Hi All,

We are continuing to experience issues that we believe are relating to 
electrical noise on our BCNC. We realize that our machine is slightly 
unorthodox, so we have a folder link with wiring diagrams and assembly 
videos to help you help us. We are in the process of testing the machine. 
We had noise issues from the spindle power lines (which are not shielded), 
but we removed them from cable bundles and that seemed to remove that 
issue. We are able to run files successfully in the air, but we receive 
limit switch errors when we begin cutting through material. our system 
seems to be rigid enough to not be the problem and our motors are strong 
enough that human force doesn't stop the system from running. We rewired 
our spndle power supply to have a seperate power cable than our primary 
power supply as well. We have tried adding debouncing code to our Hal file, 
but this caused Machinekit to not sense our limit switches (we couldn't 
complete a homing sequence). 

folder link
https://drive.google.com/drive/folders/1-BqfZynZqA0JI15VOP9ZtjejnNKbGmoU?usp=sharing
 

BCNC tour
https://www.youtube.com/watch?v=lBFH62Z3-sc  

limit switch/motor wiring
https://www.youtube.com/watch?v=_3WAHGZgA68  

spindle wiring
https://www.youtube.com/watch?v=bzvBb8_dZvA 

power supply wiring
https://www.youtube.com/watch?v=ADKeLWRwG3Y

On Saturday, July 25, 2020 at 12:41:04 PM UTC-4 [email protected] wrote:

> Hi,
>
>   You should not make a loop of wire for the ground (gnd from switch to 
> switch to switch is not good).
>   You should have one wire for the switch input, and one wire for the 
> signal ground in your switch cabling.
>   All of the grounds from the various switches should meet at one point on 
> the I/O terminal signal ground point.
>   If possible, you should use shielded cabling.  Tie all of the shields 
> (bare drain wires) at the same end near the inputs, but then connect them 
> to an *earth* ground, not the signal ground of the input.  An example of an 
> earth ground in a system would be the green wire (or green with yellow 
> stripe) of a power supply, not the V- of the power supply.
>   2-wire 22 gauge "sound and security" from Home Depot, etc. will 
> typically be stranded wire with a drain wire and shielding.  This would be 
> a good choice as it has all three of the conductors that you want.  Red for 
> signal, black for signal ground and bare drain for shielding.
>
> Jeff
>
> On Friday, July 24, 2020 at 10:40:34 AM UTC-7, Frederic RIBLE wrote:
>
>> Could you describe the wiring of these switches on your machine?
>> I am wondering if you have two wires per switch going up to the logic 
>> board, or only one, with ground sharing.
>> On 2020-07-21 19:39, Mason Millner wrote:
>>
> We are using momentary hinge limit switches (
>> https://www.amazon.com/URBESTAC-Momentary-Hinge-Roller-Switches/dp/B00MFRMFS6/ref=sr_1_3?ie=UTF8&qid=1535482225&sr=8-3&keywords=limit+switch)
>>  
>> and our spindle (
>> https://www.amazon.com/Koolertron-Spindle-Milling-Converter-Engraving/dp/B074XTKJTJ/ref=sr_1_9?ie=UTF8&qid=1535482152&sr=8-9&keywords=spindle+cnc)
>>  
>> is operating from its own power supply.  
>> The machine is fairly rigid. No limit switches are triggered from until 
>> material is being cut. The bamboo does vibrate quite a bit as it spans 65" 
>> supported only on the ends, but we have been able to successfully cut this 
>> dimension previously (on a 3-axis Techno machine).
>>
>>
>> On Tuesday, July 21, 2020 at 1:12:01 PM UTC-4 [email protected] wrote:
>>
>>> You didnt mention what type of limit switches you're using or how your 
>>> spindle works. The Y axis itself shouldn't be under any special stress 
>>> while cutting but the spindle generally takes a hard hit as soon as a tool 
>>> enters the cut. Is the spindle motor powered by the same power supply your 
>>> switches are on? Supply could be dropping low. Is the machine not ridgid 
>>> and vibration tripping the switches?
>>>
>>> On Tue, Jul 21, 2020, 8:54 AM Mason Millner <[email protected]> wrote:
>>>
>>>> Hi All,
>>>>
>>>> We are developing a 4-axis CNC to mill bamboo poles and are currently 
>>>> running tests in just three axis (x, y, z). We can dry-run g-code files 
>>>> successfully, however we receive limit switch errors (primarily on joint 
>>>> 1) 
>>>> when we begin cutting material. We suspect that the error is occuring in 
>>>> the y-axis and that possibly our drivers are causing a problem (either 
>>>> they 
>>>> are too small or not tuned adequately).. It is difficult to tell what is 
>>>> going on and how the machine is configured from the information given.
>>>>
>>>>  We have the z-axis running on the long x-axis, running on two shorter 
>>>> dual y-axes.
>>>>
>>>> The axis shaft is a ½” (12.7mm) , also the motor shaft is ¼” (6.35mm).  
>>>> we are using polyurethane insert couplers (these have regularly been 
>>>> coming 
>>>> loose though). 
>>>>
>>>> The motors are NEMA 23s with  3A rating/phase controlled by Pololu 
>>>> TB67S249FTG drivers on a Cramps 2.2 cape on the Beaglebone Black. The 
>>>> drivers have a current limit of 1.6A and are further limited to %90 for 
>>>> safety. The Current limit for the board and drivers are defiantly a bottle 
>>>> neck, but the motors have enough power to operate. [Could this be the 
>>>> problem?]
>>>>
>>>> Any help or recommendations would be greatly appreciated. If more 
>>>> information is needed please let me know. I'm fairly new to the machine 
>>>> development side of this project. Thanks.
>>>>
>>> -- 
>>>> website: http://www.machinekit.io blog: http://blog.machinekit.io 
>>>> github: https://github.com/machinekit
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>>>>
>>> -- 
>> website: http://www.machinekit.io blog: http://blog.machinekit.io 
>> github: https://github.com/machinekit
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