[bricks007]

Afternoon all from Australia,

After 2 years of owning my mill I've decided to go the CNC route, there have been some great conversion on here and the information is overwhelming and great to say the least.

So I've decided to go with the steppers for the conversion, as I'm a complete newbie I think this option would be the easiest, I really want the AC servos but they are a little expensive for my build, plus I'm just a shed hobbyist, also trying to find anything online in Australia like pulleys is just frustrating, America has the best online shopping at their finger tips, you guys are lucky, hence why im buy my equipment from automationtechnologiesinc.com

Anyway I was wondering if you guys could help a newbie out, below is what I'm going to buy but id like it if you guys could have a look and pick apart the list if you think there is an issue with my selection, or an compatibility issue. I want to go direct drive hence the motor selection.

X & Y Axis Stepper Motors (1200oz) NEMA34 1200 oz-in Stepper Motor – 1/2″ Single Shaft KL34H2120-60-4A
Z Axis Stepper Motor (2830) NEMA42 HYBRID STEPPER MOTOR 2830 oz-in KL42H2150-42-8A
Z Axis Didigtal Driver/PS KL-22083 8.3 Amp Digital Bipolar Stepper Motor Driver KL-2283
X & Y Stepper Drivers KL-8070D Digital Bipolar Stepper Motor Driver-32 bit DSP Based KL-8070D
X & Y Stepper power supply Unregulated Linear 1440W/72VDC/20A Toroidal PSU (KL-7220) KL-7220
Break Out Board C11 – 6 axis, Multifunction CNC Breakout Board

Oh and could anyone explain this for me, on the automationtechnologiesinc web site, it say the KL-22083 8.3 Amp Digital Bipolar Stepper Driver needs to be wire in series bi polar for the nema 34/42 motors, im just wondering why, im not an electrician but im guess the Nema 2830oz motor is 6amp per phase in parallel so with 2 phases on this will require 12amp driver to run? hence why the motor must be wired for serial? im ready for the constructive criticism, lol...

And does it make a difference if the Z is wired series and the X/Y are in parallel? everything will still run smoothly within Mach?

Thanks all

Brad

[Fastest1]

I havent followed many RF45 builds but where did you get your stepper selections from? They seem like very powerful steppers. A lot of people starting out (and even experienced) tend to go big when it isnt needed. If the people with similar sized machines are successful with them, use them.

Regarding the wiring. It is a bipolar stepper driver so it would make sense that the stepper be configured for it. The other part of the equation is torque and speed. Look at the charts for that stepper, it will show the torque and speed curves for each style of connection. We are really seeking torque. Speed is over rated generally we want blistering rapids but cant machine at those speeds.

Btw I am not sure if you are aware but there is a specific section for the RF45's just above this section. Or you might be well aware of it and their activity level is lower. Not trying to offend, just helping in case.

[arizonavideo]

I would run the 900 OZ steppers on the X and Y. They generate about 1600 pounds of force which is way more then you need. I have been running one on my IH mill Y for half a year and it works fine. In fact I'm running a 900 OZ on the Z because my servo blew out. It is fine but a little under powered. The 1200 oz will work fine for the Z .

[bricks007]

Thanks Guys,

Yeah im not looking for blistering speeds, just making sure I have the required torque to push the mill around without any issues, and if I can i want to stay away from any counter balancing or gas struts. This guy here from Australia has the same mill as me, like you guys say and the guy in the vid its overkill big time, but it works and who doesn't like overkill, lol.

https://www.youtube.com/watch?v=alyuZv7nIpc

So on that note, I think ill stay with 1200 oz motors on the x and y, and go a bit lower size on the z with the 1800 oz and the KL-8070D driver to run it.. Its going to cost around $1800 Australian dollars including postage, god that exchanging rate is kill us, hehe..

But another option is similar motor sizes for near half the cost, Long driver and motors seem half the cost but im concerned buying this brand, keling seem to be a reputable brand/place to purchase, might be worth the extra few dollars for piece of mind.

Thanks guys for your help, will post my progress as I go, maybe someone can learn from my mistakes, hope there isn't to many though..

[arizonavideo]

Precision Mathews sells a CNC RF-45 clone with a CNC kit on it and they use 640oz steppers on the X and Y.

The larger the stepper the slower the RPM for a given current and voltage. At 1000 RPM you will be using about 25% of the power that that stepper can make.

Lucky for you your starting with 3 times the power you need.

[Fastest1]

I havent ever run into a stepper power or torque issue. My steppers on Dynas, Sherlines, and the G0704 will all stall the spindle and or snap an end mill. Easily on a .25 end mill. .375 and above will stall the spindle instead.

[bricks007]

Well its all the electronics are on there way, $2000 aussie dollars laid out including shipping, and probably another 2k again on the rest of the components for the conversion.

Arizonavideo, is that you on youtube as arizonavideo99? Im subscribe to that channel. Have to say the ways on the pm940 nicley finished, mine look like they have been done with a roughing end mill.

One thing im stuck with is whether to build my own bearling blocks or just buy the BK BF supports. I have the equipment to make them just wondering if its worth time. From what i have read the china made one arent the best quality and have some backlash issues, maybe if i get some decent angular contact bearings and use those instead it might help with any issues.

Sent from my SM-P550 using Tapatalk

[Fastest1]

Well its all the electronics are on there way, $2000 aussie dollars laid out including shipping, and probably another 2k again on the rest of the components for the conversion.

Arizonavideo, is that you on youtube as arizonavideo99? Im subscribe to that channel. Have to say the ways on the pm940 nicley finished, mine look like they have been done with a roughing end mill.

One thing im stuck with is whether to build my own bearling blocks or just buy the BK BF supports. I have the equipment to make them just wondering if its worth time. From what i have read the china made one arent the best quality and have some backlash issues, maybe if i get some decent angular contact bearings and use those instead it might help with any issues.

Sent from my SM-P550 using Tapatalk

In my experiences its the hardware that is the issue on ball screws (Chinese). The machining will be ok but the locknuts suck. Source those some where else, even a local hardware store.