Discussion Hobbycnc Pro 4 axis CNC Chopper Driver build step by step & more

[bgriggs]

I just received the new Hobbycnc Pro Chopper driver kit. I will detail the assembly step by step.

[bgriggs]

Hobbycnc http://www.hobbycnc.com has been supplying plans and electronic kits for CNC routers for at least nine years that I am aware of. This is the third electronics kit made by them that I have assembled. Each kit has been better than the last. David Rigotti, the man behind Hobbycnc has steadily improved his products and the motor speed with each revision.

The Pro board is the second chopper board offerd by Hobbycnc. The 4AUPC was he first widely available chopper kit on the hobby market. The Pro Board is an improvement over the 4AUPC board because it is RoHS compliant which allows it to be sold in Europe, it is also a faster board and has idle current reduction. The package I purchased cost $335 but you can get started for as little as $79 for just the board. Here are a few of the specifications from the Hobby CNC site.

Specifications:

3 or 4 Axis Unipolar Chopper control.
Individual OR simultaneous control of 2/4 Phase Stepper Motors.
Accepts 5, 6, or 8 wire stepper motors only. 4 wire types are not usable.
42VDC maximum input voltage, 12VDC minimum input voltage. 24VDC Minimum Recommended Voltage.
3.0 Amps Maximum per Phase, 500ma (.5A) minimum. Each axis adjustable throughout this range.
1/1, 1/2, 1/4, 1/8, and 1/16 Microstepping.
Step and Direction Control.
Idle Current Reduction to 50% when idle for 10 seconds. Can change this time delay.
Built In Protection Circuit to help against blown chips on stepper motor short or open connections.
3.7" by 6.8" double sided with top silkscreen and thru plated holes and lead free solder PCB. (RoHS compliant).
Power On Reset.
On board voltage regulation for 5-volt logic with 24VDC cooling fan from motor power supply.
On board connections for home and limit switches with 10K pullup resistor provided to each. No need for a separate "break out" board.
Minimum of components to make assembly fast and easy!
Works with Step and Direction software such as DeskNC, TurboCNC, Mach2, etc

[bgriggs]

Here are the basic components of the complete 4 axis Pro board kit.

Picture 1 is the Pro Board kit itself. This kit contains a professionally done printed circuit with plated thru holes and silk screen labels with jumper settings called out in plain sight. The kit includes all connectors, resisters, transisters, diodes etc, ect. that are needed to populate the board. Also included is a comprehensive instruction sheet which takes you step by step through the build.

Picture 2 is the power supply kit. This kit gives you almost every thing you need to build a power supply suitable for your driver. Included is one BIGGGGG capacitors, A bridge rectifier, bleed resister, wires, several connectors, fused and the like. The only thing missing is a 24V 10 amp Transformer and a case to stuff it all in.

Picture 3. is the 24V cooling fan, with protective screen and some odds and ends.

Picture 4 is the new Hobbycnc 305 oz. High torque, unipolar stepper motor. There are 4 of these motors included in the kit. They are large enough to machine aluminum with.

[bgriggs]

Before we get started we will need to gather up the proper tools to get the job done. Those tools include:

• 1/32" rosin core solder
• side cutters
• pliers
• voltmeter
• heat sink compound
• 4-40 drill and tap.

I also found a Sharpee marker and center punch handy but not absolutly necessary.If you plan to do many more electronics projects, a fixture to hold circuit boards might also be a good idea. I have never bought one but evertime I build a circuit kit, I wish I had.

[bgriggs]

Here is the circuit board for the PRO stepper motor driver kit. The circuit board for the 3 axis kit and the 4 axis kits are the same. The only difference is that the components for the 4th axis are not included with the 3 axis kit.

The circuit board has all the components clearly printed on the board along with orientation marks for those components that need a special alignment.
The board features plated through holes and is double sided.

[Jose E Bruzual]

Oh, this could not have come at a better time... I'll have tons of questions...

is there much of a difference between this one and the Foam Cutters Driver Board Kit?

Thanks for doing this!

Jose

[bgriggs]

Originally Posted by jeb

Oh, this could not have come at a better time... I'll have tons of questions...

is there much of a difference between this one and the Foam Cutters Driver Board Kit?

Thanks for doing this!

Jose

Yes there is a difference between the two boards. The Pro board handles more amps but lacks auto heat control and timer. The construction is similar however.

Bill

[bgriggs]

The first step in the construction is to sort out all the components and make sure they are all there. I had to pay special attention to the DB25 connector because the jumper clips liked to hide in there.....

The resistors are identified by a series of color bands. Unless you have great eyesight, a magnifying glass is needed to determine the values. Sort the resistors out and group them for placement.

Once the resistors are identified, I placed them in the proper positions on the top side of the circuit board. I then flipped the board over and bent the leads to lock the resistors in place on the board.

I used a 25 Watt soldering iron to solder my parts in. I feel that a quick hot touch of the iron is better than a longer cooler touch. If you have never soldered before, don't worry, It isn't difficult. Touch the tip of the soldering iron to the component and the circuit board pad followed quickly by the solder. If the iron is hot enough, the solder will "wick" over and form a smooth joint. Big blobs are NOT what you want. I will post some pictures of good solder joints as soon as I can take some.

The 10K resistors are color banded Brown, Black,Black, Red, Brown. After I soldered the 10K resistors in place, I used a side cutter to clip the leads short to the board.

[bgriggs]

The next step in the construction was to install resistors R9-R12 and solder them in place. These are 100K resistors and they are color banded Brown, Black, Yellow, Gold. After each step in the build I checked the solder joints under a magnifying glass. It is easier to find a cold solder joint as you add parts to the board, rather than checking the entire board in one session.

[bgriggs]

Next I soldered in resistors R13, R14, R15 and R16. These resistors have differing values so double check your work with a magnifying glass.

Resistors R13 &R14 are 249R resistors and are color banded Red, Yellow, White, Black, Brown.

Resistor R15 is 6.04K Blue, Black, Yellow, Brown, Brown.

Resistor R16 is 750R Violet, Green, Black, Black Brown.

[bgriggs]

I added the .1uF capacitors C1-C7 to the board next. There is no special orientation to these parts.

[rosco]

I'll be watching...thanks for putting this up...I would dearly love to make a CNC router.
cheers
rosco

[Spaceship13]

ill have mine done by this weekend ready to run. but theres one question.? as a new cnc operator who or where do i get a newbies cnc soft? forget the big bucks one . easiest to operate is best. thanks

[bgriggs]

Originally Posted by Spaceship13

ill have mine done by this weekend ready to run. but theres one question.? as a new cnc operator who or where do i get a newbies cnc soft? forget the big bucks one . easiest to operate is best. thanks

Thanks Rosco and Spaceship13. It is good to know that someone is reading. The answers below are my personal opinions based on my own experience. I will wait to answer any similar questions later so as not to disrupt the thread.

Software, for XP and a CNC router, probably the best bang for the buck is Mach3. At $159 it is extremely hard to beat. http://www.artsoftcontrols.com.

For DOS turbocnc $60. http://www.dakeng.com/turbocnc.html.

Most other CNC software costs thousands of dollars. If you have deep pockets then Onecnc is my choice. I don't know the current pricing but it is probably in the 3 to 10K range. http://www.onecnc.net/index.htm

Bill

[bgriggs]

The 10K Resistor networks were added next. These resistors have multiple legs and have to be positioned correctly. There is a little white dot on the resistor which corresponds to the white dot on the circuit board.

Soldering the resister networks backwards is one of the most common mistakes made by first timers. Take your time building the Pro Board and you will be a happy camper.