Wiring and Testing CNC Router - Limit and Home Switches Explained

In this video we wire the CNC router machine to it's newly built stepper controller and prepare all the pins that go to all the varies switches and motors. I show some of the work around that were necessary to eliminate false switch tripping from noisy lines. Also shown are some of the important Mach3 features such as soft limits, home references and safety limit switch use.
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[@gizmobowen]

I don't think I'd be able to get Mach3 setup correctly without your helpful videos. I learn so much each time I watch one. Thank you.

[@robertwillis4029]

I really appreciate you taking the time explaining things. it's taken me a year to build my 40x36 cnc router, and a year of running into mistakes operating it. but because of all your video's i'v been able to correct them all. thanks man.

[@chirots]

I have got no experience in CNC at all, however I have been building my mini cnc milling for almost 3months since January 2019. I now try to workout how mach3 work. Your videos help me clarify a lot of question on how to use limit switches. Thank you very much

[@MrRenoman2011]

Watched this video again and must say it's the best video with awesome explanation still in the building stage with mine so will visit your page again. Thanks so much for the awesome video!

[@greywolf1708]

from someone about to setup their machine for the first time, you just gave me some major hints and tips. Thank you very much. Brilliant job.

[@GuruBrew]

Thanks for the positive comment. Good luck with yours.

[@KC-vg9ul]

Hi Steve, You have given me the confidence to set up and run my DIY CNC Router. I have been super cautious not to break anything. With your instructions I am forging ahead. Thanks

[@garyedgerton5388]

Your explanations are always clear and well done. Thank you! I heard another way to stop false triggers on the limit switches. Use shielded two wire cable with a ground wire. Hook up all the ground wires to ground only on the control board end. Leave the other end of the ground not connected to avoid ground loops.

[@jimclark6925]

I'm new to CNC and appreciate your video's very much thank you for taking the time to teach!

[@AlwynF100]

Man, that brew you put in the cup, rocks. Your channel, video's and explanations was my inspiration to design and build me own machine. This explanation on the switches just convinced me to seriously add them to my machine. I can't wait for the Mach3 setup one. It seems there is a few gremlins if it's not done correctly.

[@blackbear92201]

Very helpful video - exactly what I was looking for. thanks for posting! :D

[@shyrlw]

Thanks! I'm building a Gatton CNC and he just uses soft limits on his setup. I like your eye for safety so I set it up and it works great. One headache that I ran into is trying to find screws small enough to fit the micro switches. Just a heads up out there, it takes an M3 or a #4 screw. I had to drive 20 miles to a Lowes to find some small enough. I love that you narrate your videos. I've watched some that just go through the motions and expect you to just "get it". Great job.

[@rchavez5056]

Hello I have built a Gatton CNC as well. I have also only used soft limits as Dave for the last 2 years. I am wanting to set up my limit switches as well. Did you set your soft limits just a few steps away from touching the switch for X and Y in the positive direction?

[@PHenriqueification]

Man, thank you from Brazil! I am making a router and your video will help me a lot! Thank you so much!

[@paulwatherston6244]

Just finished building my own design cnc router and your videos I find great and easy to understand, good teaching here.

[@BuildswithBrian]

Thank you! This really helped me understand how limit and soft limits worked. You’re are very good at explaining concepts

[@scottsherman2697]

Outstanding, I am in the process of building my own CNC router and this will help me figure out some of the details that will come up. Thanks so much!

[@MACKdaddy1220]

Thanks for the cnc videos. very helpful that you take the time to show step by step tutorials. I think a mach3 series from start to finish would be great, as I think a lot of people struggle setting up and understanding all the features and settings. Also this vid on limits was very helpful. thanks again.

[@GuruBrew]

Will do, thanks!

[@jonmuir2422]

Your videos are great, I like your editing of sound & video to eliminate loud noises when running machine and even correcting your errors, as well as highlighting, very professional !!!

[@jobo2063]

Hi Steve, thanks for the video, it does help me with a lot of my queries but I think i will have to watch the video a few more times to absorb all the inforrmation. I have just completed the cnc build apart from the electronics , now the problems are likely to start. Thanks again Steve.

[@harryosinga2915]

Thnx a lot for this instruction. It was a long search to get the parameters for homing en limitting for my Chine 3040-zDQ. With this video I think I get things working.

[@markfoster6110]

Thankyou from down under

[@David.C.Velasquez]

Great job on another hugely informative video. Thanks GuruBrew!

[@nathanohaynie]

Excellent video. Very helpful. Thank you!!!

[@carbidedge]

Another brilliant, informative video. Great job keep them coming.

[@richiemag22]

Thanks for the video, very helpful , please keep them coming .

[@praveensharma4106]

Thank you, I liked your idea on lead screwa

[@thomasdturkowski9702]

Hi Steve Thanks so much for your videos they are very helpful. I'm wondering if you could show a actual schematic of the switches you used as they are the same as the ones I have. I'm just a little confused on the wiring. Otherwise awesome videos and yes I have subscribed to your channels and really enjoy all of the different things that you have covered and as we had to put our dog down in late January I'm pleased to know that Shadow is doing well. Love them as much as possible every day for the lose is immeasurable. Thanks Tom T.

[@RMosMad]

Great work!

[@fredmartinez933]

thank you for the instruction..

[@aftekengineering4140]

Good explanations without rambling and accurate information.

[@dptp9lf]

Awesome video!

[@waltfox1996]

Hi: Your videos are exceptionally informative and well done. I for one really appreciate it.

[@captainlee1]

You are my guru hero Thanks ever so much I'll keep thumbing up for you....:O)

[@WildmanTech]

I set up my Z finder as you described in that video, and it works perfectly. I set my machine up exactly as you did here (adjusting the soft limits for my machine) and it does NOT work like this at all. If I tell it to go find home, it races toward the switch and does not slow down as it approaches the soft limits. It will stop when it hits the limit switch, but it's moving so fast it bends the roller arm before it comes to a stop. Then it is stuck in an error condition because the switch is engaged and the only way to solve the issue is to shut the controller off (a Gecko g540) and manually turn the ballscrew to move the gantry away from the switch. Does this need some VB code to work too? I did adjust the debounce control as you suggested. It didn't help. The switches are configured correctly and I have verified that on the diagnostics page of mach 3.

[@beatnik1855]

I see you demonstrating that limit switch can be used as a home switch but where is the setting that allows this. When i hit ref all home, soon as it hits first limit switch, goes in to emergency mode instead of continuing to find home

[@alejandrogonzales1991]

Thank you for sharing your knowledge. but I have a question, what board are you using, I mean to control the motors.

[@jimjacques2925]

nice explanation

[@kydoan255]

thanks so lot ,

[@jaysonjames8087]

amazing good sir

[@07LUTE70]

Are those grey motors servo motors on your wooden CNC? I heard servos run much cooler and are stronger motors. I hope you don't get offended, but your shop is very messy. How do you know where everything is? I always say a clean machine is a good running machine. Don't get me wrong I still like your teaching. Your pretty informative and I can tell your a nice guy to share your knowledge with us.

[@hermit3400]

I see you have your limit switches set to "Active Low". Am I correct is assuming that the limit switches you used are the "normally open" open variety? I am trying to set up my machine and have normally closed switches. When the switch is activated I have used a 470 ohm pull up resistor to bring the pin voltage to 5 volts. In my instance I am assuming I would not check the active low box, but instead would just leave it with an X in it. Am I correct in that assumption??? Thanks for the help. I enjoy your videos!

[@chirots]

Excellent video. However I still have got a question. when my limit switch is working, mach3 put on reset. Then I can move the axis back out of the limit. What did I do wrong?

[@brentwood66]

Great video Guru. Just wondered how on the setting the soft limit switches does the soft max for the x and y know the distance?

[@sphinx19]

Hi, Just a bit of advice if you can pls. I have a Chinese CNC and I decide to upgrade the control board and stepper motors. The problem I have now is when jog to min or maximum the speed does not slow and when rich the soft limit its stop very suddenly 0.4 mm after soft limit. Whit the old cheep control board I did not have this problem, which was slowing the speed when riching the soft limits and stop exactly at the limit. Many thanks

[@jigsey.]

hey Great video as usual..im re watching because im about to install limit stitches...Just noticed you have a aldi workszone drill...never knew they were available in the States

[@GuruBrew]

Hi , I bought that drill press new right before I built my first router machine. I can't for the life of me figure out we're I bought it I just know it was new in the box for like a hundred bucks. Still works great. Good luck with your build. Steve

[@jobo2063]

Hi Steve, Thanks for your video, one thing that confuses me is the limit swithes on the "Z", where would you put the switch on the down stoke, surely the travel distance would depend on the length of the cutting tool used.

[@stephenprescott8105]

Thanks for this info ....

[@raybowns]

Thanks for your videos. I'm new to CNC. Today I want to set up my soft limits in mach3.I am going to install 2 wire limit controll switches later. You did not address the actual motor wires we need to cut into. Is there a u tube video for that? I have 3 -4wire nema 23 motors. Ray Bowns

[@umargul5644]

Great

[@wiredolphin]

Thank you for this really instructive video Sir. Anyway I'm stuck on a weird trouble: I'm using "Port and Pins" settings as yours and use two switches, the first for both X-- and X Home, the second for X++. The problem is that when I "Ref All Home", when the first switch is pushed, Mach3 does not ignore the limit switch, thus triggering the "Emergency mode" causing to stop the homing. Is there any other setting to make Mach3 ignore the limit while homing or could be that this issue is because of the use of a USB controller that makes Mach3 unable to manage that configuration of switches? Thank you in advance.

[@peterwang3052]

HI, I have a CNC machine with stationary Z. When i home all in Mach3 i would like the X axis to go to 50% of the soft limit (200mm) & the Y axis to go to 50% of the soft limit (125mm) after homing so i get the plane more or less in the middle of my machine. Do you have any idea how to modify the home all script to achieve that ?

[@ronald44181000]

I'm back trying to set up my machine after an absence and I can get Y and Z to perform correctly in Mach3. Yet the X-axis always tries to sail right on through the limits that I've set for it. I first go into Machine Co-Ordinates and SoftMax is 33" on the X-Axis, the SoftMin is 0 and it's SoftMax 14 and SoftMin 0 on the Y-Axis with SoftMax of 0 and SoftMin of 9.5 on the Z-Axis. After I've made my settings whenever I hit REF ALL it goes to the above settings and tries to continue on and on on the X-Axis. It doesn't matter if I enable Soft Limits or not. Any insight that you can provide would be greatly appreciated.

[@pontiac1978]

If I only put limit switches on the (2) X-axis and I press the button "REF ALL HOME" in Mach 3, will it ignore the Y and Z-Axis and just go till it triggers the x-axis limits?

[@azzamody]

Can you help , I have the usb Board and when l connected and activated the limit switches they didn’t work and the motors stopped working even when I removed the wires from board and deactivated the pins

[@Matt2chee]

Great even paced voice, with no oo's, oh's and y'know's. Y'know? Can I change a setting to make it come off the switch say, .125 on the homing procedure?

[@martingoedbloed4691]

Hi Steve, Nice video, much clearer now. One question though, at times (mostly when manually jogging the machine), i reach my limit. Mach3 goes into emergency, and there's no way of clearing , except disabling the switch (manual or in software). It's kinda 'stuck', due to the fact when I clear it, it goes immediatly back into emergency because the freaking switch is still pressed in. Howto recover from that situation? Thanks, Martin

[@n1cl4ssm]

I have the same issue. Did You find an answer?

[@vishakhasrivastava7951]

may i know how its backing off? because i am using grbl and when limit switch is pressed its not backing off in fact my whole machine stop working

[@IH1940HAY]

I'm not understanding the connection between soft and limit sw limits. Soft limits can only be active after the machine is homed at all axis is this correct? After turning on the machine you must home the machine on all axis before the soft limits are activated, is this correct? Are soft limits set to the same physical location as the limit switches? Or could the soft limits be set say one inch inside the switch limits, which would act as the first level of extreme travel and the limit switches as the extreme limit of travel? Thanks

[@GuruBrew]

Yes that is correct on both statements You can activate soft limits before homing but may not be accurate..

[@linhle4370]

Your video show how to hook up those switches. I got a 3040 (cheap Chinese made) from ebay and it has no terminal on board to hook up. What is your suggestion?

[@GuruBrew]

You can connect the switched directly to the computers parallel port pins using a 10k pull up resistor between each connection. Look at the Mach3 documentation for diagrams and more.

[@paulcotesr5623]

where do i find that mach 3 manual please ty

[@tepansenteolt2980]

Hello Guru Brew, I have a 3040 cnc. I knew it not come with switches. I did setup in mm.360 x360x 70. for home reference but when a set to reference home, the Z moves + but remain positive indefinitely. and not able to reset to ceros again. I did notice that XYZ remain red lit and home does not lit green. any clue? thanks.

[@vansamartey8933]

why does my TM 1325 CNC HEAD go deep down and hit the board when i set it to home.? please i need answers urgently. thank you

[@chrisguerette4307]

Great video, very timely for me as I'm in the process of setting up my CNC right now. When you do the Mach3 setup video please include an explanation about how you do the motor tuning - specifically how to determine/calculate/choose the proper velocity and acceleration values for each motor.

[@GuruBrew]

thanks, will do. when I tune the motors I do it by ear and max power and speed. no fancy calculations but I do have a few pointers

[@makermania182]

@@GuruBrew This is exactly what I like about your video, not overly technical. I get enough of that from deep dives on the forums. This vid is a great confidence builder when you feel paralyzed by all of the possibilities of electrical noise.

[@gaeproj2885]

grazie

[@redawg32]

What type of lead screws are those? Lead screws or all thread?

[@GuruBrew]

this machine has just common threaded rod. nothing fancy but works great

[@captainlee1]

on some of the schematics there are 3 resistors connected to the 3 switches near the circuit board is this true for the hobby cnc board?

[@GuruBrew]

Yip, On board connections for home and limit switches with 10K pull-up resistor provided to each. No need for a separate “break out” board.

[@captainlee1]

Thanks a bunch...:O)

[@captainlee1]

PS When I finish my jgro i'll send you a photo...:O)

[@amtpdb1]

What type of wire is the gray 6 conductor wire? All I can find is solid sprinkler wire. Thanks

[@GuruBrew]

ya, I tried locally and couldn't find any either. I ended up getting it from hobbycnc.com website for $0.75 a foot. It's 22.ga 6 conductor stranded

[@amtpdb1]

Thanks for the information. Have a nice weekend.

[@DolezalPetr]

How does the machine know where is your material located and what shape it is and how big it is?

[@GrandpawB]

You enter all that info into your CAM software.

[@DolezalPetr]

So I have to measure the material and measure the distance between the edges of my material and cnc? Or I can move the bit to the edge of my material and set that as the start point and than ad to it the dimensions? I imagine I home the machine, then move it to the edge, set it as start point and run. I am new to this...

[@GrandpawB]

I use VCarve Pro. you enter the size of your work piece then add your design and it's dimensions ,then tell it what bit and so on.

[@DolezalPetr]

GrandpawB ok thank you, I will do some more research

[@kywildcats6476]

Need your help and cant get in to ask questions

[@dadanhadiansyah8775]

Disposable what aluminum chassis

[@IceTurf]

Accuracy?