[Daznc]

Hi all,

Im a cnc programmer by trade who lives in the UK, done my time on the machines as well and now have sort of decided to bring my work home.. sad i know!

About a month ago now downloaded myself a Sieg X2 mill from Ebay and am very pleased with it, i have big plans for this little baby but not 100% on where to start regarding choice of stepper motors, driver boards and control boad etc.

My plans for the use of the mill will be mainly RC model car parts and anything else that i need to tackle with a mill, light to medium work so dont want to limit myself to much.

I have already got a Pc set up with Mach 3 and made myself a control panel which has been set up using Keygrabber and all has turned out well so far (thanks Hoss you have been a great help and inspiration in the world of home brew cnc!). So next up will be the electronis followed by the mechanical side of things.

I have read up a fair bit on what other people have done and decided that a Fusion 3 axis ballscrew kit might be the best and more successful approach, but not sure about the stepper motors, looking to be able to keep manual control so dual shaft Bipolar Nema 23's but what size 282 oz-in, 495 oz-in? Want good rapid speeds to plus potential for heavier jobs i.e dont want bottom of the range/thatl do jobbys!

Also looking for any advice on driver boards, control boards and powersupply to if anyone could help me? Planning on housing it all in a old Pc case so i should have plenty of room plus half the sockets and fixings will already be there. Already started collecting more switches, fans, plugs and sockets and not to forget a Emergency stop button to!!

Any help or advice on tried and tested or recommended parts available to me in the uk would be greatly appreciated.

Thanks

Darryll

[LongRat]

Hi Darryl.
I am in the UK too, I also make RC car parts on a converted X2 (mine is a Chester UK machine). I got some ballscrews and Gecko G201 drives from homeshopcnc. Good service, reasonable prices I thought. I used a breakout board from CNC4PC. I run my system on 39VDC and have NEMA34 450 oz.in motors. I have been very happy with this set up over the last few years and it has put in an awful lot of work. Certainly recommend this equipment if you want good stuff that is possibly a bit over-spec for the X2. I could easily get an X3 and swap everything over to that, for example.

[Daznc]

Hey Longrat,

Thanks for the speedy response! Your setup looks great, like the enclosure to helps keep all the mess where it should be, im planning on one to as want to fit flood coolant in time.
Also noticed you have dual shaft motors to, good bet as i dont fancy losing manual control either. So Nema 34's are a bit on the big side then? Did you make the rest of the parts yourself to suit?

Not confident enough at present to completly machine all the parts myself so did think that a Fusion kit would make things a bit more simple but then that would limit me to Nema 23's but from the amount of people i have seen using them i would of thought they will do the job but still not decided on what size motor will be best as there seems to be so many?!!?

Thanks once again for you advice and i will post pics as and when i get more into the project, good to see other peoples ideas!

Cheers
Darryll

[Crevice Reamer]

Hi Daznc. Welcome to the Zone!

I recommend THIS $299 driver/breakout board:

http://www.geckodrive.com/product.aspx?c=3&i=14469

And THESE $39 motors:

270 oz KL23H276-28-4B

And THIS $59 Power Supply:

48V 7.3A KL350-48

From:

http://kelinginc.net/

Both companies will ship to England.

CR.

[Daznc]

Thanks CR

I have read good things about both of those companys and have been looking at Keling Steppers, also i do like the Geko driver/breakout board as its a all in one, neat and tidy little box of tricks... plug and play like it!

Thanks very much for that!

Darryll

[hoss2006]

I'd recommend at least a 425 oz/in motor for the Z axis.
It has much more mass to move around than the X and Y.
Sucks having the X and Y whipping around at 100 IPM and the
Z is stuck at 20.
Hoss

[Daznc]

Hoss! What an honor, hello!

Good work mate keep it up, you have filled me with ideas for my conversion thanks!

A very good point you have there, was planning on adding a ballast weight to the Z axis as seen your cunning plan involving chain and sprocket, thought that that would be a help with the weight of the head but might go with a bigger motor to for a bit more lift!

Have not got my head around all the wiring of the motors yet just working out what would be best but sure it will all become clear soon, just want to get all the bits and bobs together then set to work!

Some pictures of control panel and setup so far, not much but its a start!

Thanks

Darryll

[hoss2006]

Hey Darryll,
Good job on the control panel, if you can do that, the other wiring will be a snap.
Geckos are notoriously bullet proof so no need to worry.
That counter balance gained me about 15 IPM more than stock when I used it,
look at the gas spring kit from LMS too, would be easier to install.

[Daznc]

Thanks Hoss,
Panel was quite a doddle to do just a fine hand when soldering and a bit of patience over a few evenings! Bending the case into the right shape over my bench was the fun bit!!
I think Gekos might be the way (possibly G540?) so far combined with Nema 23's 282 oz-in for X & Y & 425 oz-in from Keling on the Z with a power supply from them to topped off with a Fusion ballscrew kit! I assume i can mix different size steppers using the same drivers?
I have seen the gas spring kit but was not aware that it had 35lbs of force behind it which i believe (correct me if im wrong) that is somewhere close to the weight of the head? Might be a bit easier!

Still won't beat the monsters at work running 30,000rpm, 50mtr feed and 20mm d.o.c but hey i aint spending £500,000!!

Cheers once again Hoss

Darryll

[Crevice Reamer]

If you are going to use the G540, then the 282 oz motors aren't the best choice. They require 4.2A. Torque = amperage. The G540 can only output 3.5A. That means you will lose 17% of the torque. That motor with the G540 will only give you 234 oz of starting torque instead of 282.

Your best bet is the 270. That will give you a full 270 oz of torque and pretty good rapids with 48V. If you want to see them FLY, Invest the $75 more into the Keling 54V Power supply. (With all motors energized, The actual output will be about 50V.)

As for the Z, The 425 is not the best bet. Its max voltage is way higher than what the G540 can use, so rapids will be slower.

A far better choice would be the 382 oz KL23H2100-30-4B.

CR.

[Daznc]

Ah thanks again CR,

As i said im not 100% on what im going for yet but have alot more of an idea now, think i might have to sit down make a few notes and do a few calc's!

Cheers for the advice

Darryll

[hoss2006]

The 382 oz KL23H2100-30-4B is a 4 wire motor so it can only be used in Series,
The 425 oz KL23H286-20-8B is an 8 wire motor so it can be wired either series or parallel.
Parallel is the preferred mode as you'll get less of a drop in torque as the RPM increases versus series.
The rated voltage in parallel mode is 4.7volts, using the standard rule of 10-20 times rated voltage, puts it well within the needs of the gecko.
In series mode you get a big boost of torque at the very slowest rpm's and it
drops off to almost nothing when you need the torque for rapiding.
I have some pdf links on this page that give a good overview of stepper and driver circuits.
Helps take out some of the mystery.
Hoss

[Crevice Reamer]

The 382 oz KL23H2100-30-4B is a 4 wire motor so it can only be used in Series,
The 425 oz KL23H286-20-8B is an 8 wire motor so it can be wired either series or parallel.
Parallel is the preferred mode as you'll get less of a drop in torque as the RPM increases versus series.
The rated voltage in parallel mode is 4.7volts, using the standard rule of 10-20 times rated voltage, puts it well within the needs of the gecko.
In series mode you get a big boost of torque at the very slowest rpm's and it
drops off to almost nothing when you need the torque for rapiding.
I have some pdf links on this page that give a good overview of stepper and driver circuits.
Helps take out some of the mystery.
Hoss

You are right, Hoss. I missed that. The 382 can only be wired Bipolar Serial. The 425 will be the best choice.

EDIT TO ADD: Nope! That's not true as explained in a later post.

CR.

[Daznc]

Cheers guys!

Right so after reading Hoss's pdf files (cheers Hoss very in depth on stepper science, alot to get your head around might have to read that again!) i think that i will be going for Nema 23 bi polar (Keling dont list Dual shaft though?) 425's on all axis together with Geko drivers (can i still use the G540 with 425's on all axis?) and power supply to suit!?
Can anyone tell me whats the deal with wiring the steppers parallel or series because i have read that alot of people do prefer wiring parallel as Hoss mentioned but aslo that some people do a mix of both i.e. parallel on X & Y and series on Z??

Thanks once again, its all starting to make a bit more sense now!

[hoss2006]

I ran the Z motor in series mode for a while thinking I wanted more torque to get it moving
but when I switched to parallel mode it increased the speed by about 5 IPM.
Not a huge increase but better just by flipping a few wires.
Looking forward to hearing how yours runs with the new Geckos,
I'll probably uses them for my lathe
Hoss

[Crevice Reamer]

If you powered that 425 with 72-80 volts, you would get a LOT more than 5 IPM increase.

After further research, I have to respectfully disagree with Hoss. Apparently all 4 wire motors have 4 coils inside. SOME are wired bipolar series, and SOME are wired Bipolar parallel. This wiring is done internally and cannot be changed by the user.

4 leads - Bipolar Drive

4 Leads
The standard connection for a four lead motor.
This is the standard connection for a bipolar drive. Please note that the motor seems to have only two windings, but this is not true. There are still four windings and, depending on motor type, they are in series or parallel. Most manufacturers makes two models with the same winding, but one time connected is series and one time in parallel.

http://www.wimb.net/index.php?s=motion&page=52

http://www.cs.uiowa.edu/~jones/step/types.html

You can tell which is which though, by their amperage and inductance specs. SERIES motors have very high inductance and low amps. Parallel motors have fairly low inductance and higher amps.

Let's look at the 425:

http://kelinginc.net/KL23H286-20-08B.pdf

Wired Bipolar Parallel, the amps are 2.8 and the inductance is 6.8 mH. Wired Bipolar Series, the amps are 1.4 and the inductance goes WAY up to 27.2 mH. This high inductance is what kills the power at higher speeds.

I believe that the Keling 4 wire motors are wired internally to Bipolar Parallel. Checking the specs confirms this.

Here's the 382: 3A and 5.2 mH.

http://kelinginc.net/KL23H2100-30-4B.pdf

These are Bipolar Parallel specs even though there are only 4 wires. If they were wired series internally, they would have inductance in the >20 mH range.

Here's the 270: 2.8A 3.6 mH.

http://kelinginc.net/KL23H276-28-4B.pdf

The Keling 4 wire motors are obviously wired internally to Bipolar Parallel.

Gecko has updated their Best power supply formula. It is no longer 20 or 25 times rated voltage.

The new formula is: 32 times the square root of the inductance.

http://www.geckodrive.com/faq.aspx?n=342824

With the G540, I would recommend the 270s for your X and Y and the 382 for the Z. This should give you the best possible power and rapid speed with 48 volts.

CR.

[LongRat]

I don't think you need NEMA34 motors for the X2. But the fact is, they are actually smaller than NEMA23 motors in length which is the dimension that matters when fitting to an enclosure. And they have superb torque, I've never had a problem. I run mine at the rated 6A which of course is pretty high. I don't use the dual shaft and never will. Don't kid yourself that you will need that for manual work, I wish I had gone for single shaft really.
You won't be disappointed if you set your system up as I did, but remember I did it with future expansion to a possible bigger machine in mind. And also, there was a lot less choice around when I did it. Whatever you do, I would go with Geckos of some variety every time. They are rock solid and backed up by a true expert in the field who is not afraid to converse on technical matters openly on this forum.

[Crevice Reamer]

Hi LongRat. That's a very nice conversion!

There is no question that Nema 34 motors pack the most power in the shortest form factor. They also run cooler. However, their amps and voltage are usually beyond the G540's capabilities.

CR.

[Oldboy]

Hi Daznc
Most people use NEMA23 425OZ eight wire. So it gives you the choice to wire it up Series or Paralle. If you want speed Paralle. If you want more torque Series. Something very important to think about is HOLDING POWER.
If your using ACME screws or Ball screws. Acme has better holding than a free turning ball screw. If your not milling hard metals like steel.
You don't need as much holding power. Some found that the smaller 280oz NEMA23 steppers have more speed on the X&Y. But lack the torque of a 425oz stepper. As for the NEMA34? Some use it for driving there 4th axis.
Its more torque than speed.
You need to decide just what your mill needs to do. Meaning just how fast a feed rate you realy need? Then pick the steppers ect.
Me im more into holding power slow feed doing steel.

[hoss2006]

Hi Daznc
Most people use NEMA23 425OZ eight wire. So it gives you the choice to wire it up Series or Paralle. If you want speed Paralle. If you want more torque Series. Something very important to think about is HOLDING POWER.
If your using ACME screws or Ball screws. Acme has better holding than a free turning ball screw. If your not milling hard metals like steel.
You don't need as much holding power. Some found that the smaller 280oz NEMA23 steppers have more speed on the X&Y. But lack the torque of a 425oz stepper. As for the NEMA34? Some use it for driving there 4th axis.
Its more torque than speed.
You need to decide just what your mill needs to do. Meaning just how fast a feed rate you realy need? Then pick the steppers ect.
Me im more into holding power slow feed doing steel.

Agreed, I much prefer the versatility of an 8 wire motor not leaving it up to a manufacturer as to how I want to use it.
Not much sense worrying about what max voltage a motor can run at when the
driver is limiting it to much less.
They both can't run at more than the drivers max voltage and amps therefore the torque will depend on the size of the motor.
Everyone knows If you want to spend a bunch more money, you can get the drivers and PS that will get the max out of the motors.
As Oldboy posed, Do you need it? It's up to the individual.
Seeing how the X2 only has to move an axis 9 inches at most, it doesn't seem
worth it to me, just my opinion.