choices. YOU ARE responsible for building your machine.
We are only making suggestions. You should continue to do your due dilligence and search around for others that have successfully converted a similar sized machine, see what motors and drives they used, power supplies etc.

This forum is primarily to support the Centroid Acorn motion controller and make suggestions to help get you going with what you got.
Have you downloaded the Acorn schematic set? I suggest you do so and take a look at them.

Good luck!
Marty

martyscncgarage wrote: ↑Thu Aug 20, 2020 9:00 pm Many buy stepper on line. ME personally, I call hogwash on individual power supplies. I would never do that personally.
One good toroidal unregulated power supply properly sized would do.
Open Loop steppers are typically engineered about 20-30% over the torque needed for the typical machine. You don't have to do that with closed loop steppers or servos. When I refit. I try and stick with a similar rated motor that came off the machine.

YOU ARE RESPONSIBLE at the end of the day for making your choices. YOU ARE responsible for building your machine.
We are only making suggestions. You should continue to do your due dilligence and search around for others that have successfully converted a similar sized machine, see what motors and drives they used, power supplies etc.

This forum is primarily to support the Centroid Acorn motion controller and make suggestions to help get you going with what you got.
Have you downloaded the Acorn schematic set? I suggest you do so and take a look at them.

Good luck!
Marty

iv looked at franco's videos on youtube.
so what forum should i be in so i can actually ask the question i have? the accorn is easy its schematics just hook it up and read the literature. use to do that stuff day in day out in the military.
im here making sure i make the right choices in my power and motion choices, so far what ive gathered is i might be on a good track.
what forum do you recommend i go to so i can ask all the questions i have.

Centroid Acorn is your chosen control. (Great choice in my opinion! )
I personally think Leadshine or Stepper on line are decent brands. Better than generic.
Just check with others with similar sized machines, to find what size motors/drives/power supplies, VFD's, others are using on their machines successfully and follow suit. Ask them questions. Most are willing to share what works, doesn't work, and what they might have done better.

My fear is that you ask for advice, the suggestion is given, you buy it, it doesn't work out and then you come back and place blame because you percieve that someone told you to buy/do something and you are upset. I hope you understand what I'm getting at.

You ask for advice and opinions, we are here to share them. At the end of the day, you have to make the decision that best suits you. If this is your first machine, take the time you need to research and feel reasonably confident you are making a purchase you only have to do once. Nothing worse than trying to save a buck and having to buy twice. In the long run, that costs you more money and time than if you would have spent a little more money and bought the right thing to begin with. CNC can get expensive when you add everthing up.

CNCZONE.COM is a popular forum for questions like yours. There may be a group on www.groups.io for Precision Matthews users.
Maybe google Precision Matthews forum or Precision Mathews PM-30V CNC.

Hope for your understanding...
Marty