Long Awaited Return to Build - Paragould, AR
 

Hello all, WOW what a great place to learn about CNC building. If a person can’t find it here, then they wont find it.

My name is Larry, and I was raised up on a farm in Arkansas. Farming beans, rice and milo. We repaired all our equipment ourselves. Since then I have worked in tool and die, maintenance in manufacturing, plc programming, welding (arc, mig and tig), and now I own a computer repair shop and also an I.T. Administrator at a local college.

I want to build a 4ft x 8ft cutting area cnc router. I want to start with a typical 3 axis and gradually go with a 4th as a turntable or lathe type. I want to cut ¾” plywood mainly and sell items.

I have no cnc experience, but building comes natural to me.

I want lots of suggestions, if you don’t mine.

I thought I would start with setting up the electrical first because I don’t want to have my garage tied up too long. Even doing it this way it will take several months.

I have read a lot here and below is what I might start with. Please make comments on changes that I need to make.

Here is what I am thinking about purchasing first. Only single phase at my location

4 – Oriental PK296A2A-SG7.2 2-Phase Stepping Motor
4 - Gecko brand G203V drives
1 - AnTeck PS-8N70Rxx power supply 5 or 12 volt secondary? Is voltage too much?
1 - PMDX-122 Breakout Board and Controller
1 - Milwaukee 5625-20 3-1/2 Max HP Router



Controller box – having not found one yet

Am I missing something?

Thanks,

Welcome Larry, you look perfectly experienced to tackle one of these beasts :)

Your shopping list is good, except maybe for the power supply. I don't know Antek's numbers off by heart. For the gecko/motor supply, I aim for about 30V AC (42V DC) and about 300 to 500 VA capacity.

Maybe a trip to Doug's house for the other ozark cnc in the family is due?

Welcome Larry! You seem to have a good background so have fun. :)

Thanks all for your comments. Gerald, on the power supply do you have a recommendation on one that is fairly easy to setup? Is there any advantage going bipolar or unipolar?


I am in the process of finding the cheapest company to order the motors, drives etc.

So far it is
Oriental_Motor
Gecko 203v Drives
Breakout Board

What size control box should I get, if someday I plan on using a 4 axis?

These electrical components sure takes a bit out of the pocket book. :)

What do you think about this?

PS-5N42

I am open for options.

That power supply looks okay for your selected motors if they are wired half-coil.

Ok, Big day of shopping today.

Purchased

4 - Oriental Motors PK296B2A 7.2 with double shafts in case someday I want to add encoders.

4 - Gecko brand G203V drives
1 - AnTeck PS-8N42R power supply with 19.1A and optional fuse module.
1 - PMDX-122 Breakout Board and Controller

Can't spend money like this every day. My wife reminds me that Christmas is coming soon.

I still haven't found a place to buy the controller box that is big enough for this stuff to fit in.

What box is everyone using and where did they get it?

Thanks,

AD products in Buffalo (my personal favorite) or FactoryMation.com, or Automationdirect.com for the enclosures.

I used a tool box from Tractor Supply. I may go back and get the smaller one. About the same price and the NEMA box, but deeper. You will need a plate to put inside to mount stuff to.

http://www.mechmate.com/forums/showt...25&postcount=7

I am going to push the power on my OM's based on reading I have done in the forum.

PS-4N48R12 This is the Antek number I ordered.

Wow I reviewed my thread and I have been reading for almost a year... :( .

Trying to get the time to get going. TO many other projects running at the moment... And work... If I could just not have to work :D

Thanks Sean, I am fairly new at looking for cnc router parts, those 2 links seem like good ones. I will definately use them.

Thanks Mike,

I thought of putting all my electrical and my computer in the same box, but i was worried about heat and noise. I wanted my controller box to be sealed and just have fans inside it similar to Gerald's design. The computer will have fans with an ouside hole like most computers do.

The box design does look good. I was thinking of something like that for my computer and monitor on top look.

I order a simular PS, mine has less volts at 42 vdc, but I wanted more amps 19.1 just in case I want more motors someday.

Pictures of the Control box and internals.
 

I finally got some parts in to take pictures. The actual build will start a little later with the frame. I am testing some of these parts to see if I can get them running and to gradually hook up to a computer and see about some gcode.

Attachment 6889

This is a box I got off Ebay. It is 24" x 20" x 10"

Attachment 6898 Attachment 6899

It had cheap plastic locks, but it also had these nice heavy duty lockable locks that I put on.

Attachment 6893

This is the power supply I got. It is a heavy monster.
Attachment 6892
Im giving you some measurements of it.

Attachment 6890

I purchased this fuse option. I hope it isnt a wast of money.

I got a little bit bigger box for future expansion if I need it. The motors are on order but have not arrived yet.

Looks like Antek is making some improvements by giving multiple connectors for the outputs. Do they have a 4 fuse version? That resistor is probably for bleeding the capacitors?

Think the resistor is for the LED's

I have did quite a bit of reading and searching and I have a easy question for some of you, but I dont want to hook anything up wrong on my testing.

This post by Gerald,
Link 1 Especially this diagram.

So on Note 1, what does it mean by JP1 must move down?

PMDX-122......................................G203v
J1
Pin2----------------------------------Dir
Pin3----------------------------------Step
Common----------------------------Common


PMDX-122......................................G203v
J2
Pin4----------------------------------Dir
Pin5----------------------------------Step
Common----------------------------Common


PMDX-122......................................G203v
J3
Pin6----------------------------------Dir
Pin7----------------------------------Step
Common----------------------------Common


PMDX-122......................................G203v
J4
Pin8----------------------------------Dir
Pin9----------------------------------Step
Common----------------------------Common

Also what gauge wire?
Sorry but I am more of a visual learning.

This is JP1 "moved down":

Well its been a while, had to take care of something first. Now I am ready to continue. First I want to do a table top test and get my PK296B2A-SG7.2 motors turning.

The power supply is 42v Link.

I will be cutting plywood 3/4", in multiple passes. I want my motors running as much as I can but not burn them up.

What resister should I use on my G203V drives? Half coil?


After I get the motors working, then I will order some steel and start building.

Thanks,

There is a ton of info about this same type of question, but I couldnt find exactly what I could understand.

I was looking at these charts I see the unipolar at 24v and it has a chart for 48v for bipolar. Gerald, since you thought the 42v would be good for half coil, what resister would you are someone else recommend that I should try. I would like to go up to about 90% of max without hurting the motor. I will monitor the motor temps and keep the speed turned down to protect the motors on long runs. I really dont see me using the motors for long periods. I know speeds are determined by cutting material, diameter of end mill, and quality desired. Among a few other things.

This resistor thing has me stopped at the moment. I know the motor is rated for 3A and the 203v has that at 37k. Is that the safe max at 42v?

Thanks,

Larry, wire them half-coil and use 36 or 37k resistors (it is not critical), and then keep a hand on the motor temperatures for your types of cutting work.

Even a standard 33k resistor will work fine. A 33k resistor allows 2.9A. Also, keep in mind that most common resistors have 5% tolerance. (Whenever I'm traveling through the San Jose area of California, I visit Halted or another of the surplus electronics stores where they have isles full of resistors. I can usually find exactly what I need. But for stepper motors, the local Radio Shack has a limited selection of standard value resistors that work just as well.)

Oriental rates that motor/gearbox at 3A. The motor without a gearbox, the PK296-03AA, is rated at 4.5A, which is why it runs at moderate temperatures when run from a 42VDC power supply. Limiting the motor to 3A produces only 66% of the heat that you would get if the motor to pulled 4.5A.

The only reason I mentioned 36k was because I had a lot of 18k's and took 2 in series. ;)

I begin my quest for the mechmate a long time ago.

Now I am ready to start purchasing the steel. Finally!!!

One thing that has changed is the size of my cut area. This is now big (146 inches long x 86 inches wide.)

I would like to run this by the experienced members and get their feedback.

Since this is bigger, I am going to use bigger material

Main Longitudnal beams 8 inch channel (10 10 320)

4” channel for the Table Leg Cut will have 3 legs supporting each bean. (total of 6 legs) (10 10 332)

The z axis will the the longer 14 inch.

The cross bearing beams will be 4” x 2” steel tubing. (I have a surprise for using tubing I will share later) (10 10 302)

The low Longitudnal cut will be 4” channel. (10 10 312)
The long Angle brace will be 3” channel (10 10 316)
The Cross Angle Brace will be 3” channel (10 10 304)

The Cross Member Tube will be 4”x 2” x ⅛” tubing. (10 20 440)

Some of this is for cosmetic purposes, but some is needed for this size material. The material will be ¾” plywood fastened together as one piece 12 feet x 7 feet.

Is this strong enough especially on the Cross member tube, main Longitudnal Beams) Any worrys?

I am not too much worried about speed.

Thanks,

My longitudinal is longer then 12', still using same channel with 2 legs (total 4 legs) no adverse problem. and I got lazy & omitted the cross trusses under the beams, only the vertical & horizontal trusses. but I can't say much about the x-axis.

I'm probable good on the Longitudnal then. Thanks Ken,

The Y direction, the blueprint (10 20 440) calls for a tube 100 x 50 x 2mm which is 4" x 2" x .079".

I figured (guessing) that increasing to a 4" x 2" x .128" would be enough for cutting 86" :confused:

I know the weight might slow things down a little, but I dont require super fast speeds. Just as long as it works.