[mkenney]

I'm a newbie, but you all seem kind to us!! I've read articles on this site until my eyes got crossed and I wake up in my own sweat. I've then repeated the process and think I'm getting somewhere, probably means I'm really messed up and thinking wrong.

I have a Sieg X2 mini-mill from MicroMark and want to get into the CNC world. From reading many posts here and elsewhere I've gotten this far on the order list:

- CNCFusion Kit #4 for $559
-Kelinginc.netC: CNC 3 Axis Package with 425 oz-in motor and KL-4030 Bipolar
Driver with 24V Power Supply: $359
-Mach 3 milling ~$179

Still need: limit switches, wire and a PC with a parrell port. Sure I'm forgetting lots hopefully nothing too pricey.

Where my excitment and ready to drool and wait up at night for things to come in got killed was when I turnned to software for making my parts in. BobCAD-CAM looks to be ~$2200 and the option I see the most. Is this really where the cost gets so high or is this total overkill? I want to be able to design in a 3d environment and am totally lost as too what software you need to be able to do the CAM part of this hole thing. I have expeience in AutoCAD 2D from a few years back and some limited 3D CAD expireince. Not too worried as I'll learn it when I can get things set up to actually make what I draw!

Please help me get some clarity as too what design software I should be looking at and how many bolongna sandwiches I'll have to eat to save up to buy it. If I'm totally off base, please let me know. If there is an easier way or a good starter package, please let me know this as well. Willing to pay a little more to get things working and learn more on the next build...

Thanks in advance and I hope to become a part of this great site once I have a machine to run myself:-)

Mark [mkenney]

[hoss2006]

Welcome mark!
At least spend an extra $30 for the 36v package from Keling with the new motors.
CNC 3 Axis Package with 382 oz-in motor and KL-4030 Bipolar
Driver with 36V/8.8A Power Supply :$389

even better, though a 4 axis kit would be the new package
G540 4 axis package (1PCS G540 +4 pcs KL23H284-35-4B (1/4” Dual
shaft with a flat) 387 oz-in + 1 pcs KL-600-48 48V/12.5A 115V /230V
power supply): $635.95

Also, you should be able to get mach 3 from keling with your package purchase for $139
http://www.kelinginc.net/CNCController.html

[mkenney]

Thanks! Honestly was using your site for my shopping list:-) Went to the cost breakdown section for the list, is there an updated list somewhere on your site?

Mark [mkenney]

[hoss2006]

Thanks, I'll have to update that page, I added the g540 link under the Parts and Materials, missed that page.
Hoss

[mkenney]

Rodger, got it, GREAT SITE BTW!!!!!!! Can tell I'm going to blow my budget quickly, but ohh well:-) Not getting the 4th axis concept yet, is it a head that sits on the table that then turns? guessing this limits the part size you can build on these machines?

What are your software recomendations?

Mark [mkenney]

[hoss2006]

A 4th axis generally means a rotary axis mounted on the table to rotate a part either horizontally or vertically,
i.e. threading, gear or timing pulley work, cylindrical engraving, 3D milling, turning etc.
It's my favorite type of work to do with the mill.
I have some sample work here.
I haven't done much of anything with 3D CAD yet, just 2 1/2D, not enough time in the day to get to everything.
I've tried the Bobcad demo and it seemed ok but I'll look around when the time comes.
By the way, Keling has BOBCAD-CAM V 21: for $499 with a motor purchase.
I'll look through the CAM forums for some good reviews.
Hoss

[Crevice Reamer]

Hi Mark. Welcome to the Zone. Two things to remember about Keling kits:

1. The kit is just a suggestion. The parts in the kit cost the same whether you buy them together or separate. So you can mix and match and make up your own kit.

2. Always check availability before ordering. If John is out of what you want, he may just substitute something that you DON'T want. Specify NO SUBSTITUTIONS.

You can save some money by making up your own X2 kit. The X2 (with ball screws) doesn't need the $49 387s on the X and Y. It may give higher IPM rapids with a couple of $39 270s there:

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

If you don't plan on a fourth axis right away, you can skip THAT 387 and buy it later when you need it.

Using the smaller motors for X and Y allows you to use a smaller power supply also. The $59 KL-350-48 48V 7.3A PSU is supposed to be back in stock soon and should be fine for 2 270s and 2 387s.

So your package could look like this:

G540: $300
(2) 260 Oz. KL23H276-28-4B: $78

(1) 387 Oz. KL23H284-35-4B (For Z axis) $49

(1) KL-350-48 PSU: $59

Total X2 3 axis package = $486.

CR.

[Crevice Reamer]

It takes Michael about 2 weeks to make up a CNCFusion kit--So don't expect it the next day after you order it. If you can possibly afford it, the pre loaded ball nuts and helical couplings are worth every penny and will give nearly zero backlash. For best results you would need 3 of each.

CR.

[hoss2006]

I wouldn't skimp on the 2 260's, i'd spend the $20 and get the 387's keling recommends as designed for use with the g540, you're saving the $20 with the Mach 3 discount.

[mkenney]

WOW, you guys are just increddible!! Now I need to learn what 2 1/2D means, that is a new one too me. EXTREMLY HELPFUL to know that the kits aren't a money saver, just a configuration suggestion.

Should I be looking at a spindle speed control of some sort?? Read about it a couple places but wasn't sure if this was something you could apply to the X2s?

Sounds like I have the CNCFusion kit selected properly at least? If you all agree, I'll go ahead and place that order to start getting it on the way:-)

Mark [mkenney]

[hoss2006]

Spindle control is a nice convenience and the X2 is well suited for it.
I've had success with the C6 board from Cnc4pc,
very important to power it up with it's own 12 volt power supply, trust me.
Homann designs also makes some boards but I haven't used them.


Here's what it can do.

[ame="http://www.youtube.com/watch?v=Nig9Lq65xIc&feature=channel_page"]M3 M5[/ame]

Tormach has a good description of the difference between 2 1/2D and 3D milling.

[Crevice Reamer]

I wouldn't skimp on the 2 260's, i'd spend the $20 and get the 387's keling recommends as designed for use with the g540, you're saving the $20 with the Mach 3 discount.

The 270s are MORE than enough motor for the X2, X and Y with ball screws. And since their max voltage is 60V are thus closer to the 50V G540 voltage than the 65V 387s are, the 270s should give faster rapid speeds.

Now if you were going to be pushing the big table on an X3, then I'd say yeah go for the 387s.

Also, by being able to use the smaller $59 power supply, this saves you big bucks.

CR.

[Crevice Reamer]

Should I be looking at a spindle speed control of some sort?? Read about it a couple places but wasn't sure if this was something you could apply to the X2s?

If you go with the G540, it already HAS spindle speed control built in--All you have to do is wire it.

Sounds like I have the CNCFusion kit selected properly at least? If you all agree, I'll go ahead and place that order to start getting it on the way:-) Mark [mkenney]

That's the right one. Just give thought to the preloaded ball nut and helical couplers upgrades--They really improve the backlash. This is a MUCH more important place to spend money than unneeded oversize stepper motors and more expensive power supply.

CR.

[Crevice Reamer]

About the CNCFusion kit: This is a good kit, but because of the way it powers the Z axis this makes the gibb adjustment tedious. You have to remove the Z kit to adjust gibbs.

One way around this is to drill and tap four new gibb screw holes on the left side of the head and move the gibb strip over to that side. Another way is to put the Z mount on the left side. Either way may require different counter-balance spring arrangements.

You can always start with it mounted normally and change later though.

CR.

[Crevice Reamer]

Here is a nice cheap little design/cam program that integrates with Mach3:

http://www.d2nc.com/

Check out the demo. It's quick and dirty and you might be able to get by with this for a while.

Speaking of Mach3: The price is going to increase on January 1st. You might want to order it before then.

CR.

[Crevice Reamer]

When you order your motors from Keling, don't forget your estop switch:

http://kelinginc.net/CNCPackage.html

The G540 won't run without it--or a jumper--might as well have the safety of the switch.

CR.

[hoss2006]

The 270s are MORE than enough motor for the X2, X and Y with ball screws. And since their max voltage is 60V are thus closer to the 50V G540 voltage than the 65V 387s are, the 270s should give faster rapid speeds.

Now if you were going to be pushing the big table on an X3, then I'd say yeah go for the 387s.

Also, by being able to use the smaller $59 power supply, this saves you big bucks.

CR.

Is that all you ever think about,rapid speeds?
As someone who actually uses their mill to make parts, I know that 95% of the time, the mill is going to be cutting at a FEEDRATE and very little time
rapiding.
It's pretty easy to see in torque curves that a larger motor has more torque at these slower speeds that a smaller motor.
For a measly $20, I'd prefer to have motors that do the best job at making chips than ones that MAY in THEORY give a few more IPM for bragging rights.
That's just me.
I wouldn't spend a lot of money on a bigger power supply either especially when
the need to have all motors running at the same time at full bore would be rare.
It's been my experience that only 2 going at once would be the norm.
The idea here is to build a machine for making parts not bragging rights.
This is a lot of money to spend for something that you never get dirty.

[Crevice Reamer]

Hoss, I don't want to argue with you, but the 270 is a more efficient motor. Efficient motors are capable of fast rapids, and so it is a good indicator. You can ALWAYS run slower.

I agree that you will NEED more torque for the Z and for holding the fourth axis, although if you are only driving a rotary table, a 270 would probably suffice there also.

Certainly you can USE the 387s for all four axis, but the 3.5A 387s WILL require more amps in the power supply and thus it will be more expensive.

Mariss says it best in Stepper Motor Basics:

CHOOSING A STEP MOTOR AND POWER SUPPLY VOLTAGE

The choice of a step motor and power supply voltage is entirely application dependent. Ideally the motor should deliver sufficient torque at the highest speed the application requires and no more. Any torque capability in excess of what the application requires comes at the high cost of unnecessary motor heating.

Excess torque capability beyond a reasonable safety margin will never be used but will exact the penalty of an oversize power supply, drive stress and motor temperature. Learn to distinguish the difference between torque and power. High initial torque at low speed does not mean efficient motor utilization. Usually power is the more important.

Bias the motor’s operating point through power transmission gearing to operate the motor at its maximum power; normally just past its corner frequency.

The maximum shaft power obtainable with the drive is around 250 Watts, or 1/3 of a horsepower. This is primarily achieved with double and triple stacked size 34 motors.

Size 23 motors are physically to small to dissipate the resultant heat and size 42 motors are too big to be properly impedance matched; if their rated current is less than the 7 Amp limit of the drive, then the optimum overdrive voltage is beyond the 80 Volt limit. If the rated voltage is less than 1/25 of 80 Volts, then the phase current will probably exceed 7 Amps. Also the detent torque on a size 42 motor is significantly higher than in smaller motors. This detent torque is always a loss that must be subtracted from the potential available power output of the motor; in other words its output power drops more rapidly with speed than smaller motors. Use size 42 motors only if high torque is required at low speed and it is not practical to gear down
a smaller motor.

An efficient motor, defined as the smallest motor sufficient to meet the demands of the application, will run hot. Think of the motor as having a fixed power conversion efficiency. Some percentage of the input power will be converted to heat; the rest will be converted to mechanical power. To get the maximum performance from the motor, the waste heat must be just under what the motor can tolerate. Usually this motor will be biased to operate just past the corner speed as well.
The place to start is to determine the load torque in oz/in.

Be sure to include the torque necessary to accelerate the load. Next come up with the maximum speed the application has to operate at in full steps per second. Multiply the two together and then divide the result by 4506 to calculate the power in watts necessary to meet the application requirements. Pick a motor at a power supply voltage that provides a 40 percent reserve power margin above your requirements.

CR

[Crevice Reamer]

You can use THIS wire for motor cables and home/limit switches. Ground the drain wire ONLY at the driver end.

http://cgi.ebay.com/Servo-Motor-Wire...3286.m20.l1116

You won't need any motor connectors with the G540, as they come WITH it.

You WILL need either 2.7K or 3.5K 1/4 watt current limiting resistors. You can get them here:

http://www.digikey.com/

If you don't already HAVE them, these are excellent home switches:

http://cgi.ebay.com/6-CNC-LIMIT-SWIT...742.m153.l1262

They are NO, so only for home switches. Limit switches need to be NC. the whole set of 6 switches costs less than ONE switch would cost at Radio Shack.

CR.

[hoss2006]

Yes it would be nice if your source of knowledge Mariss, would perform bechtests to show which motors actually perform best with his products in the real world.
Keling recommends the 387's for the g540 and sorry but I would take their advice over someone that doesn't even run a g540.