Whereas anyone can Nitpick someone else's workflow or designs. The truth is in the pudding and when I asked for information on how to wire up my controller box. No one from this group or any other from within the Openbuilds Community could be bothered to assist with my many issues. While I can visualize a mechanical structure within my mind, I am scared to death of electricity and fearful of destroying my expensive Driver Assembly. I decided to go with a Gecko G540 instead of the Crap Emanating out of China by the boatload. And as far as being overpriced that's a subjective assessment considering you haven't taken into account that while you may have the appropriate Crimping Tools. The majority of us don't and a search on Amazon for said Crimping Tools and Crimps runs approximately $65.00.

 

First off, https://openbuilds.com/members/jestah.66/ :

I heartily agree with your sentiments about soldering. Solder has almost no place on a machine other than on a circuit board. A lot of guys "tin" the ends of wires thinking it will make them sturdier. This could not be further from the truth. "Tinning" a wire makes a weak point where the solder stops wicking up the wire where vibration or flexing will cause the wire to break eventually from metal fatigue. This would be the same for soldering on a crimp connector. This failure point is usually under the insulation, thus very hard to find and troubleshoot. Never solder crimp connections!

I use another crimp on device called a "wire ferrule". It's just a small metal tube usually with a plastic sleeve attached to it, available in sizes for every gage of wire. You crimp it on with a special tool that crimps all the way around it for an ironclad bond. These ferrules prevent stray strands of wire poking out and shorting to adjacent terminals, and make the end of the wire storng and easy to insert into a screw terminal. They also protect the wire from getting pinched by the terminal and creating a weak spot. Available at most electronic supply places, and on Amazon.

Second, https://openbuilds.com/members/mouldy.85989/:

NEVER connect the frame ground of the machine to the DC ground of your electronics, nor use the frame ground as a conductor. Frame ground is mostly a safety feature, protecting YOU from getting a shock if some part of the electrical insulation fails. It must never be connected to anything but the third prong on your power plug. Usually, all parts of the machine have individual ground wires run from them to a "Single Point Ground", which is a usually a screw on the chassis near the power supply. If you were making a machine to UL standards, the first connection on this screw is the incoming ground wire on the power cord, with a star washer and separate nut. Then, all the other ground wires go on top of this, separated by star washers, and finally a nylon lock nut to secure them all.

In a CNC machine, frame ground is also important to drain away static charges. Machining wood can create huge static potentials, which can discharge and fry electronics or give you a nasty surprise. You need to separately ground each moving part of the machine, since they are usually insulated from each other by the wheels, so each part needs its own ground wire. This also serves to damp down electrical noise and give it a path to ground rather than radiating into your control system.

Connecting the DC ground on the output of the power supply to this ground point is just asking for trouble, you may in fact couple a lot of unwanted noise back into the circuits if you do this. Always check using an ohmmeter after finishing up your wiring to ensure that DC circuit ground is not connected to frame ground.

Sorry for the long winded explanation, I was just criticizing somebody else about this, but this is important. This post should probably be somewhere else as well, we are kind of getting off topic on this list. Wheres a Mod when you need one???

MG

 

All of the mentionings about soldering of the wires was strictly concerning BOB's and Drivers and not connections to the actual machine itself. Concerning your point about Grounding, that was totally new to me and I thank you for the information.

 

Well, I'm glad you can run to the F***ing Store and find a Crimper and Proper Crimps in your local neighbourhood. Nobody in this City even knows what the F***ing things look like. And No they're not $25.00.

 

https://www.amazon.ca/Terminals-Con...=1516738056&sr=8-13&keywords=terminal+crimper

 

What, no profane comeback?

I have to admit, you are the first person I ever ignored on these forums...

MG

 

Thanks will take a look at those and will also try and send you my f3d file...

 

Fair call about not feeling like you will get help.... I think a lot of people shy away from giving tronics advice as there is a worry an untrained hand is far more likely to get bit.... Would you like me to shoot a vid of a few of my controllers and how I wire things up? Could you DM links to your issues/posts and I am happy to have a look as I have not been on the boards much the past year due to some family and health issues but finally getting back in the swing of it.

Regarding the G540, what a pimp little box that has a very proven track record. It is easy it is to wire and while little costly up front but the amount of "prewiring" done in the box up against a standard controller is well worth it for a new CNCer.

Here is a link for a cheap bootlace crimp tool, maybe not the best quality but will work with all common size wires. Get an assorted box of bootlace ends and put them on EVERY connection you ever make.
www.ebay.com/itm/Hot-Self-adjust-Ferrules-Crimper-Crimping-Plier-Wire-Terminal-End-Sleeves-Tool/291980283763?epid=2101112050&hash=item43fb618f73:g:qj4AAOSwcUBYS8OJ

I use them because I find the overall cost of the tools and consumables to quite small compared to the cost in time to trying to find intermittent faults that are so common in poorly wired systems. When you use crimps you gain all of the below for cents per connection.

• lower resistance connection as the wire is pre-compacted down into a tight bundle and protected from any screw that is bearing down on the connection
• less likely to come lose over time as things are pre-compacted and they do not "flow" like tinned wires do over time
• gives strain relief to the wire - most have a small plastic cap that stops the area where the wire is compressed from flexing.
• stops a small strand of wire being pushed into the wrong port or shorting to the next connection
• stops tiny bits of wire snapping off and floating around your tronics cabinet
• looks super pimp, (I have ordered custom colours in the past to super pimp a build.... So worth it ahahah)
• you can take a connection out and move it without the end becoming damaged

Use the right size bootlace for the job. Too big and it wont compress well and too small runs the risk of the excess strands that do not fit being pushed back and snapping off creating a point in the wire that will be much higher resistance (likely to heat up if any decent current is passed on this connection)

The other tool I suggest getting to make wiring a lot more fun is an auto wire stripper.... Don't fight it, just get a set as they make life so easy.
www.ebay.com/itm/Automatic-Cable-Wire-Crimper-Crimping-Tool-Stripper-Self-Adjustable-Plier-Cutter/202141825666?hash=item2f10977a82:g:IsEAAOSwvfZaK8ES

Sorry to hear your tronics have been a battle till now but hang in there and happy to help you get it back on track @Ronald4418

 

Thanks for the sweet info @Metalguru as this has always had me a bit confused over the years. Many posts on CNCzone show the DC negative side of toroidal PSU bonded to the star ground point but by the sounds of your post above this is very bad! Is this bonding ok due to the type of transformer or just old methods used on the zone that should be put in the out of date and we now know better pile?

Now time to toss you a curve ball.... What is your recommendations when using a grounded spindle with a touch plate? Most I have seen have a clip (probe input COM) that is put on the tool/spindle and then the 5v being connected to the touch plate. When the "grounding" clip is put on surely this is bonding DC/input COM to Protective Earth ? To be honest this has had me stumped for a months but may explain some of my buggness since installing a touch plate.

Cheers!

 

There are two schools of thought on this grounding issue - people who advocate NOT connecting DC ground to chassis ground, and people who are WRONG...

I have a very strong opinion about this, after a 30 year career in Instrumentation Electronics, I have found that keeping the grounds isolated causes less problems than tying them together. Now if I could just convince Computer manufacturers...

It is acceptable to creat an AC connection between the two grounds using a capacitor tied between them. This allows AC noise to bypass to ground without making a DC connection. The main issue is to keep any current from flowing between the power supply and ground. Current flowing in a ground is just asking for trouble. That's why it is recommended to only ground one end of the shield wire on a shielded cable, this prevents current flow through the shield which can do the opposite of what you intended - coupling noise INTO your circuit instead of keeping it out.. This is all black art stuff, and not an absolute - there are exceptions.

Why go to all the trouble of designing a transformer isolated power supply, and optocouplers to isolate the stepper drivers, and then just connect the grounds back together again?

About your touch plate question, this should not be an issue. Temporarily connecting the grounded spindle to the control circuitry should not be a problem for the short time that it happens. It does not remain connected when the machine is operating. But, using the grounded lead to connect to the spindle, and putting the 5V side to the puck is the right way to do it. Also, the spindle may not be grounded as well as you think it is. Bearings tend to isolate the spindle, or at least create a higher resistance connection to ground than, say, the case of the spindle.

I don't think your "bugginess" is due to the touch plate. After all, the software only pays attention to the probe input during a probe cycle, the rest of the time it is ignored and shouldn't cause problems.

MG

 

Biwahhahhahah best opening line ever! I was keen see the point clarified mainly due to the amount of posts on many boards suggesting it is a good idea. Your follow up really drives that point home too.

Now time for the truth.... Yes for the past month I have hand the input coms bonded to the spindle to avoid having to use the grounding clip because I am lazy..... just goes to show cut corners cost more in the long run as rather sure I have got a funny ground loop now in the system! Time to pull that connection out and maybe feed it into a relay and have Mach3 connect it as required. Once I have this fixed happy to take a video showing my wiring if it would help any one as well as get your opinion on my handy work!

 

Oh God Yes! Leaving your spindle ground connected to the input ground during operation is a horrible idea!

That spindle is one of the biggest noise generators ever!

MG

 

Can someone please help me! I built my C-Beam about a year ago and I'm having the hardest time trying to get it to work properly. I am trying to use Grbl panel release 1.0.3.0 with Fusion 360. I have an Arduino uno with a V3 shield. The problem I'm having is in trying to cut a simple pocket, 1" dia x 1/8" deep with maltible depth of cuts. The first cut looks great but when the bit retracts and moves over to start the second depth of cut it rapidly plunges into the part and at other times it will start the second cut in a new location. I have checked the code and the code appears to be correct. I have a 2.2 kw spindle with a cutting speed of 15,000 rpm and feed of 20 inches per minute and entry speed of 8 inches per minute. I am at a loss and ready to give up again.

 

I've got my Controller Wired up Perfectly with Zero Issues and I have a Cable Track setup to carry the X-Axis and my Hall Effect Homing Switches. There will only be Home Limit Switches and not Limit Switches at the opposite ends as I intend on using Soft Limits only. Everything works perfectly, yet I am concerned about the Cables for my Z-Axis. Other than using Cable covers such as those seen on Automobiles. Has anyone a Picture that I can use to give me an Idea on how to implement a Cable Track to carry the 2 wires that come with my Quiet Cut Spindle? I intend on using a Shielded Cable with Ground to carry these wires.

 

Sounds like a loose axis. Check to make sure you have no back and forth play on the X and Y axis, and no up and down on the Z. Grab the axis and try to move it parallel to its travel (ie left and right for X, etc) and see if there is any slack. You may have to move and retighten the lock collars, or perhaps a flex coupling is loose. Also could be improper tension on the wheels. Adjust the eccentrics until the wheel across from it just gets hard to turn with your fingers. If you cant turn it sith just your fingers, it's too tight.

Also could be a wiring issue, a loose wire on one of the drivers or motors causing lost steps on the motor.

If squares aren't square and circles aren't round, 9 times out of ten its play in the axis. You'll see it as a "jog" in the line everytime one of the axes reverses direction.

And, seriously? A 2.2 Kw spindle? Wouldn't be surprised if it wraps itself around the X axis one of these days...

MG

 

@ Metalguru THANK YOU very much!!!!! It was indeed noise coming from the spindle. I could not find shielded cable so I took the cable off of the spindle and shielded it myself and what do you know it worked. I just have to recalibrate all axis now and things should be all good. Again thank you so mush for your help!

 

Glad to help. Spindles seem to cause a lot of trouble, especially the Chinese VFD types. I can't stress enough the importance of proper grounding and using shielded cables on these spindles. I never run spindle power through the same cable chain as the motors and sensors for this very reason. When using a router, I always recommend plugging the spindle into a different circuit than the electronics and using a good power filter on the electronics and computer power. Something like this:



MG

 

How many of the parts are recycled from the C-Beam Machine? I was considering upgrading my existing C-Beam to achieve basically the same thing (adding the existing X-Axis to the Y-Axis and buying a new full-length X-Axis), but would it be more economical just to buy the parts I'm missing from this new bundle and save my self the design time?

 

Almost none. They are completely different. The only parts they have in common are a couple of pieces of 20x60x500, and some screws, nuts, and brackets. The XL uses different plates on the Z, Y and X axis.

MG

 

Hi Glenn
I am very new to this and am building a c beam machine and just ran into this problem
I see Openbuilds sell a 540mm screw which is the length I believe we both are looking for
I have a 1000mm I had planned to use for X and Y...
hate to say it but gotta cut it to 540mm and well spare parts for the next project
and goes without saying I'll be buying a 540mm
Good luck the farther I get into this project I relize Planning is better than just winging it
Casey

 

Hi Casey, Yes if you source the lead screws from alternate suppliers you need to ask/specify to them that they must supply +40mm on top of the nominal length.
This takes into account the thickness of the end plates + some to allow you something to couple your stepper motors to.
You could build the machine 40mm smaller and cut down the C-Beam.... But who want a smaller table.....

If you purchase from the Openbuild's parts store you will be guaranteed that the length will be correct, and I can guarantee that if it is not they will get the correct length to you without further charges, I had a dud motor shipped from them and they had a replacement to me under a week here in Australia, at no charge and did not want the dud one back.
They certainly stand by their product when it comes to warranty should there be any misfortune of something going wrong.

This was quite some time ago for me, I have been producing items on my machine now for the past 18 Months or so, it has not let me down once.
I can tell you that you will not be sorry you built this machine once it is completed and you see how fantastic it is.
It still blows me away every time I try something new..... Just last week I milled a prototype double sided arduino circuit board shield with some 0.3mm traces for the first time, the accuracy is insane, I could watch this thing cut all day !! Check it out......



Planning is the best advice you could give yourself for sure, take your time with the build and also take your time once you are cutting too.
It might take a longer time to produce an item by cutting slower and doing multi pass cuts etc. but at least you will end up with something produced and not just a bunch of broken bits and damaged stock. Always start slow and then start pushing the speed up to find the mechanical limits of your system, pay attention to feeds and speeds for different materials and different sized cutters that you are dealing with. After a little while you do start to get a feel for it, there is much to learn but it is a lot of fun !!!

Oh and if you are interested, as you may find some tips, my build log for the XL is here:
https://openbuilds.com/builds/the-moagie-mill-my-c-beam-xlarge.3890/

Cheers Glenn

 

Yeah Glenn
I seen after I sent you a reply that your post was back in 2016
I started woodcarving as a hobby and decided to try to produce more things
Started with a cheap laser burner machine / rebuilt it
Caught on to cnc machines and they amazed me, same workings with x y z
Now I have changed my design 3 or 4 times so I have a few spare parts
My final setup is very much like the c- beam little bit smaller
Keep telling my wife how great these things are , she just wants to see results
well another package coming Tuesday and I'm sure bits and peices after that
I'll check out your log
take care
Casey

 

Hey guys.
Would it be possible to mount the x-axis higher to give the machine more working height on the z-axis. I am new to cnc and would be thankful about some help.
Kind regards
MS

 

Sure, you can use longer uprights to elevate the X/Z axis. Be careful with this, however, as making the supports longer and increasing the length of the Z axis will increase the flex of the machine and reduce the stiffness. This could lead to chattering or inaccuracy of cuts.

MG

 

Alright folks, just added a C-Beam XL to my shop. I have an OX with an XPro, which will be replaced the second it dies, and a couple 3d printer. Just pointing out that I'm not a total noob here. Anyway, I'm torn on which control method to go with on the C-Beam? I do like using GRBL and would prefer to not purchase special software. I have some 542 drivers, some 4.2A steppers and a couple 36V power supplies from another project that I could utilize as well.
Metalguru, you seem to have extensive knowledge regarding this.



Josh

 

Hey Josh.

Well, the Arduino running GRBL is a tried and true solution. I often use the Arduino Nano with a small screw terminal block "motherboard" that I get off of Ebay. Makes wiring simple. I use Xloader to load in the GRBL firmware. Works well. Been reliable, I have built close to 50 machines and only had one failure on the arduino side of things. And yes, please get rid of that Xpro at your earliest convenience. I think you would find a significant performance improvement on your Ox with something better in the driver department. I kind of like the Panucatt Gradus M1 Pro with Bigfoot drivers for an all in one solution.

Looks like you have a breakout board designed for Mach3 there, you could use that instead of GRBL if you like Mach 3. Have to find a computer with a parallel port or use a motion controller like the UC100 or UC300 or ESS if you want to run that board. This will allow you to use USB or ethernet connectivity respectively and still run Mach 3. Be careful buying UC drivers off ebay and Ali Express, there are a lot of counterfit units out there. The ESS is a really nice board, and gives very smooth performance, but a bit spendy.

Your 542 drivers should be fine, they work pretty well. 36V power should give a bit of extra kick in the torque department.

The motors are a bit on the torquey side. I find that the high torque motors sometimes cause problems, simply because they have so much torque that you can't keep the lock collars and flex couplings tight, the motors can cause the lock collars to come loose or spin the flex couplings on the lead screw if you run into the end stops. Would definitely recommend limit switches on a machine using those motors.

You need over 500w of power supply if you want to run those motors at full power, it's hard to find a 36v 600w power supply. So, your idea of using a couple of 250+W supplies should work. Run 2 motors off each supply, and don't forget to tie the grounds together. Definitely fuse each motor driver individually. You can also set the driver current to a bit under 4A without affecting things too much. Should be able to run those motors on 1/16 microstepping without any noticeable loss of torque as well, and get really good resolution.

Should be a hot rod of a machine.

MG

 

Thanks for your input MG! I'm not opposed to purchasing new steppers or any other parts. Those steppers were supposed to be for another large machine I was designing but never developed. I have an Azteeg X3 3d printer contoller, they do make some good quality boards. I'm not using Mach 3 and I would rather not have to purchase proprietary software either. Will the Nano and screw terminal board work with the external drivers? Can you link to parts for that setup, this sounds like my best option. Oh, and can it handle 36V?

 

Nano (one of hundreds):
https://www.amazon.com/ATmega328P-M...pID=51uxsBUdZIL&preST=_SY300_QL70_&dpSrc=srch


Screw term board( (again, one of hundreds)
https://www.amazon.com/Terminal-Exp...7&sr=8-4&keywords=arduino+nano+screw+terminal




And yes, it has exactly the same pins as the Uno, just google the pinout. Simply wire the outputs into the driver modules, the drivers are opto isolated so it won't affect your computer. Daisy chain the inputs of the two Y drivers together. Nano is powered off the USB port, so no additional power supply is needed. It doesn't care what voltge your motors run at.

You could look at my blog (www.3dtechworks.ca/blog.html) for more details.

MG